Final BMP Panel Report. Definitions and Recommended Nutrient Reduction Efficiencies of

Transcription

1 Final BMP Panel Reprt Definitins and Recmmended Nutrient Reductin Efficiencies f Nutrient Management Practices Fr Use in Phase 6.0 f the Chesapeake Bay Prgram Watershed Mdel Recmmendatins fr Apprval by the Water Quality Gal Implementatin Team s Watershed Technical and Agricultural Wrkgrups Submitted by the Phase 6.0 Nutrient Management BMP Expert Panel Submitted t: Agriculture Wrkgrup Chesapeake Bay Prgram August 1, 2016 Revised September 22, 2016 Final Octber 18, 2016 Apprved as Amended by Agriculture Wrkgrup Octber 20, 2016 (see Appendix G)

2 Cntents ACRONYMS AND ABBREVIATIONS... 4 SUMMARY OF RECOMMENDATIONS INTRODUCTION PRACTICE DEFINITIONS NM CORE AND SUPPLEMENTAL ELEMENT DETAILED DEFINITIONS NITROGEN CORE NM BMP ELEMENTS PHOSPHORUS CORE NM BMP ELEMENTS NITROGEN SUPPLEMENTAL NM BMPS PHOSPHOROUS SUPPLEMENTAL NM BMPS EFFECTIVENESS ESTIMATES SUMMARY OF EFFECTIVENESS ESTIMATES N Cre NM BMPs P Cre NM BMPs N Supplemental Nutrient Management BMPs P Supplemental Nutrient Management BMPs DEVELOPMENT OF APPLICATION RATE MULTIPLIERS AND LOSS REDUCTION MULTIPLIERS FOR CORE NM BMPS AND SUPPLEMENTAL NM BMPS METHOD FOR APPLYING CORE AND SUPPLEMENTAL MULTIPLIER VALUES REVIEW OF LITERATURE AND DATA GAPS THE AVAILABLE SCIENCE FOR N BMPS THE AVAILABLE SCIENCE FOR P BMPS APPLICATION OF PRACTICE ESTIMATES LOAD SOURCES PRACTICE BASELINE HYDROLOGIC CONDITIONS SEDIMENT SPECIES OF NITROGEN AND PHOSPHORUS GEOGRAPHIC CONSIDERATIONS TEMPORAL CONSIDERATIONS PRACTICE LIMITATIONS POTENTIAL INTERACTIONS WITH OTHER PRACTICES PRACTICE MONITORING AND REPORTING PHASE 6.0 NUTRIENT MANAGEMENT TRACKING, VERIFICATION, AND REPORTING FUTURE VERIFICATION OF NUTRIENT MANAGEMENT PRACTICES REFERENCES...38 APPENDIX A: TECHNICAL REQUIREMENTS FOR REPORTING AND SIMULATING NUTRIENT MANAGEMENT BMPS IN THE PHASE 6 WATERSHED MODEL...42 APPENDIX B: METHODS TO ESTIMATE HISTORIC IMPLEMENTATION...49 APPENDIX C: NUTRIENT MANAGEMENT PHASE 6.0 EXPERT PANEL CHARGE DOCUMENT...54 APPENDIX D: APPROVED NUTRIENT MANAGEMENT EXPERT PANEL MEETING MINUTES...61 APPENDIX E: CONSOLIDATED RESPONSE TO COMMENTS ON: DEFINITIONS AND RECOMMENDED NUTRIENT REDUCTION EFFICIENCIES OF NUTRIENT MANAGEMENT FOR USE IN PHASE 6.0 OF THE CHESAPEAKE BAY PROGRAM WATERSHED MODEL (AUGUST 1, 2016 VERSION)

3 APPENDIX F: CONSOLIDATED RESPONSE TO COMMENTS ON: DEFINITIONS AND RECOMMENDED NUTRIENT REDUCTION EFFICIENCIES OF NUTRIENT MANAGEMENT FOR USE IN PHASE 6.0 OF THE CHESAPEAKE BAY PROGRAM WATERSHED MODEL (SEPTEMBER 22, 2016 VERSION) APPENDIX G: AMENDED REPORT OCTOBER 20, APPENDIX H: CONFORMITY WITH WQGIT BMP PROTOCOL Figure 1. Linkage f Cre and Supplemental N Nutrient Management Practices...13 Figure 2. Linkage f Cre and Supplemental P Nutrient Management Practices...14 Figure 3. Assignment f N Nutrient Management Credits Figure 4. Assignment f P Nutrient Management Credits Table 1. CBP Phase 6.0 Nutrient Management Expert Panel Membership... 7 Table 2. Elements f the N Cre Nutrient Management BMP... 8 Table 3. Elements f the P Cre Nutrient Management BMP... 9 Table 4. Examples f advanced N site assessments and N management tls that may be used t supprt implementatin f changes in riginally planned N applicatin rate, N applicatin placement, and/r N applicatin timing Table 5. Elements f the N Rate Supplemental Nutrient Management BMP...10 Table 6. Elements f the N Placement Supplemental Nutrient Management BMP...11 Table 7. Elements f the N Timing Supplemental Nutrient Management BMP...11 Table 8. Examples f advanced P site assessments and P management tls that may be used t supprt implementatin f changes in riginally planned P applicatin rate, P applicatin placement, and/r P applicatin timing Table 9. Elements f the P Rate Supplemental Nutrient Management BMP...12 Table 10. Elements f the P Placement Supplemental Nutrient Management BMP...12 Table 11. Elements f the P Timing Supplemental Nutrient Management BMP...12 Table 12. Cre N Nutrient Management Applicatin Rate Multiplier Values...20 Table 13. Cre P Nutrient Management Applicatin Rate Multiplier Values...21 Table 14. N Supplemental Nutrient Management BMP Lss Reductin Multiplier Values...22 Table 15. P Supplemental Nutrient Management BMP Lss Reductin Multiplier Values...22 Table 16. LGU Agrnmy Guide Recmmendatins fr Crn N Fertilizer Applicatin Rate Befre and During CBPWM Calibratin Perid Table 17. Summary f Methd fr Applying Nutrient Management Multiplier Values...29 Table 18. Land Uses t Which the Nutrient Management Practices Apply

4 Preface The Phase 6 Nutrient Management BMP Expert Panel presented its final reprt n nutrient management practices fr use in Phase 6.0 f the Chesapeake Bay Prgram Watershed Mdel (dated Octber 18, 2016) t the Agriculture Wrkgrup fr apprval n Octber 20, The Agriculture Wrkgrup apprved the reprt with amendments added by the wrkgrup. These Agriculture Wrkgrup implemented amendments t the Panel s reprt divided bth the Nitrgen Cre Nutrient Management and Phsphrus Cre Nutrient Management BMPs int tw cmpnents reflecting whether n-site specific manure analysis fr nitrgen, and bth sil and manure analysis fr phsphrus; r estimated (a.k.a. bk value) manure analysis fr nitrgen, and bth sil and manure estimated analysis fr phsphrus is used t determine nitrgen r phsphrus applicatin rates respectively. These Agriculture Wrkgrup mdificatins resulted in the need t make multiple changes in the Panel s final reprt. The Phase 6 Nutrient Management BMP Expert Panel final reprt (dated Octber 18, 2016) is cntained here as the cver page thrugh page 40 (References), plus Appendices A-F and H, minus this Preface and the Preface t Appendices n page 41. The final Panel Reprt as updated in respnse t the Agriculture Wrkgrup amendments is cntained in Appendix G, which supersedes the riginal Panel Reprt fr implementatin by the CBP partnership in all aspects as apprved. Appendices B-F fr the Panel Reprt (dated Octber 18, 2016) were nt affected by the apprved amendments and are therefre nt included in Appendix G with the amended reprt. Appendices A and Appendix H were affected by the apprved amendments and updated versins f these tw appendices are included with the amended reprt in Appendix G, and als supersede their riginal cunterparts in all aspects as apprved. The riginal versins f Appendix A and Appendix H are als prvided here fr cntext. 4

5 Acrnyms and Abbreviatins AAPFCO ac. AgWG ARS BMP bu. bu./ac. CBP CBPO CBPWM CBW CEAP CRC CSNT DE DRP EOF EONR FSNT ft. ha HUC ISNT kg lbs. LGU MD Assciatin f American Plant Fd Cntrl Officials Acre Agriculture Wrkgrup USDA Agricultural Research Service Best Management Practice Bushel Bushels per Acre Chesapeake Bay Prgram Chesapeake Bay Prgram Office Chesapeake Bay Prgram Watershed Mdel Chesapeake Bay Watershed Cnservatin Effects Assessment Prject Chesapeake Research Cnsrtium Crn Stalk Nitrate Test Delaware Disslved Reactive Phsphrus Edge f Field Ecnmic Optimum N Rate Fall Sil Nitrate Test Feet Hectare Hydrlgic Unit Cde Illinis Sil Nitrgen Test Kilgram Punds Land-Grant University Maryland N Nitrgen 5

6 N Cre NM BMP N Supplemental NM BMP NEIEN NM NMP NO 3 -N NRCS NRI NY P P Cre NM BMP P Supplemental NM BMP PA PAN Panel PET PSNT QAPP TN TP USDA VA VTCA WTWG WQGIT WV Nitrgen Cre Nutrient Management Best Management Practice Nitrgen Supplemental nutrient management Best Management Practice Natinal Envirnmental Infrmatin Exchange Netwrk Nutrient Management Nutrient Management Plan Nitrate N USDA Natural Resurces Cnservatin Service Natinal Resurces Inventry New Yrk Phsphrus Phsphrus Cre Nutrient Management Best Management Practice Phsphrus Supplemental nutrient management Best Management Practice Pennsylvania Plant Available N Nutrient Management Expert Panel Phsphrus Envirnmental Threshld Pre-sidedress Nitrate Test Quality Assurance Prject Plan Ttal Nitrgen Ttal Phsphrus U.S. Department f Agriculture Virginia Virginia Tech Crn Algrithm Watershed Technical Wrkgrup Water Quality Gal Implementatin Team West Virginia 6

7 Summary f Recmmendatins 1 Intrductin Nutrient management practices are implemented n millins f acres f agricultural lands acrss the Chesapeake Bay Watershed (CBW). It is ne f the ldest best management practices (BMPs) in agriculture and is the crnerstne f stewardship effrts by cnservatin grups, prducers and jurisdictins. This dcument summarizes the recmmendatins f the Phase 6 Nutrient Management Expert Panel (the Panel) fr revised definitins and credits fr nutrient management practices. The Panel, whse members are identified in Table 1, prpses that the Chesapeake Bay Prgram s (CBP) existing definitins and credits assciated with implementatin f Nutrient Management Plans (NMPs) be replaced by independent sets f practice elements fr nitrgen (N) and phsphrus (P) management due t the marked difference in the use, fate, and transprt f these nutrients in agricultural systems. The structures fr bth N and P nutrient management are similar, hwever, with supplemental management elements stacked nt a required cre set f management elements. Table 1. CBP Phase 6.0 Nutrient Management Expert Panel Membership Name Jurisdictin Affiliatin Rle Frank Cale Maryland University f Maryland Panel Chair Deanna Osmnd Nrth Carlina Nrth Carlina State University Panel Member Dug Beegle Pennsylvania Penn State University Panel Member Jack Meisinger Maryland USDA-Agriculture Research Panel Member Service Tm Fisher Maryland University f Maryland Center Panel Member fr Envirnmental Science Quirine Ketterings New Yrk Crnell University Panel Member Chris Brsch Delaware Delaware Department f Watershed Technical Wrkgrup Agriculture representative Matt Jhnstn Maryland University f Maryland, CBPO Mdeling Team representative Technical supprt prvided by Mark Dubin (University f Maryland, CBPO), Lindsey Grdn (CRC Staffer), and Steve Dressing (Tetra Tech). CBPO Chesapeake Bay Prgram Office; CRC Chesapeake Research Cnsrtium; USDA U.S. Department f Agriculture 2 Practice Definitins Nutrient management has fur basic cmpnents: the nutrient surce, rate, timing, and placement. Each f these fur cmpnents f NM are managed at the field r sub-field scale in a manner t supprt crp prductivity, achieve high nutrient use efficiency by the grwing crp, and t minimize nutrient lss t the envirnment. The fur cmpnents f NM planning interact with each ther n a site-specific basis and are mdified by site-specific field management, sil prperties, and weather cnditins. Thus, the Panel defines Nutrient Management as the implementatin f a site-specific cmbinatin f nutrient surce, rate, timing, and placement int a strategy that seeks t ptimize agrnmic and envirnmentally efficient utilizatin N and P. Imprvement in nutrient-use efficiency necessitates dcumentatin f NM implementatin strategies that are suitable fr independent verificatin. Nutrient management als prvides ther imprtant benefits t the agricultural and the envirnmental cmmunities. These benefits include lng-standing educatinal pprtunities cnducted in varius venues fr a wide variety f audiences that cnvey the fundamentals f NM and state-f-the-science practices and assessment tls. It is essential that an initial baseline fr NM implementatin is established that allws estimatin f prgress ver time. Applicatin f NM BMPs will 7

8 interrelate with ther agricultural nnpint surce BMPs and cmmunicatin with ther BMP Expert Panels is essential t define apprpriate implementatin and crediting. Nutrient management fr Phase 6.0 f the Chesapeake Bay Prgram Watershed Mdel (the Phase 6 mdel) is separated int independent sets f practice elements fr N and P management due t the marked difference in the use, fate, and transprt f these nutrients in agricultural systems. The structures fr bth N and P nutrient management are similar, hwever, with supplemental management elements stacked nt a required cre set f management elements. Practice Name(s) Nitrgen (N) Cre Nutrient Management BMP Phsphrus (P) Cre Nutrient Management BMP Nitrgen (N) Rate Supplemental Nutrient Management BMP Nitrgen (N) Placement Supplemental Nutrient Management BMP Nitrgen (N) Timing Supplemental Nutrient Management BMP Phsphrus (P) Rate Supplemental Nutrient Management BMP Phsphrus (P) Placement Supplemental Nutrient Management BMP Phsphrus (P) Timing Supplemental Nutrient Management BMP Cre Nutrient Management BMPs The elements f the N Cre Nutrient Management BMP are fund in Table 2. Applicatin f a N Cre NM BMP applicatin rate multiplier mdifies the crp- and land-use-specific N applicatin rate gal, which is based n Land-Grant University (LGU) crp fertilizatin recmmendatins, as mdified by the CBP partnership. In an effrt t determine the mst practicable methdlgy fr allcating fertilizer N t satisfy crp- and land-use-specific N applicatin rate gals, the Agriculture Wrkgrup cmpared the mdified LGU recmmendatins fr applicatin f supplemental inrganic N fertilizer t an alternative apprach based n cunty-level redistributin f Assciatin f American Plant Fd Cntrl Officials (AAPFCO) N fertilizer sales data. This methdlgical cmparisn indicated that there were relatively small differences between the tw methds fr estimating supplemental N fertilizer applicatins, leading the Agriculture Wrkgrup t apprve use f the redistributed AAPFCO fertilizer sales methdlgy in the Phase 6 Mdel. The Panel recmmends that similar cmparative analyses be cnducted in the future t evaluate newly available fertilizer sales data and t further evaluate the redistributed fertilizer sales methdlgy s frecasting ability. Incnsistencies between estimates generated by the tw methds shuld be investigated and rectified based n data surce quality and cnsistency using cntiguus r reginal cunty-level data. Table 2. Elements f the N Cre Nutrient Management BMP NITROGEN Cre Nutrient Management BMP (ALL applicable cre elements required t be implemented and verified) N rate accrding t LGU recmmendatins at field management unit level Manure analysis and vlume Spreader/applicatr calibratin Yield estimates and crpping plan at field management unit level Crpping and manure histry at field management unit level The elements f the P Cre Nutrient Management BMP are fund in Table 3. Applicatin f a P Cre NM BMP applicatin rate multiplier mdifies the crp- and land-use-specific P applicatin rate gal, which is based n LGU crp fertilizatin recmmendatins, as mdified by the CBP partnership. A significant mdificatin impsed by the CBP partnership was the assumptin that all agricultural acres in the CBW had a sil-test P cncentratin that crrespnded with the medium sil test interpretive categry. The Panel recgnized that, in the absence f sil-test P cncentratin data, assumed sil-test P cncentratins were necessary t facilitate CBP mdel prcesses. Hwever, the Panel als recgnized that implementatin 8

9 f the universal medium sil-test P assumptin infused a high level f site-specific uncertainty int the mdeled P applicatin rate. In general, the inherent uncertainty in P applicatin rate resulting frm the adptin f the universal medium sil-test P cncentratin assumptin is expected t be similar t r greater than the magnitude f the P applicatin rate mdificatins resulting frm implementatin f P Cre NM BMP applicatin rate multipliers. In practice, LGU recmmendatins fr P applicatin are based n crp- and site-specific sil-test P cncentratin. Currently, sil-test P cncentratin data are nt available t the CBP. The Panel recmmends that, in the future, crp- and site-specific sil-test P cncentratin data shuld be cllected, aggregated t the apprpriate scale, summarized t eliminate disclsure f cnfidential business infrmatin, and utilized as the fundatin fr determining P applicatin rate gals and the apprpriate applicatin f P Cre NM BMPs. In the absence f sil-test P data and sil-test P based applicatin rate gals, sil-test P cncentratin must be assumed and, in turn, utilized t create artificial P applicatin rate gals. Additinally, in the absence f sil-test P data, cunty-level redistributin f CBW AAPFCO P fertilizer sales data may serve as a useful surrgate fr determining P applicatin rate gals. Field management shall be cnsidered cmpliant with P fertilizatin recmmendatins when P applicatin recmmendatins resulting frm site-specific envirnmental risk assessments (i.e. P Index, P Site Index, P Management Tl, etc.) allw higher P applicatin rates than the standard LGU sil-test based recmmendatins, after accunting fr the site-specific ptential fr P lss t streams. In anther example, Virginia nutrient management planners may utilize a mre restrictive methd knwn as the Phsphrus Envirnmental Threshld (PET) in lieu f sil-test P based recmmendatins when evaluating applicatin f rganic nutrient surces. Using the PET methd, P frm rganic surces may be applied t fields that test less than a reginally-specified degree f sil P saturatin, as quantified by Mehlich 1 sil-test P cncentratin. By physigraphic regin, the PET sil-test P threshlds are: 135 ppm Eastern Shre & Lwer Castal Plain; 136 ppm - Middle & Upper Castal Plain & Piedmnt; and 162 ppm - Ridge and Valley. Nitrgen applicatins cannt exceed crp N needs when using PET. Additinal details may be fund in Virginia Nutrient Management Standards and Criteria, as revised July Other examples may be similarly applicable. The P Cre NM BMP requires a P sil test at the field management unit level. This required element may be waived if, as in the case f Pennsylvania s manure management guidelines, restrictins n manure applicatin (rates, timing, and placement) are impsed that limit ttal P applicatin rates and management t the same degree as if the site was in the high P sil test interpretive categry. Table 3. Elements f the P Cre Nutrient Management BMP PHOSPHORUS Cre Nutrient Management BMP (ALL applicable cre elements required t be implemented and verified) P rate accrding t LGU recmmendatins at field management unit level P sil tests at field management unit level Manure analysis and vlume Spreader/applicatr calibratin Yield estimates and crpping plan at field management unit level Crpping and manure histry at field management unit level Supplemental Nutrient Management BMPs The Nitrgen Supplemental Nutrient Management BMPs (N Supplemental NM BMPs) invlve applying a lss-reductin multiplier fr the N Supplemental NM BMP elements nly after satisfactry implementatin f the N Cre NM BMP. Multiple advanced site assessments and N management tls may be utilized t infrm the applicatin f the apprpriate N adjustment practices, but d nt represent a N lss reductin credit in and f themselves. A list f example N site assessments and N management tls is given in Table 4. This list is nt intended t be exhaustive. Rather, Table 4 presents examples f current techniques and tls that the Panel deems ptentially useful in supprting crediting f changes in N management and recgnizes that this listing will need t be updated ver time as new tls and prcedures are develped. 9

10 Advanced site assessments and applicatin f N management tls that result in a verifiable implementatin f a change in planned N applicatin rate, N applicatin timing r N applicatin placement may result in a N Supplemental NM BMP lss reductin credit. The actual crediting f the Supplemental NM BMPs requires placing a given BMP int a N Rate, N Timing, r N Placement Supplemental NM BMP categry (Tables 5 thrugh 7). One single N Supplemental NM BMP lss reductin multiplier may be credited fr each f the N Rate, N Timing, and N Placement categries. The actual values fr these Supplemental NM BMP lss reductin multipliers are presented later in this reprt (Table 14). Supplemental N NM BMP lss reductin credits fr N rate, N timing, and N placement are stackable, e.g., multiplicative with diminishing returns fr reducing envirnmental lss. Table 4. Examples f advanced N site assessments and N management tls that may be used t supprt implementatin f changes in riginally planned N applicatin rate, N applicatin placement, and/r N applicatin timing. Additinal assessment techniques and tls may be utilized t supprt implemented changes in N management. Advanced N Assessment Tls Pre-sidedress Nitrate Test (PSNT) Manure analysis 1 year ld On-farm replicated research Crn Stalk Nitrate Test (CSNT) N-lss risk assessments & mdels - Ammnia lss Yield mapping Illinis Sil Nitrgen Test (ISNT) On-farm strip trials N-lss risk assessments & mdels - Leaching lss Fall Sil Nitrate Test (FSNT) N-lss risk assessments & mdels - Denitrificatin lsses Whle farm balances In-seasn sensrs/remte sensing in general Ge-spatial mapping Example elements f the N Rate Supplemental NM BMP are listed in Table 5. Additinal N management practices that result in reductins in the rate f applied N may be applicable. Table 5. Elements f the N Rate Supplemental Nutrient Management BMP N Rate Adjustment Practice (implementatin f ne r mre BMPs required) N rate less than LGU recmmendatins Split N applicatins fr reduced ttal rate Variable rate N applicatin at sub-field management unit level Example elements f the N Placement Supplemental NM BMP are listed in Table 6. Subsurface injectin r incrpratin applies nly t inrganic fertilizer N. Incrpratin r injectin f manure is addressed by the Phase 6 Manure Incrpratin and Injectin Expert Panel reprt with the fllwing practices: Manure Injectin, Manure Incrpratin High Disturbance, and Manure Incrpratin Lw Disturbance. Additinal N management practices that result in purpseful physical placement f N surces such that the ptential fr N lss t the envirnment is reduced and/r crp N-use efficiency is imprved may be applicable. 10

11 Table 6. Elements f the N Placement Supplemental Nutrient Management BMP N Placement Adjustment Practice (implementatin f ne r mre BMPs required) Subsurface injectin r incrpratin f applied Inrganic N N applicatin setbacks frm water Example elements f the N Timing Supplemental NM BMP are listed in Table 7. Additinal N management practices that result in the enhanced precisin f the timing f applicatin f N surces that reduces the ptential fr N lss t the envirnment and/r imprves crp N-use efficiency may be applicable. Table 7. Elements f the N Timing Supplemental Nutrient Management BMP N Timing Adjustment Practice (implementatin f ne r mre BMPs required) Split N applicatins PSNT The Phsphrus Supplemental Nutrient Management BMPs (P Supplemental NM BMPs) invlve applying a lss-reductin multiplier fr the P Supplemental NM BMP elements nly after satisfactry implementatin f the P Cre NM BMP. Multiple advanced site assessments and P management tls may be utilized t infrm the applicatin f the apprpriate P adjustment practices, but d nt represent a P lss reductin credit in and f themselves. A list f example P site assessments and P management tls is given in Table 8. This list is nt intended t be exhaustive. Rather, Table 8 presents examples f current techniques and tls that the Panel deems ptentially useful in supprting crediting f changes in P management and will need t be updated ver time as new tls and evaluative prcedures are develped. Advanced site assessments and applicatin f P management tls that result in a verifiable implementatin f a change in planned P applicatin rate, P applicatin timing r P applicatin placement may result in a P Supplemental NM BMP efficiency credit. The actual crediting f the Supplemental NM BMPs requires placing a given BMP int either a P Rate, r P Timing, r P Placement Supplemental NM BMP categry (Tables 9 thrugh 11). One single P Supplemental NM BMP lss reductin multiplier may be credited fr each f the P Rate, P Timing, r P Placement categries. The actual values fr these Supplemental NM BMP lss reductin multipliers are presented later in the reprt (Table 15). Supplemental NM BMP lss reductin credits fr P rate, P timing, and P placement are stackable, e.g., multiplicative with diminishing returns fr reducing envirnmental lss. Table 8. Examples f advanced P site assessments and P management tls that may be used t supprt implementatin f changes in riginally planned P applicatin rate, P applicatin placement, and/r P applicatin timing. Additinal assessment techniques and tls may be utilized t supprt implemented changes in P management. Advanced P Assessment Tls Sil-test P remediatin/declining P Index assessment Grid sil sampling Manure analysis 1 year ld On-farm replicated research Yield mapping On-farm strip trials Whle farm balances Ge-spatial mapping 11

12 Example elements f the P Rate Supplemental NM BMP are listed in Table 9. Additinal P management practices that result in reductins in the rate f applied P may be applicable. Table 9. Elements f the P Rate Supplemental Nutrient Management BMP P Rate Adjustment Practice (implementatin f ne r mre BMPs required) P-based manure rate based n annual crp P remval P rate less than LGU recmmendatins Variable rate P at sub-field management unit level Example elements f the P Placement Supplemental NM BMP are listed in Table 10. The P placement practices f subsurface injectin r incrpratin apply nly t inrganic fertilizer P. Incrpratin r injectin f manure P is addressed by the Phase 6 Manure Injectin & Incrpratin Expert Panel reprt with the fllwing practices: Manure Injectin, Manure Incrpratin High Disturbance, and Manure Incrpratin Lw Disturbance. Additinal P management practices that result in the purpseful physical placement f P surces such that the ptential fr P lss t the envirnment is reduced may be applicable. Table 10. Elements f the P Placement Supplemental Nutrient Management BMP P Placement Adjustment Practice (implementatin f ne r mre BMPs required) Subsurface injectin r incrpratin f applied inrganic P P applicatin setbacks frm water Example elements f the P Timing Supplemental NM BMP are listed in Table 11. Additinal P management practices that result in the enhanced precisin f the timing f applicatin f P surces that reduces the ptential fr P lss t the envirnment may be applicable. Table 11. Elements f the P Timing Supplemental Nutrient Management BMP P Timing Adjustment Practice (implementatin f ne r mre BMPs required) P applicatin in lwer P-lss risk seasn Split P applicatins Figure 1 illustrates hw the N Cre NM BMP and the N Supplemental NM BMPs are cmbined fr credit. As described abve, N Supplemental NM BMPs can nly be credited if the N Cre NM BMP is implemented and verified. The N Supplemental NM BMPs d nt result in additinal credit unless implementatin f adjustments in N rate, N placement, r N timing is verified. The N Supplemental NM BMPs are assigned t three categries: N Rate Adjustment Practices, N Placement Adjustment Practices, and N Timing Adjustment Practices. The Supplemental NM BMP lss reductin credit fr each f these three categries can be btained if implementatin f at least ne effective practice frm each categry is verified. Fr example, if implementatin f the N Cre NM BMP is verified and implementatin f bth N applicatin setbacks frm water (a N placement adjustment) and variable rate N applicatin (a N rate adjustment) are verified, the applicatin rate multiplier credit may be claimed fr the N Cre NM and additinal lss reductin multiplier credits may be claimed fr bth the N Placement Supplemental NM BMP and the N Rate Supplemental NM BMP. In this example, n additinal lss reductin multiplier credit may be claimed fr the N Timing Supplemental NM BMP. Figure 2 illustrates hw the P Cre NM BMP and the P Supplemental NM BMPs are cmbined fr credit. As described abve, P Supplemental NM BMPs can nly be credited if the P Cre NM BMP is implemented and verified. The P Supplemental NM BMPs d nt result in additinal credit unless implementatin f adjustments in P rate, P placement, r 12

13 P timing is verified. The P Supplemental NM BMPs are assigned t three categries: P Rate Adjustment Practices, P Placement Adjustment Practices, and P Timing Adjustment Practices. The Supplemental NM BMP lss reductin credit fr each f these three categries can be btained if implementatin f at least ne effective practice frm each categry is verified. Fr example, if implementatin f the P Cre NM BMP is verified and implementatin f bth P applicatin setbacks frm water (a P placement adjustment) and P-based manure rate based n annual crp P remval (a P rate adjustment) are verified, the applicatin rate multiplier credit may be claimed fr the P Cre NM and additinal lss reductin multiplier credits may be claimed fr bth the P Placement Supplemental NM BMP and the P Rate Supplemental NM BMP. In this example, n additinal lss reductin multiplier credit may be claimed fr the P Timing Supplemental NM BMP. NITROGEN Cre Nutrient Management BMP Are ALL applicable cre elements implemented and verified? NO Credit as Nn-Nutrient Management fr N YES Credit as N Cre Nutrient Management Is Advanced N Assessment Perfrmed? NO Credit as N Cre Nutrient Management YES Additinal Credit fr N Rate Adjustment Is at Least One N Rate Adjustment Practice Implemented? N Additinal Credit Additinal Credit fr N Placement Adjustment Is at Least One N Placement Adjustment Practice Implemented? N Additinal Credit Additinal Credit fr N Timing Adjustment Is at Least One N Timing Adjustment Practice Implemented? N Additinal Credit Figure 1. Linkage f Cre and Supplemental N Nutrient Management Practices 13

14 PHOSPHORUS Cre Nutrient Management BMP Are ALL applicable cre elements implemented and verified? NO Credit as Nn-Nutrient Management fr P YES Credit as P Cre Nutrient Management Is Advanced P Assessment Perfrmed? NO Credit as P Cre Nutrient Management YES Additinal Credit fr P Rate Adjustment Is at Least One P Rate Adjustment Practice Implemented? N Additinal Credit Additinal Credit fr P Placement Adjustment Is at Least One P Placement Adjustment Practice Implemented? N Additinal Credit Additinal Credit fr P Timing Adjustment Is at Least One P Timing Adjustment Practice Implemented? N Additinal Credit Figure 2. Linkage f Cre and Supplemental P Nutrient Management Practices 2.1 NM Cre and Supplemental Element Detailed Definitins T better enable the CBP partnership and state agency partners t understand and apply the recmmendatins f the NM Panel t their unique prgrams and prductin systems, the fllwing sectin prvides additinal descriptive details t each f the NM Cre BMPs and Supplemental NM BMPs. 2.2 Nitrgen Cre NM BMP Elements All five elements, as applicable t the agricultural peratin, are required t be implemented and verified at the field management unit level t receive credit. N rate accrding t LGU recmmendatins at field management unit. The elements f the N Cre Nutrient Management BMP are fund in Table 2. Applicatin f a N Cre NM BMP efficiency mdifies the crp- and land-use-specific N applicatin rate gal, which is based n LGU crp fertilizatin recmmendatins, as mdified by the CBP partnership. In an effrt t determine the mst practicable methdlgy fr allcating fertilizer N t satisfy crp- and land-use-specific N applicatin rate gals, the Agriculture Wrkgrup cmpared the mdified LGU recmmendatins fr applicatin f supplemental inrganic N fertilizer t an alternative apprach based n cunty-level redistributin f AAPFCO N fertilizer sales data. This methdlgical cmparisn indicated that there were relatively small differences 14

15 between the tw methds fr estimating supplemental N fertilizer applicatins, leading the Agriculture Wrkgrup t apprve use f the redistributed AAPFCO fertilizer sales methdlgy in the Phase 6 Mdel. The Panel recmmends that similar cmparative analyses be cnducted in the future t evaluate newly available fertilizer sales data and t further evaluate the redistributed fertilizer sales methdlgy s frecasting ability. Incnsistencies between estimates generated by the tw methds shuld be investigated and rectified based n data surce quality and cnsistency using cntiguus r reginal cunty-level data. If applied N applicatin rates are belw the applicable CBP partnership mdified applicatin rates, the N applicatin system may still qualify fr credit as an equivalent N Cre system if it meets the remaining fur N Cre elements. A field management unit is described by the NM Panel as a cmmn land management unit defined by the farm peratr that includes similar annual crp prductin and management systems, and assciated nutrient applicatin system. The field management unit can represent any field, cllectin f multiple fields, r subprtins f a single field that are managed the same way, with similar histry and crpping practices. Manure analysis and vlume. Estimatin f manure prduced and nutrient analysis f that manure must be used in the planning prcess. It is strngly preferred that manure nutrient analyses be derived frm manure sample testing using standard labratry prtcls. In the absence f labratry manure analysis data, published manure nutrient analyses frm LGUs, natinal agricultural agencies (e.g., USDA-ARS, USDA-NRCS), natinal r reginal farm service rganizatins, r histrical analyses generated frm very similar, lcal and cnsistently managed industry-cntracted peratins may be used. If a labratry manure analysis is used t adjust the nutrient applicatin, the labratry analysis must be less than three-years ld. If labratry analysis f manure is nt available, as in the case f new, expanded r mdified livestck and pultry peratins, r is nt required under state-specific regulatins, published bk values (as described abve) may be used fr a maximum f three years, after which time labratry analysis data is strngly recmmended t be utilized t satisfy N Cre NM BMP requirements. Spreader/applicatr calibratin. The equipment being used t perfrm the nutrient applicatins by the farm peratr needs t be dcumented and verified that the machine(s) have been calibrated either accrding t manufacturer specificatins r by standard calibratin practices, preferably within ne year f the applicatin. The custm applicatr and equipment calibratin certificatins fr cmmercial applicatrs can be used as an equivalent verificatin dcumentatin fr calibrated nutrient applicatins. Yield estimates and crpping plan at field management unit level. Annual yield estimates fr field management units shuld be based n field yield samples, calibrated electrnic yield mnitrs, r field specific grain elevatr receipts. Histric yield gals are determined using a standardized methd f averaging annual yields ver time t accunt fr annual variability (e.g. average yield is based n best three ut f the past five years). A less preferred but equivalent methd is t use standard USDA sil prductivity bk values fr estimating applicable yields. The crpping plan refers t the planting and harvesting f the specific crp(s) fr which the field nutrient applicatins were based. An example f a field that wuld nt qualify under this required element is when the nutrient applicatin was based n the plant requirements fr grain crn but, due t in-seasn management decisins, the field was planted t sybeans instead. Crpping/manure histry at field management unit level. As part f develping a planned nutrient applicatin rate, the farm peratr r custm applicatr cnsidered legume residual N credits based n LGU r natinal agricultural service (e.g., USDA) recmmendatins. The manure applicatin histry during the crp rtatin must be cnsidered, including apprpriate manure mineralizatin crediting. Verified dcumentatin f manure mineralizatin N credits are included as part f the nutrient balance t accunt fr at least the three prir years. Legume residual N credits are included as part f the nutrient balance t accunt fr at least the immediately preceding year. 15

16 Nutrient management practice dcumentatin. The NM Panel defined the N Cre NM BMP t require full implementatin f a defined and applicable set f fundamental elements in rder t receive the BMP credit. Independent dcumentatin and verificatin that all f the required elements f the N Cre NM BMP were implemented is required. The five elements that cnstitute the N Cre NM BMP may r may nt be cmpnents f a frmal Nutrient Management Plan. The required nutrient management dcumentatin culd be in the frm f a frmal federal-, state-, r cunty-reviewed and certified nutrient management prgram plan, a nn-certified frmal nutrient management plan develped by a federal- r state-certified plan writer, r detailed dcumentatin and an infrmal management plan cmpiled by an peratr r private cnsultant that met the Panel s BMP recmmendatins. Equivalent Practices States may prpse equivalent practices t satisfy these requirements that must be apprved by the Agriculture Wrkgrup. 2.3 Phsphrus Cre NM BMP Elements All six elements, as applicable t the agricultural peratin, are required t be implemented and verified at the field management unit level t receive credit. P applicatin rate accrding t LGU recmmendatins at field management unit level. P applicatin rate recmmendatins that are higher than the CBP Partnership-mdified P applicatin rates are allwable when the recmmended rate is the utcme f a P-lss risk assessment tl that describes the risk f P lss t be lw. Applicatin f a P Cre NM BMP applicatin rate multiplier mdifies the crp- and land-use-specific P applicatin rate gal, which is based n LGU crp fertilizatin recmmendatins, as mdified by the CBP partnership. In practice, LGU recmmendatins fr P applicatin are based n crp- and site-specific sil-test P cncentratin. Currently, sil-test P cncentratin data are nt available t the CBP. The Panel recmmends that, in the future, crp- and site-specific sil-test P cncentratin data shuld be cllected, aggregated t the apprpriate scale, summarized t eliminate disclsure f private cnfidential business infrmatin, and utilized as the fundatin fr determining P applicatin rate gals and the apprpriate applicatin f P Cre NM BMPs. In the absence f sil-test P based applicatin rate gals, cunty-level redistributin f CBW AAPFCO P fertilizer sales data may serve as a surrgate. If applied P applicatin rates are belw the applicable LGU prescribed rates, and/r the CBP partnership mdified applicatin rates, the P applicatin system may still qualify fr credit as an equivalent P Cre NM system if it meets the remaining five P Cre elements. A field management unit is described by the NM Panel as a cmmn land management unit as defined by the farm peratr with a similar annual crp prductin and management systems, and assciated nutrient applicatin system. The field management unit can represent any field, cllectin f multiple fields, r sub-prtins f a single field that are managed the same way, with similar histry and crpping practices. P sil tests at field management unit level. The requirement fr having a P sil test may be waived if restrictins n manure applicatin (rates, timing, placement), are impsed that limit P applicatin rates and management t the same degree as if the site s sil was in the high sil-test P interpretive categry. A sil labratry analysis is required t be btained frm the field management unit using standard sil testing prtcls. If a labratry sil analysis being used t adjust the nutrient applicatin, it must be less than three-years ld. In the absence f an available sil P labratry analysis, P nutrient applicatins may be based n annual crp remval at the field management unit level as an equivalent P Cre element, assuming the site s sil was in the high sil-test P interpretive categry. Manure analysis and vlume. Estimatin f manure prduced and nutrient analysis f that manure must be used in the planning prcess. It is strngly preferred that manure nutrient analyses be derived frm manure sample testing using standard labratry prtcls. In the absence f labratry manure analysis data, published manure nutrient analyses frm LGUs, natinal agricultural agencies (e.g., USDA-ARS, USDA-NRCS), natinal r reginal farm service rganizatins, r histrical analyses generated frm very similar, lcal and cnsistently managed industry-cntracted peratins 16

17 may be used. If a labratry manure analysis is used t adjust the nutrient applicatin, the labratry analysis must be less than three-years ld. If labratry analysis f manure is nt available, as in the case f new, expanded r mdified livestck and pultry peratins, r is nt required under state-specific regulatins, published bk values (as described abve) may be used fr a maximum f three years, after which time labratry analysis data is strngly recmmended t be utilized t satisfy P Cre NM BMP requirements. Spreader/applicatr calibratin The equipment being used t perfrm the nutrient applicatins by the farm peratr needs t be dcumented and verified that the machine(s) have been calibrated either accrding t manufacturer specificatins r by standard calibratin practices, preferably within ne year f the applicatin. The custm applicatr and equipment calibratin certificatins fr cmmercial applicatrs can be used as an equivalent verificatin dcumentatin fr calibrated nutrient applicatins. Yield estimates and crpping plan at management unit level Annual yield estimates shuld be based n field yield samples, calibrated electrnic yield mnitrs, r field specific grain elevatr receipts. Histric yield gals are determined using a LGU r state standardized methd f averaging annual yields ver time t accunt fr annual variability (e.g. average yield based n the best three ut f the past five years). A less preferred but equivalent methd is t use standard USDA sil prductivity bk values fr estimating applicable crp yield. The crpping plan refers t the planting and harvesting f the specific crp(s) fr which the field nutrient applicatins were based. An example f a field that wuld nt qualify under this required element is when the nutrient applicatin was based n the plant requirements fr grain crn but, due t in-seasn management decisins, the field was planted t sybeans instead. Crpping/manure histry at field management unit level As part f develping a planned nutrient applicatin rate, the farm peratr r custm applicatr cnsidered residual P credits based n LGU r natinal agricultural service (e.g., USDA) recmmendatins. The manure applicatin histry during the crp rtatin must be cnsidered, including apprpriate residual sil P crediting. Residual sil P credits are included as part f the nutrient balance t accunt fr at least the immediately preceding year. Nutrient management practice dcumentatin. The NM Panel defined the P Cre NM BMP t require full implementatin f a defined and applicable set f fundamental elements in rder t receive the BMP credit. Rather, independent dcumentatin and verificatin that all f the required elements f the P Cre NM BMP were implemented is required. The six elements that cnstitute the P Cre NM BMP may r may nt be cmpnents f a frmal Nutrient Management Plan. The required nutrient management dcumentatin culd be in the frm f a frmal federal-, state-, r cunty-reviewed and certified nutrient management prgram plan, a nn-certified frmal nutrient management plan develped by a federal- r state-certified plan writer, r detailed dcumentatin and an infrmal management plan cmpiled by an peratr r private cnsultant that met the Panel s BMP recmmendatins. Equivalent Practices States may prpse equivalent practices t satisfy these requirements that must be apprved by the Agriculture Wrkgrup. 2.4 Nitrgen Supplemental NM BMPs Advanced N Assessment Tls. Dcumentatin needed f the use f ne r a cmbinatin f these tls. These tls shuld guide implementatin f N rate, placement, r timing. Cnducting these assessments r using these tls have n impact unless they lead t an infrmed change in implementatin f N rate, N placement r N applicatin timing. 17

18 This list is nt exhaustive r cmprehensive, and nly represents a selectin f examples that wuld cnstitute tls resulting in an implementatin change. N Rate Adjustment Practices. By implementing ne r mre f the practices listed, an additinal N credit will be applied. Hwever, implementing mre than ne f the practices captured under each supplemental practice categry will nly result in ne credit fr the practice adjustment. Within the N Rate Adjustment Practice, the rate f applicatin can be less than the LGU recmmendatin r cnsistent with partnership apprved rate applicatins, but in rder t receive supplemental credit, the rate f applicatin must be belw the rate listed fr the N Cre NM BMP. Split applicatins ver time per crp. Ttal amunt f N applicatin may r may nt change, but the applicatin is divided int multiple, lwer-rate applicatins thrughut the year. Variable rate N applicatin implies that N is applied at a variety f different applicatin rates at the sub-field scale within a management unit based n histrical data f spatially variable crp respnse due t sil type, drainage, etc. r due t in-seasn data frm ptical crp sensrs. N Placement Adjustment Practices. By implementing ne r mre f the practices listed, an additinal N credit will be applied. Hwever, implementing mre than ne f the practices captured under each supplemental practice categry will nly result in ne credit fr the practice adjustment. Where the N nutrient surce is physically lcated r placed relative t the sil surface. Subsurface injectin r incrpratin f applied inrganic N. Immediate incrpratin generally means within 24 hurs f applicatin. N applicatin setbacks frm water: purpsefully nt applying N t crpped and hay land areas adjacent t surface water bdies. Setbacks must meet the minimum standards required under applicable lcal, state, r federal prgrams and laws. Applies t bth manure and fertilizer. Credit applies t entire field management unit. N Timing Adjustment Practices. By implementing ne r mre f the practices listed, an additinal N credit will be applied. Hwever, implementing mre than ne f the practices captured under each supplemental practice categry will nly result in ne credit fr the practice adjustment. Split applicatins ver time per crp. Ttal amunt f N des nt change, but applicatin is divided int multiple applicatins thrughut the year. 2.5 Phsphrus Supplemental NM BMPs Advanced P Assessment Tls. Dcumentatin needed f the use f ne r a cmbinatin f these tls. These tls shuld guide implementatin f rate, placement, r timing. Cnducting these assessments r using these tls have n impact unless they lead t an infrmal change in implementatin f rate, placement, r timing. This list is nt exhaustive r cmprehensive, and nly represents a selectin f example that wuld cnstitute tls resulting in an implementatin change. P Rate Adjustment Practices. By implementing ne r mre f the practices listed, an additinal P credit will be applied. Hwever, implementing mre than ne f the practices captured under each supplemental practice categry will nly result in ne credit fr the practice adjustment. Within the P Rate Adjustment Practice, the rate f applicatin can be less than the LGU recmmendatin r cnsistent with partnership apprved rate applicatins, but in rder t receive supplemental credit, the rate f applicatin must be belw the rate listed fr the P Cre NM BMP. 18

19 Variable rate P applicatin implies that P is applied at variety f different applicatins rates at the sub-field scale within the management unit based spatially variable crp respnse due t sil type, drainage, etc. r due t in-seasn data frm ptical crp sensrs. A P-based manure applicatin rate equivalent t annual crp P remval is an equivalent rate adjustment practice. P Placement Adjustment Practices. By implementing ne r mre f the practices listed, an additinal P credit will be applied. Hwever, implementing mre than ne f the practices captured under each supplemental practice categry will nly result in ne credit fr the practice adjustment. Where the P nutrient surce is physically lcated r placed relative t the sil surface. Subsurface injectin r incrpratin f applied inrganic P. Immediate incrpratin generally means within 24 hurs f applicatin. Phsphrus applicatin setbacks frm water: purpsefully nt applying P t crpped and hay land areas adjacent t surface water bdies. Setbacks must meet the minimum standards required under applicable lcal, state, r federal prgrams and laws. Applies t bth manure and fertilizer. Credit applies t entire field management unit. Applicatin f manure n different fields based n the P Index assessment that results in manure applicatin n a lwer P Index rated field rather than a higher P Index rated field. P Timing Adjustment Practices. By implementing ne r mre f the practices listed, an additinal P credit will be applied. Hwever, implementing mre than ne f the practices captured under each supplemental practice categry will nly result in ne credit fr the practice adjustment. Split applicatins ver time per crp. Ttal amunt f P des nt change, but applicatin is divided int multiple applicatins thrughut the year. P applicatin in lwer P-lss risk seasn. Purpseful change the timing f manure applicatin based n the P Index assessment that results in manure applicatin at a time during the calendar year when the P Index assessment indicates a lwer risk fr P lss. Split applicatins ver time per crp. Ttal amunt f P applicatin may r may nt change, but the applicatin is divided int multiple, lwer-rate applicatins thrughut the year. 19

20 3 Effectiveness Estimates This sectin begins with a brief summary f the recmmended N and P multiplier values fr N and P Cre NM BMPs and fr lss reductin multipliers fr N and P Supplemental NM BMPs. This summary is fllwed by a discussin f the ratinale and use f specific data values frm the available literature t develp the recmmended multiplier values. Finally, details are prvided n hw the recmmended applicatin rate multiplier values fr Cre NM BMPs and lss reductin multipliers fr the Supplemental NM BMPs can be cmbined t reflect actual N and P management and verall effectiveness at a specific lcatin. 3.1 Summary f Effectiveness Estimates All numeric values fr Cre NM BMP applicatin rate multipliers and Supplemental NM BMP lss reductin multipliers have been defined by the Panel. See sectin 3.3 fr a detailed discussin f hw these values are applied in the determinatin and crediting f verall NM BMP effectiveness fr N and P N Cre NM BMPs The Panel s prpsed applicatin rate multipliers fr N Cre NM BMPs fr each applicable agricultural land use categry are given in Table 12. These applicatin rate multipliers are based n state LGU recmmendatins, as mdified by the CBP partnership, and apply t the nutrient applicatin rate gal, r input side, f nutrient management mdeling scheme. Each value represents a multiplicative mdifier f the crp- and land-use-specific N applicatin rate gal utilized in the CBP mdels. Table 12. Cre N Nutrient Management Applicatin Rate Multiplier Values Land Use Nutrient Management BMP Nitrgen Cre Nn-Nutrient Management BMP Applicatin Rate Multiplier Nitrgen Cre Nutrient Management BMP Applicatin Rate Multiplier Full Seasn Sybeans Grain w/ Manure Grain w/ Manure Legume Hay Silage w/ Manure Silage w/ Manure Small Grains and Grains Small Grains and Sybeans Specialty Crp High Specialty Crp Lw Other Agrnmic Crps Other Hay Pasture P Cre NM BMPs The Panel s prpsed applicatin rate multipliers fr P Cre NM BMPs fr each applicable agricultural land use categry are given in Table 13. These applicatin rate multipliers are based n state LGU recmmendatins, as mdified by the CBP partnership, and apply t the nutrient applicatin rate gal, r input side, f the nutrient mdeling scheme fr bth NM and nn-nm acres. Each value represents a multiplicative mdifier f the crp- and land-use-specific P applicatin rate gal utilized in the CBP mdels. Fr crps and land uses in which manure is applied, manure applicatins that result in manure P applicatin rates that are greater than r equal t the crp-specific P applicatin need results in the prhibitin f 20

21 applicatin f additinal fertilizer P. An exceptin t the prhibitin f supplemental fertilizer P additin fllwing manure applicatin is the utilizatin f relatively small quantities f starter fertilizer P, typically applied subsurface in the planting rw, accrding t LGU recmmendatins. Fr crps and land uses in which manure is applied, the ttal quantity f manure P assciated with the ttal manure applicatin rate shuld be allcated t the subject acreage. Table 13. Cre P Nutrient Management Applicatin Rate Multiplier Values Land Use Nutrient Management BMP Phsphrus Cre Nn-Nutrient Management BMP Applicatin Rate Multiplier Phsphrus Cre Nutrient Management BMP Applicatin Rate Multiplier Full Seasn Sybeans Grain w/ Manure Grain w/ Manure Legume Hay Silage w/ Manure Silage w/ Manure Small Grains and Grains Small Grains and Sybeans Specialty Crp High Specialty Crp Lw Other Agrnmic Crps Other Hay Pasture N Supplemental Nutrient Management BMPs The Panel s prpsed lss reductin multipliers fr N Supplemental NM BMPs fr each applicable agricultural land use categry are given in Table 14. These values are multiplicative mdifiers that apply t edge-f-stream delivery f N, n the utput side f the CBP mdeling scheme, and can nly be applied if the requirements fr N Cre NM BMP are met. 21

22 Table 14. N Supplemental Nutrient Management BMP Lss Reductin Multiplier Values Land Use N Rate Supplemental BMP Lss Reductin Multiplier Nutrient Management BMP N Placement Supplemental BMP Lss Reductin Multiplier N Timing Supplemental BMP Lss Reductin Multiplier Full Seasn Sybeans Grain w/ Manure Grain w/ Manure Legume Hay Silage w/ Manure Silage w/ Manure Small Grains and Grains Small Grains and Sybeans Specialty Crp High Specialty Crp Lw Other Agrnmic Crps Other Hay Pasture P Supplemental Nutrient Management BMPs The Panel s prpsed lss reductin multipliers fr P Supplemental NM BMPs fr each applicable agricultural land use categry are given in Table 15. These values are multiplicative mdifiers that apply t edge-f-stream delivery f P, n the utput side f the CBP mdeling scheme, and can nly be applied if the requirements fr P Cre NM BMP are met. Table 15. P Supplemental Nutrient Management BMP Lss Reductin Multiplier Values Land Use P Rate Supplemental BMP Lss Reductin Multipliers Nutrient Management BMP P Placement Supplemental BMP Lss Reductin Multipliers P Timing Supplemental BMP Lss Reductin Multipliers Full Seasn Sybeans Grain w/ Manure Grain w/ Manure Legume Hay Silage w/ Manure Silage w/ Manure Small Grains and Grains Small Grains and Sybeans Specialty Crp High Specialty Crp Lw Other Agrnmic Crps Other Hay Pasture

23 3.2 Develpment f Applicatin Rate Multipliers and Lss Reductin Multipliers fr Cre NM BMPs and Supplemental NM BMPs The Panel develped the prpsed Phase 6 NM applicatin rate multiplier estimates and lss reductin multiplier estimates thrugh a synthesis f applicable scientific literature (see References sectin) and the cllective best prfessinal judgment f the NM Panel members (see Table 1). The membership f the Panel represents ver 150 years f direct invlvement in research, implementatin and educatin n agricultural nutrient management practices. The entire bdy f research represented by the citatins presented in the References sectin prvided the fundatin fr the Panel s prfessinal assessment f the rate and lss reductin multipliers fr the prpsed NM BMPs. The multiplier values presented fr the Cre NM BMPs and the Supplemental NM BMPs represent either a cllectin f required elements r represent the impact f numerus applicable n-site management practices. Therefre, in rder t develp bradly pertinent NM BMP multiplier values, multiple surces f infrmatin and data were necessarily synthesized thrugh the expert lens f the Panel. Fr bth N and P BMPs, nutrient management practices are implemented at either the field r sub-field level. The diverse landfrms, hydrlgy, climate and crpping systems f the agricultural landscapes in the CBW have a multitude f impacts n bigechemical transfrmatins f N and P in the agr-ecsystem. Changes in hydrlgical pathways alne can have dramatic effects n nutrient lads t streams when viewed frm the Atlantic Castal Plain t the Appalachian Plateau. Therefre, site-specific physical cnditins and management factrs have a strng influence n the effectiveness f impsed cnservatin practices. Nutrient management BMP effectiveness must represent the average cnditin ver a wide range f real-wrld scenaris. Thus, it was incumbent upn the Panel t distill numerus lines f evidence t arrive at a single multiplier value fr each f the N and P BMPs that culd be applied equitably acrss the CBW. Belw are examples f specific analyses that were used t infrm the NM Panel in its applicatin f best prfessinal judgment t determine NM BMP applicatin rate multipliers and lss reductin multipliers. N Cre and P Cre NM BMPs The reductin in nutrient applicatin rates fr N Cre and P Cre NM BMPs were determined based n histrical (i.e., befre the Chesapeake Bay Prgram Watershed Mdel (CBPWM) simulatin perid f 1985) and mdern LGU agrnmy guides (i.e., during the calibratin perid f the CBPWM (Table 16). Histrical LGU agrnmy guides (pre-1985) evaluated by Phase NM Panel members recmmended a range f percent mre plant-available N than CBPWM calibratin perid LGU guides. In additin, the principal basis fr applicatin rate difference between nn-nm and NM fr N is a reductin in the fertilizer N requirement fr crn frm 1.2 lbs. N/bu. f expected yield in earlier LGU recmmendatins t 1.0 lbs. N/bu. f expected yield in current LGU recmmendatins. This reductin is supprted by data frm Cale (2000) wh examined crn yield respnse t fertilizer N rate with the assciated pst-harvest fall sil residual NO 3 -N cncentratin. These findings are reflected in the values fr grain and silage fund in Table 12 fr N Cre NM BMPs. Because ther crps f significant acreage did nt have cnsistently r significantly lwer recmmended N applicatin rates when the histrical (pre-1985) and current frm LGU agrnmy guides were cmpared, these agricultural land uses were assigned mre cnservative values in Table 12. N Cre NM BMP multiplier values fr Other Hay and Pasture were set at 1.00 because the CBP Partnership s mdificatin f the LGU N applicatin recmmendatins created a unifrm and much-reduced N applicatin rate gal fr these tw agricultural land uses that included an assumed implementatin rate f NM BMPs acrss the entire CBW. Therefre, the Panel culd nt apply a N applicatin rate BMP multiplier ther than 1.00 t these tw land uses. 23

24 Table 16. LGU Agrnmy Guide Recmmendatins fr Crn N Fertilizer Applicatin Rate Befre and During CBPWM Calibratin Perid. Values Presented Are Punds f Plant Available N (PAN) Per Bushel f Expected Crn Yield Land Grant University Pre-calibratin Recmmendatin Calibratin perid Recmmendatin Nrth Carlina State University 1.4 lbs. PAN lbs. PAN Pennsylvania State University University f Maryland Nrth Carlina State University Extensin Agrnmy Guide. Nrth Carlina State University. Raleigh, NC. 1 Penn State Extensin Agrnmy Guide. The Pennsylvania State University, Cllege f Agriculture Extensin Service. University Park, PA Cp. Ext. Serv Fertilizer Recmmendatins, sheet 3, crn fr grain n medium textured sils withut manure. Univ. MD Cp. Ext. Serv., Cllege Park, MD. 1 Cale, F.J Plant nutrient recmmendatins based n sil tests and yield gals. Agrnmy Mime N. 10, Cp. Ext. Serv. and Agrnmy Dept. Univ. MD, Cllege Park, MD P applicatin rate multiplier values fr P Cre NM BMPs are greater fr land uses with manure versus the crrespnding land use withut manure. Histrically (pre-1985), manure applicatins managed withut attentin t NM guidelines resulted in P applicatin rates at least three times higher, and prbably mre, than wuld be expected under P-based nutrient management. Fr nn-manured prductin systems perating utside f NM guidelines, fertilizer P verapplicatin wuld nt be expected t be nearly as great as when manure is the primary nutrient surce. These findings are reflected in the values fr grain and silage fund in Table 13 fr P Cre NM BMPs. As fr N Cre NM, P Cre NM BMP multiplier values fr Other Hay and Pasture were set at 1.00 because the CBP Partnership s mdificatin f the LGU P applicatin recmmendatins created a unifrm and much-reduced P applicatin rate gal fr these tw agricultural land uses that included an assumed implementatin rate f NM BMPs acrss the entire CBW. Therefre, the Panel culd nt apply a P applicatin rate BMP multiplier ther than 1.00 t these tw land uses. N Rate, N Placement, and N Timing Lss Reductin Multipliers Several assessments f the PSNT have resulted in N reductin rates f 6 t 42 percent, with mst demnstrating reductins f 17 percent r greater. A three-year study f crn/rye n a manured silt-lam sil in Vermnt by Durieux et al. (1995) reprted that use f the PSNT reduced nitrate leaching ptential by resulting in an average reductin in fall residual NO 3 -N (nitrate N) f 56 percent cmpared t N applicatins based n traditinal LGU N recmmendatins. On average, fall N applicatin was reduced by 29 percent (150 lbs. N/ac. t 107 lbs. N/ac.) due t applicatin f the PSNT. This exceeds the largest credit (15 percent lss reductin) given fr N Rate Supplemental BMPs (Table 14). The reduced ptential fr nitrate leaching due t PSNT applicatin was cnfirmed by Guillard et al. (1999) in a tw-year lysimeter study n a sandy-lam sil that demnstrated an average reductin in NO 3 -N leaching f 63%, cmpared t crn fertilized accrding t standard LGU recmmendatins. Fall N leaching lss was reduced by an average f 42 percent, frm 196 kg N/ha (175 lbs. N/ac.) t 113 kg N/ha (101 lbs. N/ac.), a change als greatly exceeding the N Rate Supplemental BMP credits shwn in Table 14. Data frm quarterly r annual reprts frm in-field nutrient management cnsultants were used t summarize PSNT activities and results under the Maryland (Steinhilber 2015) and Virginia (Sextn 2015) Nutrient Management Prgrams. The Maryland summaries cvered three years, encmpassing a ttal f 2,690 ac. frm the Piedmnt and 27,850 ac. frm the Castal Plain. The average estimated reductin in ttal fertilizer N applicatin resulting frm implementing the PSNT, cmpared t using university recmmendatins withut the PSNT, was 20% and 6% fr the Piedmnt and Castal Plain regins, respectively. Sextn (2015) reprted n a 5,325-ac. evaluatin f the PSNT cnducted in Virginia s Shenandah Valley cnsisting f 1,246 PSNT tests that cmpared university recmmendatins with and withut the PSNT (Fitzgerald and Baird 2014). The Virginia results shwed that use f the PSNT resulted in an estimated average savings f 30 lbs. N/ac., r a 20% N fertilizer applicatin reductin fr 29% f the PSNT evaluatins and a savings f 60 lbs. N/ac., r a 40% N fertilizer applicatin reductin, fr anther 28% f the PSNT evaluatins. The remaining 43% f the PSNT evaluatins resulting in unchanged fertilizer N applicatin rate recmmendatins. The average percent reductin f fertilizer N applicatin acrss the Virginia Piedmnt study was 17%, which is cnsistent with the Maryland Piedmnt estimate. Additinally, a tw-year study in New Yrk n a lamy-sand sil that mnitred tile drainage frm silage crn grwn in relatively large (18 m 2 ) islated plts reprted an average reductin in NO 3 -N lsses f 42% fr the PSNT treatment, 24

25 cmpared t the nn-psnt standard LGU recmmendatin (Sgbedji et al. 2000). Fall N lss rates were reduced by 25% (134 kg N/ha t 100 kg N/ha r 120 lbs. N/ac. t 89 lbs. N/ac.) due t applicatin f the PSNT. Studies n the CSNT and ISNT shwed results similar t thse fr the PSNT. In New Yrk, results reprted by Ketterings et al. (2014, 2011a, 2011b), Whartn et al. (2010), and Hng et al. (2010) suggest that abut 40% f tested crn silage fields were rated in the excess categry and fllwing the recmmendatins f the CSNT wuld result in a 20 t 30% reductin in N applicatin. Kyveryga et al. (2010) reprted that f 215 fields receiving liquid swine manure, abut 30% f fields were fund t be unrespnsive t additinal N (beynd 25 lbs. N/ac. starter). Extending this percentage ver all silage crn fields under CSNT, recmmendatins derived frm CSNT wuld have resulted in 15 t 30 lbs. N/ac. applicatin reductin annually, representing a 20 t 30% reductin ver standard N rate recmmendatins. Results f multi-year N rate trials n silage crn in New Yrk ver three crp years shwed that abut 50% f tested fields were nn-respnsive t additinal N fertilizer and, therefre, the ISNT assessment wuld recmmend n additinal N applicatin beynd starter N at 25 lbs. N/ac. (Lawrence et al. 2009, Klapwyk et al. 2006, Lawrence et al. 2008, Ketterings et al. 2009). Because these fields wuld therwise have received a recmmended applicatin f 75 t 125 lbs. N/ac., managing N applicatins based n the ISNT results reduced N applicatins n the affected fields by 50 t 100 lbs. N/ac. Discunting this reductin because nly half f crn silage fields were determined t be nn-respnsive by ISNT gives an estimated 25 t 50 lbs. N/ac. reductin in N applicatins t silage crn, a reductin f 33 t 40% in ttal N applicatins. Using unpublished data frm studies cnducted thrughut Virginia, the Phase Nutrient Management Expert Panel cmpared N applicatin rates t crn fr the Virginia Tech Crn Algrithm (VTCA) applied via the GreenSeeker system versus the standard farmer s N rate methds (Phase Nutrient Management Expert Panel 2015). Over 15 sites in 4 years, the average VTCA N rate was 24 kg/ha (apprximately 20%) less than the standard farmer s rate, with n significant difference in grain yields. Additinally, data frm field scale demnstratins frm a ttal f 1600 ac. ver tw years demnstrated a 10% decrease in N rate applied with n difference in crn yields (Virginia NRCS CIG 69-33A7-1131, final reprt). These data demnstrate the ability t reduce N applicatin rates while maintaining crp yields. Other Virginia data fr wheat (Thmasn et al and Virginia NRCS CIG 69-33A7-1131, final reprt) suggest that N rates fr wheat culd be decreased by apprximately 7% with n change in yield. The FSNT prvides an adaptive management tl fr simultaneusly imprving ecnmic prductin f small grains by identifying sites where small grains need starter N, and als reducing nitrate-n lss t grundwater by nt fertilizing N sufficient sites just befre the fall-winter-spring water-recharge seasn when mst nitrate leaching ccurs (Frrestal et al. 2014, Meisinger et al. 2015). The N reductin efficiency fr the FSNT was estimated frm fur years f lysimeter nitrate-n leaching data (Pers. cmm., J. Meisinger 2015) using the intact sil-clumn lysimeter described in Palmer et al. (2011) and fllwing the sample cllectin and analysis methds described in Meisinger et al. (2015). The lysimeter treatments were replicated twice each year with winter wheat receiving either a starter-n applicatin f 30 lbs. N/ac. r n starter-n. Lysimeter drainage mnitred NO 3 -N leaching cntinuusly between planting and the green-up develpment stage. These treatments were repeated in , , , and wheat grwing seasns. The final lysimeter-based N lss reductin efficiency was estimated t be 10%. In the lng term, achieving a balance between nutrient imprts and exprts at the whle farm level (and later at the watershed level) is believed t be an effective way t minimize nutrient surpluses, manage sil nutrient levels, and reduce runff and leaching lsses. Fr livestck farms, the whle farm nutrient balance apprach has been invaluable in identifying pprtunities fr reducing N and P imprts, making better use f n-farm nutrient surces, identifying the need fr mre land fr nutrient recycling, and increasing nutrient exprts. As shwn ver several years f research n 54 New Yrk dairy farms, nutrient balance reductins averaged 29% fr N and 36% fr P (Sbern et al. 2015, Cela et al. 2014a and 2014b). Hwever, the bserved reductins are attributable primarily t changes in feed frmulatin and management, rather than fertilizer management. N reductin efficiencies frm timing N applicatins were estimated by cmparing crn yields frm replicated N-respnse trials ver many site-years (Fx et al. 1986, Fx and Piekielek 1993, Pers. Cmm. J Meisinger 2015). These studies cmpared yield vs. N applied (as urea-ammnium-nitrate) at planting, r N applied just befre the crp begins its rapid perid f grwth. Crn had the mst N-respnse trials, which were summarized by fitting separate quadratic regressin functins fr each timing at each site-year f data, and then estimating the ecnmic ptimum N rate (EONR) fr crn 25

26 grain valued at $4.00/bu. and N priced at $0.50 per pund. These regressins allwed estimatin f the EONR and assciated yield, which prvided a methd t cmpare ptimum rates fr N applied at planting vs. at a later time that was in harmny with crp N demand. A plt-based N reductin efficiency was estimated as the difference between the EONRs at planting vs. the delayed applicatin, divided by the planting EONR. There were als adequate data frm the Castal Plain (21 site-years) and the Piedmnt (18 site-years) regins t estimate separate N reductin efficiencies. These calculatins prduced a Castal Plain estimated N reductin efficiency f abut 16%, with the crrespnding estimate fr the Piedmnt f 9%. The Castal Plain higher N-timing reductin efficiency is likely due t the regin having mre carse-textured sils and mre shallw rting depths than the Piedmnt. These reductins supprt the N Timing Supplemental BMP Efficiency values in Table 14, as d the dcumented PSNT-based N reductin rates f 6 t 42% (with mst demnstrating reductins f 17 percent r greater) described abve. N-timing reductin efficiencies fr wheat were estimated frm tw-years f field-plt ttal N uptake data frm a study that cmpared an all-at-green-up applicatin with a split f N between green-up and an applicatin apprximately ne mnth later (Gravelle et al. 1988). Fur years f lysimeter nitrate-n leaching data (Pers. cmm., J. Meisinger 2015) were als used frm intact sil-clumn lysimeters described in Palmer et al. (2011) fllwing the sample cllectin and analysis methds described in Meisinger et al. (2015). The lysimeter treatments were replicated twice in each f the fur years ( , , , and ) with winter wheat receiving either all the N at green-up, r with the same N rate applied ne-third at green-up and tw-thirds abut a mnth later. These tw data surces prduced an average wheat N-timing reductin efficiency f abut 15%, which is similar t the Castal Plain value fr crn and supprtive f the N Timing Supplemental BMP Efficiency values in Table 14. When the data summarized abve are analyzed as a whle, the literature is supprtive f the applicatin f NM BMP N lss reductin multipliers within the ranges presented in Table 14. Overall, the prpsed N lss reductin multipliers are numerically cnservative and range frm 3 t 15%, exclusive f the 0% N lss reductin multiplier that was defined fr the Other Hay and Pasture land uses. P Rate, P Placement, and P Timing Lss Reductin Multipliers Kleinman and Sharpley (2003) packed sils int runff bxes and bradcast with three manures (dairy, layer pultry, and swine) at six rates, frm 0 t 150 kg ttal P (TP)/ha (0-134 lbs. TP/ac.). Manure analysis indicated that N-based manure applicatin fr silage crn f 300 kg ttal N (TN)/ha (268 lbs. TN/ac.)) wuld result in TP applicatin rates f 70, 200, and 88 kg/ha (62, 178, and 78 lbs. TP/ac.) fr the dairy, pultry, and swine manures, respectively. Applicatin rates matching silage crn TP requirement f apprximately 25 kg TP/ha (22 lbs. TP/ac.) wuld result in TN applicatins f 151, 53, and 119 kg TN/ha (135, 47, and 106 lbs. TN/ac). Applicatin rate was related t runff P (r 2 =0.50 t r 2 =0.98), due t increased cncentratins f disslved reactive phsphrus (DRP) in runff; as applicatin rate increased, s did the cntributin f DRP t runff TP. Assuming 150 bu./ac. yields, recmmendatins fr silage crn are abut 180 lbs. TN/ac. and 103 lbs. TP/ac. fr lw t ptimum sil test levels (Rth and Heinrichs 2001). Rates fr grain crn wuld be 160 lbs. TN/ac. and 76 lbs. TP/ac. The P rates applied by Kleinman and Sharpley (0-134 lbs. TP/ac.) bracket these rates, with the highest rate 1.3 and 1.8 times the silage and grain crn rates, respectively, fr a 150 bu. /ac. yield. The effect f flw time, flwpath length, and manure psitin n P lss in verland flw frm tw central Pennsylvania sils packed in bxes f varying length were examined by cllecting runff water samples frm sil bxes with and withut 75 kg P/ha applied as swine manure ver 0.5 m f the bx slpe length at distances f 0 t 3.5 m frm the dwnslpe cllectin pint (McDwell and Sharpley 2002). Disslved reactive P cncentratin was mre clsely related t the prprtin f clay in sediment f verland flw befre (r =0.98) than after (r= 0.56) manure applicatin. This was attributed t the transprt f larger, lw-density particles after applying manure. The cncentratin f disslved P and particulate P fractins decreased with increasing flw-path length, due t dilutin rather than srptin f P by surface sil during verland flw. Ttal P lss (mainly as particulate P) frm the Watsn channery silt lam was mre than frm Berks channery silt lam, even with manure applied. Thus, while P lss in verland flw is affected by where manure is applied relative t flwpath length, initial sil P cncentratin is very imprtant when lking at areas f ptential P lss within a watershed. In the lng term, achieving a balance between nutrient imprts and exprts at the whle farm level (and later at the watershed level) is believed t be an effective way t minimize nutrient surpluses, manage sil nutrient levels, and reduce 26

27 runff and leaching lsses. Fr livestck farms, the whle farm nutrient balance apprach has been invaluable in identifying pprtunities fr reducing N and P imprts, making better use f n-farm nutrient surces, identifying the need fr mre land fr nutrient recycling, and increasing nutrient exprts. As shwn ver several years f research n 54 New Yrk dairy farms, nutrient balance reductins averaged 29% fr N and 36% fr P (Sbern et al. 2015, Cela et al. 2014a and 2014b). Hwever, the bserved reductins are attributable primarily t changes in feed frmulatin and management, rather than fertilizer management. Applicatin f a P Cre NM BMP applicatin rate multiplier mdifies the crp- and land-use-specific P applicatin rate gal, which is based n LGU crp fertilizatin recmmendatins, as mdified by the CBP partnership. A significant mdificatin impsed by the CBP partnership was the assumptin that all agricultural acres in the CBW had a sil-test P cncentratin that crrespnded with the medium sil test interpretive categry. The Panel recgnized that, in the absence f sil-test P cncentratin data, assumed sil-test P cncentratins were necessary t facilitate CBP mdel prcesses. Hwever, the Panel als recgnized that implementatin f the universal medium sil-test P assumptin infused a high level f site-specific uncertainty int the mdeled P applicatin rate. In general, the inherent uncertainty in P applicatin rate resulting frm the adptin f the universal medium sil-test P cncentratin assumptin is expected t be similar t r greater than the magnitude f the P applicatin rate mdificatins resulting frm implementatin f P Cre NM BMP applicatin rate multipliers r the P NM Supplemental BMP lss reductin multipliers. In practice, LGU recmmendatins fr P applicatin are based n crp- and site-specific sil-test P cncentratin. Currently, sil-test P cncentratin data are nt available t the CBP. The Panel recmmends that, in the future, crp- and site-specific sil-test P cncentratin data shuld be cllected, aggregated t the apprpriate scale, summarized t eliminate disclsure f cnfidential business infrmatin, and utilized as the fundatin fr determining P applicatin rate gals and the apprpriate applicatin f P Cre NM BMPs. In the absence f sil-test P data and sil-test P based applicatin rate gals, sil-test P cncentratin must be assumed and, in turn, utilized t create artificial P applicatin rate gals. 3.3 Methd fr Applying Cre and Supplemental Multiplier Values The verall BMP efficiencies fr N and P nutrient management are derived frm a cmbinatin f applicatin rate multipliers fr the Cre Nutrient Management BMPs (N r P) with their crrespnding Supplemental Nutrient Management BMP (N r P) lss reductin multipliers. The N Cre NM BMP and P Cre NM BMP address the rate f nutrient applicatin while the N Supplemental NM BMPs and P Supplemental NM BMPs address the transprt f applied nutrients. The verall effectiveness values (ne fr N and ne fr P) are calculated as the cmbined effect f changes in nutrient applicatin rate and nutrient transprt caused by the implementatin f Cre and Supplemental NM BMPs. Specific details regarding hw these cmbinatins are calculated and applied are prvided belw. Nitrgen Applicatin f the N Cre NM BMP applicatin rate multiplier credit mdifies the crp- and land-use-specific N applicatin rate gal, which is based n LGU crp fertilizatin recmmendatins, as mdified by the CBP partnership. These multipliers apply t the nutrient applicatin rate gal, r input side, f CBP nutrient mdeling scheme fr bth NM and nn-nm acres. Each multiplier value represents a multiplicative mdifier f the crp- and land-use-specific N applicatin rate gal utilized in the CBP mdels. Applicatin f lss reductin multiplier credits fr N Supplemental NM BMP elements requires satisfactry implementatin f all respective N Cre NM BMP elements. The N Supplemental NM BMP multipliers apply multiplicative mdifiers t edge-f-stream delivery f N, n the utput side f the CBP mdeling scheme, and can nly be applied if the requirements fr N Cre NM BMP are met. Multiple advanced site assessments and N management tls may be utilized t infrm the applicatin f apprpriate N adjustment practices, but d nt represent a N credit in and f themselves. Advanced site assessments and applicatin f N management tls that result in implementatin f a verifiable change in planned N applicatin rate, N applicatin timing, r N applicatin placement may result in a N Supplemental NM BMP lss reductin multiplier credit. N Supplemental NM BMP credits fr N rate, N timing, and N placement are stackable. Only ne Supplemental NM BMP credit fr N rate, ne Supplemental NM BMP credit fr N timing, and ne Supplemental NM BMP credit fr N placement may be applied. 27

28 Phsphrus Applicatin f the P Cre NM BMP applicatin rate multiplier credit mdifies the crp- and land-use-specific P applicatin rate gal, which is based n LGU crp fertilizatin recmmendatins, as mdified by the CBP partnership. These multipliers apply t the nutrient applicatin rate gal, r input side, f the nutrient mdeling scheme fr bth NM and nn- NM acres. Each multiplier value represents a multiplicative mdifier f the crp- and land-use-specific P applicatin rate gal utilized in the CBP mdels. Fr crps and land uses in which manure is applied, manure applicatins that result in manure P applicatin rates that are greater than r equal t the crp-specific P applicatin need results in the prhibitin f applicatin f additinal fertilizer P. Fr crps and land uses in which manure is applied, the ttal quantity f manure P assciated with the ttal manure applicatin rate is allcated t the subject acreage. Applicatin f the lss reductin multiplier credits fr P Supplemental NM BMP elements requires satisfactry implementatin f all respective P Cre NM BMP elements. The P Supplemental NM BMP multipliers apply multiplicative mdifiers t edge-f-stream delivery f P, n the utput side f the CBP mdeling scheme, and can nly be applied if the requirements fr P Cre NM BMP are met. Multiple advanced site assessments and P management tls may be utilized t infrm the applicatin f the apprpriate P adjustment practices, but d nt represent a P credit in and f themselves. Advanced site assessments and applicatin f P management tls that result in a verifiable implementatin f a change in planned P applicatin rate, P applicatin timing, r P applicatin placement may result in a P Supplemental NM BMP lss reductin multiplier credit. Supplemental BMP credits fr P rate, P timing, and P placement are stackable. Only ne Supplemental NM BMP credit fr P rate, ne Supplemental NM BMP credit fr P timing, and ne Supplemental NM BMP credit fr P placement may be applied. Summary As described abve and under Practice Definitins, there is ne pprtunity fr crediting per each Supplemental NM BMP categry fr N and P. There are three such categries each fr N and P Supplemental BMPs: rate, timing, and placement. Applicatin f a lss-reductin multiplier fr the N Supplemental NM BMP elements can nly ccur after satisfactry implementatin f the N Cre NM BMP. The N Supplemental NM BMP lss reductin credit fr each f these three categries (rate, timing, and placement) can be btained if implementatin f at least ne effective practice frm each categry is verified. Similarly, applicatin f a lss-reductin multiplier fr the P Supplemental NM BMP elements can nly ccur after satisfactry implementatin f the P Cre NM BMP. The P Supplemental NM BMP lss reductin credit fr each f these three categries (rate, timing, and placement) can be btained if implementatin f at least ne effective practice frm each categry is verified. N Supplemental NM BMP lss reductin credits fr N rate, N timing, and N placement are stackable, as are P Supplemental NM BMP lss reductin credits fr P rate, P timing, and P placement. The apprach fr applying bth cre and supplemental nutrient management multiplier values is summarized in Table 17. Figure 3 and Figure 4 illustrate the decisin tree fr assigning credits. 28

29 Table 17. Summary f Methd fr Applying Nutrient Management Multiplier Values Nutrient Management BMP Actin f BMP Hw the math wrks Nitrgen Cre Nn-Nutrient Management BMP Mdifies N applicatin rate gal n the nutrient input side Nitrgen Cre Nutrient Management BMP N Rate Supplemental NM BMP N Placement Supplemental NM BMP N Timing Supplemental NM BMP Mdifies N applicatin rate gal n the nutrient input side Mdifies edge f field N lss t the stream n the utflw side Mdifies edge f field N lss t the stream n the utflw side Mdifies edge f field N lss t the stream n the utflw side Multiplier value is applied t the LGU N applicatin rate gal Multiplier value is applied t the LGU N applicatin rate gal Multiplier value is applied t the calculated edge f field N lad Multiplier value is applied t the calculated edge f field N lad Multiplier value is applied t the calculated edge f field N lad Phsphrus Cre Nn-Nutrient Management BMP Phsphrus Cre Nutrient Management BMP P Rate Supplemental NM BMP P Placement Supplemental NM BMP P Timing Supplemental NM BMP Mdifies P applicatin rate gal n the nutrient input side Mdifies P applicatin rate gal n the nutrient input side Mdifies edge f field P lss t the stream n the utflw side Mdifies edge f field P lss t the stream n the utflw side Mdifies edge f field P lss t the stream n the utflw side Multiplier value is applied t the LGU P applicatin rate gal Multiplier value is applied t the LGU P applicatin rate gal Multiplier value is applied t the calculated edge f field P lad Multiplier value is applied t the calculated edge f field P lad Multiplier value is applied t the calculated edge f field P lad 29

30 NITROGEN Cre Nutrient Management BMP (ALL applicable cre elements required t be implemented and verified) N applicatin gal (N rate) accrding t LGU recmmendatins at field level NO N credit fr N Cre Nutrient Management BMP N applicatin gal = LGU recmmendatin x A Manure analysis and vlume test value r bk value Spreader/applicatin calibratin Yield estimates and crpping plan at field level Crpping and manure histry at field level YES Credit fr N Cre Nutrient Management BMP N applicatin gal = LGU recmmendatin x B NITROGEN Supplemental Nutrient Management BMPs If Cre Nutrient Management BMP efficiency is applied, fllw with advanced assessment fr Supplemental Nutrient Management BMPs Advanced N Assessment PSNT Manure analysis 1 year ld On-farm replicated research CSNT IMPLEMENTATION N Rate Adjustment (Implementatin f ne r mre BMPs required) N rate less than LGU recmmendatins Split N applicatins Variable rate N applicatin YES N Rate Supplemental NM BMP Credit = EOF lad x C N-lss risk assessments & mdels Ammnia Lss Yield mapping ISNT On-farm strip trials N-lss risk assessments & mdels Leaching lss IMPLEMENTATION N Placement Adjustment (Implementatin f ne r mre BMPs required) Subsurface injectin r incrpratin f applied N N applicatin setbacks frm water YES N Placement Supplemental NM BMP Credit = EOF lad x D FSNT N-lss risk assessments & mdels Denitrificatin lsses Whle farm balances In-seasn sensrs/remte sensing in general IMPLEMENTATION N Timing Adjustment (Implementatin f ne r mre BMPs required) Split N applicatins YES N Timing Supplemental NM BMP Credit = EOF lad x E Ge-spatial mapping Figure 3. Assignment f N Nutrient Management Credits. Variables A and B refer t the land use specific N Cre Nn-Nutrient Management BMP applicatin rate multiplier and the N Cre Nutrient Management BMP applicatin rate multiplier, respectively, as presented in Table 12. Variables C, D and E refer t the land use specific N Rate Supplemental NM BMP lss reductin multiplier, the N Placement Supplemental NM BMP lss reductin multiplier and the N Timing Supplemental NM BMP lss reductin multiplier, respectively, as presented in Table 14. EOF is edge f field. 30

31 PHOSPHORUS Cre Nutrient Management BMP (ALL applicable cre elements required t be implemented and verified) P applicatin gal (P rate) accrding t LGU recmmendatins at field level NO N credit fr P Cre Nutrient Management BMP P applicatin gal = LGU recmmendatin x F P sil tests at field level Manure analysis and vlume test value r bk value Spreader/applicatin calibratin Yield estimates and crpping plan at field level YES Credit fr P Cre Nutrient Management BMP P applicatin gal = LGU recmmendatin x G Crpping and manure histry at field level PHOSPHORUS Supplemental Nutrient Management BMPs If Cre Nutrient Management BMP efficiency is applied, fllw with advanced assessment fr Supplemental Nutrient Management BMPs Advanced P Assessment Sil test P remediatin/declining Sil tests 1 year ld P Index assessment Grid sil sampling IMPLEMENTATION P Rate Adjustment (Implementatin f ne r mre BMPs required) P-based manure rate based n annual crp remval P rate less than LGU recmmendatins Variable rate P applicatin YES P Rate Supplemental NM BMP Credit = EOF lad x H Manure analysis 1 year ld On-farm replicated research Yield mapping On-farm strip trials Whle farm balances Ge-spatial mapping IMPLEMENTATION IMPLEMENTATION P Placement Adjustment (Implementatin f ne r mre BMPs required) Subsurface injectin r incrpratin f applied P P applicatin setbacks frm water P Timing Adjustment (Implementatin f ne r mre BMPs required) P applicatin in lwer P-lss risk seasn Split P applicatin P Placement Supplemental NM BMP Credit = EOF lad x I P Timing Supplemental NM BMP Credit = EOF lad x J Figure 4. Assignment f P Nutrient Management Credits. Variables F and G refer t the land use specific P Cre Nn-Nutrient Management BMP applicatin rate multiplier and the P Cre Nutrient Management BMP applicatin rate multiplier, respectively, as presented in Table 13. Variables H, I and J refer t the land use specific P Rate Supplemental NM BMP lss reductin multiplier, the P Placement Supplemental NM BMP lss reductin multiplier and the P Timing Supplemental NM BMP Lss reductin multiplier, respectively, as presented in Table 15. EOF is edge f field. YES YES 31

32 4 Review f Literature and Data Gaps 4.1 The Available Science fr N BMPs Crp- and land-use-specific N applicatin rate gal shuld be based n LGU crp fertilizatin recmmendatins, as mdified by the CBP partnership. In an effrt t determine the mst practicable methdlgy fr allcating fertilizer N t satisfy crp- and land-use-specific N applicatin rate gals, the Agriculture Wrkgrup cmpared the mdified LGU recmmendatins fr applicatin f supplemental inrganic N fertilizer t an alternative apprach based n cunty-level redistributin f AAPFCO N fertilizer sales data. This methdlgical cmparisn indicated that there were relatively small differences between the tw methds fr estimating supplemental N fertilizer applicatins, leading the Agriculture Wrkgrup t apprve use f the redistributed AAPFCO fertilizer sales methdlgy in the Phase 6 Mdel. The Panel maintains that LGU recmmendatins shuld cntinue t serve as the fundatin fr crp and land-use-specific N applicatin gals and suggests that similar cmparative analyses be cnducted in the future as new fertilizer sales data becme available. Incnsistencies between estimates generated by the tw methds shuld be further investigated and rectified based n data surce quality and cnsistency with cntiguus r reginal cunty-level data. Nutrient management practices are implemented at either the field r sub-field level. The diverse landfrms, hydrlgy, climate and crpping systems f the agricultural landscapes in the CBW have a multitude f impacts n bigechemical transfrmatins f N in the agr-ecsystem. Changes in hydrlgical pathways alne can have dramatic effects n crp N utilizatin efficiency and N lads t streams when viewed frm the Atlantic Castal Plain t the Appalachian Plateau. Therefre, site-specific physical cnditins and management factrs have a strng influence n the effectiveness f impsed cnservatin practices. Nutrient management BMP effectiveness must represent the average cnditin ver a wide range f real-life scenaris. Thus, it was incumbent upn the Panel t distill numerus lines f evidence t arrive at a single crediting value fr N BMPs that culd be applied equitably acrss the CBW. 4.2 The Available Science fr P BMPs Similar t N, crp and land-use-specific P applicatin rate gal shuld be based n LGU crp fertilizatin recmmendatins, as mdified by the CBP partnership. Hwever, in practice, LGU recmmendatins fr P applicatin are based n crp- and site-specific sil-test P cncentratin. Currently, sil-test P cncentratin data are nt available t the CBP. The Panel recmmends that, in the future, crp- and site-specific sil-test P cncentratin data shuld be cllected, aggregated t the apprpriate scale, summarized t eliminate disclsure f private cnfidential business infrmatin, and utilized as the fundatin fr determining P applicatin rate gals and the apprpriate applicatin f P Cre NM BMPs. In the absence f sil-test P based applicatin rate gals, cunty-level redistributin f AAPFCO P fertilizer sales data may serve as a surrgate. An essential assumptin that must be impsed when cunty-level redistributin f AAPFCO P fertilizer sales data is utilized in lieu f site-specific sil-test P cncentratin data is the assumptin f a cunty-average sil-test P cncentratin. Currently, a medium sil-test P cnditin was assumed fr all situatins and lcatins. Impsitin f the medium sil-test P assumptin acrss the entire CBW is a grss ver-simplificatin f the cmplex site-specific bigechemical prcesses and n-site management practices that determine P fate and transprt in the agrecsystem. The CBP shuld strive t rectify this shrtcming in future iteratins f the mdeling suite. As stated abve relative t N, nutrient management practices are implemented at either the field r sub-field level. The diverse landfrms, hydrlgy, climate and crpping systems f the agricultural landscapes in the CBW have a multitude f impacts n bigechemical transfrmatins f P in the agr-ecsystem. Therefre, site-specific physical cnditins and management factrs have a strng influence n the effectiveness f impsed cnservatin practices. Nutrient management BMP effectiveness must represent the average cnditin ver a wide range f real-life scenaris. Thus, it was incumbent upn the Panel t distill numerus lines f evidence t arrive at a single crediting value fr the P BMPs that culd be applied equitably acrss the CBW. 32

33 5 Applicatin f Practice Estimates 5.1 Lad Surces Nutrient management can be applied t specified land uses everywhere within the Chesapeake Bay watershed. The N Cre BMP and the P Cre BMP, as well as the N and P Supplemental NM BMPs, apply t each f the partnership apprved Phase 6 agricultural land uses listed in Table 18. Table 18. Land Uses t Which the Nutrient Management Practices Apply Land Use Full Seasn Sybeans Grain with Manure Grain withut Manure Silage with Manure Silage withut Manure Legume Hay Small Grains and Grains Small Grains and Sybeans Specialty Crp High Specialty Crp Lw Other Agrnmic Crps Other Hay Pasture Descriptin Sybeans ineligible fr duble crpping Crn r srghum fr grain eligible fr manure applicatin and ineligible fr duble crpping Crn r srghum fr grain ineligible fr manure applicatin and ineligible fr duble crpping Crn r srghum fr silage eligible fr manure applicatin and ineligible fr duble crpping Crn r srghum fr silage ineligible fr manure applicatin and ineligible fr duble crpping Legume frage crps eligible fr manure Small grains and grains ther than crn r srghum eligible fr manure and ineligible fr duble crpping Sybeans duble crpped with small grains and ineligible fr manure Specialty crps with relatively high nutrient inputs with sme crps eligible fr manure Specialty crps with relatively lw nutrient inputs with sme crps eligible fr manure Other high cmmdity rw crps such as tbacc, cttn, etc., with sme crps eligible fr manure Nn-legume frage crps eligible fr manure Grazed land that receives direct manure depsitin frm animals 5.2 Practice Baseline The Panel recmmends that histric implementatin n a state-by-state basis be based n the premise that the baseline f 1985 is set at zer, r near zer acres fr N Cre NM BMP implementatin and the highest level f implementatin be represented at 2015 reprted implementatin acreages. Similarly, the zer baseline fr the P Cre NM BMP shuld be set t the date when each state intrduced P-based NM requirements and the highest level f implementatin be represented at 2015 reprted implementatin acreages. Due t the differences between state Nutrient Management prgram initiatin dates and implementatin reprting fr the six-state partnership, the baseline year is recmmended t reflect these state partnership differences. Thus, the initial Nutrient Management implementatin year fr each state will be unique. The increasing level f histric implementatin between the state Nutrient Management Prgram initiatin year and the 2015 reprted implementatin acreages represent tw pints in time n a state-by-state basis. The intervening annual representatin f implementatin acreages may be represented as a linear prgressin, in the absence f rbust implementatin data. Histric implementatin estimatin shall cnsider additinal surces f N and P reductin credits cmmensurate with State Quality Assurance Prject Plans (QAPPs) currently in place, given they are cnsistent with the BMPs and efficiency credits described by the Panel. 33

34 In cperatin with the CBPO, a state-by-state representatin f reprted NM implementatin is included as Appendix A. The state-by-state representatin was develped fr histrical N Cre NM and P Cre NM BMP implementatin. Histrical N Cre NM BMP implementatin methdlgy: Assume straight-line interplatin between 2015 Prgress acres and a starting year fr each state. Starting year was evaluated by lking at histric NEIEN data t determine when states started reprting infrmatin Prgress has acres n crp, pasture and hay. Interplatin was made fr each f these categries. Interplatin was made in each cunty. Assume all acres n crps fr New Yrk (NY), Pennsylvania (PA), and West Virginia (WV) nly apply t crp acres eligible fr receiving manure. Assume all acres n crps fr Delaware (DE), Maryland (MD) and Virginia (VA) can be distributed t crp acres with r withut manure. All acres assumed t qualify fr N Cre NM BMP. Histrical P Cre NM BMP implementatin methdlgy wuld be similar t the N Cre NM BMP implementatin methdlgy abve, except fr variable starting years fr each state. A secnd independent surce f data representing histric Nutrient Management implementatin has been requested frm the USDA Natural Resurces Cnservatin Service (NRCS) Cnservatin Effects Assessment Prject (CEAP) based n the tw existing reprts published n the Chesapeake Bay Watershed. The requested infrmatin will be evaluated n a HUC-4 (4-digit Hydrlgic Unit Cde) scale based upn the CEAP prgram s methdlgy f interviewing prducers at randmly selectin field pints frm the Natural Resurces Inventry (NRI) lists. T date, analysis f the CEAP data at the HUC-4 scale acrss the CBW has nt been cnducted. In utilizing the Panel's practice recmmendatins fr tracking and reprting practice implementatin, the Panel recmmends that acres, r percentage f acres, be reprted by Phase 6 land use, r gruping f similar land uses, by year as an annual practice. N and P Cre NM BMPs are stand-alne practices which shuld be tracked and reprted separately. Likewise, advanced N and P Supplemental NM BMPs shuld be tracked and reprted separately, but nly when the crrespnding N r P Cre NM BMP elements have been met by the Panel's recmmended practice definitins. The Panel's recmmendatin fr tracking and reprting NM BMP implementatin is that acres, r percentage f acres, be reprted by Phase 6 land use, r gruping f similar land uses, by year as an annual practice. The N Cre NM BMP and P Cre NM BMP are stand-alne practices which shuld be tracked and reprted separately. Likewise, advanced N and P Supplemental NM BMPs shuld be tracked and reprted separately, but nly when the requirements fr reprting the crrespnding N r P Cre NM BMP have been met. 5.3 Hydrlgic Cnditins The Panel represented NM BMPs that can be applied acrss all hydrlgic cnditins in the CBW. 5.4 Sediment Panel reprt specifically des nt address sediment lsses r reductins resulting frm implementatin f NM BMPs. 5.5 Species f Nitrgen and Phsphrus The Panel reprt fcused n ttal N and ttal P and did nt specify species f N r P. 5.6 Gegraphic Cnsideratins The Panel reprt represented NM BMPs that can be applied acrss all gegraphic areas f the CBW. 34

35 5.7 Tempral Cnsideratins The Panel reprt represented NM BMPs that may r may nt have tempral cnsideratins depending n the sequence f BMP implementatin within the cnstraints f farm management peratins. 5.8 Practice Limitatins There are n limitatins t the applicatin f NM BMPs. These practices may be applied t all agricultural land use categries in the CBW. 5.9 Ptential Interactins with ther Practices The Panel recgnizes that NM BMPs interact with all ther agricultural practices fr all agricultural land use categries in the CBW. 35

36 6 Practice Mnitring and Reprting 6.1 Phase 6.0 Nutrient Management Tracking, Verificatin, and Reprting The Panel recmmends that NM BMP implementatin tracking, verificatin, and reprting n a cunty-by-cunty r stateby-state basis be based n the premise that they represent annual Nn-Visual Assessment BMPs. BMP implementatin will be reprted annually t the CBPO as the number f acres r percentage f acres meeting the definitins and qualificatins set frth by the NM Panel in this reprt fr Cre N and P NM BMPs, as well as applicable N and P Supplemental NM BMPs. Nutrient Management BMPs represent an histric and ever-changing suite f BMPs fr the CBP mdeling tls ver the histry f the Prgram. As such, NM BMPs are included in the jurisdictin's verificatin plans that were submitted t the CBP in late As with all BMPs, the jurisdictins will be expected t dcument their verificatin prtcls and prcedures in their QAPP fr NM BMPs that are reprted t the CBPO fr nitrgen and phsphrus crediting reductins under the recmmended BMPs. The jurisdictins will determine if mdificatins f thse verificatin plans are required after this expert panel recmmendatin reprt is apprved by the CBP partnership fllwing the BMP Prtcl, and befre the jurisdictins are able t start submitting these BMPs in the Phase 6 mdeling tls fr annual prgress implementatin. As the states cnsider hw t verify NM BMPs and as they dcument thse prcedures in their QAPP, state partners shuld fllw the existing Agriculture Wrkgrup s BMP Verificatin guidance. The current verificatin guidance frm the Agriculture Wrkgrup (AgWG) breaks BMPs int three general categries: Visual Assessment BMPs (Single Year), Visual Assessment BMPs (Multi-Year), and Nn-Visual Assessment BMPs. The cmplete AgWG guidance is quite extensive (79 pages lng, including all tables and its wn appendices) and is nt restated in this sectin. The panel is nt prpsing any new r unique aspects f BMP verificatin fr purpses f the BMPs described in this reprt. This sectin simply explains hw the recmmended BMPs crrespnd t the existing BMP verificatin guidance. As described in this reprt, nutrient management practices are ften part f a larger nutrient management system r plan that ften invlves multiple management and physical cmpnents (e.g., animal waste strage, manure injectin and incrpratin, etc.) which can be visually assessed ver time. NM practices als incrprate nn-visual cmpnents (e.g. nutrient applicatin rate, timing, and placement) in additin t management plans r ther dcumentatin as needed under applicable state r federal agricultural permits and/r prgrams. Thus, nutrient management practices can reasnably be verified using elements f bth the Nn-Visual Assessment and Visual Assessment (Multi-Year) categries described by the AgWG. Each state will determine the mst apprpriate methds fr verifying NM BMP implementatin given their specific pririties, prgrams, needs, and capacity. Fr example, ne state may leverage existing site visits t farms t als verify that the peratin meets applicable NM BMP definitins as per the NM Panel recmmendatins. Or, the state may determine that available recrds are detailed enugh t prvide sufficient verificatin thrugh spt-checks. Ideally the state will leverage multiple existing and perhaps new avenues t verify that nutrient management practices and peratinal are sufficient t meet the NM BMP criteria as determined by a trained and/r certified independent third-party, and that the data in the peratin s recrds are accurate and up-t-date. Jurisdictins can fllw the AgWG s guidance fr Nn-Visual Assessment BMPs t verify the N and P cre NM BMPs recmmended in this reprt fr N and P reductin credits in the Phase 6 CBWM. Verificatin fr Nn-Visual Assessment BMPs depend mre n versight and checks n peratinal recrds r dcumentatin rather than visual assessment f a physical structure. 36

37 The N and P reductins fr Cre NM BMPs described in this reprt are t be based n the verified required elements f the N and P Cre NM BMPs fllwing the AgWG s guidance fr Nn-Visual Assessment BMPs. Because it is an annually reprted BMP, the mst imprtant criteria (i.e. N and P Cre NM elements) shuld be dcumented smewhere in recrds available t the applicable state agency. Given the clse assciatin between nutrient applicatin management and ther CBP-apprved BMPs (e.g., animal waste strage systems, manure transprt, etc.) the state agency can ptentially verify the type and amunt f nutrients that were managed via ne r bth f the Cre NM practices described by the panel. If the state agency finds that even this basic infrmatin cannt be verified thrugh its spt-checks r ther annual BMP verificatin prcedures described in its QAPP, then the BMP cannt satisfy the definitins and expected nitrgen reductins described in this reprt. When the state agency has mre detailed NM infrmatin available fr bth reprting and verificatin purpses, then they may be able t reprt the given nutrient applicatin system under bth the defined N and P Cre NM BMPs, as well as ne r mre f the N and P Supplemental NM BMPs. By prviding separate BMPs based n additinal rate, timing, and placement applicatin management systems fr the higher nitrgen and phsphrus reductins, the panel prvides a framewrk with additinal built-in elements f BMP verificatin. If recrds available t the applicable state agency d nt dcument the implementatin f additinal nutrient applicatin changes fr rate, timing, and/r placement described by the panel fr the N and P Supplemental NM BMPs, then the given system shuld nt be reprted under the crrespnding Supplemental NM BMP, but culd ptentially still meet the criteria f the N and/r P Cre NM BMP using the mre basic infrmatin that is available. By assigning lwer estimated reductins when nly basic infrmatin is available, it is less likely that a reprted treatment system will nt prvide the estimated nitrgen and phsphrus reductins develped by the panel. This reinfrces the basis f BMP verificatin, i.e. that the reprted practice is implemented and perating as intended. With mre detailed infrmatin abut the nutrient applicatin management factrs, verified accrding t the AgWG s guidance, the partnership can have mre cnfidence that the given nutrient applicatin system is perating mre effectively t limit excess nitrgen and phsphrus frm the envirnment. Fr mre infrmatin abut the CBP Partnership s BMP Verificatin Framewrk The full CBP partnership BMP Verificatin Framewrk is available nline (scrll dwn t Octber 2014 Basinwide BMP Verificatin Framewrk Dcument): The current Agriculture Wrkgrup s BMP Verificatin Guidance is included in Appendix B f the full Framewrk Dcument. Fr the AgWG s guidance nly, g here: Future Verificatin f Nutrient Management Practices The Panel envisins that ptential pprtunities may exist in the future fr utilizing alternative frms f BMP verificatin, including examples such as remte sensing frm satellite, aerial, and drne imagery, aggregated fertilizer industry sales infrmatin, and aggregated manure hauler/brker data. 37

38 7 References Cela, S., Q.M. Ketterings, K.J. Czymmek, M.A. Sbern, and C.N. Rasmussen. 2014a. Characterizatin f N, P, and K mass balances f dairy farms in New Yrk State. Jurnal f Dairy Science 97: Cela, S., Q.M. Ketterings, K.J. Czymmek, M. Sbern, and C. Rasmussen. 2014b. Whle farm nutrient balance benchmarks fr New Yrk dairies. Crnell Nutritin Cnference Prceedings. Syracuse NY, Octber 21, Cale, F.J Plant nutrient recmmendatins based n sil tests and yield gals. Agrnmy Mime N. 10, Cperative Extensin Service and Agrnmy Dept., Univ. MD, Cllege Park, MD. Cale, F. J Effect f Crp Rtatins n the Fate f Residual Sil Nitrgen in Maryland Grain Prductin Systems. Final prject reprt, MGPUB Grant N Maryland Grain Prducers Utilizatin Bard, Edgewater, MD. Cperative Extensin Service Fertilizer Recmmendatins, sheet 3, crn fr grain n medium textured sils withut manure. University f Maryland Cperative Extensin Service, Cllege Park, MD. Durieux, R.P., H.J. Brwn, E.J. Stewart, J.Q. Zha, W.E. Jkela, and F.R. Magdff Implicatins f nitrgen management strategies fr nitrate leaching ptential: rles f nitrgen surce and fertilizer recmmendatin system. Agrnmy Jurnal 87: Fitzgerald, R.L. and Baird, J American Farmland Trust BMP Challenge Reprt. American Farmland Trust. Frrestal, P.J., J.J. Meisinger, and R.J. Kratchvil Winter wheat starter nitrgen management: a preplant sil nitrate test and site-specific nitrgen lss ptential. Sil Science Sciety f America 78: Fx, R.H., J.M. Kern, and W.P Piekielek Nitrgen fertilizer surce, and methd and time f applicatin effects n n-till crn yield and nitrgen uptakes. Agrnmy Jurnal 78: Fx, R.H. and W.P Piekielek Management and urease inhibitr effects n nitrgen use efficiency in n-till crn. Jurnal f Prductin Agriculture. 6: Gravelle, W.D., M.M. Alley, D.E. Brann, and K.D.S.M. Jseph Split spring nitrgen applicatin effects n yield, ldging, and nutrient uptake f sft red winter wheat. Jurnal f Prductin Agriculture 1: Guillard, K., T.F. Mrris, and K.L. Kpp The pre-sidedress sil nitrate test and nitrate leaching frm crn. Jurnal f Envirnmental Quality 28(6): Hng, E., Q.M. Ketterings, G. Gdwin, S. Gami, and S. Whartn Effect f sampling height and length n crn stalk nitrate test results. What s Crpping Up? 20(2):9-11. Ketterings, Q.M., J. Lawrence, G. Gdwin, N. Glazier, P. Barney, and K.J. Czymmek Evaluatin f ISNT-based nitrgen management fr multi-year crn sites. What s Crpping Up? 19(3): Ketterings, Q.M., G. Gdwin, and K. Czymmek. 2011a. Effect f timing f nitrgen applicatin n crn stalk nitrate test (CSNT) results. What s Crpping Up? 21(4):7-10. Ketterings, Q.M., E. Hng, G. Gdwin, and K. Czymmek. 2011b. Variability f crn stalk nitrate test results as impacted by variety (BMR versus cnventinal). What s Crpping Up? 21(3):

39 Ketterings, Q.M., K. Czymmek, S. Gami, and M. Reuter Stalk Nitrate Test Results fr New Yrk Crn Fields frm 2007 thrugh What s Crpping Up? 25(1). Klapwyk, J.H., Q.M. Ketterings, G. Gdwin, and D. Wang Respnse f the Illinis Sil Nitrgen Test t liquid and cmpsted dairy manure applicatins in a crn agrecsystem. Canadian Jurnal f Sil Science 86(4): Kleinman, P.J.A. and A.N. Sharpley Effect f bradcast manure n runff phsphrus cncentratins ver successive rainfall events. Jurnal f Envirnmental Quality 32: Kleinman, P.J.A., A.N. Sharpley, T.L. Veith, R.O. Maguire, and P.A. Vadas Evaluatin f phsphrus transprt in surface runff frm packed sil bxes. Jurnal f Envirnmental Quality 33(4): Kyveryga, P. M., H. Ta, and T.F. Mrris Identificatin f Nitrgen Management Categries by Crn Stalk Nitrate Sampling Guided by Aerial Imagery. Agrnmy Jurnal, , May/June, 102(3). Lawrence, J.R., Q.M. Ketterings, and K.J. Czymmek Illinis Sil N Test (ISNT) useful tl fr NYS crn prducers. What s Crpping Up? 18(3):4-5. Lawrence, J.R., Q.M. Ketterings, M.G. Gler, J.H. Cherney, W.J. Cx, and K.J. Czymmek Illinis sil nitrgen test with rganic matter crrectin fr predicting nitrgen respnsiveness f crn in rtatin. Sil Science Sciety f America Jurnal 73(1): McDwell, R. and A. Sharpley Phsphrus transprt in verland flw in respnse t psitin f manure applicatin. Jurnal f Envirnmental Quality 31: Meisinger, J.J., R.E. Palmer, and D.J. Timlin Effects f tillage practices n drainage and nitrate leaching frm winter wheat in the Nrthern Atlantic Castal-Plain USA. Sil and Tillage Research 151: Nrth Carlina State University Extensin Agrnmy Guide. Nrth Carlina State University, Raleigh, NC. Palmer, R.E., Meisinger, J.J., Magette, W.L., Undisturbed sil-clumns fr lysimetry I. cllectin, field testing, and cnstructin. Applied Engineering in Agriculture 27, Penn State Extensin Agrnmy Guide. The Pennsylvania State University, Cllege f Agriculture Extensin Service. University Park, PA. Phase Nutrient Management Expert Panel Nutrient management definitins and recmmended nutrient reductin efficiencies f nutrient applicatin management fr use in Phase f the Chesapeake Bay Prgram Watershed Mdel - recmmendatins fr apprval by the Water Quality Gal Implementatin Team s Watershed Technical and Agricultural Wrkgrups. Submitted by the Phase Nutrient Management Expert Panel June 25, Rth, G.W. and A.J. Heinrichs Crn silage prductin and management. Agrnmy Facts 18. Penn State University Extensin. Sextn, T Persnal cmmunicatin f Virginia PSNT implementatin data as summarized by the Amer. Farmland Trust. Virginia Department f Cnservatin and Recreatin. Sbern, M.A., S. Cela, Q.M. Ketterings, C.N. Rasmussen, and K.J. Czymmek Changes in nutrient mass balances ver time and related drivers fr 54 New Yrk Dairy Farms. (in review). Sgbedji, J.M., H.M. van Es, C.L.Yang, L.D. Gehring, and F.R. Magdff Nitrate leaching and N budget as affected by maize N fertilizer rate and sil type. Jurnal f Envirnmental Quality 29:

40 Steinhilber, P.S Persnal cmmunicatin f Maryland Nutrient Management Cnsultant summaries f PSNT implementatins Thmasn, W.E., S.B. Phillips, P.H. Davis, J.G. Warren, M.M. Alley, and M.S. Reiter Variable nitrgen rate determinatin frm plant spectral reflectance in sft red winter wheat. Jurnal f Precisin Agriculture 12(5): Virginia NRCS CIG 69-33A7-1131, final reprt Water Quality Gal Implementatin Team (WQGIT) Prtcl fr the Develpment, Review, and Apprval f Lading and Effectiveness Estimates fr Nutrient and Sediment Cntrls in the Chesapeake Bay Watershed Mdel. Chesapeake Bay Prgram, Annaplis, MD. Whartn, S., Q.M. Ketterings, K. Orlski, E. Hng, G. Gdwin, and K. Czymmek Timing effects n late seasn crn stalk nitrate test. What s Crpping Up? 20(3):

41 Preface t Appendices The Agriculture Wrkgrup apprved the enclsed Panel Reprt (dated Octber 18, 2016) n Octber 20, 2016 with the additin f amendments that are summarized in the intrductry paragraph f Appendix G. The final Panel Reprt as updated in respnse t the Agriculture Wrkgrup amendments is cntained in Appendix G, which supersedes the riginal Panel Reprt fr implementatin by the CBP partnership in all aspects as apprved. Appendices B-F fr the Panel Reprt (dated Octber 18, 2016) were nt affected by the apprved amendments and are therefre nt included in Appendix G with the amended reprt. Appendices A and Appendix H were affected by the apprved amendments and updated versins f these tw appendices are included with the amended reprt in Appendix G, and als supersede their riginal cunterparts in all aspects as apprved. The riginal versins f Appendix A and Appendix H are als prvided here fr cntext. 41

42 Appendix A: Technical Requirements fr Reprting and Simulating Nutrient Management BMPs in the Phase 6 Watershed Mdel Backgrund: In June, 2013 the Water Quality Gal Implementatin Team (WQGIT) agreed that each BMP expert panel wuld wrk with CBPO staff and the Watershed Technical Wrkgrup (WTWG) t develp a technical appendix fr each expert reprt. The purpse f the technical appendix is t describe hw the expert panel s recmmendatins will be integrated int the mdeling tls including NEIEN, Scenari Builder and the Watershed Mdel. Q1. What are the individual nutrient management practices a jurisdictin may reprt in the Phase 6 Watershed Mdel? A1. The individual practices alng with their definitins are prvided belw. Nitrgen Cre NM Applicatins f nitrgen are made in accrdance t ALL the fllwing elements as applicable: Land-grant university recmmendatins fr nitrgen applicatins at field level Manure analysis and vlume using either test r bk values t determine nitrgen cntent Calibratin f spreader/applicatr Yield estimates and crpping plan at the field level Crpping and manure applicatin histry at the field level Phsphrus Cre NM Applicatins f phsphrus are made in accrdance t ALL the fllwing elements as applicable: Land-grant university recmmendatins fr phsphrus at the field level. This may include recmmendatins resulting frm advanced assessment (i.e. P Index, etc.) that recmmend higher P applicatin rates where the risk f P lss is lw. Sil test fr phsphrus levels at the field level. This requirement may be waived if restrictins n manure applicatins (rate, timing, and placement) are impsed that limit P applicatin rates and management t the same degree as if the sil test result fr phsphrus was in the high categry. Manure analysis and vlume using either test r bk values t determine phsphrus cntent Calibratin f spreader/applicatr Yield estimates and crpping plan at the field level Crpping and manure histry at the field level 42

43 Nitrgen Rate Supplemental NM Applicatins f nitrgen are made in accrdance t all elements f the Nitrgen Cre practice, and ne r mre f the fllwing practices are implemented resulting in a reductin in applicatin rate f nitrgen: Nitrgen applicatin rate made at less than land-grant university recmmendatins Nitrgen applicatins split acrss the grwing seasn resulting in lwer than planned applicatins Nitrgen applicatins are made using variable rate gals resulting in lwer than planned applicatins. Nitrgen Placement Supplemental NM Applicatins f nitrgen are made in accrdance t all elements f the Nitrgen Cre practice, and ne r mre f the fllwing practices are implemented resulting in better placement and utilizatin f nitrgen: Applicatins f inrganic nitrgen are injected int the subsurface r incrprated int the sil Applicatins f nitrgen are made with setbacks frm surface water features Nitrgen Timing Supplemental NM Applicatins f nitrgen are made in accrdance t all elements f the Nitrgen Cre practice, and are split acrss the grwing seasn int multiple applicatins t increase utilizatin f nitrgen. Phsphrus Rate Supplemental NM Applicatins f phsphrus are made in accrdance t all elements f the Phsphrus Cre practice, and ne r mre f the fllwing practices are implemented resulting in a reductin in applicatin rate f phsphrus: Applicatins f manure are based upn annual crp remval f phsphrus rather than nitrgen Applicatins f phsphrus are made at less than land-grant university recmmendatins Phsphrus applicatins are made using variable rate gals resulting in lwer than planned applicatins Phsphrus Placement Supplemental NM Applicatins f phsphrus are made in accrdance t all elements f the Phsphrus Cre practice, and ne r mre f the fllwing practices are implemented resulting in better placement and utilizatin f nitrgen: Applicatins f inrganic phsphrus are injected int the subsurface r incrprated int the sil Applicatins f phsphrus are made with setbacks frm surface water features Phsphrus Timing Supplemental NM Applicatins f phsphrus are made in accrdance t all elements f the Phsphrus Cre practice, and are made in seasns with a lwer risk f phsphrus lss. Applicatins f phsphrus are split acrss the grwing seasn resulting in lwer than planned applicatins. 43

44 Q2. What are the nutrient reductins assciated with cre practices? A2. Each acre reprted under the cre practices will have an applicatin gal adjusted slightly frm land-grant university recmmendatins. Fr example, an acre f crn nt receiving manure (a crp in the Grain withut Manure land use) under the Nitrgen Nutrient Management Cre practice will have an applicatin gal f 0.92 lbs. f nitrgen/bu./ac. The mdified land-grant university applicatins will be increased by the multipliers prvided in the tables belw fr each acre NOT under the Nutrient Management Cre practice. Fr example, an acre f crn nt receiving manure (a crp in the Grain withut Manure land use) NOT under the Nitrgen Nutrient Management Cre practice will have an applicatin gal f 1.10 lbs. f nitrgen/bu./ac. (r 0.92 X 1.20). See Example Calculatin f Cunty Crp Applicatin Gal using Cre Nutrient Management fr Nitrgen Acres n Crn fr Grain belw fr additinal details. Cre N Nutrient Management Applicatin Gal Multipliers Land Use Nutrient Management BMP Nitrgen Cre Nn-Nutrient Management Nitrgen Cre Nutrient Management Full Seasn Sybeans Grain w/ Manure Grain w/ Manure Legume Hay Silage w/ Manure Silage w/ Manure Small Grains and Grains Small Grains and Sybeans Specialty Crp High Specialty Crp Lw Other Agrnmic Crps Other Hay Pasture

45 Cre P Nutrient Management Applicatin Gal Multipliers Land Use Nutrient Management BMP Phsphrus Cre Nn-Nutrient Management Phsphrus Cre Nutrient Management Full Seasn Sybeans Grain w/ Manure Grain w/ Manure Legume Hay Silage w/ Manure Silage w/ Manure Small Grains and Grains Small Grains and Sybeans Specialty Crp High Specialty Crp Lw Other Agrnmic Crps Other Hay Pasture Example Calculatin f Cunty Crp Applicatin Gal using Cre Nutrient Management fr Nitrgen Acres n Crn fr Grain Cunty Assumptins: Acres f Crn fr Grain in Cunty: 100,000 ac. Average Yield fr Cunty: 100 bu. /ac. Nutrient Management Applicatin Gal: 0.92 lbs. f N/bu. Nn-Nutrient Management Applicatin Gal: 1.2 lbs. f N/bu. Calculatin: (0.92 lbs. N/bu.) X (1.3) Number f Acres under Nutrient Management: 20,000 ac. Number f Acres under Nn-Nutrient Management: 80,000 ac. Crp Applicatin Calculatins: Crp Applicatin Gal fr all Nutrient Management Acres: 1,840,000 lbs. N Calculatin: (20,000 ac.) X (100 bu. /ac.) X (0.92 lbs. N/bu.) = 1,840,000 lbs. N Crp Applicatin Gal fr all Nn-Nutrient Management Acres: Calculatin: (80,000 ac) X (100 bu. /ac.) X (1.2 lbs. N/bu.) = 9,600,000 lbs. N Ttal Crp Applicatin Gal fr all Acres: 11,440,000 lbs. N 45

46 Calculatin: (1,840,000 lbs. N) + (9,600,000 lbs. N) = 11,440,000 lbs. N Ttal Crp Applicatin Gal per Acre: lbs. N/ac. Calculatin: (11,440,000 lbs. N) / (100,000 ac.) = lbs. N/ac. In this way, the acres f cre nutrient management impact the verall applicatin gal fr each crp within a cunty. The mre acres f nutrient management, the lwer the gal will be, and vice versa. Hwever, the final nutrient applicatin rates fr the calibratin perid are determined by the amunt f manure and cmmercial fertilizer available within a cunty. Thus, the final applicatin rate may be higher r lwer than the lbs. N/ac. described in the example abve. Q3. What are the nutrient reductins assciated with the supplemental practices? A3. Each supplemental practice will be credited as a percent reductin t estimated runff frm the apprpriate land use. These percent reductins are listed in the tables belw. Nitrgen Supplemental Percent Reductins t Land Use Runff Nutrient Management BMP Land Use N Rate Supplemental N Placement Supplemental N Timing Supplemental Full Seasn Sybeans 0% 0% 0% Grain w/ Manure 15% 5% 10% Grain w/ Manure 5% 3% 5% Legume Hay 0% 0% 0% Silage w/ Manure 15% 5% 10% Silage w/ Manure 5% 3% 5% Small Grains and Grains 5% 3% 10% Small Grains and Sybeans 5% 3% 10% Specialty Crp High 15% 5% 5% Specialty Crp Lw 5% 3% 5% Other Agrnmic Crps 5% 3% 5% Other Hay 0% 3% 5% Pasture 0% 0% 0% 46

47 Phsphrus Supplemental Percent Reductins t Land Use Runff Nutrient Management BMP Land Use P Rate Supplemental P Placement Supplemental P Timing Supplemental Full Seasn Sybeans 5% 10% 1% Grain w/ Manure 10% 20% 20% Grain w/ Manure 5% 10% 1% Legume Hay 1% 10% 1% Silage w/ Manure 10% 20% 20% Silage w/ Manure 5% 10% 1% Small Grains and Grains 5% 10% 1% Small Grains and Sybeans 5% 10% 1% Specialty Crp High 5% 10% 1% Specialty Crp Lw 5% 10% 1% Other Agrnmic Crps 5% 10% 1% Other Hay 0% 10% 1% Pasture 0% 0% 0% Q4. Can a state reprt an acre f supplemental nutrient management n an acre that des nt fulfill the definitin f the cre practices? A4. N. The panel recmmended that every acre f supplemental nutrient management must als fully meet the definitin f the cre practice as applicable. Q5. If an acre utilizes multiple strategies listed under a single supplemental practice s definitin, shuld it be reprted twice? Fr example, if a prducer bth sets back applicatins f nitrgen frm surface waters AND injects inrganic nitrgen belw the sil surface, shuld a state reprt the acre twice as qualifying fr the Nitrgen Supplemental Placement practice? A5. N. The panel recmmended that each acre can nly qualify nce fr each f the BMPs. Hwever, an acre can qualify fr all fur types f BMPs at nce. Fr example, an acre culd be reprted under the cre practice and all three supplemental practices fr nitrgen and phsphrus if apprpriate. Q6. Hw will multiple, supplemental nutrient management practices credited n the same acre impact runff estimates? A6. A single acre f land may qualify fr up t three supplemental practices reprted fr each nutrient. The reductins fr each practice will be cmbined in a multiplicative manner t impact final runff estimates. An example calculatin fr a single acre f Grain with Manure with three supplemental practices fr nitrgen is included belw. Initial Runff Estimate: 20 lbs. N/ac. Supplemental Credits Available: 15% N Rate; 5% N Placement; 10% N Timing Final Runff Estimate: lbs. N/ac. = 20 lbs. N/ac. X (1-0.15) X (1-0.05) X (1-0.1) 47

48 Q7. Are the supplemental practices credited in any particular rder? A7. N. There wuld be n difference in the runff reductins by re-rdering the reductin efficiencies listed in the example calculatin in questin 6 due t the multiplicative nature f the credit calculatin. Q8. Hw shuld a state reprt these practices t NEIEN? A8. States shuld reprt the fllwing infrmatin: BMP Name: Nitrgen Cre NM ; Phsphrus Cre NM; Nitrgen Rate Supplemental NM; Nitrgen Timing Supplemental NM; Nitrgen Placement Supplemental NM; Phsphrus Rate Supplemental NM; Phsphrus Timing Supplemental NM; Phsphrus Placement Supplemental NM Measurement Name: Acres Land Use: Apprved NEIEN agricultural land use classes; if nne are reprted, the default will be CROP Gegraphic Lcatin: Apprved NEIEN gegraphies: Cunty; Cunty (CBW Only); Hydrlgic Unit Cde (HUC12, HUC10, HUC8, HUC6, HUC4); State (CBW Only) Date f Implementatin: Year plan was active. Q9. Are all nutrient management practices annual? A9. Yes. States shuld reprt the ttal number f acres qualifying under each practice type each year. Q10. Can states take credit fr practices n pasture? A10. N. The panel specifically recmmended reductins t applicatin gals and runff estimates n nn-pasture acres nly. 48

49 Appendix B: Methds t Estimate Histric Implementatin The Panel recmmends that histric implementatin n a state-by-state basis be based n the premise that the baseline f 1985 is set at zer, r near zer acres fr Nutrient Management Cre N and Cre P implementatin, and the highest level f implementatin be represented at 2015 reprted implementatin acreages. Due t the differences between state Nutrient Management prgram initiatin dates and implementatin reprting fr the six-state partnership, the baseline year is recmmended t reflect these state partnership differences. Thus, the initial Nutrient Management implementatin year fr each state will be unique. The increasing level f histric implementatin between the state Nutrient Management prgram initiatin year and the 2015 reprted implementatin acreages represent tw pints n a state-by-state basis. The intervening annual representatin f implementatin acreages may be represented as a linear prgressin if there is a paucity f implementatin data, r inferred by state implementatin data representative f the definitins f nutrient management prpsed by the panel. Histric implementatin estimatin shall cnsider additinal surces f nitrgen and phsphrus reductin credits cmmensurate with State Quality Assurance Prject Plans (QAPPs) currently in place, given they are cnsistent with the BMPs and efficiency credits described by the Panel. In cperatin with the Chesapeake Bay Prgram Office, a state-by-state representatin f Nutrient Management reprted implementatin fllwing the Panel s recmmendatins fr histric implementatin levels in default f additinal state implementatin data was presented bth t the Panel and the Agriculture Wrkgrup as part f the preliminary Panel recmmendatin reprt and review and apprval by the Agriculture Wrkgrup in May 19, The state-by-state representatin was develped fr N Cre Nutrient Management nly, and with the fllwing methdlgy: Assume straight-line interplatin between 2015 Prgress acres and a starting year fr each state. Starting year was evaluated by lking at histric NEIEN data t determine when states started reprting infrmatin Prgress has acres n crp, pasture and hay. Interplatin was made fr each f these categries. Interplatin was made in each cunty. Assume all acres n crps fr NY, PA, and WV nly apply t crp acres eligible fr receiving manure. Assume all acres n crps fr DE, MD and VA can be distributed t crp acres with r withut manure. All acres assumed t qualify fr cre N. N acres yet determined fr cre P. Figure B-1 illustrates the relatinship between state reprting f histric data thrugh NEIEN and the methdlgy described abve. 49

50 Figure B-1. Cmparing April Calibratin Nutrient Management Acres t Draft NMP Acres A secnd independent surce f representing histric Nutrient Management implementatin has been requested frm the USDA NRCS CEAP based n the tw existing reprts published n the Chesapeake Bay Watershed. Tables 2.7 and 2.8 frm the 2013 CEAP reprt summarize nitrgen and phsphrus management practices and percent f crpped acres within each categry fr the Chesapeake Bay regin, respectively (USDA 2013). In utilizing the Panel's practice recmmendatins fr tracking and reprting practice implementatin, the Panel recmmends that acres, r percentage f acres, be reprted by Phase 6 land use, r gruping f similar land uses, by year as an annual practice. Nutrient Management Cre N and P are stand-alne practices which shuld be tracked and reprted separately. Likewise, advanced supplemental N and P practices shuld be tracked and reprted separately, but nly when the crrespnding Cre N r P elements have been met by the Panel's recmmended practice definitins. 50

51 Table 2.7. Nitrgen management practices and percent f crpped acres within each categry fr the Chesapeake Bay regin, and 2011 (USDA 2013). Nitrgen* percent percent N N applied t any crp in rtatin 214,000 acres 87, Fr acres where N is applied: Cmmercial Fertilizer Only 2,457,000 2,177, Manure with r withut Cmmercial Fertilizer 1,608,000 2,089, Rate f applicatin: Acres receiving cmmercial fertilizer and/r manure applicatins: All crps in rtatin meet the nitrgen rate criteria described in text Sme but nt all crps in rtatin meet the nitrgen rate criteria described in text N crps in rtatin meet the nitrgen rate criteria described in text 13 6 Acres receiving cmmercial fertilizer applicatins nly: All crps in rtatin meet the nitrgen rate criteria described in text Sme but nt all crps in rtatin meet the nitrgen rate criteria described in text N crps in rtatin meet the nitrgen rate criteria described in text 6 3 Acres receiving manure with r withut cmmercial fertilizer applicatins: All crps in rtatin meet the nitrgen rate criteria described in text 17 9 Sme but nt all crps in rtatin meet the nitrgen rate criteria described in text N crps in rtatin meet the nitrgen rate criteria described in text 24 9 Time f applicatin: Acres receiving cmmercial fertilizer and/r manure applicatins: All crps in rtatin have applicatin f nitrgen fertilizer less than 21 days befre planting Sme but nt all crps have applicatin f nitrgen fertilizer within 21 days befre planting N crps in rtatin have applicatin f nitrgen fertilizer within 21 days befre planting Acres receiving cmmercial fertilizer applicatins nly: All crps in rtatin have applicatin f nitrgen fertilizer less than 21 days befre planting Sme but nt all crps have applicatin f nitrgen fertilizer within 21 days befre planting N crps in rtatin have applicatin f nitrgen fertilizer within 21 days befre planting 9 13 Acres receiving manure with r withut cmmercial fertilizer applicatins: All crps in rtatin have applicatin f manure less than 21 days befre planting Sme but nt all crps have applicatin f manure within 21 days befre planting N crps in rtatin have applicatin f manure within 21 days befre planting Methd f applicatin: Acres receiving cmmercial fertilizer and/r manure applicatins: All crps in rtatin have N applied with incrpratin r banding/fliar/spt treatment Sme but nt all crps in rtatin have N applied with incrpratin r banding/fliar/spt treatment N crps in rtatin have N applied with incrpratin r banding/fliar/spt treatment Acres receiving cmmercial fertilizer applicatins nly: All crps in rtatin have N applied with incrpratin r banding/fliar/spt treatment Sme but nt all crps in rtatin have N applied with incrpratin r banding/fliar/spt treatment N crps in rtatin have N applied with incrpratin r banding/fliar/spt treatment Acres receiving manure with r withut cmmercial fertilizer applicatins: All crps in rtatin have manure applied with incrpratin r banding/fliar/spt treatment Sme but nt all crps in rtatin have manure applied with incrpratin r banding/fliar/spt treatment N crps in rtatin have manure applied with incrpratin r banding/fliar/spt treatment Rate and timing and methd f applicatin (excludes acres nt receiving nitrgen) All crps meet the nitrgen rate criteria described in text and applicatin within 3 weeks befre planting with incrpratin r banding/fliar/spt treatment 13 7 Sme but nt all crps meet the nitrgen rate criteria described in text r applicatin within 3 weeks befre planting with incrpratin r banding/fliar/spt treatment Nitrgen and Phsphrus Crp rtatin phsphrus and nitrgen rates meet criteria described in text and all applicatins ccur within 3 weeks befre planting and include incrpratin r banding/fliar/spt treatment, including acres with n nitrgen r phsphrus applied 8 5 Nte: Percents may nt add t 100 because f runding. * These estimates include adjustments made t the reprted data n nitrgen and phsphrus applicatin rates frm the survey because f missing data and data entry errrs. In the case f phsphrus, the 3-year data perid fr which infrmatin was reprted was t shrt t pick up phsphrus applicatins made at 4- and 5-year intervals between applicatins, which is a cmmn practice fr prducers adhering t sund phsphrus management techniques. Since crp grwth, and thus canpy develpment which decreases ersin, is a functin f nitrgen and phsphrus, it was necessary t add additinal nitrgen when the reprted levels were insufficient t supprt reasnable crp yields thrughut the 52 years in the mdel simulatin. Fr additinal infrmatin n adjustment f nutrient applicatin rates, see Adjustment f CEAP Crpland Survey Nutrient Applicatin Rates fr APEX Mdeling, available at 51

52 Table 2.8. Phsphrus management practices and percent crpped acres within each categry fr the Chesapeake Bay regin, and 2011 (USDA 2013). Phsphrus* acres acres percent percent N P applied t any crp in rtatin 43,000 <1 1 <1 Fr acres where P is applied: Cmmercial Fertilizer Only 2,414,000 2,264, Manure with r withut Cmmercial Fertilizer 1,608,000 2,089, Rate f applicatin: Acres receiving cmmercial fertilizer and/r manure applicatins: Rtatin meets the phsphrus rate criteria described in text Sme but nt all crps in the rtatin meet the phsphrus rate criteria described in text Acres receiving cmmercial fertilizer applicatins nly: Rtatin meets the phsphrus rate criteria described in text Sme but nt all crps in the rtatin meet the phsphrus rate criteria described in text Acres receiving manure with r withut cmmercial fertilizer applicatins: All crps in rtatin meet the phsphrus rate criteria described in text Sme but nt all crps in the rtatin meet the phsphrus rate criteria described in text Time f applicatin: Acres receiving cmmercial fertilizer and/r manure applicatins: All applicatins f phsphrus fertilizer less than 21 days befre planting Sme but nt all applicatins f phsphrus fertilizer within 21 days befre planting N applicatins f phsphrus fertilizer within 21 days befre planting Acres receiving cmmercial fertilizer applicatins nly: All applicatins f phsphrus fertilizer less than 21 days befre planting Sme but nt all applicatins f phsphrus fertilizer within 21 days befre planting N applicatins f phsphrus fertilizer within 21 days befre planting Acres receiving manure with r withut cmmercial fertilizer applicatins: All applicatins f phsphrus fertilizer less than 21 days befre planting Sme but nt all applicatins f phsphrus fertilizer within 21 days befre planting N applicatins f phsphrus fertilizer within 21 days befre planting Methd f applicatin: Acres receiving cmmercial fertilizer and/r manure applicatins: All applicatins f phsphrus include incrpratin r banding/fliar/spt treatment Sme but nt all applicatins f phsphrus include incrpratin r banding/fliar/spt treatment N applicatins f phsphrus include incrpratin r banding/fliar/spt treatment Acres receiving cmmercial fertilizer applicatins nly: All applicatins f phsphrus include incrpratin r banding/fliar/spt treatment Sme but nt all applicatins f phsphrus include incrpratin r banding/fliar/spt treatment N applicatins f phsphrus include incrpratin r banding/fliar/spt treatment Acres receiving manure with r withut cmmercial fertilizer applicatins: All applicatins f phsphrus include incrpratin r banding/fliar/spt treatment Sme but nt all applicatins f phsphrus include incrpratin r banding/fliar/spt treatment N applicatins f phsphrus include incrpratin r banding/fliar/spt treatment Rate and timing and methd f applicatin (excludes acres nt receiving phsphrus): All applicatins meet the phsphrus rate criteria described in text and applicatin within 3 weeks befre planting with incrpratin r banding/fliar/spt treatment Sme but nt all applicatins meet the phsphrus rate criteria described in text r applicatin within 3 weeks befre planting with incrpratin r banding/fliar/spt treatment Nitrgen and Phsphrus Crp rtatin phsphrus and nitrgen rates meet criteria described in text and all applicatins ccur within 3 weeks befre planting and include incrpratin r banding/fliar/spt treatment, including acres with n nitrgen r phsphrus applied 8 5 Nte: Percents may nt add t 100 because f runding. * These estimates include adjustments made t the reprted data n nitrgen and phsphrus applicatin rates frm the survey because f missing data and data entry errrs. In the case f phsphrus, the 3-year data perid fr which infrmatin was reprted was t shrt t pick up phsphrus applicatins made at 4- and 5-year intervals between applicatins, which is a cmmn practice fr prducers adhering t sund phsphrus management techniques. Since crp grwth, and thus canpy develpment which decreases ersin, is a functin f nitrgen and phsphrus, it was necessary t add additinal phsphrus when the reprted levels were insufficient t supprt reasnable crp yields thrughut the 52 years in the mdel simulatin. (Fr additinal infrmatin n adjustment f nutrient applicatin rates, see Adjustment f CEAP Crpland Survey Nutrient Applicatin Rates fr APEX Mdeling, available at 52

53 References USDA Impacts f Cnservatin Adptin n Cultivated Acres f Crpland in the Chesapeake Bay Regin, t Cnservatin Effects Assessment Prject, U.S. Department f Agriculture, Washingtn, DC. 53

54 Appendix C: Nutrient Management Phase 6.0 Expert Panel Charge Dcument Recmmendatins fr the Nutrient Management Phase 6.0 Expert Panel Prepared fr the Chesapeake Bay Prgram Partnership s Agriculture Wrkgrup by the Nutrient Management Phase 6.0 Expert Panel Establishment Grup March 19, 2015 Backgrund The current versin f the Chesapeake Bay Prgram (CBP) partnership s Watershed Mdel (Phase r P5.3.2) credits Crp Grup Nutrient Applicatin Management (r Tier 1), under the fllwing definitin: Dcumentatin exists fr manure and/r fertilizer applicatin management activities in accrdance with basic land grant university (LGU) recmmendatins. This dcumentatin supprts farmspecific effrts t maximize grwth by applicatin f nitrgen (N) and phsphrus (P) with respect t prper nutrient surce, rate, timing and placement fr ptimum crp grwth cnsistent with LGU recmmendatins. Particular attentin is paid t: (1) standard, realistic farm-wide yield gals; (2) credit fr N surces (sil, sd, past manure and current-year applicatins); (3) P applicatin rates cnsistent with LGU recmmendatins based n sil tests fr fields withut manure; and (4) N based applicatin rates cnsistent with LGU recmmendatins fr fields receiving manure. Enhanced Nutrient Management and Decisin Agriculture BMPs are currently represented in the P5.3.2 Mdel. Hwever, these practices are expected t be replaced by Nutrient Applicatin Management Tier 2 and Tier 3 practices respectively, which are being finalized by the Nutrient Management P5.3.2 Expert Panel in spring Prpsed Tier 2 The implementatin f field-specific nutrient applicatin management effrts t maximize grwth by applicatin f nitrgen (N) and phsphrus (P) with respect t prper nutrient surce, rate, timing and placement fr ptimum crp grwth cnsistent with LGU recmmendatins incrprating a P risk assessment tl. Prpsed Tier 3 The implementatin f subfield-specific nutrient applicatin management effrts t maximize grwth by applicatin f nitrgen (N) and phsphrus (P) with respect t prper nutrient surce, rate, timing and placement fr ptimum crp grwth incrprating sub-field mnitring and peratinal practices t further refine the LGU recmmendatins fr the specific farm site and cnditins. The Nutrient Management Expert Panel Establishment Grup (EPEG) was frmed t: Identify pririty tasks fr the Phase 6.0 (P6.0) Nutrient Management Expert Panel (EP), Recmmend areas f expertise that shuld be included n the Nutrient Management EP, and Draft the Nutrient Management EP s charge fr the review prcess. Frm February 18, 2015 thrugh March 6, 2015 the EPEG met 3 times by cnference call and wrked cllabratively t cmplete this charge fr presentatin t the Agriculture Wrkgrup

55 (AgWG) n March 18-19, Final apprval f the charge was btained by nline plling f all members. Members f the EPEG are listed in Table 1. Table 1. Nutrient Management Expert Panel Establishment Grup membership and affiliatins. Member Beth McGee Chris Brsch Dug Gdlander Frank Cale Jack Meisinger Jasn Keppler EPEG Supprt Staff Emma Giese Mark Dubin Steve Dressing Affiliatin Chesapeake Bay Fundatin Virginia Tech Pennsylvania Department f Envirnmental Prtectin University f Maryland U.S. Department f Agriculture-Agricultural Research Service Maryland Department f Agriculture Chesapeake Research Cnsrtium University Maryland Tetra Tech, Inc. Methd The Nutrient Management EPEG develped its recmmendatins in accrdance with the prcess specified by the AgWG (AgWG 2014). This prcess is infrmed by the strawman prpsal presented at the December 11, 2014 AgWG meeting, the Water Quality Gal Implementatin Team (WQGIT) Best Management Practice (BMP) prtcl, input frm existing panelists and chairs, and the prcess recently undertaken by the AgWG t develp the charge fr the Manure Treatment Technlgies EP. The cllective knwledge and expertise f EPEG members frmed the basis fr the recmmendatins cntained herein. A number f EPEG members have had experience n BMP expert panels, including the P5.3.2 Nutrient Management EP. Other EPEG members have knwledge and/r expertise in state and federal prgrams, the Chesapeake Bay mdel, and nutrient management practices within the Chesapeake Bay watershed. Cmmunicatin amng EPEG members was by cnference call and . All decisins were cnsensusbased. Recmmendatins fr Expert Panel Member Expertise The AgWG expert panel rganizatin prcess directs that each expert panel is t include eight members, including ne nn-vting representative each frm the Watershed Technical Wrkgrup (WTWG) and Chesapeake Bay Prgram mdeling team. Panels are als expected t include three recgnized tpic experts and three individuals with expertise in envirnmental and water quality-related issues. A representative f USDA wh is familiar with the USDA-Natural Resurces Cnservatin Service (NRCS) cnservatin practice standards shuld be included as ne f the six individuals wh have tpic- r ther expertise. 55

56 In accrdance with the WQGIT BMP prtcl, panel members shuld nt represent entities with ptential cnflicts f interest, such as entities that culd receive a financial benefit frm Panel recmmendatins r where there is a cnflict between the private interests and the fficial respnsibilities f thse entities. All Panelists are required t identify any ptential financial r ther cnflicts f interest prir t serving n the Panel. These cnditins will minimize the risk that Expert Panels are biased tward particular interests r regins. The Nutrient Management EPEG recmmends that the P6.0 Nutrient Management EP shuld include members with the fllwing areas f expertise: Nutrient management planning and agrnmy. Expertise in farm- and field-level nutrient risk assessment tls fr N and P. Experience with carrying ut research prjects relating t nutrient management. Expertise in fate and transprt f N and/r P in agricultural systems. Knwledge f nutrient management practices implemented in the Bay jurisdictin(s). Knwledge f hw BMPs are tracked and reprted, and the Chesapeake Bay Prgram partnership s mdeling tls. Experience with verificatin f nutrient management plans and ther frms f nutrient management. Knwledge f relevant USDA-NRCS practice cdes r standards. Expert Panel Scpe f Wrk The general scpe f wrk fr the Nutrient Management P6.0 EP(s) will be t define and cnfigure the Nutrient Management BMPs in the P6.0 mdel. Specifically, the Nutrient Management EPEG recmmends the fllwing five charges with assciated tasks fr the P6.0 Nutrient Management EP: 1. Review the P5.3.2 definitins and effectiveness estimates fr the implementatin f cmpnent practices f Nutrient Management and make adjustments r mdificatins as needed fr Phase 6.0. a) Cnsider the current P5.3.2 Tier system used fr identifying levels f nutrient management implementatin activities t be credited t the mdel, and b) Recmmend if the current prpsed Tier prcess shuld remain r if a mre cmpnent riented prcess fr crediting nutrient management practices is mre apprpriate. 2. Determine hw nutrient management practices can be applied t the P6.0 land uses, taking int cnsideratin the mass balance data and nutrient spreading rutine in Scenari Builder. 3. If pssible, make recmmendatins using multi-year vs. annual mdel representatin f sil nutrient residuals fr calculatin f available nutrients t meet crp requirements n an annual basis. 4. Cllabratin with the Crpland Irrigatin Management EP n fertigatin will be critical t ensure that recmmendatins are cmplementary as well as t avid duble-cunting and ensure effective reprting f practices. 56

57 This scpe f wrk addresses nutrient management reductin efficiencies fr N and P. Under the first charge, the Nutrient Management Phase 6.0 (P6.0) Expert Panel will review the P5.3.2 definitins and effectiveness estimates fr the implementatin f cmpnent practices f Nutrient Management and make adjustments r mdificatins as needed fr Phase 6.0. This charge is necessary because the P6.0 mdel features a change in land use categries, a pssible change in the baseline cnditin, and sme likely changes in hw BMPs are applied. While the EPEG cnsiders the tiered apprach t be an imprvement ver the previus P5.3.2 apprach t nutrient management, there is interest in cnsidering an alternative apprach fr P6.0. Bth a tiered apprach and practice-specific apprach have prs and cns assciated with reprting implementatin and determining efficiency values. Items 1a and 1b specify that the P6.0 EP will cnsider the current Tier system used fr identifying levels f nutrient management implementatin activities t be credited t the mdel and recmmend if the current prpsed Tier prcess shuld remain r if a mre cmpnent riented prcess fr selecting nutrient management practices is mre apprpriate. Nutrient management Tiers 1-3 are described in the Backgrund sectin f this dcument. The secnd charge directs the P6.0 EP t determine hw nutrient management practices can be applied t the P6.0 land uses. Factrs t cnsider when perfrming tasks under this charge include the baseline cnditins assumed by the mdel (e.g., with r withut nutrient management), the nutrient spreading rutine and imprved mass balance data fr Scenari Builder, and ptential variatin in crediting fr different land uses. Residual nutrients are nt adequately accunted fr by the P5.3.2 mdel. Under the third charge, the P6.0 EP will cnsider management f residual nutrients and hw they are carried ver t subsequent years in the P6.0 mdel. This will require clse crdinatin with the Chesapeake Bay mdeling team which is ultimately respnsible fr develping the capability t add this imprtant feature t the mdel. Cllabratin with the P6.0 Crpland Irrigatin Management EP is specified under the furth charge t ensure that recmmendatins frm the tw panels are cmplementary and that practice reprting and crediting are accurate. Either panel culd address fertigatin, but bth panels shuld have a rle in determining the final recmmendatins. Timeline and Deliverables Early summer Panel stakehlder kickff meeting Summer 2015 Based n their written EPEG charge, the panel will develp a prpsed scpe f wrk including BMP structure and type, draft BMP definitin(s), and initial elements f the BMP such as assciated cmpnents and cnservatin practices, and USDA-NRCS assciated CP cdes. Initially identified literature citatins will be included t prvide a range f ptential effectiveness values that the panel will cnsider and supplement with further evaluatin. The panel will present their prvisinal BMP paper t the AgWG, WTWG, and WQGIT fr infrmatinal purpses, and fr initial partnership cmments n the prpsed directin f the panel s evaluatin. The paper will nt represent a full recmmendatin reprt, and the partnership will nt be asked fr frmal apprval at this time. 57

58 Prir t Octber 1, 2015 In the absence f a Partnership apprved panel recmmendatin reprt, the CBPO mdeling team will request a decisin by the Agriculture Wrkgrup, Watershed Technical Wrkgrup, and the Water Quality Gal Implementatin Team f whether the BMP will be represented using the existing Phase definitins, the apprved recmmendatins f the Phase Panel reprt if applicable, r the Phase 6.0 panel's prvisinal paper, in the Phase 6 Beta Scenari Builder tl t meet an early Octber deadline. Spring 2016 Final date fr panel t release full recmmendatins fr apprval by the AgWG, WTWG, and WQGIT. Early summer 2016 If apprved by the partnership, panel recmmendatins are final and will replace the interim representatin f the BMP in the final versin f the Phase 6 mdeling tls. Phase 6.0 BMP Verificatin Recmmendatins: The panel will utilize the Partnership apprved Agricultural BMP Verificatin Guidance 1, as the basis fr develping BMP verificatin guidance recmmendatins that are specific t the BMP(s) being evaluated. The panel's verificatin guidance will prvide relevant supplemental details and specific examples t prvide the Partnership with recmmended ptential ptins fr hw jurisdictins and partners can verify nutrient management practices in accrdance with the Partnership's apprved guidance. References AgWG Agriculture Wrkgrup expert panel rganizatin DRAFT January 8, Agriculture Wrkgrup, Chesapeake Bay Prgram. 1 Ag%20BMP%20Verificatin%20Guidance%20Final.pdf 58

59 Attachment 1: Outline fr Final Expert Panel Reprts Identity and expertise f Panel members Practice name/title Detailed definitin(s) f the practice Recmmended nitrgen, phsphrus, and sediment lading r effectiveness estimates - Discussin may include alternative mdeling appraches if apprpriate Justificatin fr the selected effectiveness estimates, including - List f references used (peer-reviewed, unpublished, etc.) - Detailed discussin f hw each reference was cnsidered, r if anther surce was investigated, but nt cnsidered. Descriptin f hw best prfessinal judgment was used, if applicable Land uses t which the BMP is applied Lad surces that the BMP will address and ptential interactins with ther practices Descriptin f pre-bmp and pst-bmp circumstances, including the baseline cnditins fr individual practices Cnditins under which the BMP wrks: - Shuld include cnditins where the BMP will nt wrk, r will be less effective. An example is large strms that verwhelm the design. - Any variatins in BMP effectiveness acrss the watershed due t climate, hydrgemrphic regin, r ther measureable factrs. Tempral perfrmance f the BMP including lag times between establishment and full functining (if applicable) Unit f measure (e.g., ft., ac) Lcatins within the Chesapeake Bay watershed where this practice is applicable Useful life; effectiveness f practice ver time Cumulative r annual practice Descriptin f hw the BMP will be tracked, reprted, and verified: - Include a clear indicatin that this BMP will be used and reprted by jurisdictins Suggestin fr a review timeline; when will additinal infrmatin be available that may warrant a re-evaluatin f the estimate Outstanding issues that need t be reslved in the future and a list f nging studies, if any Dcumentatin f any dissenting pinin(s) if cnsensus cannt be reached Operatin and Maintenance requirements and hw neglect alters perfrmance Additinal Guidelines Identify ancillary benefits and unintended cnsequences Include negative results - Where studies with negative pllutin reductin data are fund (i.e. the BMP acted as a surce f pllutants), they shuld be cnsidered the same as all ther data. Include results where the practice relcated pllutants t a different lcatin. Examples include where a practice eliminates a pllutant frm surface transprt but 59

60 mves the pllutant int grundwater, r where the practice will mve manure frm the farm credited fr the practice t anther farm mre in need f nutrients. In additin, the Expert Panel will fllw the data applicability guidelines utlined Table 1 f the Water Quality Gal Implementatin Team Prtcl fr the Develpment, Review, and Apprval f Lading and Effectiveness Estimates fr Nutrient and Sediment Cntrls in the Chesapeake Bay Watershed Mdel. 60

61 Appendix D: Apprved Nutrient Management Expert Panel Meeting Minutes 7/22/2015 Frank Cale, Panel Chair, welcmed the grup t the call and thanked everyne fr agreeing t cntribute t this Panel effrt. Panel members and staff intrduced themselves. Cale: The plan fr the face-t-face meeting n September is t create draft recmmendatins fllwing the meeting. Nt expecting t develp much technical cntent tday during the call, instead infrmatin will be sent ut ver t Panel members between nw and the in-persn meeting in rder t make the best use f time in September. Travel reimbursement fr the September meeting will be ffered thrugh UMD. Mark reviewed the Panel charge, which was develped by a scping grup earlier this year and apprved by the Chesapeake Bay Prgram s Agriculture Wrkgrup. The charge was sent t members in an frm Emma Giese n 7/21. Questin: Des this Panel need t address BMP verificatin mre in depth than the previus Panel? Respnse by Cale: We have been charged with addressing it. The depth f the respnse will have t be determined by ur ther recmmendatins, but we will have t lay ut a plan fr verificatin. Questin: Will there be interactin with the Chesapeake Bay Prgram s BMP Verificatin Panel? Respnse by Dubin: Likely nt, as the Panel is lking at the larger scale verview. This Panel will be wrking within the existing verificatin guidelines develped by the Agriculture Wrkgrup. Chris Brsch, chair f the previus (Phase 5) Nutrient Management Panel, gave a brief verview f this Panel s wrk t date. Chris recmmended the Panel members watch the first 40 minutes f the July 1 webinar where the Phase 5 Panel recmmendatins are recrded. Webinar recrding is available here: Frank nted that this Panel will be able t build ff f the wrk already dne by the Phase 5 Panel. Frank asked Matt Jhnstn (CBPO mdeling team) t explain hw the changes in the Phase 6 Chesapeake Bay Prgram Watershed Mdel will affect hw this Panel develps recmmendatins relevant t the Phase 5 recmmendatins. Jhnstn: The tw big changes being tested right nw fr Phase 6 that will impact what this grup des are 1) land uses (The land uses will be mre specific in Phase 6, i.e. crn, and small grains rather than rw crps ) and 2) hw the nutrients are applied (there will already be a better accunting fr right applicatin rate in Phase 6) Cale: Emma s included a link t the Phase 5 Panel webinar summarizing their recmmendatins. Once the Phase 5 Nutrient Management panel final reprt has been apprved by the Bay Prgram Partnership, it will be shared with this Panel as well. There will be dcuments distributed frm either Frank, Mark, r Emma, and cnversatins ver the cming weeks t begin cnsidering different 61

62 ptins. Frank encuraged Panel members t read these s as they are sent in rder t make the best use f time in preparatin fr and during the September meeting. Travel reimbursement frms were sent by Emma this mrning (7/22). The frm needs t be submitted befre travel (9/7/15 at the latest) in rder fr apprvals t be prcessed thrugh the university. Cntact Mark with any questins abut travel reimbursement. Participants Frank Cale Quirine Ketterings Jack Meisinger Dug Beegle Chris Brsch Deanna Osmnd Matt Jhnstn Mark Dubin Emma Giese UMD, Panel chair Crnell USDA-ARS PSU VT/VADCR, Watershed Technical Wrkgrup representative NCSU UMD, CBPO Mdeling Team UMD, Agriculture Wrkgrup crdinatr CRC, Panel staff 9/10/2015 9/11/2015 Open Stakehlder Meeting: Tm Simpsn gave a presentatin, discussing the Nutrient Management Panel s Phase Reprt, highlighting sme f the issues with this reprt, and prviding sme suggestins fr the new Phase 6 panel. Simpsn: Will substantive draft infrmatin be publicly available? What abut pprtunities fr input/cmment between pen sessin and final draft review? Mark Dubin: Frank and ther panel chairs will be presenting at the September quarterly meeting next week t prvide updates. Frank Cale: The panel will als be crrespnding with pen sessin participants as they mve frward. Mike Twining frm Willard Agri-Service presented n the adapt-n and Ec-N tl and mdeling system fr mdeling and mapping agrnmic and sil characteristics t predict future trends. Tm Fisher: Are thse mdels r measurements in the figures? Twining: They are mdeled results based n published research that was fed int the mdel. Jack Meisinger: Hw much data frm the figures yu ve shwn us is frm the Bay watershed? Twining: If yu want replicated, strip-trial data, then this develpment wrk was dne utside the Bay watershed. The mdel has been adapted t ur fieldspecific questins. Lindsay Thmpsn: Is there a general number f prducers r acres that implemented this in the crpping cycle? Twining: I wn t give a specific number, but it s in the hundreds. Quirine Ketterings: Are there farmers yu re wrking with in the Chesapeake Bay area that wuld be pen t cnducting trials in the future? Twining: We are crdinating with these farmers, but replicatin is very difficult t achieve. Our side-by-side analyses allw us t cme within statistical 62

63 cnfidence levels that are clse t a replicated trial. Deanna Osmnd: D yu include N recmmendatins frm universities when yu re thinking abut putting these trials tgether? Twining: All f ur recmmendatins are university recmmendatins, in cmpliance with Nutrient Management law. When ur mdel differs frm the recmmendatins, then we mve int mre unfamiliar territry. Matt Jhnstn: What happens when this technlgy is used t increase prfitability and yields, what wuld happen t the lsses? Hw is this technlgy changing applicatins and runff t water? Twining: As grwers adpt this tech, grwers will increase side-dress applicatins. Yields have increased year after year, but we can t prmise any kind f abslute reductin in Nitrgen. But Nitrgen use efficiency is imprving with this technlgy. Meisinger: This panel will have t wrestle with verificatin. Hw wuld yu verify Adapt-N? Twining: In my pinin, the verificatin prcess shuld cme thrugh annual implementatin reprting prcess. Ultimately, the bligatin is n the farmer t verify what they are ding n their farm. Matt Miller frm DuPnt/Pineer gave a presentatin n Encirca services, designed t increase efficiency f nitrgen management. Open discussin after presentatins: Tm Fisher: Questin t Matt Miller. Hw wuld nitrgen be applied during the tackling stage? Miller: We ve had a few different types f applicatin (aerial, fertigatin ). Quirine Ketterings: Can yu talk a little bit abut what yu re ding in these trials? Bill McCllum: We did whle-field trials, s there wasn t any replicatin. The smallscale and replicated trials are dne with the agrnmy sciences grup in Iwa. Jack Meisinger: Are there any new methds fr manure management? Twining: We are mdeling manure applicatin n fields. Twining: Mve in-seasn t in-seasn management. There s mre year-t-year variatin in Nitrgen management than there is in a field. That s what s driving us t lk at in-seasn decisin tls. There s a strng eclgical and ecnmic cmpnent t that. Frank: Can a blanket assessment be made n weather-based mdels? Twining: I wuld say yes. In the absence f mdeling tech, the risk f lss is likely greater. Tm Fisher: As lng as we cntinue with n based manure applicatin, we ll always have excess P in sils. If we g t a P based manure applicatin rate, then we ll have a surplus f manure. S we shuld create an alternative prduct(s) fr manure cmpsting, packing fr sale, energy prductin, etc. Participants: Frank Cale Chris Brsch Matt Miller Bill McCllum Deanna Osmnd Steve Dressing Jhn Dantinne Mike Twining UMD VT/VADCR DuPnt/Pineer DuPnt/Pineer NCSU Tetra Tech Willard Agri-Service Willard Agri-Service 63

64 Jack Meisinger USDA ARS Quirine Ketterings Crnell University Lindsay Thmpsn MD Assciatin f Sil Cnservatin Districts Matt Jhnstn CBPO Mark Dubin UMD Tm Simpsn Aqua Terra Science LLC Lindsey Grdn CRC Staff Frank Schneider PA DEP Tm Fisher UMCES Dawn Stlzfus MD Clean Agriculture Calitin Greg Levw Agrnmic Technlgy Crp. Jeremy Hansn VT Karl Blankenship Bay Jurnal Kelly Shenk EPA Regin 3 Kristen Hughes Evans Sustainable Chesapeake Kristen Saacke Blunk Headwaters LLC Rbin Pellican MDE Rn Krcak USDA ARS Harld Van Es Crnell University Dug Beegle PSU Seung Ah Byun Brandywine Cnservancy Clsed Panel Meeting: Actins and Decisins: ACTION: Panel will need t deliberate and determine a negative efficiency number, as well as decide if this value will be the same fr all bad actrs. ACTION: Frank Cale t ask fr candidate nminatins fr new BMPs that are nt captured n the list that has been drafted. Thursday September 10, 2015: Chris Brsch gave a presentatin f the Phase Nutrient Management tiered plan. Deanna Osmnd: Had anything really changed frm Tier 1 t Tier 2 relative t practice behavir? Brsch: Nt really, but we weren t trying t credit anyne that wanted t apply cmmercial fertilizer in the fall. Osmnd: Was the SWAT mdel the latest versin with better P rutines? When was this dne? Meisinger: Using the lder versin. Frank Cale: Can smene describe hw the Phase 6 land uses will lk and wrk? Matt Jhnstn briefed everyne n the list f new Phase 6 agricultural land uses and the Phase 6 Scenari Builder. Cale: Whatever recmmendatins cme with BMP efficiencies will be applied t this grup f acres. Meisinger: The mdel wrld shuldn t be driving the real wrld. If yu can cllect mdel validatin (we ll have t d this fr Tier 1) then that shuld impact the mdel. Dubin: One f the prblems is that we re estimating. We dn t always have gd data, and this impacts the estimates that we cme up with. It als impacts manure transprt. S unless the jurisdictins reprt manure transprt, the mdel will assume that all manure 64

65 that is made in the cunty, stays in the cunty. Steve Dressing: Manure transprt is factred in fr that initial mass cunty balance? Dubin: Nt quite. The cunties can get credit, but they need data t get the credit. Jhnstn: Whenever we estimate crp need fr crn, we ask the states what NM planners were ding in the past 3 decades. Cale: I see tw appraches in mving frward: 1) Find the path that Chris described (With the tiers here s a grup f practices that cunt ne way, and anther grup, etc ) r 2) We enumerate all the different practices we can think f. Sme will apply t sme land uses, sme wn t. Each ne f thse BMPs will have an efficiency cefficient that will apply t a practice. Then systems can be cnstructed t incrprate BMPs and determine final efficiencies. Meisinger: I m a prpnent f nn-tiering ptin #2. I wuld like t have N and P separated. I like the independent menu system, where yu can specify what tests r BMPs yu are ding. There wuld be a lt f flexibility, but the prblem is that we d have t get sme estimate f thse practices. And perhaps we culd even get a paper published ut f this. Cale: There are 3 things we have t try t assure can be dne. We can define things that can be tracked. It has t be reprtable t whatever agency is cllecting the numbers. And then it has t be verified. That s a tricky ne, but we shuld keep track f that as we g ahead. Meisinger: The menu system is much friendlier t verificatin as ppsed t a Tier system. Dressing: A menu apprach wuld als be cmpatible with a checklist apprach, which is a verificatin practice used in PA. It seems t me that yur apprach needs t be cmpatible with what the Agriculture practice panels are ding with regard t what the states have t verify. Dubin: A new cmpnent is the verificatin guidance and prtcls, which we re in the prcess f finalizing right nw. If yu re lking at a nn-visual BMP (aka NM), then yu re reduced t lking at recrds. Right nw, nne f the states have a very gd tracking system fr NM plans, but they ll be encuraged that they have t re-think that. NM plans are als represented in ther BMPS. Tm Fisher: Culd we g back t the way manure and fertilizer allcatins were dne? It seems a bit cntrived and I was wndering if it crrespnded with the way fertilizer sales in fact are distributed thrughut the state. In ther wrds, is this mdel really reflecting reality? Matt and Mark replied that predicting and measuring fertilizer use is almst impssible, because data is nt reliable enugh at this pint. Dug Beegle: One f the things I struggled with is hw we separate active planning frm the practices that are driven by planning. I think that s ne f the things we missed, that the active planning is ging t give sme benefit. Meisinger: S my thught is we wuld still have a fundamental NM piece. That s Tier 1, and everything else is a menu based ff f that. Put sme recrd keeping, sil test mnitring, and any basic tls yu want t see available (educatin might be a part f this) wuld g in that Tier 1, NM piece. There wuldn t be any practice credit fr it. Cale: Maybe there shuld be practice credit fr it. Dubin: But wuldn t that be exclusinary? Because I culd d a lt f the wrk t get the data that wuld influence applicatin rates, but I dn t have a frmally written plan, I wuld be excluded frm getting any f this. Cale: S yu may nt be required t have a NM plan. Meisinger: N and P wuld remain separate, but yu culd tie them t practices. Jhnstn: Regardless, we need t make sure that each practice results in a water quality benefit everywhere. 65

66 Dubin: I think the key t what yu were discussing earlier is nt hw much fertilizer yu put n, but what s the nitrgen efficiency? Osmnd: Hw d yu aggregate these practices and data up t a cunty level? And des everyne have the resurces t d this? Cale: Nt everyne has the resurces, and that s what the states might get upset abut if we chse t cntinue with this menu plan. Cale: Sme f the items in this menu idea wuldn t have any data at all, and sme wuld have very shaky data. S are there any ther ideas fr hw t structure this? Ketterings: What d we have that we can verify utcmes with, r can smehw make intelligent cnnectins t the utcmes with? Brsch: We establish a starting pint (1 lb. /bushel crn/acre), s if smene isn t achieving that fundamental level f NM, then they wn t get credit. Start targeting states that are nt nutrient/fertilizer balanced (mre nutrients than can be utilized), wh wuld accumulate negative credits if the baseline assumes balance. Cale: S what I m envisining is this: At the bttm f these three levels, yu have the bad actrs wh d nt invest in the base-line NM plans wuld be hit with a negative efficiency/pints/credits. Then yu wuld have the cre peple that remain neutral. Then abve this, yu can have the menu idea, which is all psitive efficiencies. Beegle: But then hw wuld yu be crediting the neutral flks? Jhnstn: We ve develped the next scenari builder t be that gd baseline (IE- yu re fllwing thse baseline recmmendatins), s that s yur baseline credit. Ketterings: Unless yu cnsider it a lad reductin allcatin, in which case yu dn t need credit. Meisinger: S hw are we ging t identify these bad actrs? We culd d the P budget, but when yu get t N it s a lt harder. We culd d it, but it s harder. Brsch: Mark had an ptin f ging t the industry and cllecting data n hw management is perfrmed. Meeting perfrmance standards. This wuld mean cllecting manure data effectiveness, and this wuld be a great ptin fr variable rate, but n necessarily fr a standard plan like we re wrking with. Grup had a planning sessin t map ut the structure f Nutrient Management recmmendatins, and what BMPs wuld be assciated with each structure level. Participants n 9/10/15: Frank Cale Chris Brsch Steve Dressing Deanna Osmnd Jack Meisinger Quirine Ketterings Matt Jhnstn Mark Dubin Lindsey Grdn Dug Beegle Tm Fisher UMD VT/VADCR Tetra Tech NCSU ARS Crnell CBPO UMD CRC Staff Penn State UMCES 66

67 Friday September 11, 2015: Jack Meisinger: In regards t the sediment questin, I think it wuld be slightly awkward t have 3 panels dealing with sediment. Mark Dubin: I think we need t have crss-discussin between the panels t figure this ut. I think we shuld keep sediment up n the list, but maybe sideline it fr nw until we talk t the ther grups. Meisinger: As yu think abut the matrix f the cre tier, that will change ver time because practices change and sme disappear, s I think we want t get clear what ur baseline is at the beginning r if we re ging t use a flating baseline acrss the time (which I dn t particularly like because it s nt well defined). The panel reviewed the 7 cre nutrient management practices drafted in yesterday s meeting Dug Beegle (in reference t sil tests fr P field level ): Cnsider an alternative, where yu wuld have bk values fr manure analysis, and yu can t put mre manure n than what crp remval is. This wuld be fairly prtective, and wuld be gd fr peple wh dn t have sil tests t be able t get thrugh the system. Dubin: D yu see many peple ging that rute? Beegle: We re a little wrried sme farmers and planners are ging that rute because it s simpler, thugh it s nt as cmprehensive as a sil test. It s nt as if we are freging sil tests; this alternative wuld be pretty restrictive. It assumes high P index, and acts as a wrkarund if yu have high sil P and shuldn t put any mre P n it. But these farms are lwdensity farms, and likely wuldn t have thse high P indexes t begin with. Meisinger: Desn t that cnflict with N-based applicatin rates, the manure analysis and vlume? I think what Dug s describing belngs as a menu item abve this. Cale: S let s remve N-based frm methd f determining NM applicatin rates BMPs listed in the Supplemental Menu are able t be stacked n tp f the Cre practices, but are nt eligible t substitute fr cre practices. Dubin: Each f these menu items will be its wn separate, and identifiable BMP. Agenda tpics fr next meeting: Meisinger: Wrk n shrinking the list f Phase 6 practices Review efficiency numbers fr Phase BMPs Mark and Lindsey t crdinate with ther panel chairs t schedule crss-panel (Cver Crps, Cnservatin Tillage, Strmwater Mgmt.) meetings n/after 2 nd week f Octber Lindsey t begin scheduling fllw-up cnference call meeting Participants n 9/11/15: Lindsey Grdn CRC Staff Matt Jhnstn CBPO Jack Meisinger ARS Quirine Ketterings Crnell Steve Dressing Tetra Tech Chris Brsch VT/VADCR Deanna Osmnd NCSU Dug Beegle Penn State Mark Dubin UMD Frank Cale UMD 67

68 11/20/2015: Actins and Decisins: ACTION: The panel members have 2 assignments t cmplete by December 20 th, sent t Lindsey Grdn (Grdn.lindsey@epa.gv) and Mark Dubin (mdubin@chesapeakebay.net). They are: Each panel member will g thrugh the land use matrix and cntinue ppulating all f the cells as t whether, fr each specific land use, N r P applies t the BMPs listed. Each panel member will additinally g thrugh each clumn f land uses, and priritize the BMPs that impact either N and/r P in that clumn as t which BMPs are the mst imprtant. Frmat shuld fllw N1, N2, N3 r P1, P2, P3, where N1 represents the mst imprtant BMP, fllwing rder f decreasing imprtance. Panel shuld priritize all f the BMPs fr each land use, where rankings are acrss bth Phase and Phase 6 BMPs. Panel members shuld begin cmpiling a list f ptential cnflicts in current recmmendatins. (Ex: allwing a plan if farmers dn t agree t use a P based applicatin f manure then they dn t have t use a sil test.) Panel Wrk Recap Frank Cale reviewed the presentatin given at the September AgWG Quarterly meeting. The verall reactin was psitive, thugh there was cncern frm state agency partners abut hw they will prvide the data and reprting. Tm Fisher expressed cncern that PSNT tests are nt included in the cre nutrient management practices. Frank Cale respnded that this is captured in the supplemental nutrient management BMP menu. Mark Dubin clarified that having a negative BMP is new, but that the effect is smething being implemented currently. Mving frward in the Phase 6 mdeling tls, there will nt be a land use set-up, and this will be applied as BMPs. Dug Beegle asked: In the riginal list, we had t have sil tests. In ur supplemental menu it seems like we wuld be penalizing farmers fr nt having a sil test and then crediting them fr a p-based applicatin rate. This wuld nt g ver well with the PA farmers, at least. Frank Cale explained hw in rder t get any f the supplemental practices, the cre practices wuld have t be met. But this culd cause big headaches, and is smething that the panel will have t wrk thrugh. Mark Dubin suggested writing in an either/r in the cre practices categry that sil tests are being dne, r in PA they can d a P-based applicatin rate as an alternative. This wuld fall mre n the reprting side, and hpefully wuldn t change the mdeling at all. Jack Meisinger asked if the panel will separate N and P n the cre practices list, because N-tests are nt traditinal. Frank Cale explained that the P test shuld stay n the cre menu, and the N based rates are built int the cmmn nutrient management plans. Preliminary Recmmendatins Panel needs t cntinue prcess f categrizing BMPs in terms f N and P, and priritize BMPs t assign efficiencies and include in the panel reprt. Partnership Feedback Mark Dubin gave a presentatin t the panel n the current mdeling f Nutrient Management in the beta Phase 6 mdel. The current mdeling methds are temprary, and will be replaced later n with the panel recmmendatins. Jack Meisinger: The basic change f utilizing the fertilizer sales data is smething we ll have t keep a clse eye n. The mdelers think they knw the rates pretty well, but in years past we ve never trusted the sales data basis s I think this is a ptential area we need t mnitr. Are yu able t d that r d we need sme ther versight? Mark Dubin replied that he has been in discussins with the mdeling flks, and that the Ag Mdeling Subcmmittee (AMS) will als need t have sme discussins with them. This 68

69 recmmendatin came frm the AMS, and it was recgnized that Ag sales data have prblems, but currently there isn t anything better. The panel will have t lk clsely at the Beta mdel runs in January and see whether it s wrking. Partnership Outreach Mark Dubin explained that the panel has an pen invitatin t meet with state nutrient management prgram representatives in rder t brief them n the panel recmmendatins and field any questins r cncerns. Mark, Frank, and Lindsey will rganize a meeting smetime in early Chris Brsch supprted this idea. He explained that prgram managers may be reluctant t adpt the panel recmmendatins, and this discussin shuld be started early n t imprve cmmunicatin. Frank clarified that this wuld nly ccur nce the panel has smething prductive t present (i.e. in a few mnths). State Nutrient Management Prgram/Panel Meeting: The WQGIT will be reviewing the Phase Nutrient Management Task Frce reprt during their December meeting. Mark Dubin explained the Task Frce will be circling back t the states t ask fr better dcumentatin n their cmpliance prgrams. If this infrmatin is unavailable, the EPA will be referencing ther reprts t gather their infrmatin. Partnership Webinars: Frank Cale will be cnducting sme webinars summarizing the panel and the prcess fr future activities and recmmendatins. If panel members wuld like t participate with Frank, they shuld send him an . Phase Nutrient Management Task Frce Reprt Mark Dubin briefed the panel n the Phase Nutrient Management Task Frce reprt. Tm Fisher: I saw a reprt frm MDA n cmpliance, and it lked like there were many places where there was nt very gd cmpliance. I gt the impressin that they were sugarcating the results, making it lk like there was significant cmpliance, when in reality ½-1/3 f the farms did nt cmply with at least ne f the questins they were asking. What is yur impressin f this? Was that generally true? Mark Dubin replied that there are many factrs that can result in a nncmpliance, but stated that the results may be slightly biased. Overall, it s a gd reprt, but yu will see a lt f variatin amng the states in their cmpliance rates. Next Steps The panel shuld be cmpleting their assignments by December 20 th, sent t Lindsey Grdn (Grdn.lindsey@epa.gv) and Mark Dubin (mdubin@chesapeakebay.net). Assignment 1: Each panel member will g thrugh the land use matrix and cntinue ppulating all f the cells as t whether fr each specific land use, N r P applies t the BMPs listed. Each panel member will additinally g thrugh each clumn f land uses, and priritize the BMPs that impact either N and/r P in that clumn as t which BMPs are the mst imprtant. Frmat shuld fllw N1, N2, N3 r P1, P2, P3, where N1 represents the mst imprtant BMP, fllwing rder f decreasing imprtance. Panel shuld priritize all f the BMPs fr each land use, where rankings are acrss bth Phase and Phase 6 BMPs. Frank specified that if panel members think certain BMPs shuld be handled by ther BMP panels, t leave the cell blank. Frank will then summarize all f the panel members submissins int ne spreadsheet. Assignment 2: Panel members shuld begin cmpiling a list f cnflicts in current recmmendatins. (Ex: allwing a plan if farmers dn t agree t use a P based applicatin f manure then they dn t have t use a sil test.) Jack asked a questin abut priritizing BMPs by regin (ex: NY is the nly state t use ISNT, but des that mean it des nt merit imprtance in the panel recmmendatins?) 69

70 Frank respnded that the BMPs can be priritized reginally, but it is smething that will have t be discussed further. Additinally, panel members shuld fcus n their lcal regins t the best f their ability. Jack nted that the linkages in the BMP matrix shuld be cmmunicated t ther panels as sn as pssible in rder t clarify the rle and jbs f the Nutrient Management Panel. Mark Dubin explained that Frank, Mark, and Ken Staver (chair f Cver Crps Panel) met t clarify the issue f cmmdity crps. Frank further nted that the Cver Crps Panel will fcus n cver crps as they re intended t functin t cnserve residual sil N levels. The Nutrient Management Panel will adpt any respnsibilities that specifically relate t the charge and scpe. Tm Fisher asked whether the CCP panel was cnsidering the flying f cver crps n sybeans. Mark explained that aerial seeding has been included fr a number f years, and they did add a lnger list f available cver crps (radishes, triticale, legumes, etc.). The Phase 6 panel will be mre fcused n cmmdity cver crps, as well as summer fallw cver crps. Jack als nted his cncern with using fertilizer sales data, and that if it will cme dwn t a cunty level estimate, that in the future the panel shuld ask whether there are specific cunties in the states that the panel feels cmfrtable estimating the actual rates at the field level. Participants: Frank Cale Lindsey Grdn Dug Beegle Tm Fisher Deanna Osmnd Steve Dressing Mark Dubin Jack Meisinger Chris Brsch Quirine Ketterings UMD CRC Penn State UMCES NC State Tetra Tech CBP USDA ARS DE Dept. f Ag/VT Crnell 2/2/2016 Actin Items: Actin: Mark and Frank will take the ranked list f 27 BMPs, and grup the BMPs int ~9 succinct categries. They will present this back t the panel at the next cnference call. Actin: Frank is asking fr vlunteers t begin tackling a few grups t determine a starting assessment f what an efficiency % wuld lk like. Actin: Mark, Frank, and Lindsey will begin develping a schedule f calls fr the panel mving frward. Frank Cale reviewed the prpsed mdeling structure f Nutrient Management that was drafted by the panel. The panel still needs t define a nn-nutrient management acre, and determine a negative efficiency value t assciate with that. Frank als reviewed the priritizatin matrix results f nutrient management BMPs. Tm Fisher: What is the assumed lss assciated with a neutral acre? Jack Meisinger: I wrked n a panel that was estimating relative N lsses fr each Phase 6 land use. Hw that relative number gets translated t a lad is still being wrked n by the mdeling team at the CBP. Frank Cale: We re lking at this whle prcess as a % efficiency relative t a baseline. These cre practices assume a 0-case scenari. Mark Dubin: The values vary between LRSEG acrss the watershed, s it wn t be a set number and will fluctuate based n calculated lading rates frm water quality mnitring. 70

71 Jack Meisinger: Sme f these tp ranked BMPs seem very similar culd we cmbine sme f them? That wuld allw the panel t lk at sme f the ther BMPs t mve int the tp 10 ranking. Frank: Abslutely we can cmbine sme f them int jint management practices. Chris Brsch: Hw much did we take int accunt the lad f effrt that the panel wuld save in this list? If we re talking abut cutting things ff, then it might be useful t cnsider that several f these BMPs were aggregated and taken care f by the panel wrk. Frank: In the tp 10, 6 f them were partially defined in the panel, and 4 f them are brand new. Chris: Only because yield mapping and variable rate N might nt get pririty frm ur panel, but fr use mving frward, sme f these BMPs ught nt t get cut ut. If we have cnfidence in the reprt recmmendatins, I wuld cut ff everything belw ranking 18. Tm Fisher: We use FSNT t shw them what s left ver in their field after they ve grwn crn r sybeans, and they actually seem t be using that infrmatin t adjust hw much fertilizer they re applying next year. We re just getting sme data n that nw, but they recgnize that if there s a high nitrate in the sil in Octber, that they have t much N, and will adjust their fertilizer applicatin accrdingly. Jack Meisinger: I think sme f these tests are a bit reginal the ISNT wuld be high in New Yrk, the FSNT wuld be high in MD and VA, s these rankings might flex acrss the regins smewhat. I dn t knw hw we wuld deal with it, but it s gd t be aware f it. Frank: Agreed and I think it s imprtant that the list be lnger rather than shrter. Quirine Ketterings: Can we grup them int categries fr enhanced sil management r smething similar? That wuld allw states t pick which ne is mst relevant. Mark Dubin: Wuld there be a value t identify the rankings by state? Frank: If anyne has a few that they think are highly imprtant that came up shrt n priritizatin, then we can revisit that. Quirine suggested a categry fr spatial field variability management ge-spatial mapping, etc. Jack identified the imprtant f whle farm P balances. Quirine agreed that whle farm balances sit apart frm the rest f the BMPs, and suggested they shuld perhaps be treated separately. Frank nted that the panel will have t determine numerical values t represent lsses, and that it might be difficult t cme up with a specific number fr the mre unique BMPs. Mark Dubin nted that it wuld make sense if relative efficiency values were similar if the panel agrees t grup sme f the BMPs tgether. Jack suggested that Frank and ther panel members cmplete sme draft grupings f the BMPs, and then the panel wuld review what grupings the Phase panel culd give preliminary estimates n. Frank suggested the panel culd take each f the BMPs as they are ranked, and decide which nes the panel currently wants t address. Then, within that cllectin, the panel wuld grup similar BMPs tgether. Each gruping wuld have a single efficiency value, and then states wuld decide which BMPs are cunted within that gruping. Then the panel wuld g back t each gruping t identify relative efficiencies. Tm asked if there was enugh literature fr the panel t d all f the BMPs, r if the panel will have t use its best prfessinal judgement t determine values. Mark expressed cncern abut cutting ff the ranking at rank 18 based n the imprtance f reginality fr sme BMPs. Dug Beegle suggested that instead f having many different types f N and P lss risk assessments, t grup them tgether and have ne single multiplier t all f them. Mark Dubin 71

72 and Jack Meisinger supprted this suggestin. Matt Jhnstn reminded the grup that the Ag Mdeling Subcmmittee reviewed utputs frm the newest versin f the mdel, and Frank nted that the panel is nt lking at rate very much. Frank: Sme f these d mdify rate, but the verall grss determinatin f rate is part f the cre determinatin f practices. Jack nted that the panel shuld cnsider their timeline mving frward, making sure t be aware f the mdeler s needs. Frank suggested that the panel shuld begin cmpiling efficiency values based n their persnal expertise. Deanna made nte that the panel shuld be aware that the practices listed are mre plans, and may nt result in any change t the farm-level nutrient management. Frank replied that the panel shuld specify that based n the results f the tls, that the farmer wuld implement any recmmended changes. Jack Meisinger nted that Phase 6 will be requiring mre stringent verificatin than Phase 5, and asked if the panel wuld have t make verificatin suggestins. Mark replied that the panels are expected t address verificatin n the recmmendatins they are making. Matt Jhnstn: The mdelers wrry that the new frmat may run int a situatin where a negative/psitive efficiency wuld duble cunt the nutrient lads/reductins. Frank: The basic assumptin when yu achieve thse cre practices is a mre apprpriate rate. Jack: Matt is talking abut trying t make cunty-level estimates n fertilizers and manures, which the mdel will be better able t d, but it may nt be able enugh t supersede what a nutrient management apprach wuld d. S I think that decisin is still up in the air. Matt: We re pretty far dwn the line with the bucket apprach, but everything s still up in the air fr Phase 6. But I want t nte that because we re tracking changes in fertilizer use, we think the mdel will accunt fr applicatin rate. But we feel that ding anything +/- efficiency fr rate wuld be duble cunting. Chris Brsch: It s wrth nting that while that apprach was agreed upn, we knw nw that agriculture fertilizer sales data is as much as 40% t high, at least in DE. I think that s the impetus fr us nt being cnfident in ur prir decisin. Jack: And remember that the 4 Rs are nt independent, and there are interactins. Deanna: Quite a number f these items are assciated with rate, s as we g thrugh this next exercise, culd yu clarify if we cnsider rate? Frank: If yu think abut where we re mst cncerned in the real wrld, it s manure driven. Our mst imprtant thing in a NM plan is manure rate, and then in the mdel we distribute manure where there s t much, and where there s nt enugh we backfill with fertilizer. S if the number 1 benefit f a NM plan is t get manure management crrect, if we can t adjust the rate fr peple that aren t at the cre practice threshld, then I find that hard t swallw. Matt: The impact f thse NM plans n manure rate shuld be reflected in manure transprt data r fertilizer sales. It shuld be different practices. The plan itself isn t the practice, it s everything the plan creates/incentivizes. Jack suggested inviting the mdelers nt the next cnference call t cnfirm that the panel recmmendatins are cmpatible with the mdeling infrastructure. Chris nted that the applicatin rate is a mving baseline fr the newest versin f the mdel. 72

73 Participants: Lindsey Grdn Frank Cale Chris Brsch Dug Beegle Deanna Osmnd Jack Meisinger Tm Fisher Quirine Ketterings Mark Dubin Matt Jhnstn CRC UMD DDA Penn State Nrth Carlina State University USDA UMCES Crnell UMD UMD 2/24/2016 Actins & Decisins: DECISION: The NMP and the AMS need t crdinate and reslve the issue f using fertilizer sales data as well as the baseline cnditins. A subset f the NMP will attend the next meeting f the AMS: Frank Cale, Jack Meisinger, Mark Dubin, and Chris Brsch. DECISION: The NMP agreed t mve frward with the revised cnceptual NMP structure prpsed by Frank. A few panel members nted that it may require sme tweaking mving frward. Review f Prpsed NM Structure Frank briefly reviewed the prpsed NM apprach previusly defined by the panel, and supprting materials. Jack Meisinger: The field buffer that s ging t the frest buffer panel that des nt include setbacks? Cale: That wuld be a nn-crp vegetated buffer. Review f New Prpsed NM Structure Frank intrduced and reviewed a new cnceptual NM structure based n previus input frm the panel and discussins with individual members. Meisinger: Yu re suggesting setting aside the negative efficiency apprach Cale: That s right and this is just a cncept fr us t discuss tday. We re ging t create a cre grup f BMPs that wuld have an efficiency we apply t a baseline f sme srt. Fisher: I can see the value, but I lk at this grup and there s variability assciated with each f the cre BMPs, and assigning ne number t represent thse as a grup may be difficult. Dug Beegle: I think there is a value t ding these assessments that may nt be captured in the specific practices. I wuld argue fr a small efficiency just fr ging thrugh the prcess f ding the assessment, because I think that farmers d a better jb f managing just frm ging thrugh that prcess, and it may be hard t capture all that he did. Cale: I tend t agree with that cncept. If we d decide t d this, it wuld have t be a pretty small efficiency value. Beegle: I agree, and it might even have t be at least sme kind f frmalized prcess. Quirine Ketterings: Is this really 3 years fr the manure analysis? Fr us, it s required t have them every year, s 1 year ld at mst with sil testing every 3 years. Mark suggested revising s that manure analyses can be 1-3 years ld. Dug made a pint that a farmer culd d mre than ne BMP within a brader categry, and nly get credit fr that ne entire categry. 73

74 Cale: The idea is that yu get credit per categry, and nt fr each individual practice. Beegle: I m playing devil s advcate here, s I wuld just pick the easiest BMP ut f all f them and this might discurage sme farmers frm ding mre beneficial practices. Brsch: It s ften true that even thugh a farmer desn t have a cdified plan, they are still practicing all f the cre BMPs. Is there a scenari where a farmer culd get credit fr the cre and variable rate applicatins withut a dcumented plan? Cale: Yu re ging t have t cllect this data smehw, and I, as an academic, culdn t care less whether it s a plan. Hwever a state can cver the fact that this is being dne withut plans, then that wuld be fine. Brsch: I think it wuld g a lng way fr a state that desn t have that requirement in their law, t have that ptin. Meisinger: Wuldn t verificatin require checking ff thse cre practices? Cale: Abslutely, but it desn t necessarily have t be in a state-sanctined NM plan. It culd be thrugh a service prvider, which supplies the dcumentatin. Meisinger: S maybe states culd have sme flexibility as t hw they define a plan. Fisher: These hierarchical schemes make sense, but I m wndering if we have enugh empirical evidence t assign an efficiency t this large number f BMPs. Cale: Sme f these elements will have better data than thers. Beegle: There s a lt f details here that give me heartburn. One that s unique t PA but is a reality is that in the cre, yu require P sil tests, which I ttally agree with but we have an ptin in PA t try and get peple t at least d a plan. If they dn t have a sil test, we assume they re high and they have t g t a P-based manure rate, which is ne f ur advanced BMPs. S in place f the sil test, they adpt an advanced BMP. Cale: We culd include that as an asterisk the either/r plicy. Dubin: We culd treat it like an equivalency. Phase 6.0 Mdeling Frank mderated a discussin between the panel members and the CBPO mdeling team representatives regarding the current and future directins fr the develpment f the Phase 6.0 mdeling tls, and their influence n the representatin f NM. Shenk: Cmmented that the cnceptual apprach being cnsidered by the panel included the adjustment f nutrient applicatin rates, which is currently being represented in the SB Phase 6.0 mdeling tls by recmmendatin and apprval f the AMS and the partnership. Representing a change in rate wuld seem t duble cunt fr this factr, but timing culd be a separate management functin fr cnsideratin. Dubin: Nted that nt all f the panel members may be aware f what "AMS" stands fr and that an explanatin may be helpful. Shenk: Agreed, and prvided a brief descriptin f the Agricultural Mdeling Subcmmittee (AMS) as a subgrup under the Agriculture Wrkgrup (AgWG) fr prviding mdeling recmmendatins pertinent t agricultural land uses and functins. Meisinger: The fertilizer sales data are still under cnsideratin. They aren t apprved quite yet. Yu re right in saying that we ve gt a pint f ptential duble cunting, but the die is nt cast fr using the sales data. Shenk: I think we re in agreement. It s duble cunting; the die is cast but there s sme discussin f it being un-cast. Beegle: The manure rate is determined by the amunt f manure that s prduced, and then spread evenly? Shenk: The ttal amunt f manure in a cunty = ttal amunt prduced lsses fr strage and handling. It s spread accrding t an algrithm that the AMS develped. Yu wuld spread first t the mst imprtant crps, and then it ges t the less imprtant crps. If yu 74

75 have t much, it wuld g n pasture. Fr fertilizer, there s a ttal amunt f fertilizer available in a cunty, and then it s spread thrugh a similar prcess relative t hw much remaining crp need there is after the manure is placed. Jhnstn: There s 3 big things in the manure and fertilizer spread. 1) There s a number fr each cunty ttal punds f N and P. 2) Yu re priritizing applicatin t the highest cmmdity crps. 3) The actual rates yu re trying t hit with the buckets actually d change thrugh time. Meisinger: S yu re saying that the sliding NM plan, there s n baseline and s I dn t knw hw t cme up with a reductin efficiency if there s n baseline. Shenk: The rate is already taken int accunt, s there wuldn t be a reductin efficiency fr rate unless that was changed. But yu culd still d timing. Beegle: We re saying a farmer is wrking ut the apprpriate rate n a given field, as ppsed t blanket rates based n crp type. That itself may nt be captured in the mdel, but it shuld be an efficiency ver this generic distributin. Like a rate adjustment. Jhnstn: Wuld that adjustment result in a water quality change n 2 fields cmbined? Beegle: It wuld. Even thugh the same ttal amunt is being spread, this is where the advanced management BMP n rate wuld cme int play. Shenk: I think we re saying that rate cunts, it s just already cunted in the way that the AMS has set up the inputs. Jhnstn: I agree with Dug, and saw that as abve and beynd the cre practices. I think all f the enhanced practices are legitimate in that type f a mdel. Cale: S we culd mdify r adjust the credit we re giving fr rate thrugh an efficiency that s tied t a measurable practice n the field level. Jhnstn: I think s, if we stick with the way it s currently built. Shenk: When we re talking abut planning, and mving frward, then NM int the future wuld still be a reductin because we re talking abut adjusting the amunt f fertilizer frm what we have at this mment. That wuld still cunt, and when states are develping WIPs, yu wuld still need a reductin assciated with NM int the future. But nce the fertilizer sales data cme in, then we have ur facts n the grund fr what actually happened relative t what was planned. Meisinger: But ur reductin efficiencies wuld be based n a mving baseline, and wrking with actually estimating reductin efficiencies using the ld N BMP 1980 s baseline, tk the panel a lng time t get thse wrked ut. If we have t d thse fr a mving baseline, I dn t knw if we culd d it it s just a lt f wrk. Fisher: What if we used N-use efficiency? All yu wuld need is N cntent, and then yu d be able t estimate the N-use efficiency. The nly ther thing yu need besides applicatin is the sil mineralizatin rate. Jhnstn: Thse mechanisms are in the current versin f the mdel. Brsch: The use efficiency is a separate cncept frm a NM plan, because it s cmpletely dependent n weather. And the NM plan is setting gals that are based n reasnable expectatins f gd weather. Fisher: But that might help the mdel explain differences year t year. Cale: There s sme cnsternatin abut using fertilizer sales data at all. I knw there s a lt f cncern abut its usability, and the scientist in me is just nt cmfrtable with using that as the determining factr fr what ur applicatin base rate is. Shenk: That s smething nt necessarily aimed at us. The histry f fertilizer sales at the CBP is always in mtin, and fr every mdel develpment, we ve always used smething ther than fertilizer sales. It s smething that shuld be taken up by the AMS. Matt and I are nt making this decisin, but we just need a partnership apprved prcess. Meisinger: The AMS has nly apprved cnsidering fertilizer sales data, and nt the use f them quite yet. One prblem is that NM is field-scale, and we re trying t take cunty-scale 75

76 rates and adjust them dwn. Brsch: We have much mre recent data suggesting that, at least in DE, the numbers are 40% ff. And Gary s pint abut nt being able t capture changing P-inputs, I think, is a factr f nt having a P-based nutrient applicatin schedule. NM Panel Technical Assistance Mark and Steve discussed the increased level f technical assistance that is being made available t the panel and related supprting materials. Steve presented a draft f the literature review spreadsheet t the panel. The panel agreed t defer their review f the spreadsheet until the panel representatives and the AMS have reslved issues relating t fertilizer sales data and baseline cnditins. Participants: Frank Cale Lindsey Grdn Mark Dubin Quirine Ketterings Steve Dressing Tm Fisher Dug Beegle Gary Shenk Matt Jhnstn Jack Meisinger Chris Brsch UMD CRC UMD Crnell Tetra Tech UMCES Penn State USGS UMD USDA DDA 3/31/2016 Actins & Decisins: DECISION: The panel came t unanimus cnsensus n fllwing the apprach t representing nutrient management laid ut in the Straw Man #3, where P and N credit will each cntain cre BMP practices that can supplemented with BMPs that wuld affect the rate, timing, and placement f BMPs. The next step f the panel is t determine the efficiency values that wuld apply t each f the practice categries. DECISION: The panel agreed t mve frward with the fur-step prcess utline by Frank n determining ttal N applicatin (spread). DECISION: The panel agreed t mve frward with explring hw the CEAP 1 Reprt fr the Bay Watershed calculated a fertilizer sales cap, and whether it aligns with what the panel has utlined in ptin 4 (f Straw Man #3) fr determining ttal N applicatin. Panel will discuss using a cmbinatin f nutrient management implementatin and fertilizer sales data that parallels the CEAP methdlgy during their next meeting. ACTION: Mark will wrk with Lee Nrfleet frm USDA t gather infrmatin n the methdlgy fr using fertilizer sales used by CEAP and will present it t the panel during their next call. ACTION: Panel shuld review the white paper that has been drafted, and prvide cmments and feedback in advance f the AgWG s mnthly meeting n April 21 st. Review f New Prpsed NM Structure Frank intrduced and reviewed a new cnceptual NM structure (Straw Man #3) based n previus input frm the panel and discussins with individual members. Meisinger: D yu want t assign all f thse P-placement tls t ne f thse slts? Is that the wrk 76

77 t be dne? Cale: The tls I envisin as a nn-limited list that we culd add assessment tls t ver time, as lng as we thse tls t drive change in implementatin. The key is that what tls did I d, and what did it result in? Like, what wuld happen if I did a P-index assessment? Ptentially nthing wuld change. But if the assessment changed the rate, then yu culd get the rate credit, etc. Frank asked the panel t cme t cnsensus n the lgic f rganizing N and P int cre practices with supplemental efficiencies n rate, placement, and timing. Frank discussed ptins fr incrprating and representing N applicatin/spread in the Phase 6 mdel. Fisher: Fr manure, is the assumptin that if manure is generated in a cunty that it s assumed t stay within a cunty? Cale: We re nt getting int that part, but it s based n recrds f whether it s transprted acrss cunty lines. But that s beynd what we ve been charged with at this pint. Beegle: Is there ne plant available N fr the whle cunty? Hw des that wrk? Jhnstn: After yu ve cunted the animals, each animal type prduces a different amunt f N and P in their manure. Yu apply sme BMPs, and in the end yu get a cunty bucket f ttal punds f N and P manure. Yu apply sme mineralizatin factrs, take ff vlatilized ammnia, and yu re result is a big pile f plant available N and P in each cunty. That s distributed t the crps based n the applicatin gals. But just because yu have an applicatin gal desn t mean yu always meet it if there s nt always enugh manure in a cunty. Beegle: Yu said yu subtract ff the ammnia and add in mineralizatin. Is that smehw ne average fr the whle cunty, r is there a breakdwn? Jhnstn: Everything s brken dwn t individual nutrient species at the animal type level. Beegle: All dairy cws in the cunty have ne assumed vlatilizatin lss then, right? Jhnstn: The baseline assumptin is everything is the same until we get BMP data that tells us therwise. Brsch: The plant available N t P rati fr a cunty is lcked in based n the mix f animal types, right? They re nt really separate piles at the manure stage. Jhnstn: Crrect. Frank reviewed the steps t and 4 different ptins fr calculating fertilizer N applicatin gal limit per cunty. Meisinger: Fertilizer sales separates N and P, and I see yu ve als dne that here. Jhnstn: True. In ptin 2, there are actually 2 factrs that g int redistributing thse fertilizer sales. One is basically ptin 1 the fractin f fertilizer gal fr the cunty. The secnd factr is Ag census dllars spent n fertilizer and sil amendments. And s that s a hybrid apprach ptin 2 is already a hybrid, where yu re already cnsidering N and P applicatin gals, but yu re als bringing in dllars spent which are nt specific t N and P. Cale: Hw are thse 2 subsets balanced? Jhnstn: They re multiplied by 50%. Fisher: I m nt sure hw yu wuld translate 1 lb. N/bushel int an N-use efficiency. I m wndering if ur lb. N/bushel shuld be mre f a rate. Cale: Applicatin rates that are belw the recmmended rate wuld be given a credit in ur N supplemental credits. S we ll capture it there. Jhnstn: It s als currently captured when yu cap things at the fertilizer sales level, yu dn t hit 1.0 lb. N/bushel/acre n every acre f crn acrss the watershed. Meisinger: Are lime sales included? 77

78 Jhnstn: Punds are nt included, but dllars spent includes thse spent n lime. Cale: Optin 1 sets fertilizer sales limit t be parallel t what we determine fr NM applicatin + nn-nm applicatin. Beegle: But isn t that limiting yu t step 3? The fertilizer N applicatin gal in Optin 1 is that nt the answer we gt in step 3? Cale: It is, but it d be the rati f that cunty t the whle watershed. Beegle: But the limit fr that cunty is the gal, i.e. step 3. Brsch: Is it fair t cnsider gal limit as fertilizer N applied? Cale: Yes they are synnymus. Jhnstn: It s really fertilizer N supplied that WILL get applied in the mdel in the cunty. Beegle: S if we use Optin 1 that s what the mdel wuld apply t that cunty? Jhnstn: Crrect. The AMS had lked at Phase 5, and it s built n ptin 1, and they fund there was 30-50% mre N the mdel thught shuld be ging dwn when cmpared t fertilizer sales data. That s what led us int ptin 2. Jhnstn: Optin 3 culd be rewritten as fert N applicatin gal / dllars spent. Beegle: If yu have cnfidence in the N sales value, why dn t yu use that number? That plus N fixatin culd be N delivery. Cale: It s a very nisy data pl, especially when yu break it dwn t the cunty level. Fisher: It wuld be helpful t see hw big f an impact that wuld have based n CEAP. Dubin: CEAP is using the natinal resurce inventry pints acrss the watershed. They re ding surveys n thse pints, and they d an interview with the wner/peratr n the mgmt. activities that happened n the past 3 years. They lk at applicatin, timing, placement, tillage, crpping systems, everything. It s dne with NASS survey persnnel. They have their wn database lking at the exact nutrient applicatins n the exact crps, etc. That survey data s used in a cmparisn against ERS reprts, and they lk at fertilizers sales. They cmpare the three pints, and they want the NRI reprt t be smewhere in the middle f the fertilizer sales and the NRI reprt. Jhnstn: At what level des CEAP lk at fertilizer sales as a cap? In ptin 4, we re lking at a cunty level, which is pretty fine-scale. What des CEAP d? Dubin: They re wrking n a HUC4 scale, because that s what they use fr NRI and ARM, and fertilizer. They re distributing fert sales within a basin level, and using that distributin infrmatin t d the cmparisn t the NRI pints. Jhnstn: The AMS lked at cmparing ptin 1 with fert sales at a basin level, and the cmparisn was pretty pr. And it s pr nw because we dn t have access t all that data. Osmnd: We struggle with this same issue, because we knw fert sales data by cunty isn t indicative f much. I dn t knw hw yu think thrugh these strategies, but smetimes we have kept strategies that ther peple have used, like ptin 4, because at least there s a basis fr using that strategy there. Beegle: If the NRI data fits in with this, then that wuld give me a lt mre cnfidence. Osmnd: Culd we ask Lee Nrfleet t cme and talk abut the CEAP reprts at anther meeting? Dubin: Mst definitely. Lee said he wuld welcme the pprtunity. Cale: S CEAP has published a cncept that is very similar t what we re representing in ptin 4? Dubin: It s in the CEAP 1 Reprt fr the Ches. Bay Watershed. Jhnstn: The Mdeling Team can definitely prvide results fr ptin 4. But because f everything we ve lked at in the past, I think it ll shw similar results and shw us that we need t imprve ur estimates f LGU recmmendatins that are ging int the mdel. But it may nt result in much difference. S dn t expect 78

79 ptin 4 t lk much different frm what s currently in there. Yu ll get very different answers between ptins 1 and 2. But ptin 4 says if crp need is higher than fert sales, take fert sales. But in almst all cases, crp need is higher than fert sales, s yu end up using fert sales everywhere almst. Meisinger: Step #3: The N applicatin gal per cunty. Why d we g t the whle watershed basis? It s a cmbinatin f NM with a LGU recmmendatin basis. Cale: We re just taking the land uses and taking them t create a cmbined weighted average per cunty. It was dne because all f the ther decisins are abut cunty level based. Jhnstn: Phase 6 recmmendatins fr every crp are based n states lking at LGU recmmendatins fr every crp. It s just missing the NM and nn-nm acres this grup is suggesting the AMS tie-in. Cale: After this, we need t determine NM implementatin rates ging back t Frm here frward, it s ging t be incumbent upn the states t reprt their verified implementatin rates. Meisinger: But I dn t see why we wuldn t use LGU recmmendatins as the size f the bucket. Jhnstn: We d use thse. If yu were back-filling step 1, yu nly need t knw the cunty crp need that s nt met with manure. But if yu re trying t redistribute a watershed-wide bucket f fertilizer, yu need t knw the fractin f need. S it s needed in sme places, and nt thers. NM Panel White Paper Mark Dubin prvided an verview f the request fr all AgWG panels t develp and draft a brief white paper that utlines the structure f the BMP, applicable land uses, and BMP definitin in rder t begin incrprating elements f the BMP int Scenari Builder and facilitate state histric reprting. The AgWG will be reviewing the white papers during their April 2016 meeting, and the panel will be asked t review the draft and prvide edits. Panel's Next Steps Panel will review and present white paper t AgWG. Panel will begin cnsidering efficiency values. Participants: Frank Cale Lindsey Grdn Mark Dubin Quirine Ketterings Steve Dressing Tm Fisher Dug Beegle Matt Jhnstn Jack Meisinger Chris Brsch Deanna Osmnd UMD CRC UMD Crnell Tetra Tech UMCES Penn State UMD USDA DDA NC State University 79

80 4/14/2016 Actins & Decisins: DECISION: Panel came t cnsensus n mving frward with the methdlgy laid ut in Optin 4 f Straw Man #3, where fertilizer sales data will be used as a cap t the calculated nutrient lads. ACTION: The panel is asked t review the drafted versin f their preliminary reprt that will be presented t the Agriculture Wrkgrup during their April face-t-face meeting n Thursday, 4/21. Please prvide fatal flaw cmments back t Mark Dubin and Lindsey Grdn by n later than COB Tuesday April 19 th. DECISION: The NMP agreed t set a 1985 baseline in their recmmendatins, t be included in their preliminary reprt. ACTION: Mark and Lindsey will incrprate panel s suggested edits t the preliminary reprt, and redistribute fr final review befre it is presented t the Agriculture Wrkgrup during their April meeting. ACTION: Frank will crrespnd with panel members in the cming weeks t begin assigning leads n develping efficiency values fr the NM BMPs. Panel members shuld cnsider their expertise in helping t determine these efficiencies. Discussin f CEAP nutrient spread methdlgy Frank prvided a brief verview f the Straw Man #3 prpsal that the NMP is cnsidering t use fr their BMP representatin. Lee Nrfleet, USDA, discussed the methdlgy used by the USDA NRCS CEAP reprts t calculate and represent nutrient spread. This facilitated discussin between the Agricultural Mdeling Subcmmittee (AMS) and the panel n representing nutrient spread in the Phase 6 mdel. Ptential appraches will be presented t the Agriculture Wrkgrup during their April face-t-face meeting, with a fllw-up presentatin during the May meeting. Lee discussed verall methdlgy fr gathering data and cnducting CEAP reprts. Results are reprted at the HUC4 level. Cale: Yur cmment abut fertilizer sales data yu use that as a maximum value? Nrfleet: Right. And we knw we shuldn t g abve that amunt because sme f that fertilizer is ging n ther land uses besides cultivated crp land. Dubin: Yu just released a reprt fr Lake Eerie, which uses a mre advanced prcess. Did that reprt include pasture and hayland as well? Nrfleet: It desn t. The Califrnia Bay Delta survey tried t use that methd, but we ve run int a few issues with defining pasture land. Nrfleet: We use a prcess mdel t generate ur yields and effects. Jhnstn: It sunds like yu lk at the survey results fr estimated rates f applicatin f N and P, and then yu extraplate that ut t all the acres f cultivated crp land in a HUC4, and then yu cmpare that number f N lbs. ging dwn n cultivated crp land t ttal fertilizer sales fr farm use in that watershed. S mst f the time, yu re under that value because yu aren t capturing pasture and hay in that equatin. Nrfleet: Right. And I shuld reinfrce that it s a rugh check and we just use it t ensure that we re belw the sales number. And we expand ur results ne survey result gets expanded t represent 5,000 acres. Dubin: Will yu be lking at this fr the CEAP III, including the surveys fr pasture and permanent hay land? If they re included in yur values, hw clse d yu think yu wuld cme t the fertilizer sales data set? Nrfleet: I m nt sure at this mment. 80

81 Jhnstn: I ve lked at it, and yu d cme very clse t the fertilizer sales data when yu sum up everything. But what years are represented in this chart? IE what dates f fertilizer sales shuld I cmpare this t? Nrfleet: The table may have bth survey perids, but the 2011 survey ges back 3 years. S an average fr Fr the CEAP 1 survey, yu wuld cmpare it against the average fr Meisinger: The table rughly lists that if the cultivated crpland = 1, then the sum f pasture and hayland als = 1. S, rughly, the tnnage f fertilizer is getting split almst evenly between crpland, and hayland/pasture. Dubin: In rder t use fertilizer sales reprted at a cunty scale, yu have t break thse ut where cunties split between watersheds. What s the prcess yu use t create a fertilizer sales value fr a watershed like the Ptmac? Nrfleet: We dn t g with the cunty level at all. We have sme estimates frm the 90 s, and thers frm the surveys. But all f ur wrk is at the watershed scale. We d the same thing with ur yields, and uptake is derived frm thse yields. Jhnstn: A quick lk at fertilizer sales data acrss the watershed that we have, shws that we are <1% ff frm what s reprted in the CEAP table. Nrfleet: But that s the grss amunt, and each acre will behave differently with yield and lss ptentials. Beegle: Questin n the size f the areas this is applied t it s at a HUC4, which is an entire watershed. S it s distributed unifrmly, regardless f where it is in the watershed? Nrfleet: That s the scale that we reprt at, but we mdel at the in-stream at the HUC8. Osmnd: When yu lk at N lsses, yu used the wrd runff. Are thse runff and leaching, r just runff? Nrfleet: I have run-ff ptential, and then the runff treatment level. The ttal that yu see is the tw cmbined. Nrfleet: I ve learned mst that yu have t take int accunt the differences in the sils and the crps being prduced. At sme pint, the marriage between ur sils layer and the NASS crp data layer will imprve yur estimates greatly, because it ll shift a lt. Meisinger: Knwing the Bay mdel has n sils data, hw wuld we capture that? Right nw, the panel is capturing it thrugh the LGU recmmendatins. What are yur thughts n that apprach? Nrfleet: At sme level, yu need t accunt fr different sil types, s if yu use LGU recmmendatins, they re ften parsed by sil type. Jhnstn: Sils are nt explicitly in any f the calculatins, but the LGU recmmendatins are yieldbased, and we use NASS yearly yields fr the majr crps, which differ dramatically acrss the watershed. Any cmments n that as a prxy? Nrfleet: Yu have the crp yield, but yu dn t have hw thse different sils may have different lss characteristics. Jhnstn: Inputs are based n yields, and we have a sil characteristic parameter when calculating runff, and that cmes frm SPARROW analysis frm USGS. Dubin: Other than starting t incrprate NRI survey data, is there anything else that yu fresee yu wanting t d differently if yu culd start frm scratch? Nrfleet: If we started ver, we wuld address cmplexities at the field scale, and tailr ur management t that scale. Panel Discussin f nutrient spread The Nutrient Management Panel discussed and deliberated n an apprach t represent nutrient spread in the Phase 6 mdeling tls. Cale: S CEAP uses the NRI survey data t determine their rate, and they check it against fertilizer sales data fr the regin just t make sure their calculated applicatin rate desn t exceed the fertilizer 81

82 sales data. That s very similar t what we prpsed in ptin 4 f Straw Man #3, where we use ur NM versus ur nn-nm acres and the assumed applicatin rate fr each land use, add thse ttal rates up fr NM and nn-nm acres, and if that s less than the fertilizer sales ttal fr that cunty, then we mve frward. If it was mre, then we wuld use the fertilizer sales as a cap fr that cunty. Panel agreed with Frank s thughts n CEAP methdlgy versus prpsed panel methdlgy. Frank nted that this decisin will be presented t the Agriculture Wrkgrup during their mnthly meeting n April 21 st. The panel next needs t cnsider determining efficiency values fr Nitrgen and Phsphrus practices. Request t review NMP Preliminary Reprt Mark reviewed the drafted preliminary reprt that will be presented t the Agriculture Wrkgrup during their mnthly meeting n Thursday, April 21 st. Meisinger: When we start t d reductin efficiencies, it s imprtant we have a baseline stated. Withut that, we can t get efficiencies r reductins. S we need t state that we re using a 1985 baseline smewhere in the reprt, if the panel is agreeable t that prpsal. Fisher: Is the assumptin here that the 1985 data represents what wuld happen nw if there were n cnservatin practices? Dubin: Pre-1985 is cnsidered as a n-bmp scenari, s that s ur baseline. Anything that happens after that is cnsidered as an additin t implementatin and reductins. Fisher: But mst farmers wuld argue that their fertilizer rates and yields have increased in the last few years. Cale: That s built int why we have a baseline that s s far back in time. We want t assume that s when things were at their minimum as far as BMP implementatin is cncerned. Fisher: In the mdel, if yu had farmland with n cnservatin practices, then it wuld lk like 1985 N lsses, is that crrect? Dubin: Yes there s pre-bmp implementatin, and we wuld represent that with 1985 cunty level prductin numbers fr crpping systems as well. We start ff using the 1982 Ag census as ur starting pint, and that wuld mve frward and yields wuld increase thrugh time. Ketterings: Des that include 1985 fertilizer use with the same apprach? Dubin: I believe s. Meisinger: That s the baseline that ther panels use t. Fisher: S if yu had a n-bmp scenari tday, wuld the lsses and nutrient inputs scale up based n the recmmendatins and data frm tday? Dubin: Yes, essentially. Brsch: The implementatin between what is the surce? And is this referring t specifically the baseline, r all the elements in ur prpsal, including ur supplemental menu? Dubin: What we re lking t d here is prvide sme guidance, and we wuld recmmend the WTWG t have sme mre discussins abut that with the Mdeling Team. I gt a similar questin fr ne f the ther panels. Brsch: S we ll determine the implementatin rates in an n-ging prcess, then? Dubin: Yes. And I think we re suggesting that we ll have a default where a state partner desn t have histrical infrmatin. Brsch: I d be cncerned with using the NEIEN infrmatin as the true implementatin fr baseline nutrient management in 2015, at least in DE. I think this paragraph needs t reflect the difference between implementatin and verified implementatin as well. Hw d yu intend t wrk in verificatin, as in we re nt wrried abut it, r the number representing implementatin shuld accunt fr verificatin acres? Dubin: We ll have t wrk n that, perhaps making reference back t the Task Frce reprt. 82

83 Meisinger: Isn t there a verificatin panel? Dubin: The panel has been sunsetted, but we d have the BMP verificatin guidance, but isn t required fr full implementatin acrss all BMPs until Meisinger: We culd draft ur verificatin statements, and ptentially run that by smene else t make sure we ve captured what we think we have. Dubin: Well I wuld suggest the AgWG. Fisher: If yu have a high verificatin rate, des that mean yu d reduce the efficiency by a certain percentage? Dubin: It wuld translate in a reductin f acres reprted fr implementatin. Beegle: Shuld smething related t state flexibility with sil tests be included in this reprt? Panel's Next Steps Meisinger: Will these efficiencies be fr each different land use? Cale: Fr N, we shuld be able t lean heavily n the existing dataset, but P will present sme new challenges. Participants: Lindsey Grdn Mark Dubin Frank Cale Matt Jhnstn Deanna Osmnd Dug Beegle Jack Meisinger Steve Dressing Chris Brsch Tm Fisher Ken Staver Quirine Ketterings Alisha Mulkey Lee Nrfleet CRC UMD UMD UMD Nrth Carlina State University Penn State USDA Tetra Tech DDA UMCES UMD Crnell MDA USDA 83

84 5/6/2016 Actins & Decisins: ACTION: The panel agreed t have Jack fllw-up with Dr. Lee Nrfleet in rder t get data f percent BMP implementatin fr nutrient management at the HUC4 level. ACTION: Deanna will review the Smith 1999 paper in rder t pull ut additinal infrmatin n Phsphrus fr ACTION: Matt Jhnstn will wrk n breaking ut the prpsed NM acres t % acres implemented at the HUC4 scale, with additinal data brken ut by manured versus fertilized acres. This will be used t cmpare against the HUC4 data t be prvided by Dr. Lee Nrfleet frm the CEAP reprt. DECISION: Matt Jhnstn will use the drafted implementatin acres based n 2015 NEIEN data in a test run f the mdel t cmpare different nutrient management appraches, and will present this t the AgWG during their May meeting. ACTION: Jack and Deanna will take the lead n develping efficiency recmmendatins fr Nitrgen acrss all land uses. Quirine, Frank, and Dug will wrk n develping efficiency recmmendatins fr Phsphrus acrss all land uses. ACTION: By mid-day Tuesday May 10, the panel will prvide Matt with better estimates f efficiency values fr the 13 land uses t be used in preliminary mdel runs. Recap f AgWG Discussin Frank gave the panel an verview f the presentatin and update that was given t the AgWG during their April 21 st meeting. There was feedback frm the AgWG that the prpsed representatin wuld be difficult t implement frm the state agency s perspective. The AgWG charged the panel t cntinue develping their scheme fr representing the BMP, and t present it back t the AgWG during their May meeting. Jack Meisinger asked if the prpsed structure f the BMP culd be revised, r it if was set in stne. Frank cautined against making any majr changes befre it s presented back t the AgWG. Histrical BMP Implementatin Schemes Jack presented an apprach fr estimating implementatin f nutrient management practices ver time. The fcus f this prpsal will be using rate data t track implementatin. Fisher: What abut type? Meisinger: It s basically either fertilizer r manure, and that s assumed here. Fisher: I was thinking urea vs. ammnium nitrate vs. manure vs. sludge there s a lt f ptins ut there. Meisinger: Gd pints. We ve never dealt with sludge; I think that s being cvered under anther ad hc grup right nw. We re nt ging t separate urea and ammnium nitrate because data is s limited. Ketterings: S this crp remval frm the CEAP reprt is what we re cnsidering using in ur recmmendatins? Cale: Nt quantitatively, but this basis is what we culd use t determine an apprpriate rate t use fr crediting nutrient management. Deanna Osmnd agreed that these values generally agree with what the NRCS values are. Ketterings: Our P fertilizer use is very small up in NY, s I m nt sure hw t interpret these numbers yu ve pulled ut. We have a sizeable acreage that receives manure acrss the bard. Fr fields that d receive fertilizer, where the applicatin rates are way belw 1.2, the value here shuld prbably be higher. Fr acres receiving manure, I wuld think that it wuld have t be a higher % than 32. Cale: Fr the manured acres the 32% and 35% is prbably a little bit lw? Ketterings: I wuld think ur acres that receive manure - a larger % f thse acres falls under the 1.2 Jhnstn: Frm ther data (industry reprts, USGS, USDA) are shwing plummeting use f P in rganic fertilizer acrss ur regin since Sme suggest that N is pretty steady, but P is cut almst in half. Jack asked the panel if they wuld like t use % implementatin values t be prvided by Lee Nrfleet at the 84

85 HUC4 level. Jhnstn: The Bay Prgram has asked fr this infrmatin at a finer scale befre, but the CEAP statistical analysis is nly cnfident at the HUC4 scale. Dubin: I think having this infrmatin wuld be great t reference later n when develping their final reprt. Cale: Fr ur purpses here f ding sme histrical back-casting, I think this infrmatin wuld be very helpful. Jack asked if Deanna wuld be willing t review the Smith 1999 reprt fr her t review the Phsphrus material and infrmatin that is cntained. Mark presented n an alternative apprach t estimating histrical BMP implementatin. Cale: Hw wuld we take this analysis and cmpare it t the CEAP analysis? Culd yu regenerate this in % f acres by state? Jhnstn: Wuldn t be difficult t d the cnversin t %. And we did the cmparisn fr 2015 prgress, and what yu ll see is that in MD and DE, we re higher than the CEAP values, but the ppsite is true fr WVa and PA. S it just varies. Meisinger: Are these acres that have a plan? Or are they acres that have an implemented plan that meets sme criteria? Dubin: These are self-reprted, implemented acres. Meisinger: CEAP data are NRI summaries, which is als self-reprted, but has a different level f scrutiny. Meisinger: D yu think yu culd parse this ut int HUC4s at sme level f reasnableness? Jhnstn: I think s we wuld just have t break up VA and MD. And I als wanted t say that since this is a BMP in a management mdel, it ll always be up t the states t track and reprt this data, and this infrmatin is what we expect states t reprt in the future. CEAP gives us a gd idea f what farmers are ding regardless f regulatin, but the states have t reprt actual tracked data and 2017 prgress, and future implementatin data, will nt be assumed, and will lk like the end f these dtted lines. S it behves us t use smething akin t thse dtted lines in ur calibratin. Cale: S if we can get that HUC4 data frm Lee Nrfleet, and if Matt can get this analysis dne at the HUC4 level, then we wuld have 2 datasets t cmpare and we culd develp a slid recmmendatin mving frward. Jhnstn: That s a gd idea, but the CBP was asked t prvide side-by-side mdel results by May 19th, and I wuld like t get this in frnt f the AMS and this panel befre then. S the secnd we can agree t testing acres, then we can press g and get the results distributed. Meisinger: We saw manured acres behave different than fertilized acres, s is it pssible t break that ut f the % HUC4 data? Jhnstn: S we said the data cming in fr 2015 prgress was cming in n crp, hay, and pasture, but we ve brken it ut int lines fr each land use. S yes it wuld be pssible t break ut that infrmatin as well. Cale: S I m thinking that what Matt s presented culd be used t demnstrate t the AgWG, and we wuld need t fllw-up with the panel t lk at the NRI pints and d an independent verificatin f whether it makes sense. S I d like t ask the grup if they re cmfrtable with mving frward with this apprach laid ut by Matt slely t d a test run f the mdel that can be presented t the AgWG. Meisinger: We als have t remember this is all fr N at this stage; we can t frget abut P. Fisher: I m wndering if we re nt ging t cause the mdel prblems, because the real wrld isn t a straight line. If they re trying t match mdel predictins t empirical measurements, I m wndering if it wuldn t be better t reprt the actual vetted values with the variatins in them. Jhnstn: Great pint there and I actually expect that WVa and VA will submit t the Bay Prgram smething that lks like their slid lines. This is just a prf f cncept. I suspect PA and DE will have t g back t the drawing bard. But in the end it s up t the states t define what the acres are, and all we can give them is justificatin and aid in ding s. Meisinger: One wrd f cautin as I lked at sme f these surveys, it became apparent that there s a big farm size difference in BMP implementatin, with larger farms having mre implemented BMPs than smaller farms, s we have t be careful with bth the NRI and the reprted data if they re weighted twards CAFOs and large peratins. 85

86 Nutrient Management BMP Efficiency Apprximatins Frank reviewed the efficiency matrix that he distributed t panel members, and asked panel members t vlunteer taking the lead n develping first draft efficiency values. Jack ffered t take n sme f the N efficiency estimates. He nted that the pasture and ther hay land uses may be the mst prblematic. Nn-NM acres culd be fertilized less than the NM acres in thse instances. Deanna Osmnd ffered t help Jack with this effrt. Jhnstn: MD tld the mdelers t make their crp applicatin rate fr pasture t equal 15 lbs. assuming NM, s in this case we wuld use that 15 lbs. in MD and multiply it by 1.2 fr every acre f pasture nt reprted NM. That s hw I read the chart. Cale: S the reprted gal that the states set can be mdified t be different frm LGU recmmendatins. Jhnstn: And the states have already dne that. Meisinger: S we need t knw what thse are, because sme states will use lbs. n pasture, and ther states will be 15. Jhnstn: S we lked thrugh all the LGU recmmendatins, gave it t the states, and asked them fr their best estimate. A lt f wrk has gne int base applicatin gal in the mdel, and I wuld suggest we multiply thse gals by 1.2 fr N. Cale: S we re ging t mve frward with assuming ur basis is the LGU recmmendatin, and we ll figure ut the relative deviatins between NM and nn-nm. Meisinger: Matt, it wuld be helpful if yu culd send it ut by land uses what the LGU recmmendatin is, and what yu re using nw as far as an adjusted applicatin rate. Jhnstn: We dn t have that by land uses because the mdel wrks by crps. Meisinger: But yu cnvert yur crps t land uses smewhere alng the line? Cale: S Matt, hw des the way we re perceiving everything acrss the land uses get integrated? Jhnstn: Applicatins f manure/fertilizer are dne n individual crp gals, and at the end f the prcess thse crps are aggregated up t land uses. Quirine Ketterings, Frank Cale, and Dug Beegle will wrk n drafting Phsphrus efficiencies. Jhnstn: S we we the results f this preliminary run by the 18 th, s I wuld ask the grup since it s a prf f cncept, can I use 1.2 fr N and 1.5 fr P with a huge caveat that this is a prf f cncept and mre wrk is being dne? Meisinger: I wuld say n. Cale: I agree with Jack s hesitatin. If we want t give yu a really quick dirty update f this table, when d yu need it? Jhnstn: Hnestly, ASAP. Because the nutrient spread is the biggest decisin being made n May 19 th, and I d like t get the results in frnt f this grup, the AMS, and the AgWG lng befre May 19. We re gd t g with the acres, and we were ging t assume 1.2 and 1.4 fr nn-nm acres, but therwise ASAP. Tday wuld be preferable. Clsing Thughts Meisinger: The way we ve set up this BMP, we ll be using fertilizer sales r LGU recmmendatins, depending which ne gives the lwer value. I wuld prpse that we cnsider using thse tw, nt as ne r the ther, but t cmpare with each ther with the gal f saying that they shuld cmpare within 20% f each ther r smething. And in the end, the fertilizer sales data nly be used during that cmparisn, and nly use the LGU value if we can figure ut which value gives the prper estimate. S if the 2 agree use the LGU value. If they dn t agree, then cnvene and figure ut which value is questinable. Jhnstn cautined against this because the AMS had a specific charge frm the AgWG t develp these data, and making significant changes t the BMP apprach des nt prvide enugh time t get everything dne. Participants: Deanna Osmnd NC State University 86

87 Lindsey Grdn Frank Cale Tm Fisher Matt Jhnstn Jack Meisinger Mark Dubin Steve Dressing Quirine Ketterings CRC UMD UMCES UMD USDA UMD Tetra Tech Crnell 6/28/2016 Frank Cale reviewed the wrk f the panel thus far, as well as the prpsed structure and efficiencies t represent nutrient management. Tm Fisher: Is the extra 20% n the efficiency fr nn-nm plans based n any empirical evidence, r just the idea that if yu aren t ding NM then yu prbably dn t fllw the LGU recmmendatins very well? Cale: Sme states have a histrical precedent befre NM was utilized. A lt is als based n best prfessinal judgement f hw far abve NM applicatin rates a cmmn applicatin rate wuld be if smene s nt adhering t a plan. Fisher: S there s n real empirical evidence fr that. Regardless, the number seems reasnable t me. Cale: In mst cases, there isn t empirical evidence. Questin n the timing f when supplemental practices have t be implemented relative t cre practices in rder t receive credit. Dubin: This is an annual BMP, s if a farmer is implementing the cre practices, and adds a supplemental practice n tp then they will be receiving credit fr that. Frank nted that the panel needs t evaluate the accuracy f the efficiency values fr the nutrient management elements fr each f the 13 land uses. Questin n the difference between edge f field and edge f stream. Fisher: In the real wrld, the same field may have ne r mre f these crps n it, and when yu get actual delivery t a stream, it will prbably reflect the last 5-10 years f crpping practices. I m just trying t think abut hw this seems almst verly detailed if yu re trying t match what s delivered t a stream in the real wrld. Panel agreed t mve frward with finalizing the matrix f BMP efficiencies fr each f the 13 land uses. Frank Cale reviewed the drafted excel spreadsheet f crp applicatin rates, and nted that these numbers will be used in lieu f LGU recmmendatins in the NM BMP flwchart. Panel discussed efficiency and applicatin rate values fr pasture and hay. The panel agreed that pasture and ther hay will nt be eligible fr nutrient management and will receive an efficiency value f Panel needs t find literature citatins supprting the prpsed efficiency values. Steve Dressing and Mark Dubin reviewed the current wrk n the literature review and citatin spreadsheets. Mark nted that the panel and partnership is pen t published and nn-published, grey literature surces, and if any panel member wuld like t include a literature surce but des nt have access t the surce, they shuld get in tuch with either Mark r Frank. Frank asked fr vlunteers t take small prtins f the BMP efficiency table and review the values based n available data and literature: Tm Fisher will lk int sybeans. Frank will review specialty crps high and lw, ther agrnmic crps, and hay and pasture fr N and P. Jack will review his wrk n the Phase panel, and will wrk with Deanna and Tm n reviewing N values fr full seasn sybeans, grains with and withut manure, legume hay, silage with and withut manure, small grains and grains, and small grains and sybeans. Dug, Frank and Quirine will wrk n reviewing the P values fr full seasn sybeans, grains with and withut manure, legume hay, silage with and withut manure, small grains and grains, and small grains and sybeans. 87

88 Panel members shuld have cmpleted their wrk by July 14. Mark reviewed the timeline fr the panel cmpleting their wrk. The panel shuld plan t release their draft reprt fr partnership cmments in late July. The AgWG will begin reviewing during August, and the reprt will g t the AgWG, WTWG, and WQGIT fr final apprval in September. Participants: Lindsey Grdn Mark Dubin Gary Shenk Chris Brsch Deanna Osmnd Frank Cale Dug Beegle Jack Meisinger Steve Dressing Tm Fisher CRC UMD USGS DDA Nrth Carlina State University UMD Penn State University USDA Tetra Tech UMCES 7/19/2016 Actins and Decisins: DECISION: The panel agreed t mve frward with recmmending the appraches t nutrient management laid ut in the mtin put frth by Jack Meisinger ( First draft mtin fr Nutrient Management Panel.dcx. ACTION: Frank Cale will revise the PwerPint presentatin with the panel s guiding principles based n feedback frm the panel members in advance f the July AgWG meeting. LGU recmmendatins versus fertilizer sales apprach fr setting applicatin gal: N and P. Jack presented a first draft mtin fr the panel t cnsider specific recmmendatins n representing nutrient spread and using fertilizer sales data in the Phase 6 mdel. These recmmendatins include using the State Partners Fertilizer Applicatin Rate Table as a check against the AAPFCO Fertilizer Sales data fr Nitrgen, and using the State Partner Fertilizer Applicatin Rate Table t distribute the AAPFCO Fertilizer Sales data fr P applicatins. Mark Dubin explained the Phase 6 Mdel Beta 3a and 3b appraches t nutrient spread, as well as a prpsed hybrid apprach that uses the fertilizer sales data in cmbinatin with the LGU recmmendatins/agrnmic need as a weighting factr t distribute the fertilizer back dwn t the cunties. Jack nted that the descriptin in 3a (f the first draft mtin dcument) is a straight use f the LGU recmmendatins as an apprach, and nly using fertilizer sales as a check-pint; in line with the CEAP methdlgy. This methdlgy is nt identical t the hybrid apprach laid ut by Mark. Jack als nted cncern with using fertilizer sales data because it is nt as effective a selling-pint fr farmers as LGU recmmendatins. Tm Fisher: Is PSNT represented in this methdlgy? Dubin: The PSNT is a mre advanced tl that we wuld use t re-adjust the applicatin. This is included as a separate crediting functin within the current recmmendatins f the panel. Cale: S what Jack is prpsing is the final applicatin f fertilizer is determined the LGU recmmendatins f what each crp was determined t need. Meisinger: Yes. And it turns ut that the difference between the Phase 6 Beta 3a and 3b is abut 100,000,000 punds f N, which t me, is very small and suggests there is n difference between thse tw appraches. One big factr is the number f acres f pasture in the watershed, which is ur biggest and mst uncertain land use. If that number is incrrect, it can have a significant impact. The ther biggest land use is ther hay, s if that s cmbined with pasture, they accunt fr 5.5 millin acres ut f the 12 millin ttal acres. A small difference in their estimatin can have huge impacts in applicatins. S I dn t trust the fertilizer sales data befre 2007, and my apprach wuld use AAPFCO Fertilizer Sales data nly after

89 Tm Fisher: I think it mre clsely represents the actual practices in the DelMarVa. Meisinger: Actually, since pasture and ther hay aren t prminent in the DelMarVa, there isn t as much a difference in the Phase 6 Beta 3a and 3b appraches. Questin frm Tm Fisher is the fertilizer sales data includes fertilizer used in winter de-icing. Mark Dubin replied that the AAPFCO data separates ut urban and agricultural fertilizer sales, and that this piece f the mdel will nly lk at agricultural fertilizer sales data. Deanna Osmnd: I agree with Jack the fertilizer sales data is always tricky, especially with the pasture land uses. I supprt Jack s cmment. Tm Fisher: Which is the larger f the tw estimates fr P when yu cmpare them? Meisinger: I think the LGU apprach was abut % higher than fertilizer sales. Dubin: The discrepancy varies by state, but yes there is a large difference. A lt f factrs are influencing this variatin Meisinger: S we wuld basically use fertilizer sales in tw different ways fr N and P, and the panel has already separated N and P mnths ag, s I dn t see any prblems with that. Dubin: And I wuld like t remind everyne that whichever decisin cmes dwn frm the partnership, this is a main structural element f the mdeling tls and s it will be in place until we get anther mdel tl. There wn t be an pprtunity t change it until we get t the next phase f the mdel. Frank Cale: Given the panel agrees n items 1 and 2, I wuld summarize item 3 that we think applicatin rates fr N and P shuld fllw the same decisin making prcedures that states use t determine nutrient applicatin rates. Fr P, this invlves knwledge f sil-test P levels, and until the Bay Prgram cllects and utilizes sil test P data, then a surrgate fr that wuld be using fertilizer sales data as a prxy fr P-distributin until sil-p data can be included in the mdeling tls. Meisinger: Crrect. We wuld prefer a unified apprach, but it s nt required fr N and P and there s a gd reasn that we can t reach that pint right nw. Dubin: Jack, did yu want t make sure that N-residuals frm legumes, etc., are included in the fertilizer sales infrmatin, as part f 3a? Meisinger: When yu say N-residuals frm legumes, they are already included in the LGU recmmendatins in the cre element. S they re already wrapped in. Dubin: Right. I just want t make sure they re recgnized in the N-applicatins. Meisinger: Yeah and Mark is referring t crn acreage right nw. When yu lk at ur cre requirements, legume credits are included in them, because they ve always been included in LGU recmmendatins. S the actual amunt f N applied t crn fllwing sybeans wuld be less than the standard 1 lb. /bushel. S thse legume credits are already in the cre element fr NM, and they dn t need t be in the AMS, because that wuld be duble-cunting. Tm Fisher: Is there an adjustment fr cver crps in thse recmmendatins? Meisinger: This is where the LGU recmmendatins really help, because if they credit cver crps, then it s flded int the NM. Tm Fisher asked if there needed t be a check in place fr P, similar t the sales data as a check fr N. Frank respnded that there was nthing really t check the P-data against. Dubin: One thing we saw with the cmparisn between the Phase 6 Beta 3a and 3b runs was there with N, there is a fairly gd relatinship between the tw ver time. There was a separatin with punds f fertilizer fr the states, but the relatinship was steady. S maybe that s the check the relatinship. Jack nted a preference fr the LGU recmmendatins being based upn the field scale, as ppsed t the fertilizer sales data, which is at the cunty scale, citing the fact that NM ccurs at the field scale in the real wrld. Jack and Frank nted that the panel can cnsider whether t allw fr crediting f supplemental nutrient management practices abve the 1-practice per categry (rate, placement, timing). Tm Fisher: In ur experimental watersheds, we ve been encuraging farmers t use PSNT and FSNT sil tests. S I wuld think it s a great idea t credit bth f thse. Cale: Our riginal premise was that any type f thse tests/assessments have t demnstrate a change in rate/timing/placement as a result f ding that assessment. S I m thinking we shuld phrase this as if yu d PSNT and changed yur rate, yu shuld get that credit, and if yu d a separate practice and make an additinal change in rate, yu can get that credit again. As lng as it s nt trying t take multiple credits 89

90 fr the same change in implementatin. Meisinger: That makes sense, but I m nt sure hw the reprting wuld wrk with that. Dubin: We re ging t ask the states t track these elements anyway, but I think it will definitely add t the reprting thrugh NEIEN, because we re tracking multiple ptential changes n different acres, etc., s that wuld make it mre difficult, yes. But we als need t cnsider that this is an annual practice, and these changes may ccur thrugh different years. Meisinger: Maybe this time we can stick with 1 practice, and then future panels can cnsider expanding the crediting t 2 r mre supplemental practices if they feel it s necessary. Steve Dressing: I wnder if yu d need t accunt fr additive practices by using a discunted efficiency when these practices are cmbined. Panel agreed t remain with crediting 1 practice per supplemental categry, and will describe their thughts n the ptentiality f crediting multiple supplemental practices in the Future Research Needs sectin f their final reprt. CBP mdeler survey f NM questins Frank and Matt reviewed the survey f NM questins that was develped by Matt Jhnstn in rder fr the CBP Mdeling Team t develp multipliers fr every acre that is nt under nutrient management. Cale: We develped the efficiency factr table fr the cre and supplemental BMPs fr N and P. Thse numbers range a lt. Hw will this infrmatin be used tgether with the infrmatin we re presenting in ur final reprt, with thse efficiency values? Jhnstn: The supplemental stuff can be set aside because that s an efficiency. We re lking at written plans f NM n acres. The states will tell us their acres f written plans. Using the multiplier table, every acre with a written plan receives an LGU rate, and every acre withut a plan receives smething abve that. But we dn t have P-values fr acres with plans. This data wuld supersede the values frm the efficiency table, but als gets at the questin f whether the plan equals an LGU recmmended rate fr P. Right nw, the answer t that is n. Meisinger: I am ging t byctt this pll, primarily because the panel is nt charged with ding the implementatin, and these are implementatin questins. We d reductin efficiencies, and we suggest pssible implementatin appraches nly. Jhnstn: And the grup can certainly g that way, and recmmend the previusly develped efficiency table. But we still are ging t be receiving acres under plans frm states, and we nly have values fr N, and nt P. Cale: I wuld guess that mst acres frm states cme clse t satisfying the cre requirements fr N, and a majrity prbably dn t cme clse t satisfying the P cre requirements. Jack Meisinger made a cmment abut the need t include P-based management in the mdel. Jhnstn: The cde is in the mdel, and I was talking t MD abut getting the acres that we need t use in that part f the mdel. MD said they can give it their best effrt, but they dn t have the infrmatin available t say the # f acres in each cunty where manure was applied t meet P. MD prbably knws the mst abut what their farmers are ding, s if MD can t get it, we prbably can t get it elsewhere. If we d eventually get that data, we can abslutely run P-based management in the mdel. Meisinger suggested ding a test t make sure the cde wrks. In rder t include P-based management, Frank suggested picking the 0-pint fr state data in time, and take the mst recent data frm the states fr P-based management, which at this time wuld be 0. Tm Fisher: I wrk with 40 farmers in DelMarVa, and my impressin is that they treat their sils as having a P bank accunt. They mnitr hw much P is there, and every nce in a while add sme manure r smething, and the accunt fluctuates but they re cnstantly tracking it. Unlike N, P stays in place, s they can mnitr what s ging n and make sure they keep it in a specific range. S that s the kind f P-management I see being dne in the field in ur grup f farmers. Cale: I agree with yur bservatins and Jack s pint, and I think the panel needs t recmmend that sil P levels is ultimately included in the mdel smehw. It shuld be cllected, and utilized eventually, since it s the baseline determining factr fr P management. S we shuld make that pint very clear in ur reprt as a future research need. 90

91 Review f AgWG presentatin Frank reviewed the NMP s guiding principles that will be included in their final recmmendatins. Mark suggested including a qualifier n the efficiency table nting that they are still draft, and are subject t change based n feedback frm the partnership and the determinatins f the panel. Discussin f Panel Timeline fr Cmpleting Recmmendatins Mark Dubin: Our timeline fr having a fully partnership apprved panel recmmendatin set is September 30. If yu wrk back frm that, then we will need a 30-day review perid f the reprt and time built in fr the apprval prcess by the CBP wrkgrups and GITs. S we have been wrking n develping a draft reprt in rder t begin a 30-day review prcess beginning in August. Steve, Frank, and I have been wrking n building ut this draft reprt, and we anticipate getting a draft reprt in the hands f the panel very sn. Cale: Exactly. We ll be sending this draft reprt t panel members, and will be asking fr a very quick turnarund. Given this tight turn-arund, if yu are nly able t review the sub-tpics that are particularly relevant t yu, that s great. We ll have time t d mre plishing and tweaking during the cmment received and respnse perid that will ccur after/during the partnership review. The gal is t have a draft versin t the panel within the next days. Panel agreed that the prpsed timeline fr cmpleting the panel s wrk is agreeable. Participants: Lindsey Grdn CRC Frank Cale UMD Matt Jhnstn UMD Mark Dubin UMD Deanna Osmnd NC State Steve Dressing Tetra Tech Chris Brsch DDA Jack Meisinger USDA ARS Tm Fisher UMCES 91

92 Appendix E: Cnslidated Respnse t Cmments n: Definitins and Recmmended Nutrient Reductin Efficiencies f Nutrient Management fr Use in Phase 6.0 f the Chesapeake Bay Prgram Watershed Mdel (August 1, 2016 Versin) Cmmenter identificatin is highlighted in bld underline. Specific cmments/questins are highlighted in bld italics. Relevant text frm the draft reprt (8/1/16) is cntained within qutatin marks. Respnses are in italics. Sectin 2: Practice Definitins West Virginia It is essential that an initial baseline fr NM implementatin is established that allws estimatin f prgress ver time. What year will be used fr this baseline? Respnse: The Phase 6.0 Nutrient Management Expert Panel (the Panel) recmmendatins are established n a baseline f 1985 t mirrr the Chesapeake Bay Prgram partnership s mdeling tls baseline fr BMP implementatin and mdel calibratin. The individual partner jurisdictins are separately respnsible fr reprting their histrical BMP implementatin t the Chesapeake Bay Prgram Office thrugh the Natinal Envirnmental Infrmatin Exchange Netwrk (NEIEN) fr the Phase 6 mdel calibratin perid ( ) based n the CBP partnership-apprved BMP structure and definitins. Hwever, the Panel reprt includes an alternative methd, c-develped with the CBP Mdeling Team, which prvides a simplistic state-by-state template fr representing histric BMP implementatin based n the 1985 n-bmp baseline and a 2015 prgress implementatin level. Spreader/applicatr calibratin: The equipment being used t perfrm the nutrient applicatins by the farm peratr needs t be dcumented and verified that the machine(s) have been calibrated either accrding t manufacturer specificatins r by standard calibratin practices within ne year f the applicatin. Need flexibility n this pint in bth verificatin methdlgy and length f time between calibratin. Wuld recmmend remving within ne year f the applicatin language. Respnse: The Panel s descriptin f spreader/applicatr calibratin has been mdified in the reprt t insert preferably within ne year f the applicatin. Operatr dcumentatin f previus spreader/applicatr calibratins can and shuld be utilized as part f verificatin, thus nt requiring the verifier t persnally cnduct r versee the equipment calibratin within ne year f the applicatin. Verified dcumentatin f manure mineralizatin N credits are included as part f the nutrient balance t accunt fr at least the three prir years. This seems like verkill and while it may nt be s much f an issue with small farms, it wuld be a sizeable issue fr large farms. It wuld be very time cnsuming fr plan writers t sit dwn with farmers t retrieve all the data needed fr this exercise. Respnse: The Panel recgnized that rganic N surces mineralize ver multiple years and cnvert t a frm available fr plant uptake. A three-year recrd f sil rganic N mineralizatin is standard LGU practice in determining plant N availability. The dcumentatin and verificatin f manure mineralizatin N credits t develp a nutrient balance was nt develped by the Panel but is instead based n the CBP partnership-apprved BMP Verificatin Guidance, which relies n sil analysis and farm management recrds reviewed by an independent trained and/r certified party. The CBP partnership-apprved BMP Prtcl requires all BMP Panel recmmendatin reprts t incrprate the BMP Verificatin Guidance int the Panel s recmmendatins. Farm management recrds can be cmplex GPS applicatin maps, electrnic datasets, r as simple as hand-written ntes cmpiled by the peratr during the mineralizatin perid. 92

93 Rather, independent dcumentatin and verificatin that all f the required elements f the N Cre NM BMP were implemented is required. We were surprised that the Panel did nt require plans t be written by a certified plan writer. This represents significant flexibility while ther prtins f the dcument did nt. Respnse: The Panel recmmendatins describe the management elements required t meet the Cre N and P BMPs, which when cupled with the CBP partnership-apprved BMP Verificatin Guidance, wuld require written and/r electrnic dcumentatin t sufficiently enable a trained and/r certified independent third-party t recrd, track, and verify the BMP(s). The required nutrient management dcumentatin culd be in the frm f a frmal federal-, state-, r cunty-reviewed and certified nutrient management prgram plan, a nn-certified frmal nutrient management plan develped by a federal- r state-certified plan writer, r detailed dcumentatin and an infrmal management plan cmpiled by an peratr r private cnsultant that met the Panel s BMP recmmendatins. New Yrk Upper Susquehanna Calitin Recmmending that farms receive credit fr setbacks under the cnditin that they fllw state guidelines fr setback widths is prblematic in that sme states may have narrwer setbacks than thers, therefre causing a disparity between the states. While every farm shuld be fllwing their state s requirements fr setbacks, we feel that the credit in the Bay Mdel shuld be given t all states at the same setback distance. We recmmend setting a standardized setback distance in which all states can receive credit fr Placement Adjustment in the Bay Mdel, regardless f their state s minimum setback requirements. Chesapeake Bay Cmmissin: Is there a minimum setback in rder t receive credit? Cmment reiterated by Maryland Department f Agriculture. Respnse: The Panel cnsidered the questin f recmmending a standard applicatin setback distance and crediting value as part f the BMP evaluatin prcess. Given the great diversity amng the physigegraphic znes f the watershed, including sils, slpes, pathways fr nutrient envirnmental lsses, etc., the Panel chse nt t be prescriptive in recmmending a standard applicatin setback fr the entire regin. Instead, the Panel elected t rely upn the existing cnservatin standards established by the lcally respnsible federal and state agricultural and cnservatin agencies. Similar t representing a diversity f LGU recmmendatins acrss the six-state watershed, the Panel recmmended an apprach f crediting peratrs wh are fllwing lcal cnservatin standards, and managing their nutrient applicatins in cmpliance with thse standards. Furthermre, the Panel was nt able t identify sufficient scientific evidence which wuld supprt a significant difference in crediting based slely n the width f an applicatin setback given the multitude f influencing factrs. The Panel s reprt has been mdified t include the fllwing language: Setbacks must meet the minimum standards required under applicable lcal, state, r federal prgrams and laws. Envirnmental Integrity Prject The reprt is nt clear abut hw split applicatins will be treated. Split P applicatins appear in nly ne categry n pages 11 and 25, but appear in bth rate and timing categries n page 17. The reprt shuld be revised t make it internally cnsistent n this pint. Overall, it wuld help t have a mre cmplete explanatin f hw split N r P applicatins shuld be reprted. Respnse: Split N applicatin is bth a N Rate Supplemental NM BMP and a N Timing Supplemental NM BMP, whereas split P applicatin is nly a P Rate Supplemental NM BMP. Fr bth N and P, a split applicatin can result in mre efficient use f nutrients because crp prgress can be tracked and anticipated yields reassessed between the initial and final nutrient applicatin. This allws the peratr t avid a single nutrient applicatin in anticipatin f maximum average yield, resulting in a reduced ttal applicatin rate better matched t crp needs. Fr N there is als a timing benefit because - depending n sil type, climate, agrnmic practices, and ther factrs - N fertilizer can be vulnerable t envirnmental lsses. Denitrificatin, leaching, and vlatilizatin can all result in lsses f N and decreased nutrient applicatin efficiency. Fr this reasn, there is als a timing benefit t split N applicatin. The risk f P lss, hwever, is much lwer s there is n timing credit fr split P applicatins. Therefre, lss reductin multiplier credits can be earned fr bth N Rate and N Timing if split N applicatin is implemented, whereas nly a single lss reductin multiplier credit fr P Rate can be earned with split P applicatin. 93

94 Chesapeake Bay Cmmissin One single NM Supplemental BMP efficiency may be credited fr each f the N Rate, N Timing, and N Placement categries. - S, this means that there is a single credit per categry, crrect? Nt that nly ne practice per categry can be credited? These questins als apply t P. Respnse: The Panel recmmendatins prvide ne pprtunity fr crediting per each Supplemental NM BMP categry fr N and P. There are three such categries each fr N and P Supplemental BMPs: rate, timing, and placement. Applicatin f a lss-reductin multiplier fr the N NM Supplemental BMP elements can nly ccur after satisfactry implementatin f the N Cre NM BMP. The N Supplemental NM BMP lss reductin credit fr each f these three categries (rate, timing, and placement) can be btained if implementatin f at least ne effective practice frm each categry is verified. Similarly, applicatin f a lss-reductin multiplier fr the P Supplemental NM BMP elements can nly ccur after satisfactry implementatin f the P Cre NM BMP. The P Supplemental NM BMP lss reductin credit fr each f these three categries (rate, timing, and placement) can be btained if implementatin f at least ne effective practice frm each categry is verified. Supplemental N NM BMP lss reductin credits fr N rate, N timing, and N placement are stackable, e.g. multiplicative with diminishing returns fr reducing envirnmental lss, as are Supplemental P NM BMP lss reductin credits fr P rate, P timing, and P placement. Regarding Table 7: PSNT is listed in Table 4 as an Assessment Tl. Assessment tls are described n p. 8 as nt representing an efficiency credit in and f themselves. Therefre, why is PSNT given credit here? Respnse: The Panel recmmendatins recgnize the value f utilizing N and P assessment tls t better infrm peratr decisins in managing nutrients. Hwever, the use f assessment tls alne withut a crrespnding infrmed adjustment t nutrient management fr rate, timing, and/r placement des nt represent a credit accrding t the Panel. Instead, the Panel chse t prvide credit based n the implementatin f the management infrmatin prvided by the N and/r P assessment tl. Page 16: Crpping/manure histry at field management unit level, and Federal and/r state certified Nutrient Management Plan nt required These tw practices are listed under P, but the descriptive language discusses hw they relate t N. Perhaps a cut and past errr. Respnse: The Panel recmmendatins have been mdified t reflect the intended descriptive language. Page 16 N Rate Adjustment Practices: By implementing ne r mre f the practices listed, an additinal N credit will be applied. Hwever, implementing mre than ne f the practices captured under each supplemental practice categry will nly result in ne credit fr the practice adjustment. - This limit (ne credit per categry) is nly listed in the Rate sectin, s I assume it des nt apply t the Placement r Timing categries. Is that crrect? Split applicatins ver time per crp. Ttal amunt f N applicatin may r may nt change, but the applicatin is divided int multiple, lwerrate applicatins thrughut the year. - What if the ttal f the split applicatins is greater than the Cre NM rate? Respnse: The Panel recmmendatins prvide n mre than ne pprtunity fr crediting per each NM Supplemental BMP fr N and P (e.g., rate, timing, and placement), but instead prvide a framewrk f multiple management ptins fr achieving each Supplemental BMP credit fr N and P. The Panel recmmendatins have been mdified t include the same language fr each f the N and P Supplemental BMPs. The Panel decisin t limit ne credit fr each NM Supplemental BMP was based n the recgnitin that multiple management actins applied t the same nutrient management prcess (e.g., rate, timing, and placement) prvide a diminishing return. Split applicatins may r may nt result in a change f the ttal applicatin rate, in additin t timing. Split applicatins can reduce envirnmental lss and thereby ptentially reduce the ttal nutrient applicatin need if alternatively applied in nly ne applicatin. Hwever, the Cre NM BMP practices must be adhered t first befre additinal credits can be achieved thrugh Supplemental NM BMPs. In neither case can the ttal applicatin rate exceed the Cre NM BMP rate and be credited as a Supplemental NM BMP. 94

95 Page 17: By implementing ne r mre f the practices listed, an additinal P credit will be applied. Hwever, implementing mre than ne f the practices captured under each supplemental practice categry will nly result in ne credit fr the practice adjustment. - This limit (ne credit per categry) is nly listed in the Rate sectin, s I assume it des nt apply t the Placement r Timing categries. Is that crrect? Split applicatins ver time per crp. Ttal amunt f P applicatin may r may nt change, but the applicatin is divided int multiple, lwer-rate applicatins thrughut the year. - What if the ttal f the split applicatins is greater than the Cre NM rate? Respnse: The Panel recmmendatins prvide n mre than ne pprtunity fr crediting per each NM Supplemental BMP fr N and P (e.g., rate, timing, and placement), but instead prvide a framewrk f multiple management ptins fr achieving each Supplemental BMP credit fr N and P. The Panel recmmendatins have been mdified t include the same language fr each f the N and P Supplemental BMPs. The Panel decisin t limit ne credit fr each NM Supplemental BMP was based n the recgnitin that multiple management actins applied t the same nutrient management prcess (e.g., rate, timing, and placement) prvide a diminishing return. Split N applicatin is bth a N Rate Supplemental NM BMP and a N Timing Supplemental NM BMP, whereas split P applicatin is nly a P Rate Supplemental NM BMP. Split N applicatins may r may nt result in a change f the ttal applicatin rate, in additin t timing. Split applicatins can reduce envirnmental lss and thereby ptentially reduce the ttal nutrient applicatin need if alternatively applied in nly ne applicatin. Hwever, the Cre NM BMP practices must be adhered t first befre additinal credits can be achieved thrugh Supplemental NM BMPs. In neither case can the ttal applicatin rate exceed the Cre NM BMP rate and be credited as a Supplemental NM BMP. Page 17 Sectin 2.5: Subsurface injectin r incrpratin f applied inrganic N. - P instead f N? Respnse: The Panel recmmendatins have been mdified t crrect this errr (i.e., P instead f N). Page 19, Sectin 3.1.3: These efficiencies apply multiplicative mdifiers t edge-f-stream delivery f N, n the utput side f the CBP mdeling scheme, and can nly be applied if the requirements fr N Cre NM BMP are met. - Is there an rder in which the efficiencies are applied? In ther wrds, apply the Rate efficiency, and then the Placement and then the Timing? Des it matter? Given the differences in efficiencies, it seems like there wuld be different utcmes depending n the rder in which efficiencies were applied. This questin als applies t P. Respnse: The Appendix A f the Panel recmmendatin reprt prvides additinal clarificatin and examples f hw the Cre and Supplemental NM BMPs will be represented and applied in the Phase 6 mdeling tls. Supplemental N NM BMP lss reductin credits fr N rate, N timing, and N placement are stackable, e.g. multiplicative with diminishing returns fr reducing envirnmental lss, as are Supplemental P NM BMP lss reductin credits fr P rate, P timing, and P placement. Pennsylvania DEP Cncerns and questins regarding language n pages 7-8 n specific definitins f field management unit, the meaning f the term vlume, and the specific requirements f manure spreader calibratin. Fr example, Pennsylvania wuld like t see the language regarding manure spreader calibratin read Spreader calibratin and/r applicatin rate dcumentatin, as we have cncerns abut ur ability t dcument calibratin fr prir develped manure management plans, but we can dcument manure applicatin rates relating t plan implementatin. Respnse: The Panel s descriptin f spreader/applicatr calibratin has been mdified in the reprt t insert preferably within ne year f the applicatin. Operatr dcumentatin f previus spreader/applicatr calibratins can and shuld be utilized as part f verificatin, thus nt requiring the verifier t persnally cnduct r versee the equipment calibratin within ne year f the applicatin. The Panel descriptin als includes recgnitin f standard calibratin practices fr addressing equipment calibratin, which culd include multiple recgnized frms, e.g. small area calibratin, field scale calibratin, etc. Large scale calibratin wuld require dcumentatin f full capacities f the applicatin equipment, e.g. tns r gallns, a cnsistent applicatin methd, and the number f spreader/tanker applicatins applied nt a knwn acreage. 95

96 Table 2 (and Table 3 where apprpriate): We have a number f cmments regarding this table: What des "and Verified" mean? Each state has their wn verificatin plan dcument and QAPP, s this reference seems redundant if that is the reference. Is this referencing sme ther verificatin? We need a clearer definitin f "field management unit". We wuld like t see this read; "N rate accrding t LGU recmmendatins at crp r field management unit". Maybe the definitin buried n pg 14 culd be brught frward? We have cncern abut the term vlume and wuld like t see "and vlume" stricken r alternatively t read "Manure analysis and applied vlume". Fr spreader calibratin we wuld like t see this read "Spreader/applicatr calibratin and/r applicatin dcumentatin". We have cncerns abut ur ability t dcument calibratin but we can dcument mass applied ver area. The yield estimate line wuld be mre crrect if it read "Planned crp and yield estimate at the field management unit" Crpping plan implies a multi-year plan fr an annual practice. Respnse: The incrpratin f verificatin requirements within the Panel reprt was nt develped by the Panel but is instead based n the CBP partnership-apprved BMP Verificatin Guidance, which relies n farm management recrds reviewed by a trained and/r certified independent third party. The CBP partnership-apprved BMP Prtcl requires all BMP Panel recmmendatin reprts t incrprate the BMP Verificatin Guidance int the Panel s recmmendatins. The specifics f what thse verificatin requirements are based n the BMP Verificatin Guidance, but will vary frm state t state based n their BMP verificatin plan and QAPP requirements. The Panel s descriptin f a field management unit as the basis fr develping and implementing nutrient applicatin recmmendatins was utilized t apply t a range f management cnditins and scales acrss the six-state regin. Accrding t the Panel recmmendatins, The field management unit can represent any field, cllectin f multiple fields, r sub-prtins f a single field that are managed the same way, with similar histry and crpping practices. This statement can accmmdate LGU recmmendatins prvided at a crp scale if the ther descriptive parameters are satisfied, e.g. managed the same way with similar histry and crpping practices. The Panel s descriptin including the use f nutrient cncentratins and vlumes is a standard basis f measurement utilized t determine the apprpriate nutrient applicatin rate based n crp need. The Panel descriptin fr spreader/applicatr calibratin als includes recgnitin f standard calibratin practices fr addressing equipment calibratin, which culd include multiple recgnized frms, e.g. small area calibratin, field scale calibratin, etc. Large scale calibratin wuld require dcumentatin f full capacities f the applicatin equipment, e.g. tns r gallns, a cnsistent applicatin methd, and the number f spreader/tank applicatins applied nt a knwn acreage. The Panel s use f the term crpping plan implies that mre than ne crp may be managed n a given field management unit in a given year. Duble and multiple crpping systems are cmmnly implemented acrss the six-state regin every year, and the management f nutrients n a field management unit shuld reflect the nutrient needs and applicatin management f ne r mre crps being implemented in any given year. Table 5: Need clarificatin: Is split applicatin fr a ttal reduced rate belw LGU rate? Respnse: Split applicatins may r may nt result in a change f the ttal applicatin rate as well as timing. Split applicatins can reduce envirnmental lss and thereby ptentially reduce the ttal nutrient applicatin need if alternatively applied in nly ne applicatin. Hwever, the Cre NM BMP practices must be adhered t first befre additinal credits can be achieved thrugh Supplemental NM BMPs. In neither case can the ttal applicatin rate exceed the Cre NM BMP rate and be credited as a Supplemental NM BMP. Table 6: We take this t mean the state-required setback. Respnse: The Panel recmmendatin reprt has been mdified t include the fllwing language regarding applicatin setbacks: Setbacks must meet the minimum standards required under applicable lcal, state, r federal prgrams and laws. 96

97 Table 11: We are nt sure that we wuld ever be able t prvide this detail. This is actually dne during the develpment f the plan and is effectively "baked int the cake". Respnse: The Panel recmmendatins fr the P Supplemental NM BMP fr applicatin timing recgnized that management pprtunities fr implementatin are mre limited than with N applicatin timing due t their inherent characteristics in the sil envirnment. The structure f the Panel s recmmendatins prvide an pprtunity fr the partnership t track, verify and reprt accrding t their abilities fr multiple levels f nutrient management. If a partner is nt in a psitin nw t track, verify and reprt P applicatin timing, it will nt exclude them frm ding s with ther related nutrient management BMPs. Page 14, Spreader/Applicatr Calibratin : We are unaware f manufactures' actually develping these specificatins and suggest mdifying the last part f the sentence t: "accrding t recmmended LGU practice r by jurisdictinal regulatin requirements within ne year f the applicatin." Respnse: The Panels descriptin fr Spreader/Applicatr Calibratin described that the machine(s) have been calibrated either accrding t manufacturer specificatins r by standard calibratin practices, preferably within ne year f the applicatin. The Panel is aware that equipment manufactures may nt prvide calibratin tables r charts, hwever, they d recmmend the use f calibratin prcedures cnsistent with the applicatin capacities and methds f their equipment. The reprt als includes the recgnitin f standard calibratin practices fr addressing equipment calibratin, which culd include multiple recgnized frms, e.g. small area calibratin, field scale calibratin, etc., including jurisdictinal regulatry requirements. Sectin 3: Effectiveness Estimates Kelly Shenk A significant shrtcming f the Panel s reprt is that it des nt prvide sufficient dcumentatin n hw the Panel arrived at the nutrient reductin efficiencies. Citing a cllective 150 years f experience, the use f Best Prfessinal Judgement, and listing references evaluated is insufficient detail in justifying the final efficiencies. Develping nutrient management efficiencies is the crux f the Panel s charge and having sufficient dcumentatin t justify the efficiencies derived is critical. I recgnize the extensive nutrient management expertise f the Panel members and trust that the Panel can write a sectin in the reprt that prvides explains hw they arrived at the efficiencies. Recmmendatin: Prvide further descriptin f hw the Panel arrived at the nutrient reductin efficiencies that cvers: what data were evaluated fr what gegraphic regins, the range f efficiencies evaluated, hw the Panel distilled all the data int ne number fr N and P fr the entire watershed, justificatin fr why the efficiencies are representative f the watershed, the level f cnfidence in the efficiencies and any caveats that need t be highlighted, indicatin f the level f cnservatism the efficiencies represent, and any cmparative analysis if apprpriate that sets the efficiencies in the cntext f any similar effrts thrughut the cuntry. Reiterated by Delaware: First, this reprt draws frm unprecedented levels f best prfessinal judgement. The cnclusins are drawn frm numerus primary surce, peer-reviewed, dcuments withut a transparent cnnectin. While Nutrient Management is a wrthwhile enterprise fr reaching TMDL gals and the benefits f this activity as parameterized by this reprt service that gal, a higher standard f rigr shuld be brught t the Agriculture Wrkgrup. Reiterated by Jeff Sweeney: The reprt is thrugh regarding 1) BMP definitins, 2) recmmended verificatin prcedures, and 3) descriptins f hw t apply infrmatin in the mdels. Hwever, the reprt des nt adequately describe the basis f the recmmended efficiencies and, therefre, des nt fllw the BMP Prtcl. Sectin 3.2 Justificatin fr Effectiveness Estimates shuld be the mst detailed sectin in this reprt and amng all CBP Expert Panel reprts. The BMPs are, in part, designed t minimize excess nutrients frm manure and chemical fertilizers, the greatest surce f pllutin t the Chesapeake Bay and many ther waterbdies in agrnmic regins thrughut the wrld. Clear justificatins f why the 97

98 efficiencies are what they are is essential. What s needed are changes similar t revisins t the initial draft Phase 5 Nutrient Management reprt. Fllwing the prtcl, there shuld be a matrix f relevant specific studies and data that yielded quantificatins f the recmmended lad reductins fr each element f Nutrient Management. There shuld be dcumentatin f greater weight being given t study findings that are mre relevant, lcal, recent, etc. It needs t g cnsiderably beynd BPJ and a reference sectin fr BMPs designed t maximize prductin and prfitability and minimize cnsequences t the envirnment. Reiterated by Chesapeake Bay Fundatin: We are very cncerned, hwever, with the lack f scientific supprt fr the pllutin remval efficiencies assciated with the supplemental BMPs. The scientific justificatin can be summarized by this statement frm page 20: The entire bdy f research represented by the citatins presented in the References sectin prvided the fundatin fr the Panel s prfessinal assessment f the effectiveness f the prpsed NM BMPs. With all due respect t the very capable and qualified members f the Panel, there needs t be mre specific dcumentatin regarding hw these efficiencies were derived. As nted in the Appendix (p 56 and 57) and is specified in guidance fr BMP expert panels, the expert panel reprts shuld include: Justificatin fr the selected effectiveness estimates... including a detailed discussin f hw each reference was cnsidered, r if anther surce was investigated, but nt cnsidered. This level f analysis and transparency is nt included in this reprt. As nted in the intrductin, NM BMPs apply t literally millins f acres, s ensuring the science is sund and decisinmaking is transparent, is critical fr the integrity f the scientific underpinnings, but als fr the credibility f the Chesapeake Bay Prgram. S, we respectfully request that the Panel mre clsely fllw the expert panel guidelines and prvide the ratinale and scientific fundatin fr decisins regarding pllutin remval efficiencies as well as the land uses/crp types t which the supplemental BMP shuld be applied (e.g., d we expect that variable rate nitrgen n wheat wuld have the same benefits n crn? explicitly cnsider gegraphic variatin e.g., were data representative f the different sils, ectnes we have in the Bay regin? As well as nte what range f efficiencies were nted in the reviewed data? e.g., are estimates cnservative r d they represent the mean? and n a related nte, what level f cnfidence d yu have in the numbers? Was there lts f infrmatin fr sme practices, but little fr thers? Frm the infrmatin that was presented in the draft reprt, we have n idea f the answers t these questins. Reiterated by Envirnmental Integrity Prject: The Phase 6 panel is presenting much higher efficiencies than the Phase panel, with n explanatin f hw these efficiencies were derived. The reprt des nt explain hw the efficiency recmmendatins relate t the scientific literature. Reiterated by Pennsylvania DEP: While it is recgnized that best prfessinal judgement f the Expert Panel was necessary t determine the BMP efficiencies n pages 18-20, it is difficult t determine the basis fr the develpment f the nn-nm efficiencies. Sme explanatin f this wuld be useful, particularly if it is pssible t address in simple terms. Respnse: The Panel has mdified sectin 3.2 t include a thrugh discussin f the literature used in cnjunctin with best prfessinal judgment t determine the recmmended values fr the applicatin rate multipliers fr the Cre Nutrient Management BMPs and the lss reductin multipliers fr the Supplemental Nutrient Management BMP. Jim Crpper I hesitate thugh using the term Nn-Nutrient Management BMP Efficiency in tables 12, 13, and 16 and in figures 3 and 4 captins and Cntents, titles fr figures 3 and 4. I wuld drp BMP ut f the term as nn-nutrient management is n best management practice. It is a farming practice but certainly nt a best ne. My greatest fear with this exercise is that we cmpletely discredit the use f nutrient management t reduce the availability f nutrients. An efficiency value f 1 fr bth nn-nutrient management and nutrient management des that. An average is nt very meaningful because it des nt indicate the range that created that average. Tday if smene was t d a nutrient management plan n pasture and implement it, they appear t get n credit fr ding it even thugh they may have been putting dwn a lt f extra N and P inadvertently. It makes it lk like the practice has n practical value. If that is the case, then the practice name is a misnmer. It des depend n the purpse by which nutrient 98

99 management is applied - imprve water quality r imprve yields. They can wrk cunter t each ther if they used apart frm each ther. Respnse: The Panel recmmendatins include the use f N and P applicatin rate multipliers fr nutrient management and nn-nutrient management acres. The applicatin rate multipliers by land use are based n a 1985 baseline cnditin, and are cupled with the Agricultural Mdeling Subcmmittee -derived applicatin rate table t represent baseline applicatin rate targets versus prescriptive annual nutrient applicatins. The Agricultural Mdeling Subcmmittee-derived applicatin rate table, which was apprved by the Agriculture Wrkgrup, significantly mdified the LGU nutrient applicatin recmmendatins acrss the six states fr nn-legume hay and pasture land uses. The apprved applicatin rates fr pasture are nw reflective f an average applicatin rate cnditin, which represents a range f annual nutrient applicatins frm zer t abve the recmmended applicatin rates frm the LGU. Cnsequently, the Panel recmmendatins were mdified t address this new baseline f applicatin rates frm the Agricultural Mdeling Subcmmittee by creating a neutral multiplier fr nn-legume hay and pasture land uses. By ding s, the Panel recmmendatins are aviding the duble crediting f nutrient management n these land uses as the mdel credit as already been represented in the base mdel cnditin established by the AMS applicatin rate table. One ptential ptin fr the partnership t cnsider wuld be the representatin f several management levels fr pasture land uses in the future. Currently, nly ne pasture land use is available in Phase 6. Gene Yagw I think the terminlgy used in Appendix A is much mre straight-frward in referring t the Cre Applicatin Gal mdifiers as "multipliers", rather than as "efficiencies", as used in the bdy f the reprt. I think it is very cnfusing and a mis-use f the term "efficiency". Respnse: The Panel has mdified the reprt t use the phrases rate multipliers fr the Cre Nutrient Management BMPs and lss reductin multipliers fr Supplemental Nutrient Management BMPs in lieu f efficiency. Delaware The cmbinatin f disparate applicatin rate gals between nutrient management and nn-nutrient management acres under the CORE lacks equity amngst the states while the final distributin f fertilizer sales is the true measure f applicatin rates. The synthesis f CORE NM cverage and distributed fertilizer sales will result in states with higher adptin and cmpliance rates. This will frce neighbring states t absrb additinal fertilizer, in effect duble-cunting the detrimental effect nn-nm acres. A mre equitable slutin t apply the benefit f NM r detriment f nn-nm acres, culd be t summarize current levels f CORE NM acrss the watershed and simulate disparate applicatin gals in scping runs that yield a resulting efficiency credit fr acres f CORE NM which culd be applied universally. This credit culd be calculated by an average r ther arithmetic methd fllwing the scping runs, t be reviewed by the AMS and Agriculture Wrkgrup. Attempting t apply 30% mre P t nn-nm crn fr grain acres and instead frcibly applying upwards f 40% mre t cunties with lagging implementatin, will cause fluctuating benefits thrugh time and acrss jurisdictins as implementatin creeps twards 2025 gals. Dcumented levels f effrt can be run in the mdels, resulting in an average benefit that can be substituted fr this variable rate that wrks much the same as Phase 5 s land use change methd fr credit. This wuld have the benefit f increasing equity f BMPs and cnsistency thrugh simulatins and prgress runs that better cmmunicate exceedances and shrtfalls in nutrient reductin gals. Recent surveys and lab data have fund that reginally, ver 80% f farmers have current manure and/r sils analysis and 75% are maintaining apprpriate levels f sil fertility. Such evidence is supprtive f the cnservativeness f recent state implementatin rates and the cnsistency f implementatin acrss vast areas f agriculture. Respnse: The Panel recmmendatins include the use f N and P applicatin rate multipliers fr nutrient management and nn-nutrient management acres. The applicatin rate multipliers by land use are based n a 1985 baseline cnditin, and when cupled with the Agricultural Mdeling Subcmmittee derived applicatin rate table, represent baseline applicatin rate targets rather than prescriptive annual nutrient applicatins acrss the six Bay states and three decades f time. The Panel applicatin rate targets are in effect mdified by the annual availability f nutrients fr applicatin, which will vary by state and year depending n transprted rganic nutrients, livestck generated rganic nutrients, inrganic nutrient sales, etc. The representatin f nutrient management and nn-nutrient management acres 99

100 within cunties r states ver time is reflective f the implementatin, tracking, and reprting f nutrient management acres by the partnership n an annual basis, which can vary ver time due t many factrs. Jeff Sweeney In rder fr efficiencies (that) apply multiplicative mdifiers t edge-f-stream delivery f N, the recmmended benefits needed t be grunded in studies that lked at mnitred in-stream changes in lads r cncentratins, e.g. paired watershed studies. Is this the case r did mst studies used in the Panel s evaluatins lk at, fr example, edge f field changes? Respnse: The Panel has mdified sectin 3.2 t include a thrugh discussin f the literature used in cnjunctin with best prfessinal judgment t determine the recmmended values fr the applicatin rate multipliers fr the Cre Nutrient Management BMPs and the lss reductin multipliers fr the Supplemental Nutrient Management BMP. The Panel has mdified the reprt t use the phrases rate multipliers fr the Cre Nutrient Management BMPs and lss reductin multipliers fr Supplemental Nutrient Management BMPs in lieu f efficiency. Gene Yagw On page 21, the supplemental BMP efficiencies are referred t as being "additive", whereas Table 16 and the examples shw that they are instead "multiplicative". Fr further clarificatin, an example shuld be given that shws hw the math wrks ut when mre than ne supplemental credit is applied. Currently, all the examples just shw ne supplemental BMP being credited at a time. Reiterated by Chesapeake Bay Cmmissin: What is the prcess by which C, D and E are "additive"? Hw is the final calculatin made when multiple adjustments (rate, placement and timing) are present? This questin applies t the P calculatin belw as well. Respnse: The Panel has mdified the reprt t use the phrases rate multipliers fr the Cre Nutrient Management BMPs and lss reductin multipliers fr Supplemental Nutrient Management BMPs in lieu f efficiency. In additin, the reprt language has been mdified t replace additive with stackable and multiplicative. Appendix A f the Panel recmmendatin reprt prvides additinal clarificatin and examples f hw the Supplemental NM BMPs will be represented and applied in the Phase 6 mdeling tls. Supplemental N NM BMP lss reductin credits fr N rate, N timing, and N placement are stackable, e.g. multiplicative with diminishing returns fr reducing envirnmental lss, as are Supplemental P NM BMP lss reductin credits fr P rate, P timing, and P placement. Pennsylvania DEP It wuld be valuable t understand the impact f nn-nm efficiencies within the Phase 6 mdeling structure. Respnse: The Panel has mdified the reprt t use the phrases rate multipliers fr the Cre Nutrient Management BMPs and lss reductin multipliers fr Supplemental Nutrient Management BMPs in lieu f efficiency. The applicatin rate multipliers by land use are based n a 1985 baseline cnditin, and when cupled with the Agricultural Mdeling Subcmmittee derived applicatin rate table, represent baseline applicatin rate targets rather than prescriptive annual nutrient applicatins acrss the six Bay states and three decades f time. The Panel applicatin rate targets are in effect mdified by the annual availability f nutrients fr applicatin, which will vary by state and year depending n transprted rganic nutrients, livestck generated rganic nutrients, inrganic nutrient sales, etc. The representatin f nutrient management and nn-nutrient management acres within cunties r states ver time is reflective f the implementatin, tracking, and reprting f nutrient management acres by the partnership n an annual basis, which can vary ver time due t many factrs. Virginia Cre Nutrient Management: 1. We recgnize cre is meant t be the base r lwest level f recgnized implementatin. Hwever and mre imprtantly, cre is the fundatin n which any nutrient management credit, including the enhancements, will rest upn. Shuldn t that base be built upn such fundamental, agrnmically sund building blcks fr 100

101 nutrient management as actual sil and manure test values nt bk values? The nly time manure bk values shuld be acceptable fr cre nutrient management is at start up fr new peratins that have yet t prduce manure. Only lcal r mid-atlantic based bk values shuld be cnsidered reasnable even then. This allwance shuld nly be valid fr initial planning purpses and a manure analysis shuld be attained and utilized t adjust recmmendatins when manure is first available fr land applicatin and frm that pint frward. There shuld be n exceptin t using sil test at the field level less than 3 years ld as the basis fr phsphrus cre nutrient management. Even n fields testing t high fr a land grant university phsphrus recmmendatin, the sil test value is generally a cmpnent f a phsphrus lss assessment tl t determine if phsphrus may be applied. Using an assumed sil test value based n a waiver with such tls may allw greater phsphrus applicatin n fields than an actual sil test value used with the tl wuld indicate fr that field. We recgnize sme jurisdictins currently utilize such waivers t achieve nutrient management r manure management planning. These jurisdictins will need a ramp up r grace perid t begin implementatin f cre nutrient management withut such waivers. Three years seems t be recgnized as a typical plan life cycle and culd be cnsidered as a timeframe fr such a ramp up. New Yrk Upper Susquehanna Calitin supprted this cmment. Maryland Department f Agriculture reiterated this cmment. Respnse: The Panel agrees that the use f actual and current sil and manure test values are preferable ver the use f applicable bk values fr sund nutrient management decisins by the peratr. The Panel recgnized the present diversity f nutrient management planning effrts acrss the six Bay states with the utilizatin f applicable bk values in place f actual and current sil and/r manure analysis. Hwever, ttally eliminating the apprpriate use f bk values culd be detrimental t federal and state nutrient management prgrams t varying degrees. Fr example, nutrient management planning effrts typically rely n applicable bk values when develping plans fr new r expanding livestck peratins when a representative manure analysis is nt pssible r available. Sme nutrient management prgrams currently permit by prgram guidance r regulatin the use f applicable bk values fr sil and/r manure nutrients as part f their planning effrts. Mdificatins t these regulatry and permit prgrams may require legislative actin t effectively limit the use f bk values fr planning effrts. Cnsequently, the Panel reprt has prvided mdified language within the reprt which places greater limits n the use f bk values in place f manure and sil analysis. In a separate actin, US EPA is develping a supprting dcument fr partnership supprt which prvides a prcess whereby the jurisdictins can mdify their existing prgrams ver time t address prgrammatic and legislative actins. The Panel, hwever, fully supprts the preferential use f current sil and manure analysis data t guide nutrient management implementatin. Virginia 2. The reprt states Federal and/r state certified Nutrient Management Plan nt required. The NM Panel did nt define the N (r P) Cre NM BMP t require a cmprehensive and/r certified Nutrient Management Plan (NMP) in rder t receive the BMP credit. Upn initial review these statements did nt seem vertly alarming r cncerning. Hwever, fllwing mre in depth thught and discussins with clleagues they d present sme trublesme undertnes. Nutrient management r manure management plans (aka: plan(s)) have been the cre f nutrient management prgramming effrts in essentially every jurisdictin within the Chesapeake Bay Watershed since inceptin f these state run prgrams. Eliminating the requirement fr plans t serve as the mechanism t deliver and reprt the cre elements f nutrient management may very well serve t erde the validity f these plans and the prgrams we have wrked s diligently t develp. Currently, plans are required fr a multitude f purpses such as permitting and cst share f varius practices. Hw can we return t ur respective states and still assert that a plan is required fr any purpse if we have agreed it is nt necessary t achieve credit fr cre nutrient management? Nt nly that, but nwhere in the prpsal des implementing a plan garner credit. Prducers and rganizatins that have fught the develpment f plans fr years culd very easily demand such plans be eliminated based n ur agreement they are nt an essential part f cre nutrient management. As stated abve, plans serve as the current mechanism fr reprting. Many f ur activities and effrts revlve arund attaining, maintaining and especially reprting plans. Withut this framewrk called a plan what mechanism will be utilized t capture cre nutrient management acres? Hw much time, effrt and 101

102 mney wuld be needed t facilitate use f a new r additinal reprting prcess? Hw wuld we attain the needed data n these cre practices withut a plan? The pint being, the plan has been a valuable tl that has been adapted and utilized ver nearly three decades. T discard r even minimize it nw withut careful deliberatin may well prve t be an errr in judgement. Respnse: The Panel defined the N and P Cre NM BMPs t require full implementatin f a defined set f fundamental elements in rder t receive the recmmended practice credits. The elements that cnstitute the N and P Cre NM BMPs may r may nt be cmpnents f a frmal Nutrient Management Plan. The required nutrient management dcumentatin culd be in the frm f a frmal federal, state, r cunty-reviewed and certified nutrient management prgram plan, a nn-certified frmal nutrient management plan develped by a federal- r state-certified plan writer, r detailed dcumentatin and an infrmal management plan cmpiled by an peratr r private cnsultant that met the Panel s BMP recmmendatins. The incrpratin f verificatin requirements within the Panel reprt, based n the CBP partnership-apprved BMP Verificatin Guidance, will rely n farm management recrds reviewed by a trained and/r certified independent third party. Federal and state regulatry nutriment management plans currently ffer ne accepted methd t track, verify and reprt NM BMP implementatin. Hwever, the Panel als identified ther existing examples f implementatin dcumentatin cupled with privately develped management plans which culd ptentially meet and exceed the management f nutrients assciated with regulatry prgrams. The Panel cnsidered excluding the recgnitin f these nn-regulatry nutrient management effrts, but elected t be inclusive f planning systems which achieved full implementatin f the required elements. Virginia Advanced Nutrient Management 1. Manure analysis < 3 years ld is listed as an Advanced N Assessment and an Advanced P Assessment in the reprt. Sil test < 3 years ld and P index Assessment are als shwn as Advanced P Assessment items in the reprt. Each f these are als enumerated in the required elements fr cre nutrient management. Sil and manure testing are specifically detailed in the cre table while the p lss assessment is included as an ptin under Land Grant University recmmendatins used t determine p applicatin gals at the field level. Depicting these items as bth cre and advanced elements may be cnfusing and, pssibly, suggestive f an attempt t garner und duble crediting fr these items. Respnse: The Panel reprt language has been mdified t represent manure analysis less than ne year ld in the Advanced N and P Assessment tables. In additin, the reprt has been mdified t represent sil tests as a Cre NM element nly, and P index as an Advanced P Assessment tl. 2. Elements required t attain cre nutrient management credit fr n r p r bth cannt be cnsidered as advanced nutrient management. Als, elements that may be used t attain cre nutrient management credit fr n r p r bth, such as p lss assessment, cannt be cnsidered as advanced nutrient management. Respnse: The Panel defined Cre NM BMP elements as the basis fr implementing enhanced management represented by the Supplemental NM BMPs. The crediting fr Cre and Supplemental NM BMPs are separate and apply different multipliers t applicatin rates and envirnmental lsses respectively. The Panel reprt has been mdified t mre fully separate the required NM practices fr Cre and Supplemental NM BMPs. 3. Sil testing at lesser intervals than 3 years (fr instance, sil test < 1 year ld) shuld nt be cnsidered fr advanced p assessment. Inclusin f such a practice will nly entice sme grups t seek cst share funding fr these practices based slely n their inclusin n a list f advanced n r p assessment in the mdel. Funding fr such additinal practices that may garner little benefit is nt feasible r prudent. Respnse: The Panel s recmmendatins have been mdified t represent sil testing at less than three-years ld as a required element fr Cre NM, nt fr a Supplemental NM BMP. 102

103 Similar Cmments frm Chesapeake Bay Fundatin: Table 6 and 10: It is unclear why credit wuld be given fr setbacks frm water. Desn t the applicatin f cre NMPs require there t be sme setbacks frm water? Table 8: Having a sil test fr P that is less than 3 years ld is a parameter fr the cre NMP BMP credit, s why is it als listed fr supplemental timing credit? Similarly manure nutrient analysis and use f a Phsphrus index are als listed as a cre requirements, but als listed as an examples f advanced nutrient management. This shuld be clarified. Respnse: Applicatin setbacks are nt universally implemented r required in all cases, nr were they histrically represented ging back t the base calibratin year f Thus, the Panel chse t represent applicatin setbacks as a ptential Supplemental NM BMP fr nutrient placement. The Panel s recmmendatins have been mdified t represent sil testing at less than three-years ld as a required element fr Cre NM, nt fr a Supplemental NM BMP. The reprt has als been mdified t represent manure nutrient analysis as a required Cre NM element, hwever, the use f P index tl is represented as an Advanced P Assessment Tl which has t be cupled with dcumented implementatin adjusting nutrient applicatins in rder t btain credit. VA DEQ PSNT is listed in Advanced Assessment Tl and N Timing Adjustment. S is it that a PSNT is recmmended in the plan r actually dne? And if dne des it get credit fr timing and advanced assessment r just timing? It is pssible nce a PSNT is dne that additinal N fertilizer is nt needed. Wuld that als nt be a rate adjustment since additinal N fertilizer is nt used? Respnse: The Panel s recmmendatins represent the use f PSNT as bth an Advanced N Assessment Tl and as a Supplemental N Timing BMP. Assessment tls d nt btain an envirnmental lss reductin credit unt themselves. The credit fr reducing envirnmental lss is nly btained by the infrmed implementatin f the recmmendatins stemming frm the use f the Assessment Tl, in this case the implementatin f split applicatins f N affecting timing f nutrient applicatins. New Yrk Upper Susquehanna Calitin The supplemental P efficiencies n page 20 f the reprt fr Legume Hay shuld als be used fr Other Hay. We ask the Panel t develp nn-zer supplemental N management practice efficiencies fr Other Hay, perhaps at similar percentages t thse used fr P. Respnse: The Panel recmmendatins include the use f N and P applicatin rate multipliers fr nutrient management and nn-nutrient management acres. The applicatin rate multipliers by land use are based n a 1985 baseline cnditin, and are cupled with the Agricultural Mdeling Subcmmittee -derived applicatin rate table t represent baseline applicatin rate targets versus prescriptive annual nutrient applicatins. The Agricultural Mdeling Subcmmittee-derived applicatin rate table, which was apprved by the Agriculture Wrkgrup, significantly mdified the LGU nutrient applicatin recmmendatins acrss the six states fr nn-legume hay. The apprved applicatin rates fr nn-legume hay are nw reflective f an average applicatin rate cnditin, which represents a range f annual nutrient applicatins frm zer t abve the recmmended applicatin rates frm the LGU. Cnsequently, the Panel recmmendatins were mdified t address this new baseline f applicatin rates frm the Agricultural Mdeling Subcmmittee by creating a neutral multiplier fr nn-legume hay land uses. By ding s, the Panel recmmendatins are aviding the duble crediting f nutrient management n these land uses as the mdel credit as already been represented in the base mdel cnditin established by the AMS applicatin rate table. Pennsylvania DEP Table 12: Legume hay has a "penalty" applied but there is n NM BPB that can be applied against it. This seems unfair t LH-rich jurisdictins and suggest that this value be 1.00 withut supprting infrmatin as t why it shuld be Respnse: The Panel recmmendatins include an applicatin rate multiplier fr Cre N NM f 1.00 and a nn-nm 103

104 Cre N multiplier f Table 13: 3x LGU rate seems high. Is there scientific literature t establish this? Otherwise, it needs further explanatin like the prir table. Wuld 2.5 be a better number? And what is the verall effect (sensitivity) f changing this multiplier? Respnse: The Panel recmmendatins are established n a baseline f 1985 t mirrr the Chesapeake Bay Prgram partnership s mdeling tls baseline fr BMP implementatin and mdel calibratin. The Panel has mdified sectin 3.2 t include a thrugh discussin f the literature used in cnjunctin with best prfessinal judgment t determine the recmmended values fr the applicatin rate multipliers fr nn-nm and Cre Nutrient Management BMPs. Sectin 4: Review f Literature and Data Gaps Jeff Sweeney What s the status f the secnd independent surce f data representing histric Nutrient Management implementatin [that] has been requested frm the USDA NRCS CEAP based n the tw existing reprts published n the Chesapeake Bay Watershed? Is this statement abut HUC-4 scale infrmatin still relevant and, if s, are there results that can be used in the Nutrient Management reprt? Respnse: The Panel did review implementatin data frm USDA-NRCS CEAP based n the existing tw reprts published n the Chesapeake Bay Watershed. The infrmatin was utilized by the Panel as an independent reference during the Panel s cnsideratins fr histric NM implementatin at a HUC 4 scale. Sectin 5: Applicatin f Practice Estimates Kelly Shenk Significant Imprvements frm Phase 5 Apprach: The fllwing are significant imprvements t the Phase 5 apprach that will help increase transparency in verifying, reprting, and crediting nutrient management activities that are resulting in verified actins that will reduce nutrient lsses. Imprvements include: Mving away frm crediting plans t crediting specific suites f verified practices that are implemented t manage nutrients related t surce rate, timing, and placement. Crediting the supplemental practices nly after the cre nutrient management BMP is implemented t ensure a baseline level f nutrient management n which t build the mre advanced appraches. Crediting supplemental practices nly when implementatin f adjustments in nutrient rates, placement r timing is verified s that we are crediting the nutrient reductins that are happening due t these advanced practices. Respnse: The Panel s recmmendatins were built upn the scientific expertise f the panel members in an academic apprach t the BMP evaluatin, and the initial grund wrk established by the Phase Panel. Jeff Sweeney In sectin 5.8 Practice Limitatins, These practices may be applied t all agricultural land use categries in the CBW yet it appears there s n recmmendatin fr benefits f pasture and nursery nutrient management fr practices similar t thse in the reprt. In ther wrds, if pasture nutrient management is anything beynd, fr example, prescribed r rtatinal grazing, alternative watering and fencing, please clearly describe in this reprt and fr nursery as well. There s been uncertainty abut what, exactly, shuld be reprted fr pasture nutrient management s this is the time t reslve the issue. Respnse: The Panel recmmendatins include the use f N and P applicatin rate multipliers fr nutrient management and nn-nutrient management acres. The applicatin rate multipliers by land use are based n a 1985 baseline 104

105 cnditin, and are cupled with the Agricultural Mdeling Subcmmittee -derived applicatin rate table t represent baseline applicatin rate targets versus prescriptive annual nutrient applicatins. The Agricultural Mdeling Subcmmittee-derived applicatin rate table, which was apprved by the Agriculture Wrkgrup, significantly mdified the LGU nutrient applicatin recmmendatins acrss the six states fr pasture land uses. The apprved applicatin rates fr pasture are nw reflective f an average applicatin rate cnditin, which represents a range f annual nutrient applicatins frm zer t abve the recmmended applicatin rates frm the LGU. Cnsequently, the Panel recmmendatins were mdified t address this new baseline f applicatin rates frm the Agricultural Mdeling Subcmmittee by creating a neutral multiplier fr pasture land uses. By ding s, the Panel recmmendatins are aviding the duble crediting f nutrient management n these land uses as the mdel credit as already been represented in the base mdel cnditin established by the AMS applicatin rate table. Other pasture related BMPs such as prescribed grazing and alternative watering will cntinue t be applicable and represent separate and independent crediting pprtunities Nursery is represented in the Phase 6 mdeling tls as Specialty Crp Lw and High. The Panel s recmmendatins include separate multiplier values fr bth nn-nm and NM fr N and P which represent a credit value fr NM applicatin rates. Jim Crpper Mre cnsideratin shuld be given t pasture and the nutrient inputs it receives, either frm manure, pultry litter, r cmmercial fertilizer. N applicatin rates n pastures based n frage prductin remval rates, as if they were hayfields with n grazing livestck n them, is nt a valid methd f determining N requirements fr pastures. This has the same effect (r larger) as saying that it takes 1.2 punds f N t prduce a bushel f crn. On average 85 percent f the N ingested by the grazing animal is returned t the pasture, therefre there is n need t imprt large amunts f N t a pasture any mre than t imprt cal t Newcastle. I am hpeful this is nt a prblem with LGU's within the Chesapeake Bay. I knw it is a prcedure used elsewhere as I have been t their websites and have seen it mentined in ppular agricultural press. T d therwise, is t thrughly discunt any f the N returned t the pasture by the grazing animal as being available fr plant uptake. N applied either with cmmercial fertilizer r manures must be reduced t accunt fr N being returned by the wastes excreted n the pasture by the grazing animal, imprted feeds N cntributins, and als N cntributed by legumes grwing in the pasture if they cmpse greater than 10 percent f the frage mass prduced. In ther wrds, a mass balance f N needs t be dne befre making any additinal N fertilizer recmmendatins n pasture. We really d need t get a handle n hw many acres f pasture d receive manure. It als appears that we need t knw where exprted manure ges and its rate f applicatin that is spread ff the farm prducing it. I knw this is a tuchy subject, but it wuld appear if the manure is ging ff the farm that every place it ges t must be a part f the whle nutrient management plan fr the prducing farm, nt just cver the prducing farm acreage. The data shuld be available in each state ding nutrient management planning, but it may be incmplete if exprted manure is nt tracked. Respnse: The Panel recmmendatins include the use f N and P applicatin rate multipliers fr nutrient management and nn-nutrient management acres. The applicatin rate multipliers by land use are based n a 1985 baseline cnditin, and are cupled with the Agricultural Mdeling Subcmmittee -derived applicatin rate table t represent baseline applicatin rate targets versus prescriptive annual nutrient applicatins. Fr pasture land uses, the panel chse t recmmend a neutral multiplier fr applicatin rates. Hwever, the Phase 6 mdeling tls will distribute nutrients t applicable land uses within each cunty based n factrs such as manure nutrient generatin, manure nutrient transprt, and nn-rganic nutrients. The Agricultural Mdeling Subcmmittee s recmmendatins n nutrient applicatin curves and distributin, apprved by the AgWG, will affect the final representatin f nutrients being applied within pasture land uses with a cunty n an average cnditin. Jim Crpper The zer baseline has t be when P-based requirements were initiated by each State as it relates t pastures that receive pultry litter. Unfertilized pastures may as well have the baseline be Fr pastures where supplemental feeding f hay r TMR ccurred, the zer baseline wuld be when nutrient mass balances were initiated that began t limit additinal P int the feeding system as peratrs began fllwing the prtcls. 105

106 Respnse: The Panel recmmendatins are based n a 1985 baseline cnditin which cmpliments the BMP implementatin baseline cnditins lng established by the Chesapeake Bay Prgram partnership and its assciated mdeling tls. BMP tracking and reprting by the CBP partnership begins with the 1985 baseline fr representing BMP implementatin frm that year frward, including nutrient management. BMPs that may have been implemented prir t 1985 are represented by their influence n water quality data cllected n and after the baseline year versus as a direct BMP implementatin reprtable input int the CBP mdeling tls. VA DEQ We are very cncerned that this panel is indicating n benefit t NM n ther hay and pasture. Other hay wuld include Bermuda grass hay where hg r ther animal wastes are applied. In these situatins permitted peratins must have a NMP. Yet this panel wuld seem t indicate n benefit t such a plan r permit requirement??? Hw can this be cnsidering the prspect f dispsal rates verses LGU recmmendatins? Basically lking at land use as prvided by CBP Virginia s agriculture is rughly 50% pasture, 25% hay, and 25% crpland. Withut knwing the use f legumes within planned acres f hay there is a cncern that CBP will default t all NM reprted by VA n hay as applied t ther hay? This wuld seem t relegate 75% f Virginia s agriculture t nt needing a NMP r n benefit t reprting them. This des nt seem cngruent with the educatinal aspects a NMP has fr a farm r with VA being able t meet ur Bay TMDLs reductin gals r situatins where animal wastes r bislids are utilized n pastures, pastures that are als hayed and dedicated hay prductin fields. A prepnderance f the reprted NM acres n pasture in VA are assciated with bislids permits and applicatins. Is this panel actually saying there is n benefit t NM planning n these sites? It seems that the Panel is nly fcused n fertilizer applicatins t pasture and hay and is ignring rganic surces. Suggest the Panel recnsider NM planning benefits t pasture and ther hay especially in situatins where they are tied t manure and bislids applicatins. Respnse: The Panel recmmendatins include the use f N and P applicatin rate multipliers fr nutrient management and nn-nutrient management acres. The applicatin rate multipliers by land use are based n a 1985 baseline cnditin, and are cupled with the Agricultural Mdeling Subcmmittee -derived applicatin rate table t represent baseline applicatin rate targets versus prescriptive annual nutrient applicatins. The Agricultural Mdeling Subcmmittee-derived applicatin rate table, which was apprved by the Agriculture Wrkgrup, significantly mdified the LGU nutrient applicatin recmmendatins acrss the six states fr pasture land uses. The apprved applicatin rates fr pasture are nw reflective f an average applicatin rate cnditin, which represents a range f annual nutrient applicatins frm zer t abve the recmmended applicatin rates frm the LGU. Cnsequently, the Panel recmmendatins were mdified t address this new baseline f applicatin rates frm the Agricultural Mdeling Subcmmittee by creating a neutral multiplier fr pasture land uses. By ding s, the Panel recmmendatins are aviding the duble crediting f nutrient management n these land uses as the mdel credit as already been represented in the base mdel cnditin established by the AMS applicatin rate table. Hwever, the Phase 6 mdeling tls will distribute nutrients t applicable land uses within each cunty based n factrs such as manure nutrient generatin, manure nutrient transprt, and nn-rganic nutrients. The Agricultural Mdeling Subcmmittee s recmmendatins n nutrient applicatin curves and distributin, apprved by the AgWG, will affect the final representatin f nutrients being applied within pasture land uses with a cunty n an average cnditin. Sectin 6: Practice Mnitring and Reprting Jeff Sweeney The Panel recmmends that the highest level f Nutrient Management implementatin be represented in the mdels at reprted 2015 acres. Hwever, mst states did nt have a strng quantitative basis fr their reprted acres that wuld satisfy the guidelines fr verificatin that the Panel recmmends is needed. There was a cmpliance crss-walk f acres in varius state nutrient management prgrams; hwever, there were ften weak cnnectins between that infrmatin and what was reprted fr the 2015 mdel assessment. Hw d we rectify this situatin? Respnse: The incrpratin f verificatin requirements within the Panel reprt was nt develped by the Panel but is instead based n the CBP partnership-apprved BMP Verificatin Guidance, which relies n farm management recrds reviewed by a trained and/r certified independent third party. The CBP partnership-apprved BMP Prtcl requires 106

107 all BMP Panel recmmendatin reprts t incrprate the BMP Verificatin Guidance int the Panel s recmmendatins. The specifics f what thse verificatin requirements are based n the BMP Verificatin Guidance, but will vary frm state t state based n their BMP verificatin plan and QAPP requirements. Full implementatin f BMP verificatin was established between the partners fr 2018, at which time all reprted BMPs are required t satisfy the guidelines fr verificatin. Delaware Secnd, states tracking prtcls shuld use a simple apprach t tracking and reprting. This is best accmplished by using a menu r check list f advanced NM tls enumerated in the reprt beynd CORE. While the science behind elements f advanced NM techniques, like PSNT, variable rate nutrient applicatin and banding f nutrients are dcumented, a cmmn interpretatin f an index, tl r test is t in-fact implement n change. Please cntinue t make this pint t nn-state stakehlders t prevent any cnfusin. Respnse: The Panel s recmmendatins have been mdified t prvide additinal clarity n the applicatin f Advanced Assessment Tls and their rle in infrming nutrient management practices fr Supplemental NM BMP tracking, verificatin, and reprting. VA DEQ Suggest a single statement n the needs fr NM practices t be develped cnsistent with each states verificatin prgram. As is the current reprt use f the terms related t verificatin (verified, implemented and verified) is redundant and unnecessary. It is nt needed in multiple tables, figures, and repeatedly within the same paragraph (page 11). Current use in this reprt is verkill when a single statement r paragraph culd suffice. Respnse: The incrpratin f verificatin requirements within the Panel reprt was nt develped by the Panel but is instead based n the CBP partnership-apprved BMP Verificatin Guidance, which relies n farm management recrds reviewed by a trained and/r certified independent third party. The CBP partnership-apprved BMP Prtcl requires all BMP Panel recmmendatin reprts t incrprate the BMP Verificatin Guidance int the Panel s recmmendatins. The specifics f what thse verificatin requirements are based n the BMP Verificatin Guidance, but will vary frm state t state based n their BMP verificatin plan and QAPP requirements. Envirnmental Integrity Prject The reprt is nt clear abut the mechanics f verificatin reprting, r the cnsequences fr failure t fully dcument verificatin results. We assume that the Panel intends t give credit fr all nutrient management acres, nt just the acres with a verificatin inspectin and paper trail. As we understand the mechanics f BMP verificatin t wrk, each state will verify a subset f BMP acres and use the results f that sub-sampling t discunt ttal reprted BMP acres. That prcess raises a few questins fr the NM BMP, which is in practice nt a single BMP, but a suite f BMPs: Shuld each state estimate the rate f verall nncmpliance with nutrient management BMPs and use that nncmpliance rate t discunt ttal nutrient management acres? If s, what cnstitutes nncmpliance? Fr example, if a farmer intends t implement three supplemental practices t be eligible fr all three categries f supplemental N credit, but nly implements tw, with the result that the farmer is nly eligible fr tw categries f credit, wuld that be cmpliance, nncmpliance, r smething in between? Perhaps, instead, the Panel wuld like t see each state sampling, and reprting with sampling-based discunts, each categry. Fr example, Maryland might sample all N Rate Adjustment Practices and discunt the ttal reprted N Rate Adjustment Practices by the nncmpliance rate fund in sampling. Or perhaps the Panel wuld like t see each state sampling and reprting at the practice level (e.g., split N applicatins). The expert panel shuld clearly state hw verificatin results shuld be used t discunt BMP reprting. Fr example, the Panel culd say smething like the fllwing: Nutrient management acres fail verificatin inspectins if the farmer has nt implemented all f the cre elements. Nutrient management acres additinally fail verificatin inspectins fr each categry f supplemental BMP if the farmer has failed t adequately implement at least ne 107

108 practice within that categry. Fr example, if a farmer claims credit fr a P Timing BMP, but has nt limited P applicatin t the lwer P-lss risk seasn, then that farm will have failed the verificatin inspectin. Regardless f whether a BMP underges subsequent crrective actin, the results f the initial inspectin shall be used as representative f the success r failure f that BMP. Each state shuld calculate a cumulative failure rate fr all nutrient management BMPs and apply that rate t discunt the reprting f each nutrient management BMP. Respnse: The jurisdictins will be expected t determine if the current verificatin prtcls and prcedures in their QAPP fr NM BMPs are sufficient fr the recmmended Cre and Supplemental NM BMPs after this expert panel recmmendatin reprt is apprved by the CBP partnership. This will be dne befre the jurisdictins are able t start submitting these BMPs in the Phase 6 mdeling tls fr annual prgress implementatin. Nutrient management practices incrprate bth nn-visual (e.g., nutrient applicatin rate) and visual cmpnents (e.g., manure injectin and incrpratin), bth f which can reasnably be verified using elements f bth the Nn-Visual Assessment and Visual Assessment (Annual) categries described in the AgWG verificatin guidance. The Panel is nt prpsing any new r unique aspects f BMP verificatin fr purpses f the BMPs described in this reprt. Sectin 6 f this reprt simply explains hw the recmmended BMPs crrespnd t the existing BMP verificatin guidance. Each jurisdictin will determine the mst apprpriate methds fr verifying NM BMP implementatin given their specific pririties, prgrams, needs, and capacity. The states can fllw the AgWG s guidance fr Nn-Visual Assessment BMPs t verify the N and P Cre NM BMPs fr reductin credits in the Phase 6 CBWM. The N and P reductins fr Cre NM BMPs are t be based n the verified required elements f the N and P Cre NM BMPs which shuld be dcumented in the recrds available t the applicable state agency. If the state finds that this basic infrmatin fr N and P Cre NM BMPs cannt be verified thrugh spt-checks r ther annual BMP verificatin prcedures described in its BMP Verificatin Plan and QAPP, then the BMP cannt be reprted fr credit. Fr N and P Supplemental NM BMPs, recrds available t the state must dcument the implementatin f additinal nutrient applicatin changes fr rate, timing, and/r placement described by the Panel fr these supplemental BMPs in rder t receive credit; nte that credit fr N and/r P Supplemental NM BMPs cannt be btained unless satisfactry implementatin f the respective Cre NM BMP (N r P) is dcumented. Absent dcumentatin f Supplemental NM BMP implementatin, credit may still be btained fr Cre NM BMPs fr which implementatin is dcumented. Chesapeake Bay Cmmissin Page 30 - The Panel recmmends that NM BMP implementatin tracking, verificatin, and reprting n a cunty-bycunty r state-by-state basis be based n the premise that they represent annual Nn-Visual Assessment BMPs. - Given the discussin belw f hw visual and nn-visual assessments can be applied, this blanket statement is nt apprpriate here. Respnse: The Panel s reprt has been mdified t address changes in the language regarding BMP verificatin. Pennsylvania DEP Pg. 30, Since it is an annually reprted BMP, the mst imprtant criteria (i.e. NM Cre N and Cre P elements) shuld be dcumented smewhere in the recrds available t the applicable state agency. Cmment: Understand that plans are written fr a three-year perid f time. Respnse: The Panel is aware that many, but nt all, nutrient management plans are develped fr a three-year perid f implementatin. Dcumentatin f the implementatin f thse plans during the perid f implementatin is a fundamental element f BMP verificatin accrding t the partnership s BMP Verificatin Guidance. Appendix A: Technical Requirements fr Reprting and Simulating Nutrient Management BMPs in the Phase 6 Watershed Mdel Gene Yagw Appendix A als defines the supplemental BMPs as percent reductins, while the main bdy f the reprt talks abut efficiencies (1 - percent reductins). Percent reductins are additive, while efficiencies are multiplicative, thugh nt 108

109 exactly s. Take the fllwing example with 100 lbs. f P applied t Grain w/ Manure with rate, placement, and timing percent reductins f 5%, 10%, and 1%, respectively. Percent Reductin Basis: 100 * (1 - ( )) = 84.0 Efficiency Basis: 100 * 0.95 * 0.90 * 0.99 = These are nt fully equivalent, s whichever basis is used, it shuld be used cnsistently bth in the dcument and in the reprting requirements as in Appendix A. Similar cmments reiterated by Envirnmental Integrity Prject: Cumulative nutrient reductins can be much higher in Phase 6 than they were in Phase 5, and supplemental BMP efficiency values shuld nt be additive. Respnse: The Panel has mdified the reprt t use the phrases rate multipliers fr the Cre Nutrient Management BMPs and lss reductin multipliers fr Supplemental Nutrient Management BMPs in lieu f efficiency. In additin, the reprt language has been mdified t replace additive with stackable and multiplicative. Appendix A f the Panel recmmendatin reprt prvides additinal clarificatin and examples f hw the Supplemental NM BMPs will be represented and applied in the Phase 6 mdeling tls. Supplemental N NM BMP lss reductin credits fr N rate, N timing, and N placement are stackable, e.g. multiplicative with diminishing returns fr reducing envirnmental lss, as are Supplemental P NM BMP lss reductin credits fr P rate, P timing, and P placement. VA DEQ Nt all farms have manure s when it says all elements must be implemented and verified suggest yu preface manure sampling with the wrds if applicable. Nt sure hw a NM plan writer can verify the spreader/applicatr equipment f a custm applicatr (fertilizer dealer) is calibrated. Likewise nt sure hw t verify a farmer actually implements the plan recmmendatins withut tracking fertilizer sales receipts by farm and field. Similar fr crpping histry in that a planner might dcument such a histry in the plan but nt sure hw ne actually verifies a farmer did what he said he did in terms f which crps were planted in which field in any given year. Again suggest instead f saying implemented and verified s ften have ne blanket statement smewhere in the reprt indicating cnsistency with state verificatin guidelines. Respnse: The Panel recmmendatins fr Cre NM BMPs required elements include the need fr the calibratin f applicatin equipment, regardless that be in the frm f an applicatin f rganic r inrganic nutrients. Operatrs wh hire custm applicatrs are recmmended t maintain dcumentatin f the applicatins, and the custm applicatr s cntact infrmatin, s that dcumentatin f calibratin can be btained. The Panel descriptin als includes recgnitin f standard calibratin practices fr addressing equipment calibratin, which culd include multiple recgnized frms, e.g. small area calibratin, field scale calibratin, etc. Large scale calibratin wuld require dcumentatin f full capacities f the applicatin equipment, e.g. tns r gallns, a cnsistent applicatin methd, and the number f spreader/tanker applicatins applied nt a knwn acreage. Envirnmental Integrity Prject It is nt clear hw this BMP will interact with the Bay Mdel. Our understanding f BMP efficiencies is that they will be used t mdify Bay Mdel edge-f-stream lad estimates. Yet the expert panel is als suggesting changes t the input side. If the expert panel recmmendatins are in fact changing the input side f all agricultural acres, it will be a substantial change in the mechanics f the Phase 6 mdel that deserves brader discussin. Adding t the cnfusin are discussins f a cmparisn between the mdified LGU recmmendatins fr applicatin f supplemental inrganic N fertilizer and an alternative apprach based n cunty-level redistributin f AAPFCO N fertilizer sales. This is cnfusing because it is nt clear hw this cmparisn affects the expert panel s recmmendatins, the alternative apprach appears t be the Phase 6 Mdel apprach, and these discussins nly address supplemental inrganic fertilizer, and nt manure. 109

110 Respnse: The applicatin f a N Cre NM BMP applicatin rate multiplier mdifies the crp- and land-use-specific N applicatin rate gal, which is based n Land-Grant University (LGU) crp fertilizatin recmmendatins, as mdified by the CBP partnership. In an effrt t determine the mst practicable methdlgy fr allcating fertilizer N t satisfy crp- and land-use-specific N applicatin rate gals, the Agriculture Wrkgrup cmpared the mdified LGU recmmendatins fr applicatin f supplemental inrganic N fertilizer t an alternative apprach based n cunty-level redistributin f Assciatin f American Plant Fd Cntrl Officials (AAPFCO) N fertilizer sales data. Because there were relatively small differences between the tw methds fr estimating supplemental N fertilizer applicatins, the Agriculture Wrkgrup apprved use f the redistributed AAPFCO fertilizer sales methdlgy in the Phase 6 Mdel. Applicatin f a P Cre NM BMP applicatin rate multiplier mdifies the crp- and land-use-specific P applicatin rate gal, which is based n LGU crp fertilizatin recmmendatins, as mdified by the CBP partnership. A significant mdificatin impsed by the CBP partnership was the assumptin that all agricultural acres in the CBW had a sil-test P cncentratin that crrespnded with the medium sil test interpretive categry. The Panel recgnized that, in the absence f sil-test P cncentratin data, assumed sil-test P cncentratins were necessary t create artificial P applicatin rate gals t facilitate CBP mdel prcesses. Additinally, in the absence f sil-test P data, cunty-level redistributin f CBW AAPFCO P fertilizer sales data may serve as a useful surrgate fr determining P applicatin rate gals. The Panel als cncluded that the inherent uncertainty in P applicatin rate resulting frm the adptin f the universal medium sil-test P cncentratin assumptin is expected t be similar t r greater than the magnitude f the P applicatin rate mdificatins resulting frm implementatin f P Cre NM BMP applicatin rate multipliers. The Panel s prpsed applicatin rate multipliers fr bth N and P Cre NM BMPs are based n state LGU recmmendatins, as mdified by the CBP partnership, and apply t the nutrient applicatin rate gal, r input side, f nutrient management mdeling scheme fr bth NM and nn-nm acres. Each value represents a multiplicative mdifier f the crp- and land-use-specific N r P applicatin rate gal utilized in the CBP mdels. The Panel s prpsed lss reductin multipliers fr N and P Supplemental NM BMPs fr each applicable agricultural land use categry are multiplicative mdifiers that apply t edge-f-stream delivery f N, n the utput side f the CBP mdeling scheme, and can nly be applied if the requirements fr N r P Cre NM BMPs are met. The verall BMP efficiencies fr N and P nutrient management are derived frm a cmbinatin f applicatin rate multipliers fr the Cre Nutrient Management BMPs (N r P) with their crrespnding Supplemental Nutrient Management BMP (N r P) lss reductin multipliers. These multipliers are stackable. The N Cre NM BMP and P Cre NM BMP address the rate f nutrient applicatin while the N Supplemental NM BMPs and P Supplemental NM BMPs address the transprt f applied nutrients. The verall effectiveness values (ne fr N and ne fr P) are calculated as the cmbined effect f changes in nutrient applicatin rate and nutrient transprt caused by the implementatin f Cre and Supplemental NM BMPs. Additinal details are prvided in Sectin 3.3 f the reprt. Pennsylvania DEP Q1/A1 (pg. 41): These sectins shuld reflect the final reprt text. Cnsider "Calibratin f spreader/applicatr and/r applicatin dcumentatin". We have cncerns n ur ability t reprt calibratin data but are mre cnfident n mass/area reprting. Respnse: The Panel s descriptin f spreader/applicatr calibratin has been mdified in the reprt t insert preferably within ne year f the applicatin. Operatr dcumentatin f previus spreader/applicatr calibratins can and shuld be utilized as part f verificatin, thus nt requiring the verifier t persnally cnduct r versee the equipment calibratin within ne year f the applicatin. The Panel descriptin als includes recgnitin f standard calibratin practices fr addressing equipment calibratin, which culd include multiple recgnized frms, e.g. small area calibratin, field scale calibratin, etc. Large scale calibratin wuld require dcumentatin f full capacities f the applicatin equipment, e.g. tns r gallns, a cnsistent applicatin methd, and the number f spreader/tanker applicatins applied nt a knwn acreage. Q6/A6 (pg. 45) regarding land use reprting t NEIEN: We may have difficulty reprting t this level f detail fr mst data surces. 110

111 Respnse: The Panel s recmmendatins fr tracking, verificatin and reprting thrugh NEIEN are based n the apprved Phase 6 land uses. The jurisdictins have the pprtunity t reprt BMP acreage directly t specific land uses, r in a general land use descriptin such as Rw Crps depending n their ability t track and reprt the implementatin infrmatin. Appendix B: Methds t Estimate Histric Implementatin General Cmments Jeff Sweeney Mst lines and sectins in the reprt are repeated several times thrughut. It gives the impressin f a lt f filler t make it lk lng. I suggest nt repeating lines and sectins as in a slid prfessinal reprt. Respnse: The Panel reprt has been mdified based n partner cmments where apprpriate. Delaware Finally, as states prgrams evlve t this reprt and mre imprtantly, t science, sme cnsideratin fr the legislative and administrative prcedural pace needs t be given. Fr that reasn, I suggest ne utcme f the reprt shuld be a dialg with states abut timelines t mdify their NM prgrams in rder t adaptively manage necessary updates. Similar cmment frm West Virginia Mst ntably, because Nutrient Management Prgrams vary drastically thrughut the jurisdictins, flexibility needs t be incrprated as t hw each state achieves the cre elements and hw these cre elements are verified. This will bviusly be addressed specifically in the states verificatin prgrams. With this being said, it seems redundant hw much verificatin language is included thrughut the dcument, t the pint that it detracts frm the Nutrient Management fcus. Als, due t new definitins and requirements West Virginia wuld request that a three-year ramp up perid be implemented t allw all states t make the necessary changes r adjustments t their prgrams t ensure that they can still receive full credit fr Nutrient Management Plans. Similar cmment frm VA DEQ Many aspects f the prpsed changes in this reprt have nt been tracked r reprted in the past. Actual rates, placement, timing, PSNT, CSNT, P-index use amngst ther things are currently nt tracked. This is a significant change that will require time t implement assuming nthing changes based n cmment and subsequent wrkgrup and WQGIT meetings/apprval. A ramp up perid will be needed. Similar cmment frm PA DEP The Phase 6 Nutrient Management apprach is cnsiderably different frm the past and it wuld be very useful t have a functinal phase-in perid t ensure that jurisdictins receive full credit fr nutrient management plans similar t the Tier 2 crediting, until additinal tracking mechanisms can be established t dcument implementatin f individual Cre and Supplemental BMPs. The existing PA Chapter 83 NM Prgram culd include sme elements f the NM Supplemental BMPs, hwever nt all peratins with a Chapter 83 NM Plan utilize all f the Supplemental BMPs and PA s prgram des nt have any cllectin mechanism fr each f these Supplemental NM BMPs. Maryland Dept. f Agriculture The new Supplemental Adjustment BMPs have nt been tracked r evaluated t the same degree as the Cre Nutrient Management practices. Mdificatin in the Nutrient Management Prgram reprting requirements will be necessary t quantify the extent f implementatin in Maryland. The Department therefre requests flexibility in reprting until new prgram reprting requirements can be established. Further, jurisdictins shuld be given the pprtunity t estimate histrical Supplemental BMP implementatin as it wuld be extremely difficult t glean actual supprting data. 111

112 Respnse: The Panel recmmendatins have been mdified t reflect a transitinal perid which may be required fr sme partner prgrams. In additin, US EPA is develping a supprting dcument fr partnership supprt which prvides a prcess whereby the jurisdictins can mdify their existing prgrams ver time t address prgrammatic and legislative actins. VA DEQ It is nt clear hw this panel s recmmendatins square with the p5 AgNM panel recmmendatins that prduce varius tiers f NM planning and benefit. Under the tier system NM n pasture and ther hay did prduce a reductin. Did the phase 5 NM panel cnsider science the phase 6 panel did nt? Or has there been new science since the p5 NM panel reprt was finalized? A crss walk frm the phase 5 tier system t the prpsed phase 6 panel recmmendatins is needed t fully understand the ptential impacts t the histrical representatin f AgNM in phase 6 as earlier versins f phase 6 utilized the tier system fr the histrical reprting. Respnse: The Panel s recmmendatins were built upn the scientific expertise f the panel members in an academic apprach t the BMP evaluatin, and the initial grund wrk established by the Phase Panel. Sme but nt all f the Phase 6 NM panel members als served n the Phase NM Panel. The present Panel elected t address nutrient management practices in a different apprach than the Phase panel, many times utilizing the same scientific infrmatin evaluated by the previus panel. The Panel reprt des address histrical NM implementatin fr the mdel calibratin perid. Appendix D: Apprved Nutrient Management Expert Panel Meeting Minutes Chesapeake Bay Fundatin Appendix D, the minutes frm the Panel meetings was nt included. We find this infrmatin extremely useful as it prvides insights t the discussins and deliberatins f the Panel members and can highlight areas where there was cnsensus and areas where there was mre debate. We encurage the CBP t include this infrmatin in draft reprts f ther expert panels. Respnse: The Final Reprt f the Panel includes the full meeting minutes f the NM Panel as per the requirements f the partnership s BMP Prtcl. Cmments Submitted by: U.S. EPA Kelly Shenk and Jeff Sweeney Jim Crpper, Nrtheast Pasture Cnsrtium Gene Yagw, Virginia Tech Delaware Department f Agriculture (Delaware) Virginia Department f Cnservatin & Recreatin (Virginia) Virginia Department f Envirnmental Quality (VA DEQ) West Virginia Department f Agriculture (West Virginia) Pennsylvania Department f Envirnmental Prtectin (PA DEP) Maryland Department f Agriculture New Yrk Upper Susquehanna Calitin Chesapeake Bay Cmmissin Chesapeake Bay Fundatin Envirnmental Integrity Prject, Ptmac Riverkeeper Netwrk, Midshre Riverkeeper Cnservancy, Assateague Castkeeper 112

113 Appendix F: Cnslidated Respnse t Cmments n: Definitins and Recmmended Nutrient Reductin Efficiencies f Nutrient Management fr Use in Phase 6.0 f the Chesapeake Bay Prgram Watershed Mdel (September 22, 2016 Versin) Envirnmental Integrity Prject The reprt is nt clear abut hw split applicatins will be treated. Split P applicatins appear in nly ne categry n pages 11 and 25, but appear in bth rate and timing categries n page 17. The reprt shuld be revised t make it internally cnsistent n this pint. Overall, it wuld help t have a mre cmplete explanatin f hw split N r P applicatins shuld be reprted. Respnse: The NM Panel s recmmendatins have been mdified t cnsistently represent split P applicatins as a P Timing Adjustment Practice, nt as a P Rate Adjustment Practice as previusly represented in the Panel s draft and draft Final Reprt. Split P applicatins may reduce the envirnmental risk f P runff and leaching due t sil water saturatin cnditins and precipitatin events fllwing applicatin. New Yrk Department f Agriculture and Markets, DEC, and Upper Susquehanna Calitin Thank yu fr yur and the Panel s wrk n the Phase 6 NM Reprt. Please find cmments frm NY n the supplemental N and P cefficients fr legume hay and ther hay, attached. The cmments are captured in bubbles adjacent t the highlighted text starting n PDF page 111, with specific recmmendatins fr the supplemental cefficients in Tables 14 and 15 n PDF page 22 f the reprt. If yu have truble viewing the cmments, let me knw and I ll get them ver t yu in anther frmat. The recmmended changes in the cmments imprve cnsistency amng crps and supplemental management types in Tables 14 and 15 and better reflect manure applicatins t hay land n dairy farms perating under nutrient management. My sense frm prir panel reprts t the Ag Wrkgrup, the Panel s meeting ntes, as well as the revised justificatin fr the supplemental cefficients in Tables 14 and 15 is that the fcus was n rw crps, with hay land as mre f an afterthught. Manure is managed differently n hay fields when farms implement nutrient management, justifying credit in the supplemental placement and timing categries fr N and P. Please first see ur respnse t the Panel's cmments n PDF page 111 within this draft. The recmmended updates t the N supplemental and P supplemental multipliers are then highlighted in Tables 14 and 15, immediately belw [fr Legume Hay and Other Hay land uses fr N Supplemental BMPs, and Other Hay fr P Supplemental BMPs.] Please change [N Placement] t 0.97 t value the reality f manure applicatin setbacks frm watercurses and frm cncentrated flws within fields. Fertilizer N is nt applied in the setback znes. Please change [N Timing] t 0.95 t value shifts in manure applicatin timing away frm higher risk times f the year (and/r frecasted cnditins) as well as breaking up annual applicatins as splits between hay cuttings. Please change [P Placement] t 0.90 t value the reality f manure applicatin setbacks frm watercurses and frm cncentrated flws within fields. Fertilizer P is nt applied in the setback znes. Please change [P Timing] t 0.99 t value shifts in manure applicatin timing away frm higher risk times f the year (and/r frecasted cnditins) as well as breaking up annual applicatins as splits between hay cuttings. Respnse: The Panel recmmendatins have been mdified t recgnize the value f utilizing nutrient applicatin setbacks fr N and P applicatins n predminantly grass hays represented under the Other Hay land use as N and P 113

114 Placement Supplemental NM BMPs. Nutrient injectin applicatins are als currently technically pssible, and may becme mre prevalent in the future. Respnse: The Panel recmmendatins have been mdified t recgnize the value f split nutrient applicatins and lwer envirnmental risk annual timing fr N and P applicatins n predminantly grass hays represented under the Other Hay land use as N and P Timing Supplemental NM BMPs. Respnse: The Panel recmmendatins have nt been mdified fr N applicatins n predminantly legume hays due t the N fixatin capability f legumes, and the reginal LGU recmmendatins fr aviding N applicatins n legumes. Pennsylvania DEP (see Attachment) Pennsylvania (PA) wuld like t recgnize the Nutrient Management BMP Expert Panel and applaud their effrts t draft Nutrient Management BMP reprt. The riginal reprt dated August 1, 2016, was an apprach t nutrient management that culd span acrss the seven jurisdictins. PA culd live with the recmmendatins within that dcument and we were ready t reach cnsensus and mve frward with the reprt. Hwever, the revisins that were made between August 1 and September 21 the date that the final revised Nutrient Management BMP expert panel reprt was released are very cncerning as thse revisins preclude PA frm gaining credit fr the substantial number f farms that are regulated under Chapter 91 and PA s Clean Streams Law. The final reprt remves ne f PA s key means f shwing prgress by including a restrictin that was nt in the riginal Expert Panel reprt and has n real envirnmental benefit. Respnse: The Panel received significant partnership cmments n the Panel s draft recmmendatin reprt dated August 1, Multiple partner cmments were received requesting the Panel recnsider its draft recmmendatins regarding the equal acceptance f published bk values in place f manure analysis beynd new, expanded r mdified livestck and pultry peratins. The Chesapeake Bay Prgram Partnership s apprved BMP Prtcl prcedures required that the NM Panel directly respnd t these partnership cmments as part f the finalizatin f the Panel s reprt. The Panel fllwed the BMP Prtcl requirements and cnsidered these cmments in develping the draft Final Reprt, chsing t fllw standard land-grant university (LGU) recmmendatins which priritize the use f sil and manure sampling and labratry analysis versus published bk values with the exceptins nted in the reprt. Penn State University s (PSU) Nutrient Management extensin publicatin, as well as the ther Bay reginal LGU s, fully supprt the Panel s recmmendatins t give precedence t sampling and labratry analysis results fr planning purpses versus published bk values. The PSU extensin publicatins refer t manure analysis testing results as essential and frming the basis fr determining apprpriate manure applicatins rates t meet crp nutrient needs. The publicatins recgnize the very wide variance f manure nutrient cncentratins when cmpared t published bk values, and recmmend the use f bk values cnsistent with the peratinal exemptins as cited by the NM Panel reprt, e.g. The remval f bk values fr manure analysis in the N and P Cre tables, and the intrductin f the fllwing language that is fund n pages 14 and 16, nt nly cncerns PA, but prevents us frm apprving the final revised reprt. We respectfully request that the fllwing language be remved frm the dcument, as well as allwing fr manure nutrient bk values t be used in lieu f analysis as was stated in the previus draft dcument. If labratry analysis f manure is nt available, as in the case f new, expanded r mdified livestck and pultry peratins, r is nt required under state-specific regulatins, published bk values (as described abve) may be used fr a maximum f three years, after which time labratry analysis data must be utilized t satisfy N Cre (r P Cre) NM BMP requirements. 114

115 Respnse: The Panel respnded t numerus Chesapeake Bay Prgram partnership cmments regarding the Panel s initial draft reprt. In respnse t thse cmments, and in cncert with the Phase 6 NM addendum plicy statement develped by EPA Regin 3 which was unanimusly apprved by the Agriculture Wrkgrup n September 22, 2016, the Panel placed a cnsistent prgrammatic phase-in perid f three-years fr the phasing ut f equal definitinal acceptance f published bk values in lieu f sampling and labratry analysis recmmendatins with the exceptin f new, expanded r mdified livestck and pultry peratins. The language cited abve in the draft Final Reprt has been mdified t replace the wrd must with the phrase is strngly recmmended fr nt equating published bk values in lieu f peratinal manure analysis values fllwing the prgrammatic phase-in perid. The current USDA Natural Resurces Cnservatin Service (NRCS) Cnservatin Practice Standard fr Nutrient Management (CP 590) als supprts the Panel s recmmendatins by incrprating the requirement fr the cllectin and analysis f manure, rganic by-prducts, and bislids at least annually, r mre frequently if needed t accunt fr peratinal changes. Cnsistent with the Panel s reprt, the NRCS CP 590 Standard likewise recgnizes that when planning fr a new r mdified livestck peratins, acceptable bk values recgnized by the NRCS and the landgrant university, r analysis frm similar peratins in the gegraphical area, may be used if they accurately estimate nutrient utput frm the prpsed peratin. The NRCS practice standard further requires and defines current sil tests as thse which are n lder than three-years, but may be taken n an interval recmmended by the land-grant university, e.g. The revisins t the reprt suggest that PA s regulatry requirements are cnsidered t be less than the partnership s vluntary recmmendatins. PA s Manure Management regulatins apply t all farms in PA that prduce r apply manure, regardless f size and number f livestck. This includes farms that have a few laying hens r a cuple f gats r hrses; small dairy peratins with limited strage capacity; and many ther types f lw-intensity peratins. While all large farms (CAOs and CAFOs) are required t take sil and manure tests, and mst f the medium sized farms d testing, the implementatin f Chapter allws fr the use f bk values t encurage cmpliance with the regulatins. It is nt nly unreasnable but als unrealistic t require a manure analysis fr every ne f these small farms in rder t develp a manure management plan and receive credit in the Bay Mdel via implementatin f that plan. A manure sample will nt be representative f the nutrient cntent applied thrughut the year; therefre, PA allws fr the use f standard bk values develped by PA s Land Grant University. The bk values have been built int the calculatin f the prescribed applicatin rates fr each animal type and crp grup. This leads t standardizatin, cnsistency, and accuracy acrss the estimated 30,000 farms regulated by Chapter 91 in PA s prtin f the Chesapeake Bay Watershed. Respnse: The Panel s draft Final Reprt represents the recmmendatins f an agricultural science panel membership represented f the Bay regin. Pennsylvania s land-grant university is directly represented n the Panel by the Cmmnwealth s leading academic expert n Nutrient Management. Specific language was incrprated int the Panel s initial Draft Reprt and its draft Final Reprt t address specific Pennsylvania prgrammatic characteristics, including the Cmmnwealth s Manure Management regulatins. Hwever, the NM Panel reprt is als intended t be applied t all agricultural lands within the Chesapeake Bay watershed based n applicable and established land-grant university standards acrss the six-state regin. Identified differences between the separate land-grant university recmmendatins were incrprated, but they were cnvincingly cnsistent n the recgnitin that manure sample cllectin and analysis is strngly recmmended ver published bk values as a basis fr Nutrient Management recmmendatins. The Panel s recmmendatins regarding the preference fr sil analysis testing, retains and further clarifies the recgnitin that a requirement fr having a P sil test may be waived if restrictins n manure applicatin (rates, timing, placement), are impsed that limit P applicatin rates and management t the same degree as if the site s sil was in the high sil-test interpretive categry. The clarificatin is that the replacement f a P sil analysis fr a given site is with a high sil-test interpretive value. Other cmments and cncerns regarding the revised dcument are as fllws: 115

116 Page 7, Table 2 and Page 8, Table 3 Tables shuld reflect and summarize what is written in the narrative f the dcument. The remval f the descriptive detail that was cntained in the riginal draft final nw creates a difference between what is written in the text and what is prvided in the tables. Page 7, Table 2 and Page 8, Table 3 Instead f Manure analysis and vlume, we recmmend stating Must accunt fr manure nutrient cntent. This will allw fr the use f bk values r individual analysis. Page 8, Table 3 Instead f P sil tests at field management unit level, we recmmend stating Must accunt fr P residual in sil. This will allw fr restrictins based n crp P remval and nt n sil tests. Page 9, Table 4 and Page 10, Table 8 Instead f Manure analysis < 1 year ld, we recmmend stating, Manure analysis less than r equal t 1 year ld Page 12, Figure 1 and Page 13, Figure 2; Page 13 and Page 15 While this is nt a change frm the previus versin, the statement f All elements are required t btain Cre N r Cre P is cnfusing. We recmmend inserting as applicable, since there are peratins that strictly use cmmercial fertilizer. As written, it can be inferred that thse nn-manure peratins culd nt btain Cre (r Supplemental) credit. Respnse: The Panel draft Final Reprt utilized the N and P Cre NM BMP descriptive Tables as a way f bradly presenting the elements f these BMPs in a simple frmat. The Panel placed detailed descriptins f the N and P Cre NM BMPs in the reprt s narrative sectins starting with Sectin 2.2 thrugh Sectin 2.3. This frmat enables additinal descriptive infrmatin t be presented which wuld therwise be difficult in a table frmat. The descriptive sectins represent the Panel s full recmmended descriptin f the BMPs fr tracking, verificatin and reprting purpses. Respnse: The Panel draft Final Reprt utilized the N and P Cre NM BMP descriptive Tables as a way f bradly presenting the elements f these BMPs in a simple frmat. The Panel placed detailed descriptins f the N and P Cre NM BMPs in the reprt s narrative sectins starting with Sectin 2.2 thrugh Sectin 2.3. This frmat enables additinal descriptive infrmatin t be presented which wuld therwise be difficult in a table frmat. The descriptive sectins represent the Panel s full recmmended descriptin f the BMPs fr tracking, verificatin and reprting purpses. Respnse: The Panel s element descriptin in the P Cre NM BMP descriptive table f P sil tests at field management unit level represents the Panel s preference fr P sil tests fr determining the P sil residual value. The Panel did recgnize that the requirement fr having a P sil test may be waived if restrictins n manure applicatin (rates, timing, placement), are impsed that limit P applicatin rates and management t the same degree as if the site s sil was in the high sil-test interpretive categry. Respnse: The Panel s recmmendatins fr Advanced N and P Assessment Tls have been mdified t represent a Manure analysis less than r equal t 1 year ld as suggested. Respnse: The Panel s recmmendatins fr N and P Cre NM BMPs have been mdified t include the descriptive term as applicable thrughut the reprt t mre apprpriately represent thse peratins which may utilize nly nnrganic nutrient surces that already have a knwn and regulated nutrient analysis. 116

117 Nutrient Management Octber 2016 Attachment 117

118 Nutrient Management Octber

119 Appendix G: Amended Reprt Octber 20, 2016 The Phase 6 Nutrient Management Expert Panel presented its final reprt n nutrient management practices fr use in Phase 6.0 f the Chesapeake Bay Prgram Watershed Mdel t the Agriculture Wrkgrup fr apprval n Octber 20, The Agriculture Wrkgrup apprved the reprt with amendments added by the wrkgrup. These Agriculture Wrkgrup implemented amendments t the Panel s reprt divided bth the Nitrgen Cre Nutrient Management and Phsphrus Cre Nutrient Management BMPs int tw cmpnents reflecting whether n-site specific manure analysis fr nitrgen, and bth sil and manure analysis fr phsphrus; r estimated (a.k.a. bk value) manure analysis fr nitrgen, and bth sil and manure estimated analysis fr phsphrus is used t determine nitrgen r phsphrus applicatin rates respectively. These Agriculture Wrkgrup mdificatins resulted in the need t make multiple changes in the Panel s final reprt. All substantive changes resulting frm the Agriculture Wrkgrup s mdificatins are highlighted with gray shading in the fllwing amended reprt. In additin t the main bdy f the reprt, Appendices A and H were als amended t reflect the changes made by the Agriculture Wrkgrup. 119

120 Final BMP Panel Reprt Definitins and Recmmended Nutrient Reductin Efficiencies f Nutrient Management Practices Fr Use in Phase 6.0 f the Chesapeake Bay Prgram Watershed Mdel Recmmendatins fr Apprval by the Water Quality Gal Implementatin Team s Watershed Technical and Agricultural Wrkgrups Submitted by the Phase 6.0 Nutrient Management BMP Expert Panel Submitted t: Agriculture Wrkgrup Chesapeake Bay Prgram August 1, 2016 Revised September 22, 2016 Final Octber 18, 2016 Apprved as Amended by Agriculture Wrkgrup Octber 20,

121 Cntents ACRONYMS AND ABBREVIATIONS... 5 SUMMARY OF RECOMMENDATIONS INTRODUCTION PRACTICE DEFINITIONS NM CORE AND SUPPLEMENTAL ELEMENT DETAILED DEFINITIONS NITROGEN CORE NM BMP ELEMENTS PHOSPHORUS CORE NM BMP ELEMENTS NITROGEN SUPPLEMENTAL NM BMPS PHOSPHOROUS SUPPLEMENTAL NM BMPS EFFECTIVENESS ESTIMATES SUMMARY OF EFFECTIVENESS ESTIMATES N Cre NM BMPs P Cre NM BMPs N Supplemental Nutrient Management BMPs P Supplemental Nutrient Management BMPs DEVELOPMENT OF APPLICATION RATE MULTIPLIERS AND LOSS REDUCTION MULTIPLIERS FOR CORE NM BMPS AND SUPPLEMENTAL NM BMPS METHOD FOR APPLYING CORE AND SUPPLEMENTAL MULTIPLIER VALUES REVIEW OF LITERATURE AND DATA GAPS THE AVAILABLE SCIENCE FOR N BMPS THE AVAILABLE SCIENCE FOR P BMPS APPLICATION OF PRACTICE ESTIMATES LOAD SOURCES PRACTICE BASELINE HYDROLOGIC CONDITIONS SEDIMENT SPECIES OF NITROGEN AND PHOSPHORUS GEOGRAPHIC CONSIDERATIONS TEMPORAL CONSIDERATIONS PRACTICE LIMITATIONS POTENTIAL INTERACTIONS WITH OTHER PRACTICES PRACTICE MONITORING AND REPORTING PHASE 6.0 NUTRIENT MANAGEMENT TRACKING, VERIFICATION, AND REPORTING FUTURE VERIFICATION OF NUTRIENT MANAGEMENT PRACTICES REFERENCES Figure 1. Linkage f Cre and Supplemental N Nutrient Management Practices Figure 2. Linkage f Cre and Supplemental P Nutrient Management Practices Figure 3. Assignment f N Nutrient Management Credits fr N Cre NM OMA BMP Figure 4. Assignment f N Nutrient Management Credits fr N Cre NM EMA BMP Figure 5. Assignment f P Nutrient Management Credits fr P Cre NM OSMA BMP Figure 6. Assignment f P Nutrient Management Credits fr P Cre NM ESMA BMP Table 1. CBP Phase 6.0 Nutrient Management Expert Panel Membership

122 Table 2. Elements f the N Cre Nutrient Management BMP... 9 Table 3. Elements f the P Cre Nutrient Management BMP Table 4. Examples f advanced N site assessments and N management tls that may be used t supprt implementatin f changes in riginally planned N applicatin rate, N applicatin placement, and/r N applicatin timing Table 5. Elements f the N Rate Supplemental Nutrient Management BMP Table 6. Elements f the N Placement Supplemental Nutrient Management BMP Table 7. Elements f the N Timing Supplemental Nutrient Management BMP Table 8. Examples f advanced P site assessments and P management tls that may be used t supprt implementatin f changes in riginally planned P applicatin rate, P applicatin placement, and/r P applicatin timing Table 9. Elements f the P Rate Supplemental Nutrient Management BMP Table 10. Elements f the P Placement Supplemental Nutrient Management BMP Table 11. Elements f the P Timing Supplemental Nutrient Management BMP Table 12. Cre N Nutrient Management Applicatin Rate Multiplier Values Table 13. Cre P Nutrient Management Applicatin Rate Multiplier Values Table 14. N Supplemental Nutrient Management BMP Lss Reductin Multiplier Values Table 15. P Supplemental Nutrient Management BMP Lss Reductin Multiplier Values Table 16. LGU Agrnmy Guide Recmmendatins fr Crn N Fertilizer Applicatin Rate Befre and During CBPWM Calibratin Perid Table 17. Summary f Methd fr Applying Nutrient Management Multiplier Values Table 18. Land Uses t Which the Nutrient Management Practices Apply

123 Preface The Phase 6 Nutrient Management Expert Panel presented its final reprt n nutrient management practices fr use in Phase 6.0 f the Chesapeake Bay Prgram Watershed Mdel t the Agriculture Wrkgrup fr apprval n Octber 20, The Agriculture Wrkgrup apprved the reprt with amendments added by the wrkgrup. These Agriculture Wrkgrup implemented amendments t the Panel s reprt divided bth the Nitrgen Cre Nutrient Management and Phsphrus Cre Nutrient Management BMPs int tw cmpnents reflecting whether n-site specific manure analysis fr nitrgen, and bth sil and manure analysis fr phsphrus; r estimated (a.k.a. bk value) manure analysis fr nitrgen, and bth sil and manure estimated analysis fr phsphrus is used t determine nitrgen r phsphrus applicatin rates respectively. These Agriculture Wrkgrup mdificatins resulted in the need t make multiple changes in the Panel s final reprt. All substantive changes resulting frm the Agriculture Wrkgrup s mdificatins are highlighted with light-gray shading. 123

124 Acrnyms and Abbreviatins AAPFCO ac. AgWG ARS BMP bu. bu./ac. CBP CBPO CBPWM CBW CEAP CRC CSNT DE DRP EOF EONR FSNT ft. ha HUC ISNT kg lbs. LGU MD Assciatin f American Plant Fd Cntrl Officials Acre Agriculture Wrkgrup USDA Agricultural Research Service Best Management Practice Bushel Bushels per Acre Chesapeake Bay Prgram Chesapeake Bay Prgram Office Chesapeake Bay Prgram Watershed Mdel Chesapeake Bay Watershed Cnservatin Effects Assessment Prject Chesapeake Research Cnsrtium Crn Stalk Nitrate Test Delaware Disslved Reactive Phsphrus Edge f Field Ecnmic Optimum N Rate Fall Sil Nitrate Test Feet Hectare Hydrlgic Unit Cde Illinis Sil Nitrgen Test Kilgram Punds Land-Grant University Maryland N Nitrgen 124

125 N Cre NM EMA BMP N Cre NM OMA BMP N Supplemental NM BMP NEIEN NM NMP NO 3 -N NRCS NRI NY P P Cre NM ESMA BMP P Cre NM OSMA BMP P Supplemental NM BMP PA PAN Panel PET PSNT QAPP TN TP USDA VA VTCA WTWG WQGIT Nitrgen Cre Nutrient Management Estimated Manure Analysis Best Management Practice Nitrgen Cre Nutrient Management On-Site Manure Analysis Best Management Practice Nitrgen Supplemental nutrient management Best Management Practice Natinal Envirnmental Infrmatin Exchange Netwrk Nutrient Management Nutrient Management Plan Nitrate N USDA Natural Resurces Cnservatin Service Natinal Resurces Inventry New Yrk Phsphrus Phsphrus Cre Nutrient Management Estimated Sil & Manure Analysis Best Management Practice Phsphrus Cre Nutrient Management On-Site Sil & Manure Analysis Best Management Practice Phsphrus Supplemental nutrient management Best Management Practice Pennsylvania Plant Available N Nutrient Management Expert Panel Phsphrus Envirnmental Threshld Pre-sidedress Nitrate Test Quality Assurance Prject Plan Ttal Nitrgen Ttal Phsphrus U.S. Department f Agriculture Virginia Virginia Tech Crn Algrithm Watershed Technical Wrkgrup Water Quality Gal Implementatin Team WV West Virginia 125

126 Summary f Recmmendatins 8 Intrductin Nutrient management practices are implemented n millins f acres f agricultural lands acrss the Chesapeake Bay Watershed (CBW). It is ne f the ldest best management practices (BMPs) in agriculture and is the crnerstne f stewardship effrts by cnservatin grups, prducers and jurisdictins. This dcument summarizes the recmmendatins f the Phase 6 Nutrient Management Expert Panel (the Panel) fr revised definitins and credits fr nutrient management practices. The Panel, whse members are identified in Table 1, prpses that the Chesapeake Bay Prgram s (CBP) existing definitins and credits assciated with implementatin f Nutrient Management Plans (NMPs) be replaced by independent sets f practice elements fr nitrgen (N) and phsphrus (P) management due t the marked difference in the use, fate, and transprt f these nutrients in agricultural systems. The structures fr bth N and P nutrient management are similar, hwever, with supplemental management elements stacked nt a required cre set f management elements. Table 1. CBP Phase 6.0 Nutrient Management Expert Panel Membership Name Jurisdictin Affiliatin Rle Frank Cale Maryland University f Maryland Panel Chair Deanna Osmnd Nrth Carlina Nrth Carlina State University Panel Member Dug Beegle Pennsylvania Penn State University Panel Member Jack Meisinger Maryland USDA-Agriculture Research Panel Member Service Tm Fisher Maryland University f Maryland Center Panel Member fr Envirnmental Science Quirine Ketterings New Yrk Crnell University Panel Member Chris Brsch Delaware Delaware Department f Watershed Technical Wrkgrup Agriculture representative Matt Jhnstn Maryland University f Maryland, CBPO Mdeling Team representative Technical supprt prvided by Mark Dubin (University f Maryland, CBPO), Lindsey Grdn (CRC Staffer), and Steve Dressing (Tetra Tech). CBPO Chesapeake Bay Prgram Office; CRC Chesapeake Research Cnsrtium; USDA U.S. Department f Agriculture 9 Practice Definitins Nutrient management has fur basic cmpnents: the nutrient surce, rate, timing, and placement. Each f these fur cmpnents f NM are managed at the field r sub-field scale in a manner t supprt crp prductivity, achieve high nutrient use efficiency by the grwing crp, and t minimize nutrient lss t the envirnment. The fur cmpnents f NM planning interact with each ther n a site-specific basis and are mdified by site-specific field management, sil prperties, and weather cnditins. Thus, the Panel defines Nutrient Management as the implementatin f a site-specific cmbinatin f nutrient surce, rate, timing, and placement int a strategy that seeks t ptimize agrnmic and envirnmentally efficient utilizatin N and P. Imprvement in nutrient-use efficiency necessitates dcumentatin f NM implementatin strategies that are suitable fr independent verificatin. Nutrient management als prvides ther imprtant benefits t the agricultural and the envirnmental cmmunities. These benefits include lng-standing educatinal pprtunities cnducted in varius venues fr a wide variety f audiences that cnvey the fundamentals f NM and state-f-the-science practices and assessment tls. It is essential that an initial baseline fr NM implementatin is established that allws estimatin f prgress ver time. Applicatin f NM BMPs 126

127 will interrelate with ther agricultural nnpint surce BMPs and cmmunicatin with ther BMP Expert Panels is essential t define apprpriate implementatin and crediting. Nutrient management fr Phase 6.0 f the Chesapeake Bay Prgram Watershed Mdel (the Phase 6 mdel) is separated int independent sets f practice elements fr N and P management due t the marked difference in the use, fate, and transprt f these nutrients in agricultural systems. The structures fr bth N and P nutrient management are similar, hwever, with supplemental management elements stacked nt a required cre set f management elements. Practice Name(s) Nitrgen (N) Cre Nutrient Management Estimated Manure Analysis BMP Nitrgen (N) Cre Nutrient Management On-Site Manure Analysis BMP Phsphrus (P) Cre Nutrient Management Estimated Sil & Manure Analysis BMP Phsphrus (P) Cre Nutrient Management On-Site Sil & Manure Analysis BMP Nitrgen (N) Rate Supplemental Nutrient Management BMP Nitrgen (N) Placement Supplemental Nutrient Management BMP Nitrgen (N) Timing Supplemental Nutrient Management BMP Phsphrus (P) Rate Supplemental Nutrient Management BMP Phsphrus (P) Placement Supplemental Nutrient Management BMP Phsphrus (P) Timing Supplemental Nutrient Management BMP Cre Nutrient Management BMPs The elements f the N Cre Nutrient Management BMPs are fund in Table 2. Applicatin f a N Cre NM BMP applicatin rate multiplier mdifies the crp- and land-use-specific N applicatin rate gal, which is based n Land-Grant University (LGU) crp fertilizatin recmmendatins, as mdified by the CBP partnership. In an effrt t determine the mst practicable methdlgy fr allcating fertilizer N t satisfy crp- and land-use-specific N applicatin rate gals, the Agriculture Wrkgrup cmpared the mdified LGU recmmendatins fr applicatin f supplemental inrganic N fertilizer t an alternative apprach based n cunty-level redistributin f Assciatin f American Plant Fd Cntrl Officials (AAPFCO) N fertilizer sales data. This methdlgical cmparisn indicated that there were relatively small differences between the tw methds fr estimating supplemental N fertilizer applicatins, leading the Agriculture Wrkgrup t apprve use f the redistributed AAPFCO fertilizer sales methdlgy in the Phase 6 Mdel. The Panel recmmends that similar cmparative analyses be cnducted in the future t evaluate newly available fertilizer sales data and t further evaluate the redistributed fertilizer sales methdlgy s frecasting ability. Incnsistencies between estimates generated by the tw methds shuld be investigated and rectified based n data surce quality and cnsistency using cntiguus r reginal cunty-level data. 127

128 Table 2. Elements f the N Cre Nutrient Management BMPs NITROGEN Cre Nutrient Management On-Site Manure Analysis BMP (ALL applicable cre elements required t be implemented and verified) N rate accrding t LGU recmmendatins at field management unit level Manure analysis and vlume using test values t determine nitrgen cntent Spreader/applicatr calibratin Yield estimates and crpping plan at field management unit level Crpping and manure histry at field management unit level NITROGEN Cre Nutrient Management Estimated Manure Analysis BMP (ALL applicable cre elements required t be implemented and verified) N rate accrding t LGU recmmendatins at field management unit level Manure analysis and vlume using bk values t determine nitrgen cntent Spreader/applicatr calibratin Yield estimates and crpping plan at field management unit level Crpping and manure histry at field management unit level The elements f the P Cre Nutrient Management BMPs are fund in Table 3. Applicatin f a P Cre NM BMP applicatin rate multiplier mdifies the crp- and land-use-specific P applicatin rate gal, which is based n LGU crp fertilizatin recmmendatins, as mdified by the CBP partnership. A significant mdificatin impsed by the CBP partnership was the assumptin that all agricultural acres in the CBW had a sil-test P cncentratin that crrespnded with the medium sil test interpretive categry. The Panel recgnized that, in the absence f sil-test P cncentratin data, assumed sil-test P cncentratins were necessary t facilitate CBP mdel prcesses. Hwever, the Panel als recgnized that implementatin f the universal medium sil-test P assumptin infused a high level f site-specific uncertainty int the mdeled P applicatin rate. In general, the inherent uncertainty in P applicatin rate resulting frm the adptin f the universal medium sil-test P cncentratin assumptin is expected t be similar t r greater than the magnitude f the P applicatin rate mdificatins resulting frm implementatin f P Cre NM BMP applicatin rate multipliers. In practice, LGU recmmendatins fr P applicatin are based n crp- and site-specific sil-test P cncentratin. Currently, sil-test P cncentratin data are nt available t the CBP. The Panel recmmends that, in the future, crp- and site-specific sil-test P cncentratin data shuld be cllected, aggregated t the apprpriate scale, summarized t eliminate disclsure f cnfidential business infrmatin, and utilized as the fundatin fr determining P applicatin rate gals and the apprpriate applicatin f P Cre NM BMPs. In the absence f sil-test P data and sil-test P based applicatin rate gals, sil-test P cncentratin must be assumed and, in turn, utilized t create artificial P applicatin rate gals. Additinally, in the absence f sil-test P data, cunty-level redistributin f CBW AAPFCO P fertilizer sales data may serve as a useful surrgate fr determining P applicatin rate gals. Field management shall be cnsidered cmpliant with P fertilizatin recmmendatins when P applicatin recmmendatins resulting frm site-specific envirnmental risk assessments (i.e. P Index, P Site Index, P Management Tl, etc.) allw higher P applicatin rates than the standard LGU sil-test based recmmendatins, after accunting fr the site-specific ptential fr P lss t streams. In anther example, Virginia nutrient management planners may utilize a mre restrictive methd knwn as the Phsphrus Envirnmental Threshld (PET) in lieu f sil-test P based recmmendatins when evaluating applicatin f rganic nutrient surces. Using the PET methd, P frm rganic surces may be applied t fields that test less than a reginally-specified degree f sil P saturatin, as quantified by Mehlich 1 sil-test P cncentratin. By physigraphic regin, the PET sil-test P threshlds are: 135 ppm Eastern Shre & Lwer Castal Plain; 136 ppm - Middle & Upper Castal Plain & Piedmnt; and 162 ppm - Ridge and Valley. Nitrgen applicatins cannt exceed crp N needs when using PET. Additinal details may be fund in Virginia Nutrient Management Standards and Criteria, as revised July Other examples may be similarly applicable. 128

129 The P Cre NM On-Site Sil & Manure Analysis BMP (P Cre NM OSMA BMP) requires a P sil test at the field management unit level. This required element may be waived under the P Cre NM Estimated Sil & Manure Analysis BMP (P Cre NM ESMA BMP) if, as in the case f Pennsylvania s manure management guidelines, restrictins n manure applicatin (rates, timing, and placement) are impsed that limit ttal P applicatin rates and management t the same degree as if the site was in the high P sil test interpretive categry. Table 3. Elements f the P Cre Nutrient Management BMPs PHOSPHORUS Cre Nutrient Management On-Site Sil & Manure Analysis BMP (ALL applicable cre elements required t be implemented and verified) P rate accrding t LGU recmmendatins at field management unit level P sil tests at field management unit level Manure analysis and vlume using test values t determine phsphrus cntent Spreader/applicatr calibratin Yield estimates and crpping plan at field management unit level Crpping and manure histry at field management unit level PHOSPHORUS Cre Nutrient Management Estimated Sil & Manure Analysis BMP (ALL applicable cre elements required t be implemented and verified) P rate accrding t LGU recmmendatins at field management unit level P sil tests at field management unit level. Sil testing requirement may be waived if restrictins n manure applicatins (rate, timing, and placement) are impsed that limit P applicatin rates and management t the same degree as if the sil test result fr phsphrus was in the high categry. Manure analysis and vlume using bk values t determine phsphrus cntent Spreader/applicatr calibratin Yield estimates and crpping plan at field management unit level Crpping and manure histry at field management unit level Supplemental Nutrient Management BMPs The Nitrgen Supplemental Nutrient Management BMPs (N Supplemental NM BMPs) invlve applying a lss-reductin multiplier fr the N Supplemental NM BMP elements nly after satisfactry implementatin f either the N Cre NM On- Site Manure Analysis BMP (N Cre NM OMA BMP) r the N Cre NM Estimated Manure Analysis BMP (N Cre NM EMA BMP). Multiple advanced site assessments and N management tls may be utilized t infrm the applicatin f the apprpriate N adjustment practices, but d nt represent a N lss reductin credit in and f themselves. A list f example N site assessments and N management tls is given in Table 4. This list is nt intended t be exhaustive. Rather, Table 4 presents examples f current techniques and tls that the Panel deems ptentially useful in supprting crediting f changes in N management and recgnizes that this listing will need t be updated ver time as new tls and prcedures are develped. Advanced site assessments and applicatin f N management tls that result in a verifiable implementatin f a change in planned N applicatin rate, N applicatin timing r N applicatin placement may result in a N Supplemental NM BMP lss reductin credit. The actual crediting f the Supplemental NM BMPs requires placing a given BMP int a N Rate, N Timing, r N Placement Supplemental NM BMP categry (Tables 5 thrugh 7). One single N Supplemental NM BMP lss reductin multiplier may be credited fr each f the N Rate, N Timing, and N Placement categries. The actual values fr these Supplemental NM BMP lss reductin multipliers are presented later in this reprt (Table 14). Supplemental N NM BMP lss reductin credits fr N rate, N timing, and N placement are stackable, e.g., multiplicative with diminishing returns fr reducing envirnmental lss. 129

130 Table 4. Examples f advanced N site assessments and N management tls that may be used t supprt implementatin f changes in riginally planned N applicatin rate, N applicatin placement, and/r N applicatin timing. Additinal assessment techniques and tls may be utilized t supprt implemented changes in N management. Advanced N Assessment Tls Pre-sidedress Nitrate Test (PSNT) Manure analysis 1 year ld On-farm replicated research Crn Stalk Nitrate Test (CSNT) N-lss risk assessments & mdels - Ammnia lss Yield mapping Illinis Sil Nitrgen Test (ISNT) On-farm strip trials N-lss risk assessments & mdels - Leaching lss Fall Sil Nitrate Test (FSNT) N-lss risk assessments & mdels - Denitrificatin lsses Whle farm balances In-seasn sensrs/remte sensing in general Ge-spatial mapping Example elements f the N Rate Supplemental NM BMP are listed in Table 5. Additinal N management practices that result in reductins in the rate f applied N may be applicable. Table 5. Elements f the N Rate Supplemental Nutrient Management BMP N Rate Adjustment Practice (implementatin f ne r mre BMPs required) N rate less than LGU recmmendatins Split N applicatins fr reduced ttal rate Variable rate N applicatin at sub-field management unit level Example elements f the N Placement Supplemental NM BMP are listed in Table 6. Subsurface injectin r incrpratin applies nly t inrganic fertilizer N. Incrpratin r injectin f manure is addressed by the Phase 6 Manure Incrpratin and Injectin Expert Panel reprt with the fllwing practices: Manure Injectin, Manure Incrpratin High Disturbance, and Manure Incrpratin Lw Disturbance. Additinal N management practices that result in purpseful physical placement f N surces such that the ptential fr N lss t the envirnment is reduced and/r crp N- use efficiency is imprved may be applicable. 130

131 Table 6. Elements f the N Placement Supplemental Nutrient Management BMP N Placement Adjustment Practice (implementatin f ne r mre BMPs required) Subsurface injectin r incrpratin f applied Inrganic N N applicatin setbacks frm water Example elements f the N Timing Supplemental NM BMP are listed in Table 7. Additinal N management practices that result in the enhanced precisin f the timing f applicatin f N surces that reduces the ptential fr N lss t the envirnment and/r imprves crp N-use efficiency may be applicable. Table 7. Elements f the N Timing Supplemental Nutrient Management BMP N Timing Adjustment Practice (implementatin f ne r mre BMPs required) Split N applicatins PSNT The Phsphrus Supplemental Nutrient Management BMPs (P Supplemental NM BMPs) invlve applying a lssreductin multiplier fr the P Supplemental NM BMP elements nly after satisfactry implementatin f either the P Cre NM OSMA BMP r the P Cre NM ESMA BMP. Multiple advanced site assessments and P management tls may be utilized t infrm the applicatin f the apprpriate P adjustment practices, but d nt represent a P lss reductin credit in and f themselves. A list f example P site assessments and P management tls is given in Table 8. This list is nt intended t be exhaustive. Rather, Table 8 presents examples f current techniques and tls that the Panel deems ptentially useful in supprting crediting f changes in P management and will need t be updated ver time as new tls and evaluative prcedures are develped. Advanced site assessments and applicatin f P management tls that result in a verifiable implementatin f a change in planned P applicatin rate, P applicatin timing r P applicatin placement may result in a P Supplemental NM BMP efficiency credit. The actual crediting f the Supplemental NM BMPs requires placing a given BMP int either a P Rate, r P Timing, r P Placement Supplemental NM BMP categry (Tables 9 thrugh 11). One single P Supplemental NM BMP lss reductin multiplier may be credited fr each f the P Rate, P Timing, r P Placement categries. The actual values fr these Supplemental NM BMP lss reductin multipliers are presented later in the reprt (Table 15). Supplemental NM BMP lss reductin credits fr P rate, P timing, and P placement are stackable, e.g., multiplicative with diminishing returns fr reducing envirnmental lss. Table 8. Examples f advanced P site assessments and P management tls that may be used t supprt implementatin f changes in riginally planned P applicatin rate, P applicatin placement, and/r P applicatin timing. Additinal assessment techniques and tls may be utilized t supprt implemented changes in P management. Advanced P Assessment Tls Sil-test P remediatin/declining P Index assessment Grid sil sampling Manure analysis 1 year ld On-farm replicated research Yield mapping On-farm strip trials Whle farm balances Ge-spatial mapping 131

132 Example elements f the P Rate Supplemental NM BMP are listed in Table 9. Additinal P management practices that result in reductins in the rate f applied P may be applicable. Table 9. Elements f the P Rate Supplemental Nutrient Management BMP P Rate Adjustment Practice (implementatin f ne r mre BMPs required) P-based manure rate based n annual crp P remval P rate less than LGU recmmendatins Variable rate P at sub-field management unit level Example elements f the P Placement Supplemental NM BMP are listed in Table 10. The P placement practices f subsurface injectin r incrpratin apply nly t inrganic fertilizer P. Incrpratin r injectin f manure P is addressed by the Phase 6 Manure Injectin & Incrpratin Expert Panel reprt with the fllwing practices: Manure Injectin, Manure Incrpratin High Disturbance, and Manure Incrpratin Lw Disturbance. Additinal P management practices that result in the purpseful physical placement f P surces such that the ptential fr P lss t the envirnment is reduced may be applicable. Table 10. Elements f the P Placement Supplemental Nutrient Management BMP P Placement Adjustment Practice (implementatin f ne r mre BMPs required) Subsurface injectin r incrpratin f applied inrganic P P applicatin setbacks frm water Example elements f the P Timing Supplemental NM BMP are listed in Table 11. Additinal P management practices that result in the enhanced precisin f the timing f applicatin f P surces that reduces the ptential fr P lss t the envirnment may be applicable. Table 11. Elements f the P Timing Supplemental Nutrient Management BMP P Timing Adjustment Practice (implementatin f ne r mre BMPs required) P applicatin in lwer P-lss risk seasn Split P applicatins Figure 1 illustrates hw the N Cre NM BMPs and the N Supplemental NM BMPs are cmbined fr credit. As described abve, N Supplemental NM BMPs can nly be credited if either the N Cre NM OMA BMP r the N Cre NM EMA BMP is implemented and verified. The N Supplemental NM BMPs d nt result in additinal credit unless implementatin f adjustments in N rate, N placement, r N timing is verified. The N Supplemental NM BMPs are assigned t three categries: N Rate Adjustment Practices, N Placement Adjustment Practices, and N Timing Adjustment Practices. The Supplemental NM BMP lss reductin credit fr each f these three categries can be btained if implementatin f at least ne effective practice frm each categry is verified. Fr example, if implementatin f the N Cre NM OMA BMP is verified and implementatin f bth N applicatin setbacks frm water (a N placement adjustment) and variable rate N applicatin (a N rate adjustment) are verified, the applicatin rate multiplier credit may be claimed fr the N Cre NM OMA BMP and additinal lss reductin multiplier credits may be claimed fr bth the N Placement Supplemental NM BMP and the N Rate Supplemental NM BMP. In this example, n additinal lss reductin multiplier credit may be claimed fr the N Timing Supplemental NM BMP. Figure 2 illustrates hw the P Cre NM BMPs and the P Supplemental NM BMPs are cmbined fr credit. As described 132

133 abve, P Supplemental NM BMPs can nly be credited if either the P Cre NM OSMA BMP r the P Cre NM ESMA BMP is implemented and verified. The P Supplemental NM BMPs d nt result in additinal credit unless implementatin f adjustments in P rate, P placement, r P timing is verified. The P Supplemental NM BMPs are assigned t three categries: P Rate Adjustment Practices, P Placement Adjustment Practices, and P Timing Adjustment Practices. The Supplemental NM BMP lss reductin credit fr each f these three categries can be btained if implementatin f at least ne effective practice frm each categry is verified. Fr example, if implementatin f the P Cre NM OSMA BMP is verified and implementatin f bth P applicatin setbacks frm water (a P placement adjustment) and P-based manure rate based n annual crp P remval (a P rate adjustment) are verified, the applicatin rate multiplier credit may be claimed fr the P Cre NM OSMA BMP and additinal lss reductin multiplier credits may be claimed fr bth the P Placement Supplemental NM BMP and the P Rate Supplemental NM BMP. In this example, n additinal lss reductin multiplier credit may be claimed fr the P Timing Supplemental NM BMP. NITROGEN Cre Nutrient Management On-Site Manure Analysis BMP Are ALL applicable cre elements implemented and verified? NO NITROGEN Cre Nutrient Management Estimated Manure Analysis BMP Are ALL applicable cre elements implemented and verified? NO Credit as Nn- Nutrient Management fr N YES YES Credit as N Cre Nutrient Management OMA Credit as N Cre Nutrient Management EMA Credit as N Cre Nutrient Management OMA NO Is Advanced N Assessment Perfrmed? Is Advanced N Assessment Perfrmed? NO Credit as N Cre Nutrient Management EMA YES YES Additinal Credit fr N Rate Adjustment Is at Least One N Rate Adjustment Practice Implemented? N Additinal Credit Additinal Credit fr N Placement Adjustment Is at Least One N Placement Adjustment Practice Implemented? N Additinal Credit Additinal Credit fr N Timing Adjustment Is at Least One N Timing Adjustment Practice Implemented? N Additinal Credit Figure 1. Linkage f Cre and Supplemental N Nutrient Management Practices 133

134 PHOSPHORUS Cre Nutrient Management On-Site Sil & Manure Analysis BMP Are ALL applicable cre elements implemented and verified? NO PHOSPHORUS Cre Nutrient Management Estimated Sil & Manure Analysis BMP Are ALL applicable cre elements implemented and verified? NO Credit as Nn- Nutrient Management fr P YES YES Credit as P Cre Nutrient Management OSMA Credit as P Cre Nutrient Management ESMA Credit as P Cre Nutrient Management OSMA NO Is Advanced P Assessment Perfrmed? Is Advanced P Assessment Perfrmed? NO Credit as P Cre Nutrient Management ESMA YES YES Additinal Credit fr P Rate Adjustment Is at Least One P Rate Adjustment Practice Implemented? N Additinal Credit Additinal Credit fr P Placement Adjustment Is at Least One P Placement Adjustment Practice Implemented? N Additinal Credit Additinal Credit fr P Timing Adjustment Is at Least One P Timing Adjustment Practice Implemented? N Additinal Credit Figure 2. Linkage f Cre and Supplemental P Nutrient Management Practices 9.1 NM Cre and Supplemental Element Detailed Definitins T better enable the CBP partnership and state agency partners t understand and apply the recmmendatins f the NM Panel t their unique prgrams and prductin systems, the fllwing sectin prvides additinal descriptive details t each f the NM Cre BMPs and Supplemental NM BMPs. 9.2 Nitrgen Cre NM BMP Elements Nitrgen Cre NM On-Site Manure Analysis All five elements, as applicable t the agricultural peratin, are required t be implemented and verified at the field management unit level t receive credit. N rate accrding t LGU recmmendatins at field management unit. The elements f the N Cre Nutrient Management On-Site Manure Analysis BMP are fund in Table 2. Applicatin f a N Cre NM BMP OMA efficiency mdifies the crp- and land-use-specific N applicatin rate gal, which is based n LGU crp fertilizatin recmmendatins, as mdified by the CBP partnership. In an effrt t determine the mst practicable methdlgy fr allcating fertilizer N t satisfy crp- and landuse-specific N applicatin rate gals, the Agriculture Wrkgrup cmpared the mdified LGU recmmendatins fr applicatin f supplemental inrganic N fertilizer t an alternative apprach based n 134

135 cunty-level redistributin f AAPFCO N fertilizer sales data. This methdlgical cmparisn indicated that there were relatively small differences between the tw methds fr estimating supplemental N fertilizer applicatins, leading the Agriculture Wrkgrup t apprve use f the redistributed AAPFCO fertilizer sales methdlgy in the Phase 6 Mdel. The Panel recmmends that similar cmparative analyses be cnducted in the future t evaluate newly available fertilizer sales data and t further evaluate the redistributed fertilizer sales methdlgy s frecasting ability. Incnsistencies between estimates generated by the tw methds shuld be investigated and rectified based n data surce quality and cnsistency using cntiguus r reginal cunty-level data. If applied N applicatin rates are belw the applicable CBP partnership mdified applicatin rates, the N applicatin system may still qualify fr credit as an equivalent N Cre system if it meets the remaining fur N Cre elements. A field management unit is described by the NM Panel as a cmmn land management unit defined by the farm peratr that includes similar annual crp prductin and management systems, and assciated nutrient applicatin system. The field management unit can represent any field, cllectin f multiple fields, r subprtins f a single field that are managed the same way, with similar histry and crpping practices. Manure analysis and vlume. Estimatin f manure prduced and nutrient analysis f that manure must be used in the planning prcess. Manure nutrient analyses must be derived frm manure sample testing using standard labratry prtcls. If a labratry manure analysis is used t adjust the nutrient applicatin, the labratry analysis must be less than three-years ld. If labratry analysis f manure is nt available, as in the case f new, expanded r mdified livestck and pultry peratins, published bk values (as described abve) may be used fr a maximum f three years, after which time labratry analysis data must be utilized t satisfy N Cre NM BMP requirements. Spreader/applicatr calibratin. The equipment being used t perfrm the nutrient applicatins by the farm peratr needs t be dcumented and verified that the machine(s) have been calibrated either accrding t manufacturer specificatins r by standard calibratin practices, preferably within ne year f the applicatin. The custm applicatr and equipment calibratin certificatins fr cmmercial applicatrs can be used as an equivalent verificatin dcumentatin fr calibrated nutrient applicatins. Yield estimates and crpping plan at field management unit level. Annual yield estimates fr field management units shuld be based n field yield samples, calibrated electrnic yield mnitrs, r field specific grain elevatr receipts. Histric yield gals are determined using a standardized methd f averaging annual yields ver time t accunt fr annual variability (e.g. average yield is based n best three ut f the past five years). A less preferred but equivalent methd is t use standard USDA sil prductivity bk values fr estimating applicable yields. The crpping plan refers t the planting and harvesting f the specific crp(s) fr which the field nutrient applicatins were based. An example f a field that wuld nt qualify under this required element is when the nutrient applicatin was based n the plant requirements fr grain crn but, due t in-seasn management decisins, the field was planted t sybeans instead. Crpping/manure histry at field management unit level. As part f develping a planned nutrient applicatin rate, the farm peratr r custm applicatr cnsidered legume residual N credits based n LGU r natinal agricultural service (e.g., USDA) recmmendatins. The manure applicatin histry during the crp rtatin must be cnsidered, including apprpriate manure mineralizatin crediting. Verified dcumentatin f manure mineralizatin N credits are included as part f the nutrient balance t accunt fr at least the three prir years. Legume residual N credits are included as part f the nutrient balance t accunt fr at least the immediately preceding year. Nutrient management practice dcumentatin. The NM Panel defined the N Cre NM OMA BMP t require full implementatin f a defined and applicable set f fundamental elements in rder t receive the BMP credit. Independent dcumentatin and verificatin 135

136 that all f the required elements f the N Cre NM OMA BMP were implemented is required. The five elements that cnstitute the N Cre NM OMA BMP may r may nt be cmpnents f a frmal Nutrient Management Plan. The required nutrient management dcumentatin culd be in the frm f a frmal federal-, state-, r cunty-reviewed and certified nutrient management prgram plan, a nn-certified frmal nutrient management plan develped by a federal- r state-certified plan writer, r detailed dcumentatin and an infrmal management plan cmpiled by an peratr r private cnsultant that met the Panel s BMP recmmendatins. Equivalent Practices States may prpse equivalent practices t satisfy these requirements that must be apprved by the Agriculture Wrkgrup. Nitrgen Cre NM Estimated Manure Analysis All five elements, as applicable t the agricultural peratin, are required t be implemented and verified at the field management unit level t receive credit. N rate accrding t LGU recmmendatins at field management unit. The elements f the N Cre Nutrient Management Estimated Manure Analysis BMP are fund in Table 2. Applicatin f a N Cre NM BMP EMA efficiency mdifies the crp- and land-use-specific N applicatin rate gal, which is based n LGU crp fertilizatin recmmendatins, as mdified by the CBP partnership. In an effrt t determine the mst practicable methdlgy fr allcating fertilizer N t satisfy crp- and landuse-specific N applicatin rate gals, the Agriculture Wrkgrup cmpared the mdified LGU recmmendatins fr applicatin f supplemental inrganic N fertilizer t an alternative apprach based n cunty-level redistributin f AAPFCO N fertilizer sales data. This methdlgical cmparisn indicated that there were relatively small differences between the tw methds fr estimating supplemental N fertilizer applicatins, leading the Agriculture Wrkgrup t apprve use f the redistributed AAPFCO fertilizer sales methdlgy in the Phase 6 Mdel. The Panel recmmends that similar cmparative analyses be cnducted in the future t evaluate newly available fertilizer sales data and t further evaluate the redistributed fertilizer sales methdlgy s frecasting ability. Incnsistencies between estimates generated by the tw methds shuld be investigated and rectified based n data surce quality and cnsistency using cntiguus r reginal cunty-level data. If applied N applicatin rates are belw the applicable CBP partnership mdified applicatin rates, the N applicatin system may still qualify fr credit as an equivalent N Cre system if it meets the remaining fur N Cre elements. A field management unit is described by the NM Panel as a cmmn land management unit defined by the farm peratr that includes similar annual crp prductin and management systems, and assciated nutrient applicatin system. The field management unit can represent any field, cllectin f multiple fields, r subprtins f a single field that are managed the same way, with similar histry and crpping practices. Manure analysis and vlume. Estimatin f manure prduced and nutrient analysis f that manure must be used in the planning prcess. Published manure nutrient analyses frm LGUs, natinal agricultural agencies (e.g., USDA-ARS, USDA- NRCS), natinal r reginal farm service rganizatins, r histrical analyses generated frm very similar, lcal and cnsistently managed industry-cntracted peratins may be used. Spreader/applicatr calibratin. The equipment being used t perfrm the nutrient applicatins by the farm peratr needs t be dcumented and verified that the machine(s) have been calibrated either accrding t manufacturer specificatins r by standard calibratin practices, preferably within ne year f the applicatin. The custm applicatr and equipment calibratin certificatins fr cmmercial applicatrs can be used as an equivalent verificatin dcumentatin fr calibrated nutrient applicatins. Yield estimates and crpping plan at field management unit level. Annual yield estimates fr field management units shuld be based n field yield samples, calibrated electrnic yield mnitrs, r field specific grain elevatr receipts. Histric yield gals are determined using a standardized methd f averaging annual yields ver time t accunt fr annual variability (e.g. average yield is based n best three ut f the past five years). 136

137 A less preferred but equivalent methd is t use standard USDA sil prductivity bk values fr estimating applicable yields. The crpping plan refers t the planting and harvesting f the specific crp(s) fr which the field nutrient applicatins were based. An example f a field that wuld nt qualify under this required element is when the nutrient applicatin was based n the plant requirements fr grain crn but, due t in-seasn management decisins, the field was planted t sybeans instead. Crpping/manure histry at field management unit level. As part f develping a planned nutrient applicatin rate, the farm peratr r custm applicatr cnsidered legume residual N credits based n LGU r natinal agricultural service (e.g., USDA) recmmendatins. The manure applicatin histry during the crp rtatin must be cnsidered, including apprpriate manure mineralizatin crediting. Verified dcumentatin f manure mineralizatin N credits are included as part f the nutrient balance t accunt fr at least the three prir years. Legume residual N credits are included as part f the nutrient balance t accunt fr at least the immediately preceding year. Nutrient management practice dcumentatin. The NM Panel defined the N Cre NM EMA BMP t require full implementatin f a defined and applicable set f fundamental elements in rder t receive the BMP credit. Independent dcumentatin and verificatin that all f the required elements f the N Cre NM EMA BMP were implemented is required. The five elements that cnstitute the N Cre NM EMA BMP may r may nt be cmpnents f a frmal Nutrient Management Plan. The required nutrient management dcumentatin culd be in the frm f a frmal federal-, state-, r cunty-reviewed and certified nutrient management prgram plan, a nn-certified frmal nutrient management plan develped by a federal- r state-certified plan writer, r detailed dcumentatin and an infrmal management plan cmpiled by an peratr r private cnsultant that met the Panel s BMP recmmendatins. Equivalent Practices States may prpse equivalent practices t satisfy these requirements that must be apprved by the Agriculture Wrkgrup. 9.3 Phsphrus Cre NM BMP Elements Phsphrus Cre NM On-Site Sil & Manure Analysis All six elements, as applicable t the agricultural peratin, are required t be implemented and verified at the field management unit level t receive credit. P applicatin rate accrding t LGU recmmendatins at field management unit level. P applicatin rate recmmendatins that are higher than the CBP Partnership-mdified P applicatin rates are allwable when the recmmended rate is the utcme f a P-lss risk assessment tl that describes the risk f P lss t be lw. Applicatin f a P Cre NM On-Site Sil & Manure Analysis BMP applicatin rate multiplier mdifies the crpand land-use-specific P applicatin rate gal, which is based n LGU crp fertilizatin recmmendatins, as mdified by the CBP partnership. In practice, LGU recmmendatins fr P applicatin are based n crp- and site-specific sil-test P cncentratin. Currently, sil-test P cncentratin data are nt available t the CBP. The Panel recmmends that, in the future, crp- and site-specific sil-test P cncentratin data shuld be cllected, aggregated t the apprpriate scale, summarized t eliminate disclsure f private cnfidential business infrmatin, and utilized as the fundatin fr determining P applicatin rate gals and the apprpriate applicatin f P Cre NM OSMA BMPs. In the absence f sil-test P based applicatin rate gals, cunty-level redistributin f CBW AAPFCO P fertilizer sales data may serve as a surrgate. If applied P applicatin rates are belw the applicable LGU prescribed rates, and/r the CBP partnership mdified applicatin rates, the P applicatin system may still qualify fr credit as an equivalent P Cre NM OSMA system if it meets the remaining five P Cre NM OSMA elements. 137

138 A field management unit is described by the NM Panel as a cmmn land management unit as defined by the farm peratr with a similar annual crp prductin and management systems, and assciated nutrient applicatin system. The field management unit can represent any field, cllectin f multiple fields, r sub-prtins f a single field that are managed the same way, with similar histry and crpping practices. P sil tests at field management unit level. A sil labratry analysis is required t be btained frm the field management unit using standard sil testing prtcls. If a labratry sil analysis being used t adjust the nutrient applicatin, it must be less than three-years ld. Manure analysis and vlume. Estimatin f manure prduced and nutrient analysis f that manure must be used in the planning prcess. Manure nutrient analyses must be derived frm manure sample testing using standard labratry prtcls. If a labratry manure analysis is used t adjust the nutrient applicatin, the labratry analysis must be less than three-years ld. If labratry analysis f manure is nt available, as in the case f new, expanded r mdified livestck and pultry peratins, published bk values (as described abve) may be used fr a maximum f three years, after which time labratry analysis data must be utilized t satisfy P Cre NM BMP requirements. Spreader/applicatr calibratin The equipment being used t perfrm the nutrient applicatins by the farm peratr needs t be dcumented and verified that the machine(s) have been calibrated either accrding t manufacturer specificatins r by standard calibratin practices, preferably within ne year f the applicatin. The custm applicatr and equipment calibratin certificatins fr cmmercial applicatrs can be used as an equivalent verificatin dcumentatin fr calibrated nutrient applicatins. Yield estimates and crpping plan at management unit level Annual yield estimates shuld be based n field yield samples, calibrated electrnic yield mnitrs, r field specific grain elevatr receipts. Histric yield gals are determined using a LGU r state standardized methd f averaging annual yields ver time t accunt fr annual variability (e.g. average yield based n the best three ut f the past five years). A less preferred but equivalent methd is t use standard USDA sil prductivity bk values fr estimating applicable crp yield. The crpping plan refers t the planting and harvesting f the specific crp(s) fr which the field nutrient applicatins were based. An example f a field that wuld nt qualify under this required element is when the nutrient applicatin was based n the plant requirements fr grain crn but, due t in-seasn management decisins, the field was planted t sybeans instead. Crpping/manure histry at field management unit level As part f develping a planned nutrient applicatin rate, the farm peratr r custm applicatr cnsidered residual P credits based n LGU r natinal agricultural service (e.g., USDA) recmmendatins. The manure applicatin histry during the crp rtatin must be cnsidered, including apprpriate residual sil P crediting. Residual sil P credits are included as part f the nutrient balance t accunt fr at least the immediately preceding year. Nutrient management practice dcumentatin. The NM Panel defined the P Cre NM OSMA BMP t require full implementatin f a defined and applicable set f fundamental elements in rder t receive the BMP credit. Rather, independent dcumentatin and verificatin that all f the required elements f the P Cre NM OSMA BMP were implemented is required. The six elements that cnstitute the P Cre NM OSMA BMP may r may nt be cmpnents f a frmal Nutrient Management Plan. The required nutrient management dcumentatin culd be in the frm f a frmal federal-, state-, r cunty-reviewed and certified nutrient management prgram plan, a nn-certified frmal nutrient management plan develped by a federal- r state-certified plan writer, r detailed dcumentatin and an infrmal management plan cmpiled by an peratr r private cnsultant that met the Panel s BMP recmmendatins. Equivalent Practices 138

139 States may prpse equivalent practices t satisfy these requirements that must be apprved by the Agriculture Wrkgrup. Phsphrus Cre NM Estimated Sil & Manure Analysis All six elements, as applicable t the agricultural peratin, are required t be implemented and verified at the field management unit level t receive credit. P applicatin rate accrding t LGU recmmendatins at field management unit level. P applicatin rate recmmendatins that are higher than the CBP Partnership-mdified P applicatin rates are allwable when the recmmended rate is the utcme f a P-lss risk assessment tl that describes the risk f P lss t be lw. Applicatin f a P Cre NM Estimated Sil & Manure Analysis BMP applicatin rate multiplier mdifies the crp- and land-use-specific P applicatin rate gal, which is based n LGU crp fertilizatin recmmendatins, as mdified by the CBP partnership. In practice, LGU recmmendatins fr P applicatin are based n crp- and site-specific sil-test P cncentratin. Currently, sil-test P cncentratin data are nt available t the CBP. The Panel recmmends that, in the future, crp- and site-specific sil-test P cncentratin data shuld be cllected, aggregated t the apprpriate scale, summarized t eliminate disclsure f private cnfidential business infrmatin, and utilized as the fundatin fr determining P applicatin rate gals and the apprpriate applicatin f P Cre NM ESMA BMPs. In the absence f sil-test P based applicatin rate gals, cunty-level redistributin f CBW AAPFCO P fertilizer sales data may serve as a surrgate. If applied P applicatin rates are belw the applicable LGU prescribed rates, and/r the CBP partnership mdified applicatin rates, the P applicatin system may still qualify fr credit as an equivalent P Cre NM ESMA system if it meets the remaining five P Cre NM ESMA elements. A field management unit is described by the NM Panel as a cmmn land management unit as defined by the farm peratr with a similar annual crp prductin and management systems, and assciated nutrient applicatin system. The field management unit can represent any field, cllectin f multiple fields, r sub-prtins f a single field that are managed the same way, with similar histry and crpping practices. The requirement fr having a P sil test may be waived if restrictins n manure applicatin (rates, timing, placement), are impsed that limit P applicatin rates and management t the same degree as if the site s sil was in the high sil-test P interpretive categry. P nutrient applicatins may be based n annual crp remval at the field management unit level as an equivalent P Cre element, assuming the site s sil was in the high sil-test P interpretive categry. Manure analysis and vlume. Estimatin f manure prduced and nutrient analysis f that manure must be used in the planning prcess. Published manure nutrient analyses frm LGUs, natinal agricultural agencies (e.g., USDA-ARS, USDA- NRCS), natinal r reginal farm service rganizatins, r histrical analyses generated frm very similar, lcal and cnsistently managed industry-cntracted peratins may be used. Spreader/applicatr calibratin The equipment being used t perfrm the nutrient applicatins by the farm peratr needs t be dcumented and verified that the machine(s) have been calibrated either accrding t manufacturer specificatins r by standard calibratin practices, preferably within ne year f the applicatin. The custm applicatr and equipment calibratin certificatins fr cmmercial applicatrs can be used as an equivalent verificatin dcumentatin fr calibrated nutrient applicatins. Yield estimates and crpping plan at management unit level Annual yield estimates shuld be based n field yield samples, calibrated electrnic yield mnitrs, r field specific grain elevatr receipts. Histric yield gals are determined using a LGU r state standardized methd f averaging annual yields ver time t accunt fr annual variability (e.g. average yield based n the best three ut f the past five years). A less preferred but equivalent methd is t use standard USDA sil prductivity bk values fr estimating applicable crp yield. The crpping plan refers t the planting and harvesting f the specific crp(s) fr which the field nutrient applicatins were based. An example f a field that wuld nt qualify under this required element is when the 139

140 nutrient applicatin was based n the plant requirements fr grain crn but, due t in-seasn management decisins, the field was planted t sybeans instead. Crpping/manure histry at field management unit level As part f develping a planned nutrient applicatin rate, the farm peratr r custm applicatr cnsidered residual P credits based n LGU r natinal agricultural service (e.g., USDA) recmmendatins. The manure applicatin histry during the crp rtatin must be cnsidered, including apprpriate residual sil P crediting. Residual sil P credits are included as part f the nutrient balance t accunt fr at least the immediately preceding year. Nutrient management practice dcumentatin. The NM Panel defined the P Cre NM ESMA BMP t require full implementatin f a defined and applicable set f fundamental elements in rder t receive the BMP credit. Rather, independent dcumentatin and verificatin that all f the required elements f the P Cre NM ESMA BMP were implemented is required. The six elements that cnstitute the P Cre NM ESMA BMP may r may nt be cmpnents f a frmal Nutrient Management Plan. The required nutrient management dcumentatin culd be in the frm f a frmal federal-, state-, r cunty-reviewed and certified nutrient management prgram plan, a nn-certified frmal nutrient management plan develped by a federal- r state-certified plan writer, r detailed dcumentatin and an infrmal management plan cmpiled by an peratr r private cnsultant that met the Panel s BMP recmmendatins. Equivalent Practices States may prpse equivalent practices t satisfy these requirements that must be apprved by the Agriculture Wrkgrup. 9.4 Nitrgen Supplemental NM BMPs Advanced N Assessment Tls. Dcumentatin needed f the use f ne r a cmbinatin f these tls. These tls shuld guide implementatin f N rate, placement, r timing. Cnducting these assessments r using these tls have n impact unless they lead t an infrmed change in implementatin f N rate, N placement r N applicatin timing. This list is nt exhaustive r cmprehensive, and nly represents a selectin f examples that wuld cnstitute tls resulting in an implementatin change. N Rate Adjustment Practices. By implementing ne r mre f the practices listed, an additinal N credit will be applied. Hwever, implementing mre than ne f the practices captured under each supplemental practice categry will nly result in ne credit fr the practice adjustment. Within the N Rate Adjustment Practice, the rate f applicatin can be less than the LGU recmmendatin r cnsistent with partnership apprved rate applicatins, but in rder t receive supplemental credit, the rate f applicatin must be belw the rate listed fr the N Cre NM OMA BMP r the N Cre NM EMA BMP. Split applicatins ver time per crp. Ttal amunt f N applicatin may r may nt change, but the applicatin is divided int multiple, lwer-rate applicatins thrughut the year. Variable rate N applicatin implies that N is applied at a variety f different applicatin rates at the subfield scale within a management unit based n histrical data f spatially variable crp respnse due t sil type, drainage, etc. r due t in-seasn data frm ptical crp sensrs. N Placement Adjustment Practices. By implementing ne r mre f the practices listed, an additinal N credit will be applied. Hwever, implementing mre than ne f the practices captured under each supplemental practice categry will nly result in ne credit fr the practice adjustment. Where the N nutrient surce is physically lcated r placed relative t the sil surface. 140

141 Subsurface injectin r incrpratin f applied inrganic N. Immediate incrpratin generally means within 24 hurs f applicatin. N applicatin setbacks frm water: purpsefully nt applying N t crpped and hay land areas adjacent t surface water bdies. Setbacks must meet the minimum standards required under applicable lcal, state, r federal prgrams and laws. Applies t bth manure and fertilizer. Credit applies t entire field management unit. N Timing Adjustment Practices. By implementing ne r mre f the practices listed, an additinal N credit will be applied. Hwever, implementing mre than ne f the practices captured under each supplemental practice categry will nly result in ne credit fr the practice adjustment. Split applicatins ver time per crp. Ttal amunt f N des nt change, but applicatin is divided int multiple applicatins thrughut the year. 9.5 Phsphrus Supplemental NM BMPs Advanced P Assessment Tls. Dcumentatin needed f the use f ne r a cmbinatin f these tls. These tls shuld guide implementatin f rate, placement, r timing. Cnducting these assessments r using these tls have n impact unless they lead t an infrmal change in implementatin f rate, placement, r timing. This list is nt exhaustive r cmprehensive, and nly represents a selectin f example that wuld cnstitute tls resulting in an implementatin change. P Rate Adjustment Practices. By implementing ne r mre f the practices listed, an additinal P credit will be applied. Hwever, implementing mre than ne f the practices captured under each supplemental practice categry will nly result in ne credit fr the practice adjustment. Within the P Rate Adjustment Practice, the rate f applicatin can be less than the LGU recmmendatin r cnsistent with partnership apprved rate applicatins, but in rder t receive supplemental credit, the rate f applicatin must be belw the rate listed fr the P Cre NM OSMA BMP r the P Cre NM ESMA BMP. Variable rate P applicatin implies that P is applied at variety f different applicatins rates at the sub-field scale within the management unit based spatially variable crp respnse due t sil type, drainage, etc. r due t in-seasn data frm ptical crp sensrs. A P-based manure applicatin rate equivalent t annual crp P remval is an equivalent rate adjustment practice. P Placement Adjustment Practices. By implementing ne r mre f the practices listed, an additinal P credit will be applied. Hwever, implementing mre than ne f the practices captured under each supplemental practice categry will nly result in ne credit fr the practice adjustment. Where the P nutrient surce is physically lcated r placed relative t the sil surface. Subsurface injectin r incrpratin f applied inrganic P. Immediate incrpratin generally means within 24 hurs f applicatin. Phsphrus applicatin setbacks frm water: purpsefully nt applying P t crpped and hay land areas adjacent t surface water bdies. Setbacks must meet the minimum standards required under applicable lcal, state, r federal prgrams and laws. Applies t bth manure and fertilizer. Credit applies t entire field management unit. Applicatin f manure n different fields based n the P Index assessment that results in manure applicatin n a lwer P Index rated field rather than a higher P Index rated field. 141

142 P Timing Adjustment Practices. By implementing ne r mre f the practices listed, an additinal P credit will be applied. Hwever, implementing mre than ne f the practices captured under each supplemental practice categry will nly result in ne credit fr the practice adjustment. Split applicatins ver time per crp. Ttal amunt f P des nt change, but applicatin is divided int multiple applicatins thrughut the year. P applicatin in lwer P-lss risk seasn. Purpseful change the timing f manure applicatin based n the P Index assessment that results in manure applicatin at a time during the calendar year when the P Index assessment indicates a lwer risk fr P lss. Split applicatins ver time per crp. Ttal amunt f P applicatin may r may nt change, but the applicatin is divided int multiple, lwer-rate applicatins thrughut the year. 142

143 10 Effectiveness Estimates This sectin begins with a brief summary f the recmmended N and P multiplier values fr N and P Cre NM BMPs and fr lss reductin multipliers fr N and P Supplemental NM BMPs. This summary is fllwed by a discussin f the ratinale and use f specific data values frm the available literature t develp the recmmended multiplier values. Finally, details are prvided n hw the recmmended applicatin rate multiplier values fr Cre NM BMPs and lss reductin multipliers fr the Supplemental NM BMPs can be cmbined t reflect actual N and P management and verall effectiveness at a specific lcatin Summary f Effectiveness Estimates All numeric values fr the N Cre NM On-Site Manure Analysis BMP and the P Cre NM On-Site Sil & Manure Analysis BMP applicatin rate multipliers and the Supplemental NM BMP lss reductin multipliers have been defined by the Panel. Numeric values fr the N Cre NM Estimated Manure Analysis and the P Cre NM Estimated Sil & Manure Analysis BMP applicatin rate multipliers have been defined by the Agriculture Wrkgrup. See sectin 3.3 fr a detailed discussin f hw these values are applied in the determinatin and crediting f verall NM BMP effectiveness fr N and P N Cre NM BMPs The prpsed applicatin rate multipliers fr N Cre NM OMA and EMA BMPs fr each applicable agricultural land use categry are given in Table 12. These applicatin rate multipliers are based n state LGU recmmendatins, as mdified by the CBP partnership, and apply t the nutrient applicatin rate gal, r input side, f nutrient management mdeling scheme. Each value represents a multiplicative mdifier f the crp- and land-use-specific N applicatin rate gal utilized in the CBP mdels. Table 12. Cre N Nutrient Management Applicatin Rate Multiplier Values Land Use Nitrgen Cre Nn-Nutrient Management BMP Applicatin Rate Multiplier Nutrient Management BMP Nitrgen Cre Nutrient Management Estimated Manure Analysis Rate Multiplier Nitrgen Cre Nutrient Management On-Site Manure Analysis Rate Multiplier Full Seasn Sybeans Grain w/ Manure Grain w/ Manure Legume Hay Silage w/ Manure Silage w/ Manure Small Grains and Grains Small Grains and Sybeans Specialty Crp High Specialty Crp Lw Other Agrnmic Crps Other Hay Pasture P Cre NM BMPs The prpsed applicatin rate multipliers fr P Cre NM OSMA and ESMA BMPs fr each applicable agricultural land use categry are given in Table 13. These applicatin rate multipliers are based n state LGU recmmendatins, as 143

144 mdified by the CBP partnership, and apply t the nutrient applicatin rate gal, r input side, f the nutrient mdeling scheme fr bth NM and nn-nm acres. Each value represents a multiplicative mdifier f the crp- and land-usespecific P applicatin rate gal utilized in the CBP mdels. Fr crps and land uses in which manure is applied, manure applicatins that result in manure P applicatin rates that are greater than r equal t the crp-specific P applicatin need results in the prhibitin f applicatin f additinal fertilizer P. An exceptin t the prhibitin f supplemental fertilizer P additin fllwing manure applicatin is the utilizatin f relatively small quantities f starter fertilizer P, typically applied subsurface in the planting rw, accrding t LGU recmmendatins. Fr crps and land uses in which manure is applied, the ttal quantity f manure P assciated with the ttal manure applicatin rate shuld be allcated t the subject acreage. Table 13. Cre P Nutrient Management Applicatin Rate Multiplier Values Land Use Phsphrus Cre Nn-Nutrient Management BMP Applicatin Rate Multiplier Nutrient Management BMP Phsphrus Cre Nutrient Management Estimated Manure Analysis Rate Multiplier Phsphrus Cre Nutrient Management On-Site Manure Rate Multiplier Full Seasn Sybeans Grain w/ Manure Grain w/ Manure Legume Hay Silage w/ Manure Silage w/ Manure Small Grains and Grains Small Grains and Sybeans Specialty Crp High Specialty Crp Lw Other Agrnmic Crps Other Hay Pasture N Supplemental Nutrient Management BMPs The Panel s prpsed lss reductin multipliers fr N Supplemental NM BMPs fr each applicable agricultural land use categry are given in Table 14. These values are multiplicative mdifiers that apply t edge-f-stream delivery f N, n the utput side f the CBP mdeling scheme, and can nly be applied if the requirements fr either the N Cre NM OMA r the N Cre NM EMA BMP are met. 144

145 Table 14. N Supplemental Nutrient Management BMP Lss Reductin Multiplier Values Land Use N Rate Supplemental BMP Lss Reductin Multiplier Nutrient Management BMP N Placement Supplemental BMP Lss Reductin Multiplier N Timing Supplemental BMP Lss Reductin Multiplier Full Seasn Sybeans Grain w/ Manure Grain w/ Manure Legume Hay Silage w/ Manure Silage w/ Manure Small Grains and Grains Small Grains and Sybeans Specialty Crp High Specialty Crp Lw Other Agrnmic Crps Other Hay Pasture P Supplemental Nutrient Management BMPs The Panel s prpsed lss reductin multipliers fr P Supplemental NM BMPs fr each applicable agricultural land use categry are given in Table 15. These values are multiplicative mdifiers that apply t edge-f-stream delivery f P, n the utput side f the CBP mdeling scheme, and can nly be applied if the requirements fr either the P Cre NM OSMA BMP r the P Cre NM ESMA BMP are met. Table 15. P Supplemental Nutrient Management BMP Lss Reductin Multiplier Values Land Use P Rate Supplemental BMP Lss Reductin Multipliers Nutrient Management BMP P Placement Supplemental BMP Lss Reductin Multipliers P Timing Supplemental BMP Lss Reductin Multipliers Full Seasn Sybeans Grain w/ Manure Grain w/ Manure Legume Hay Silage w/ Manure Silage w/ Manure Small Grains and Grains Small Grains and Sybeans Specialty Crp High Specialty Crp Lw Other Agrnmic Crps Other Hay Pasture

146 10.2 Develpment f Applicatin Rate Multipliers and Lss Reductin Multipliers fr Cre NM BMPs and Supplemental NM BMPs The Panel develped the prpsed Phase 6 NM applicatin rate multiplier estimates and lss reductin multiplier estimates thrugh a synthesis f applicable scientific literature (see References sectin) and the cllective best prfessinal judgment f the NM Panel members (see Table 1). The membership f the Panel represents ver 150 years f direct invlvement in research, implementatin and educatin n agricultural nutrient management practices. The entire bdy f research represented by the citatins presented in the References sectin prvided the fundatin fr the Panel s prfessinal assessment f the rate and lss reductin multipliers fr the prpsed NM BMPs. The multiplier values presented fr the Cre NM BMPs and the Supplemental NM BMPs represent either a cllectin f required elements r represent the impact f numerus applicable n-site management practices. Therefre, in rder t develp bradly pertinent NM BMP multiplier values, multiple surces f infrmatin and data were necessarily synthesized thrugh the expert lens f the Panel. Fr bth N and P BMPs, nutrient management practices are implemented at either the field r sub-field level. The diverse landfrms, hydrlgy, climate and crpping systems f the agricultural landscapes in the CBW have a multitude f impacts n bigechemical transfrmatins f N and P in the agr-ecsystem. Changes in hydrlgical pathways alne can have dramatic effects n nutrient lads t streams when viewed frm the Atlantic Castal Plain t the Appalachian Plateau. Therefre, site-specific physical cnditins and management factrs have a strng influence n the effectiveness f impsed cnservatin practices. Nutrient management BMP effectiveness must represent the average cnditin ver a wide range f real-wrld scenaris. Thus, it was incumbent upn the Panel t distill numerus lines f evidence t arrive at a single multiplier value fr each f the N and P BMPs that culd be applied equitably acrss the CBW. Belw are examples f specific analyses that were used t infrm the NM Panel in its applicatin f best prfessinal judgment t determine NM BMP applicatin rate multipliers (fr the N Cre NM OMA BMP and the P Cre NM OSMA BMP) and lss reductin multipliers. The NM BMP applicatin rate multipliers fr the N Cre NM EMA BMP and the P Cre NM ESMA BMP were determined based n the best prfessinal judgment f the Agriculture Wrkgrup in light f the applicatin rate multipliers determined fr the N Cre Nn-Nutrient Management BMP and N Cre NM OMA BMP in Table 12 and the P Cre Nn-Nutrient Management BMP and P Cre NM OSMA BMP in Table 13. N Cre and P Cre NM BMPs The reductin in nutrient applicatin rates fr N Cre and P Cre NM BMPs were determined based n histrical (i.e., befre the Chesapeake Bay Prgram Watershed Mdel (CBPWM) simulatin perid f 1985) and mdern LGU agrnmy guides (i.e., during the calibratin perid f the CBPWM (Table 16). Histrical LGU agrnmy guides (pre- 1985) evaluated by Phase NM Panel members recmmended a range f percent mre plant-available N than CBPWM calibratin perid LGU guides. In additin, the principal basis fr applicatin rate difference between nn-nm and NM fr N is a reductin in the fertilizer N requirement fr crn frm 1.2 lbs. N/bu. f expected yield in earlier LGU recmmendatins t 1.0 lbs. N/bu. f expected yield in current LGU recmmendatins. This reductin is supprted by data frm Cale (2000) wh examined crn yield respnse t fertilizer N rate with the assciated pst-harvest fall sil residual NO 3 -N cncentratin. These findings are reflected in the values fr grain and silage fund in Table 12 fr N Cre NM OMA BMPs. Because ther crps f significant acreage did nt have cnsistently r significantly lwer recmmended N applicatin rates when the histrical (pre-1985) and current frm LGU agrnmy guides were cmpared, these agricultural land uses were assigned mre cnservative values in Table 12. N Cre NM BMP multiplier values fr Other Hay and Pasture were set at 1.00 because the CBP Partnership s mdificatin f the LGU N applicatin recmmendatins created a unifrm and much-reduced N applicatin rate gal fr these tw agricultural land uses that included an assumed implementatin rate f NM BMPs acrss the entire CBW. Therefre, the Panel culd nt apply a N applicatin rate BMP multiplier ther than 1.00 t these tw land uses. 146

147 Table 16. LGU Agrnmy Guide Recmmendatins fr Crn N Fertilizer Applicatin Rate Befre and During CBPWM Calibratin Perid. Values Presented Are Punds f Plant Available N (PAN) Per Bushel f Expected Crn Yield Land Grant University Pre-calibratin Recmmendatin Calibratin perid Recmmendatin Nrth Carlina State University 1.4 lbs. PAN lbs. PAN Pennsylvania State University University f Maryland Nrth Carlina State University Extensin Agrnmy Guide. Nrth Carlina State University. Raleigh, NC. 1 Penn State Extensin Agrnmy Guide. The Pennsylvania State University, Cllege f Agriculture Extensin Service. University Park, PA Cp. Ext. Serv Fertilizer Recmmendatins, sheet 3, crn fr grain n medium textured sils withut manure. Univ. MD Cp. Ext. Serv., Cllege Park, MD. 1 Cale, F.J Plant nutrient recmmendatins based n sil tests and yield gals. Agrnmy Mime N. 10, Cp. Ext. Serv. and Agrnmy Dept. Univ. MD, Cllege Park, MD P applicatin rate multiplier values fr P Cre NM OSMA BMPs are greater fr land uses with manure versus the crrespnding land use withut manure. Histrically (pre-1985), manure applicatins managed withut attentin t NM guidelines resulted in P applicatin rates at least three times higher, and prbably mre, than wuld be expected under P- based nutrient management. Fr nn-manured prductin systems perating utside f NM guidelines, fertilizer P verapplicatin wuld nt be expected t be nearly as great as when manure is the primary nutrient surce. These findings are reflected in the values fr grain and silage fund in Table 13 fr P Cre NM OSMA BMPs. As fr N Cre NM, P Cre NM BMP multiplier values fr Other Hay and Pasture were set at 1.00 because the CBP Partnership s mdificatin f the LGU P applicatin recmmendatins created a unifrm and much-reduced P applicatin rate gal fr these tw agricultural land uses that included an assumed implementatin rate f NM BMPs acrss the entire CBW. Therefre, the Panel culd nt apply a P applicatin rate BMP multiplier ther than 1.00 t these tw land uses. N Rate, N Placement, and N Timing Lss Reductin Multipliers Several assessments f the PSNT have resulted in N reductin rates f 6 t 42 percent, with mst demnstrating reductins f 17 percent r greater. A three-year study f crn/rye n a manured silt-lam sil in Vermnt by Durieux et al. (1995) reprted that use f the PSNT reduced nitrate leaching ptential by resulting in an average reductin in fall residual NO 3 -N (nitrate N) f 56 percent cmpared t N applicatins based n traditinal LGU N recmmendatins. On average, fall N applicatin was reduced by 29 percent (150 lbs. N/ac. t 107 lbs. N/ac.) due t applicatin f the PSNT. This exceeds the largest credit (15 percent lss reductin) given fr N Rate Supplemental BMPs (Table 14). The reduced ptential fr nitrate leaching due t PSNT applicatin was cnfirmed by Guillard et al. (1999) in a tw-year lysimeter study n a sandy-lam sil that demnstrated an average reductin in NO 3 -N leaching f 63%, cmpared t crn fertilized accrding t standard LGU recmmendatins. Fall N leaching lss was reduced by an average f 42 percent, frm 196 kg N/ha (175 lbs. N/ac.) t 113 kg N/ha (101 lbs. N/ac.), a change als greatly exceeding the N Rate Supplemental BMP credits shwn in Table 14. Data frm quarterly r annual reprts frm in-field nutrient management cnsultants were used t summarize PSNT activities and results under the Maryland (Steinhilber 2015) and Virginia (Sextn 2015) Nutrient Management Prgrams. The Maryland summaries cvered three years, encmpassing a ttal f 2,690 ac. frm the Piedmnt and 27,850 ac. frm the Castal Plain. The average estimated reductin in ttal fertilizer N applicatin resulting frm implementing the PSNT, cmpared t using university recmmendatins withut the PSNT, was 20% and 6% fr the Piedmnt and Castal Plain regins, respectively. Sextn (2015) reprted n a 5,325-ac. evaluatin f the PSNT cnducted in Virginia s Shenandah Valley cnsisting f 1,246 PSNT tests that cmpared university recmmendatins with and withut the PSNT (Fitzgerald and Baird 2014). The Virginia results shwed that use f the PSNT resulted in an estimated average savings f 30 lbs. N/ac., r a 20% N fertilizer applicatin reductin fr 29% f the PSNT evaluatins and a savings f 60 lbs. N/ac., r a 40% N fertilizer applicatin reductin, fr anther 28% f the PSNT evaluatins. The remaining 43% f the PSNT evaluatins resulting in unchanged fertilizer N applicatin rate recmmendatins. The average percent reductin f fertilizer N applicatin acrss the Virginia Piedmnt study was 17%, which is cnsistent with the Maryland Piedmnt estimate. Additinally, a tw-year study in New Yrk n a lamy-sand sil that mnitred tile drainage frm silage crn 147

148 grwn in relatively large (18 m 2 ) islated plts reprted an average reductin in NO 3 -N lsses f 42% fr the PSNT treatment, cmpared t the nn-psnt standard LGU recmmendatin (Sgbedji et al. 2000). Fall N lss rates were reduced by 25% (134 kg N/ha t 100 kg N/ha r 120 lbs. N/ac. t 89 lbs. N/ac.) due t applicatin f the PSNT. Studies n the CSNT and ISNT shwed results similar t thse fr the PSNT. In New Yrk, results reprted by Ketterings et al. (2014, 2011a, 2011b), Whartn et al. (2010), and Hng et al. (2010) suggest that abut 40% f tested crn silage fields were rated in the excess categry and fllwing the recmmendatins f the CSNT wuld result in a 20 t 30% reductin in N applicatin. Kyveryga et al. (2010) reprted that f 215 fields receiving liquid swine manure, abut 30% f fields were fund t be unrespnsive t additinal N (beynd 25 lbs. N/ac. starter). Extending this percentage ver all silage crn fields under CSNT, recmmendatins derived frm CSNT wuld have resulted in 15 t 30 lbs. N/ac. applicatin reductin annually, representing a 20 t 30% reductin ver standard N rate recmmendatins. Results f multi-year N rate trials n silage crn in New Yrk ver three crp years shwed that abut 50% f tested fields were nn-respnsive t additinal N fertilizer and, therefre, the ISNT assessment wuld recmmend n additinal N applicatin beynd starter N at 25 lbs. N/ac. (Lawrence et al. 2009, Klapwyk et al. 2006, Lawrence et al. 2008, Ketterings et al. 2009). Because these fields wuld therwise have received a recmmended applicatin f 75 t 125 lbs. N/ac., managing N applicatins based n the ISNT results reduced N applicatins n the affected fields by 50 t 100 lbs. N/ac. Discunting this reductin because nly half f crn silage fields were determined t be nn-respnsive by ISNT gives an estimated 25 t 50 lbs. N/ac. reductin in N applicatins t silage crn, a reductin f 33 t 40% in ttal N applicatins. Using unpublished data frm studies cnducted thrughut Virginia, the Phase Nutrient Management Expert Panel cmpared N applicatin rates t crn fr the Virginia Tech Crn Algrithm (VTCA) applied via the GreenSeeker system versus the standard farmer s N rate methds (Phase Nutrient Management Expert Panel 2015). Over 15 sites in 4 years, the average VTCA N rate was 24 kg/ha (apprximately 20%) less than the standard farmer s rate, with n significant difference in grain yields. Additinally, data frm field scale demnstratins frm a ttal f 1600 ac. ver tw years demnstrated a 10% decrease in N rate applied with n difference in crn yields (Virginia NRCS CIG 69-33A7-1131, final reprt). These data demnstrate the ability t reduce N applicatin rates while maintaining crp yields. Other Virginia data fr wheat (Thmasn et al and Virginia NRCS CIG 69-33A7-1131, final reprt) suggest that N rates fr wheat culd be decreased by apprximately 7% with n change in yield. The FSNT prvides an adaptive management tl fr simultaneusly imprving ecnmic prductin f small grains by identifying sites where small grains need starter N, and als reducing nitrate-n lss t grundwater by nt fertilizing N sufficient sites just befre the fall-winter-spring water-recharge seasn when mst nitrate leaching ccurs (Frrestal et al. 2014, Meisinger et al. 2015). The N reductin efficiency fr the FSNT was estimated frm fur years f lysimeter nitrate- N leaching data (Pers. cmm., J. Meisinger 2015) using the intact sil-clumn lysimeter described in Palmer et al. (2011) and fllwing the sample cllectin and analysis methds described in Meisinger et al. (2015). The lysimeter treatments were replicated twice each year with winter wheat receiving either a starter-n applicatin f 30 lbs. N/ac. r n starter-n. Lysimeter drainage mnitred NO 3 -N leaching cntinuusly between planting and the green-up develpment stage. These treatments were repeated in , , , and wheat grwing seasns. The final lysimeter-based N lss reductin efficiency was estimated t be 10%. In the lng term, achieving a balance between nutrient imprts and exprts at the whle farm level (and later at the watershed level) is believed t be an effective way t minimize nutrient surpluses, manage sil nutrient levels, and reduce runff and leaching lsses. Fr livestck farms, the whle farm nutrient balance apprach has been invaluable in identifying pprtunities fr reducing N and P imprts, making better use f n-farm nutrient surces, identifying the need fr mre land fr nutrient recycling, and increasing nutrient exprts. As shwn ver several years f research n 54 New Yrk dairy farms, nutrient balance reductins averaged 29% fr N and 36% fr P (Sbern et al. 2015, Cela et al. 2014a and 2014b). Hwever, the bserved reductins are attributable primarily t changes in feed frmulatin and management, rather than fertilizer management. N reductin efficiencies frm timing N applicatins were estimated by cmparing crn yields frm replicated N-respnse trials ver many site-years (Fx et al. 1986, Fx and Piekielek 1993, Pers. Cmm. J Meisinger 2015). These studies cmpared yield vs. N applied (as urea-ammnium-nitrate) at planting, r N applied just befre the crp begins its rapid 148

149 perid f grwth. Crn had the mst N-respnse trials, which were summarized by fitting separate quadratic regressin functins fr each timing at each site-year f data, and then estimating the ecnmic ptimum N rate (EONR) fr crn grain valued at $4.00/bu. and N priced at $0.50 per pund. These regressins allwed estimatin f the EONR and assciated yield, which prvided a methd t cmpare ptimum rates fr N applied at planting vs. at a later time that was in harmny with crp N demand. A plt-based N reductin efficiency was estimated as the difference between the EONRs at planting vs. the delayed applicatin, divided by the planting EONR. There were als adequate data frm the Castal Plain (21 site-years) and the Piedmnt (18 site-years) regins t estimate separate N reductin efficiencies. These calculatins prduced a Castal Plain estimated N reductin efficiency f abut 16%, with the crrespnding estimate fr the Piedmnt f 9%. The Castal Plain higher N-timing reductin efficiency is likely due t the regin having mre carse-textured sils and mre shallw rting depths than the Piedmnt. These reductins supprt the N Timing Supplemental BMP Efficiency values in Table 14, as d the dcumented PSNT-based N reductin rates f 6 t 42% (with mst demnstrating reductins f 17 percent r greater) described abve. N-timing reductin efficiencies fr wheat were estimated frm tw-years f field-plt ttal N uptake data frm a study that cmpared an all-at-green-up applicatin with a split f N between green-up and an applicatin apprximately ne mnth later (Gravelle et al. 1988). Fur years f lysimeter nitrate-n leaching data (Pers. cmm., J. Meisinger 2015) were als used frm intact sil-clumn lysimeters described in Palmer et al. (2011) fllwing the sample cllectin and analysis methds described in Meisinger et al. (2015). The lysimeter treatments were replicated twice in each f the fur years ( , , , and ) with winter wheat receiving either all the N at green-up, r with the same N rate applied ne-third at green-up and tw-thirds abut a mnth later. These tw data surces prduced an average wheat N-timing reductin efficiency f abut 15%, which is similar t the Castal Plain value fr crn and supprtive f the N Timing Supplemental BMP Efficiency values in Table 14. When the data summarized abve are analyzed as a whle, the literature is supprtive f the applicatin f NM BMP N lss reductin multipliers within the ranges presented in Table 14. Overall, the prpsed N lss reductin multipliers are numerically cnservative and range frm 3 t 15%, exclusive f the 0% N lss reductin multiplier that was defined fr the Other Hay and Pasture land uses. P Rate, P Placement, and P Timing Lss Reductin Multipliers Kleinman and Sharpley (2003) packed sils int runff bxes and bradcast with three manures (dairy, layer pultry, and swine) at six rates, frm 0 t 150 kg ttal P (TP)/ha (0-134 lbs. TP/ac.). Manure analysis indicated that N-based manure applicatin fr silage crn f 300 kg ttal N (TN)/ha (268 lbs. TN/ac.)) wuld result in TP applicatin rates f 70, 200, and 88 kg/ha (62, 178, and 78 lbs. TP/ac.) fr the dairy, pultry, and swine manures, respectively. Applicatin rates matching silage crn TP requirement f apprximately 25 kg TP/ha (22 lbs. TP/ac.) wuld result in TN applicatins f 151, 53, and 119 kg TN/ha (135, 47, and 106 lbs. TN/ac). Applicatin rate was related t runff P (r 2 =0.50 t r 2 =0.98), due t increased cncentratins f disslved reactive phsphrus (DRP) in runff; as applicatin rate increased, s did the cntributin f DRP t runff TP. Assuming 150 bu./ac. yields, recmmendatins fr silage crn are abut 180 lbs. TN/ac. and 103 lbs. TP/ac. fr lw t ptimum sil test levels (Rth and Heinrichs 2001). Rates fr grain crn wuld be 160 lbs. TN/ac. and 76 lbs. TP/ac. The P rates applied by Kleinman and Sharpley (0-134 lbs. TP/ac.) bracket these rates, with the highest rate 1.3 and 1.8 times the silage and grain crn rates, respectively, fr a 150 bu. /ac. yield. The effect f flw time, flwpath length, and manure psitin n P lss in verland flw frm tw central Pennsylvania sils packed in bxes f varying length were examined by cllecting runff water samples frm sil bxes with and withut 75 kg P/ha applied as swine manure ver 0.5 m f the bx slpe length at distances f 0 t 3.5 m frm the dwnslpe cllectin pint (McDwell and Sharpley 2002). Disslved reactive P cncentratin was mre clsely related t the prprtin f clay in sediment f verland flw befre (r =0.98) than after (r= 0.56) manure applicatin. This was attributed t the transprt f larger, lw-density particles after applying manure. The cncentratin f disslved P and particulate P fractins decreased with increasing flw-path length, due t dilutin rather than srptin f P by surface sil during verland flw. Ttal P lss (mainly as particulate P) frm the Watsn channery silt lam was mre than frm Berks channery silt lam, even with manure applied. Thus, while P lss in verland flw is affected by where manure is applied relative t flwpath length, initial sil P cncentratin is very imprtant when lking at areas f ptential P lss within a watershed. 149

150 In the lng term, achieving a balance between nutrient imprts and exprts at the whle farm level (and later at the watershed level) is believed t be an effective way t minimize nutrient surpluses, manage sil nutrient levels, and reduce runff and leaching lsses. Fr livestck farms, the whle farm nutrient balance apprach has been invaluable in identifying pprtunities fr reducing N and P imprts, making better use f n-farm nutrient surces, identifying the need fr mre land fr nutrient recycling, and increasing nutrient exprts. As shwn ver several years f research n 54 New Yrk dairy farms, nutrient balance reductins averaged 29% fr N and 36% fr P (Sbern et al. 2015, Cela et al. 2014a and 2014b). Hwever, the bserved reductins are attributable primarily t changes in feed frmulatin and management, rather than fertilizer management. Applicatin f a P Cre NM BMP applicatin rate multiplier mdifies the crp- and land-use-specific P applicatin rate gal, which is based n LGU crp fertilizatin recmmendatins, as mdified by the CBP partnership. A significant mdificatin impsed by the CBP partnership was the assumptin that all agricultural acres in the CBW had a sil-test P cncentratin that crrespnded with the medium sil test interpretive categry. The Panel recgnized that, in the absence f sil-test P cncentratin data, assumed sil-test P cncentratins were necessary t facilitate CBP mdel prcesses. Hwever, the Panel als recgnized that implementatin f the universal medium sil-test P assumptin infused a high level f site-specific uncertainty int the mdeled P applicatin rate. In general, the inherent uncertainty in P applicatin rate resulting frm the adptin f the universal medium sil-test P cncentratin assumptin is expected t be similar t r greater than the magnitude f the P applicatin rate mdificatins resulting frm implementatin f P Cre NM BMP applicatin rate multipliers r the P NM Supplemental BMP lss reductin multipliers. In practice, LGU recmmendatins fr P applicatin are based n crp- and site-specific sil-test P cncentratin. Currently, sil-test P cncentratin data are nt available t the CBP. The Panel recmmends that, in the future, crp- and site-specific sil-test P cncentratin data shuld be cllected, aggregated t the apprpriate scale, summarized t eliminate disclsure f cnfidential business infrmatin, and utilized as the fundatin fr determining P applicatin rate gals and the apprpriate applicatin f P Cre NM BMPs. In the absence f sil-test P data and sil-test P based applicatin rate gals, sil-test P cncentratin must be assumed and, in turn, utilized t create artificial P applicatin rate gals Methd fr Applying Cre and Supplemental Multiplier Values The verall BMP efficiencies fr N and P nutrient management are derived frm a cmbinatin f applicatin rate multipliers fr the Cre Nutrient Management BMPs (N r P) with their crrespnding Supplemental Nutrient Management BMP (N r P) lss reductin multipliers. The N Cre NM BMP and P Cre NM BMP address the rate f nutrient applicatin while the N Supplemental NM BMPs and P Supplemental NM BMPs address the transprt f applied nutrients. The verall effectiveness values (ne fr N and ne fr P) are calculated as the cmbined effect f changes in nutrient applicatin rate and nutrient transprt caused by the implementatin f Cre and Supplemental NM BMPs. Specific details regarding hw these cmbinatins are calculated and applied are prvided belw. Nitrgen Applicatin f the N Cre NM BMP applicatin rate multiplier credit mdifies the crp- and land-use-specific N applicatin rate gal, which is based n LGU crp fertilizatin recmmendatins, as mdified by the CBP partnership. These multipliers apply t the nutrient applicatin rate gal, r input side, f CBP nutrient mdeling scheme fr bth NM and nn-nm acres. Each multiplier value represents a multiplicative mdifier f the crp- and land-use-specific N applicatin rate gal utilized in the CBP mdels. Applicatin f lss reductin multiplier credits fr N Supplemental NM BMP elements requires satisfactry implementatin f all respective N Cre NM BMP elements (either NM OMA r NM EMA). The N Supplemental NM BMP multipliers apply multiplicative mdifiers t edge-f-stream delivery f N, n the utput side f the CBP mdeling scheme, and can nly be applied if the requirements fr either N Cre NM BMP are met. Multiple advanced site assessments and N management tls may be utilized t infrm the applicatin f apprpriate N adjustment practices, but d nt represent a N credit in and f themselves. Advanced site assessments and applicatin f N management tls that result in implementatin f a verifiable change in planned N applicatin rate, N applicatin timing, r N applicatin 150

151 placement may result in a N Supplemental NM BMP lss reductin multiplier credit. N Supplemental NM BMP credits fr N rate, N timing, and N placement are stackable. Only ne Supplemental NM BMP credit fr N rate, ne Supplemental NM BMP credit fr N timing, and ne Supplemental NM BMP credit fr N placement may be applied. Phsphrus Applicatin f the P Cre NM BMP applicatin rate multiplier credit mdifies the crp- and land-use-specific P applicatin rate gal, which is based n LGU crp fertilizatin recmmendatins, as mdified by the CBP partnership. These multipliers apply t the nutrient applicatin rate gal, r input side, f the nutrient mdeling scheme fr bth NM and nn-nm acres. Each multiplier value represents a multiplicative mdifier f the crp- and land-use-specific P applicatin rate gal utilized in the CBP mdels. Fr crps and land uses in which manure is applied, manure applicatins that result in manure P applicatin rates that are greater than r equal t the crp-specific P applicatin need results in the prhibitin f applicatin f additinal fertilizer P. Fr crps and land uses in which manure is applied, the ttal quantity f manure P assciated with the ttal manure applicatin rate is allcated t the subject acreage. Applicatin f the lss reductin multiplier credits fr P Supplemental NM BMP elements requires satisfactry implementatin f all respective P Cre NM BMP elements (either NM OSMA r NM ESMA). The P Supplemental NM BMP multipliers apply multiplicative mdifiers t edge-f-stream delivery f P, n the utput side f the CBP mdeling scheme, and can nly be applied if the requirements fr either P Cre NM BMP are met. Multiple advanced site assessments and P management tls may be utilized t infrm the applicatin f the apprpriate P adjustment practices, but d nt represent a P credit in and f themselves. Advanced site assessments and applicatin f P management tls that result in a verifiable implementatin f a change in planned P applicatin rate, P applicatin timing, r P applicatin placement may result in a P Supplemental NM BMP lss reductin multiplier credit. Supplemental BMP credits fr P rate, P timing, and P placement are stackable. Only ne Supplemental NM BMP credit fr P rate, ne Supplemental NM BMP credit fr P timing, and ne Supplemental NM BMP credit fr P placement may be applied. Summary As described abve and under Practice Definitins, there is ne pprtunity fr crediting per each Supplemental NM BMP categry fr N and P. There are three such categries each fr N and P Supplemental BMPs: rate, timing, and placement. Applicatin f a lss-reductin multiplier fr the N Supplemental NM BMP elements can nly ccur after satisfactry implementatin f either the N Cre NM OMA BMP r the N Cre NM EMA BMP. The N Supplemental NM BMP lss reductin credit fr each f these three categries (rate, timing, and placement) can be btained if implementatin f at least ne effective practice frm each categry is verified. Similarly, applicatin f a lss-reductin multiplier fr the P Supplemental NM BMP elements can nly ccur after satisfactry implementatin f either the P Cre NM OSMA BMP r the P Cre NM ESMA BMP. The P Supplemental NM BMP lss reductin credit fr each f these three categries (rate, timing, and placement) can be btained if implementatin f at least ne effective practice frm each categry is verified. N Supplemental NM BMP lss reductin credits fr N rate, N timing, and N placement are stackable, as are P Supplemental NM BMP lss reductin credits fr P rate, P timing, and P placement. The apprach fr applying bth cre and supplemental nutrient management multiplier values is summarized in Table 17. Figures 3-6 illustrate the decisin tree fr assigning credits. 151

152 Table 17. Summary f Methd fr Applying Nutrient Management Multiplier Values Nutrient Management BMP Actin f BMP Hw the math wrks Nitrgen Cre Nn-Nutrient Management BMP Mdifies N applicatin rate gal n the nutrient input side Nitrgen Cre Nutrient Management BMP (OMA r EMA) N Rate Supplemental NM BMP N Placement Supplemental NM BMP N Timing Supplemental NM BMP Mdifies N applicatin rate gal n the nutrient input side Mdifies edge f field N lss t the stream n the utflw side Mdifies edge f field N lss t the stream n the utflw side Mdifies edge f field N lss t the stream n the utflw side Multiplier value is applied t the LGU N applicatin rate gal Multiplier value is applied t the LGU N applicatin rate gal Multiplier value is applied t the calculated edge f field N lad Multiplier value is applied t the calculated edge f field N lad Multiplier value is applied t the calculated edge f field N lad Phsphrus Cre Nn-Nutrient Management BMP Phsphrus Cre Nutrient Management BMP (OSMA r ESMA) P Rate Supplemental NM BMP P Placement Supplemental NM BMP P Timing Supplemental NM BMP Mdifies P applicatin rate gal n the nutrient input side Mdifies P applicatin rate gal n the nutrient input side Mdifies edge f field P lss t the stream n the utflw side Mdifies edge f field P lss t the stream n the utflw side Mdifies edge f field P lss t the stream n the utflw side Multiplier value is applied t the LGU P applicatin rate gal Multiplier value is applied t the LGU P applicatin rate gal Multiplier value is applied t the calculated edge f field P lad Multiplier value is applied t the calculated edge f field P lad Multiplier value is applied t the calculated edge f field P lad 152

153 NITROGEN Cre Nutrient Management On-Site Manure Analysis BMP (ALL applicable cre elements required t be implemented N applicatin gal (N rate) accrding t LGU recmmendatins at field level Manure analysis and vlume test value Spreader/applicatin calibratin Yield estimates and crpping plan at field level Crpping and manure histry at field level NO YES N credit fr N Cre Nutrient Management OMA BMP Credit fr N Cre Nutrient Management OMA BMP N applicatin gal = LGU recmmendatin x A N applicatin gal = LGU recmmendatin x B NITROGEN Supplemental Nutrient Management BMPs If Cre Nutrient Management OMA BMP efficiency is applied, fllw with advanced assessment fr Supplemental Nutrient Management BMPs Advanced N Assessment PSNT Manure analysis 1 year ld On-farm replicated research CSNT IMPLEMENTATION N Rate Adjustment (Implementatin f ne r mre BMPs required) N rate less than LGU recmmendatins Split N applicatins Variable rate N applicatin YES N Rate Supplemental NM BMP Credit = EOF lad x C N-lss risk assessments & mdels Ammnia Lss Yield mapping ISNT On-farm strip trials N-lss risk assessments & mdels Leaching lss IMPLEMENTATION N Placement Adjustment (Implementatin f ne r mre BMPs required) Subsurface injectin r incrpratin f applied N N applicatin setbacks frm water YES N Placement Supplemental NM BMP Credit = EOF lad x D FSNT N-lss risk assessments & mdels Denitrificatin lsses Whle farm balances In-seasn sensrs/remte sensing in general IMPLEMENTATION N Timing Adjustment (Implementatin f ne r mre BMPs required) Split N applicatins YES N Timing Supplemental NM BMP Credit = EOF lad x E Ge-spatial mapping Figure 3. Assignment f N Nutrient Management Credits. Variables A and B refer t the land use specific N Cre Nn-Nutrient Management BMP applicatin rate multiplier and the N Cre Nutrient Management On-Site Manure Analysis BMP applicatin rate multiplier, respectively, as presented in Table 12. Variables C, D and E refer t the land use specific N Rate Supplemental NM BMP lss reductin multiplier, the N Placement Supplemental NM BMP lss reductin multiplier and the N Timing Supplemental NM BMP lss reductin multiplier, respectively, as presented in Table 14. EOF is edge f field. 153

154 NITROGEN Cre Nutrient Management Estimated Manure Analysis BMP (ALL applicable cre elements required t be implemented N applicatin gal (N rate) accrding t LGU recmmendatins at field level NO N credit fr N Cre Nutrient Management EMA BMP N applicatin gal = LGU recmmendatin x A Manure analysis and vlume bk value Spreader/applicatin calibratin Yield estimates and crpping plan at field level Crpping and manure histry at field level YES Credit fr N Cre Nutrient Management EMA BMP N applicatin gal = LGU recmmendatin x B NITROGEN Supplemental Nutrient Management BMPs If Cre Nutrient Management EMA BMP efficiency is applied, fllw with advanced assessment fr Supplemental Nutrient Management BMPs Advanced N Assessment PSNT Manure analysis 1 year ld On-farm replicated research CSNT IMPLEMENTATION N Rate Adjustment (Implementatin f ne r mre BMPs required) N rate less than LGU recmmendatins Split N applicatins Variable rate N applicatin YES N Rate Supplemental NM BMP Credit = EOF lad x C N-lss risk assessments & mdels Ammnia Lss Yield mapping ISNT On-farm strip trials N-lss risk assessments & mdels Leaching lss IMPLEMENTATION N Placement Adjustment (Implementatin f ne r mre BMPs required) Subsurface injectin r incrpratin f applied N N applicatin setbacks frm water YES N Placement Supplemental NM BMP Credit = EOF lad x D FSNT N-lss risk assessments & mdels Denitrificatin lsses Whle farm balances In-seasn sensrs/remte sensing in general IMPLEMENTATION N Timing Adjustment (Implementatin f ne r mre BMPs required) Split N applicatins YES N Timing Supplemental NM BMP Credit = EOF lad x E Ge-spatial mapping Figure 4. Assignment f N Nutrient Management Credits. Variables A and B refer t the land use specific N Cre Nn-Nutrient Management BMP applicatin rate multiplier and the N Cre Nutrient Management Estimated Manure Analysis BMP applicatin rate multiplier, respectively, as presented in Table 12. Variables C, D and E refer t the land use specific N Rate Supplemental NM BMP lss reductin multiplier, the N Placement Supplemental NM BMP lss reductin multiplier and the N Timing Supplemental NM BMP lss reductin multiplier, respectively, as presented in Table 14. EOF is edge f field. 154

155 PHOSPHORUS Cre Nutrient Management On-Site Sil & Manure Analysis BMP (ALL applicable cre elements required t be implemented P applicatin gal (P rate) accrding t LGU recmmendatins at field level NO N credit fr P Cre Nutrient Management OSMA BMP P applicatin gal = LGU recmmendatin x F P sil tests at field level Manure analysis and vlume test value Spreader/applicatin calibratin Yield estimates and crpping plan at field level YES Credit fr P Cre Nutrient Management OSMA BMP P applicatin gal = LGU recmmendatin x G Crpping and manure histry at field level PHOSPHORUS Supplemental Nutrient Management BMPs If Cre Nutrient Management OSMA BMP efficiency is applied, fllw with advanced assessment fr Supplemental Nutrient Management BMPs Advanced P Assessment Sil test P remediatin/declining Sil tests 1 year ld P Index assessment Grid sil sampling IMPLEMENTATION P Rate Adjustment (Implementatin f ne r mre BMPs required) P-based manure rate based n annual crp remval P rate less than LGU recmmendatins Variable rate P applicatin YES P Rate Supplemental NM BMP Credit = EOF lad x H Manure analysis 1 year ld On-farm replicated research Yield mapping On-farm strip trials Whle farm balances Ge-spatial mapping IMPLEMENTATION IMPLEMENTATION P Placement Adjustment (Implementatin f ne r mre BMPs required) Subsurface injectin r incrpratin f applied P P applicatin setbacks frm water P Timing Adjustment (Implementatin f ne r mre BMPs required) P applicatin in lwer P-lss risk seasn Split P applicatin P Placement Supplemental NM BMP Credit = EOF lad x I P Timing Supplemental NM BMP Credit = EOF lad x J Figure 5. Assignment f P Nutrient Management Credits. Variables F and G refer t the land use specific P Cre Nn-Nutrient Management BMP applicatin rate multiplier and the P Cre Nutrient Management OSMA BMP applicatin rate multiplier, respectively, as presented in Table 13. Variables H, I and J refer t the land use specific P Rate Supplemental NM BMP lss reductin multiplier, the P Placement Supplemental NM BMP lss reductin multiplier and the P Timing Supplemental NM BMP Lss reductin multiplier, respectively, as presented in Table 15. EOF is edge f field. YES YES 155

156 PHOSPHORUS Cre Nutrient Management Estimated Sil & Manure Analysis BMP (ALL applicable cre elements required t be implemented P applicatin gal (P rate) accrding t LGU recmmendatins at field level NO N credit fr P Cre Nutrient Management ESMA BMP P applicatin gal = LGU recmmendatin x F P sil tests may be waived Manure analysis and vlume bk value Spreader/applicatin calibratin Yield estimates and crpping plan at field level YES Credit fr P Cre Nutrient Management ESMA BMP P applicatin gal = LGU recmmendatin x G Crpping and manure histry at field level PHOSPHORUS Supplemental Nutrient Management BMPs If Cre Nutrient Management ESMA BMP efficiency is applied, fllw with advanced assessment fr Supplemental Nutrient Management BMPs Advanced P Assessment Sil test P remediatin/declining Sil tests 1 year ld P Index assessment Grid sil sampling IMPLEMENTATION P Rate Adjustment (Implementatin f ne r mre BMPs required) P-based manure rate based n annual crp remval P rate less than LGU recmmendatins Variable rate P applicatin YES P Rate Supplemental NM BMP Credit = EOF lad x H Manure analysis 1 year ld On-farm replicated research Yield mapping IMPLEMENTATION P Placement Adjustment (Implementatin f ne r mre BMPs required) Subsurface injectin r incrpratin f applied P YES P Placement Supplemental NM BMP Credit = EOF lad x I On-farm strip trials P applicatin setbacks frm water Whle farm balances Ge-spatial mapping IMPLEMENTATION P Timing Adjustment (Implementatin f ne r mre BMPs required) P applicatin in lwer P-lss risk seasn YES P Timing Supplemental NM BMP Credit = EOF lad x J Split P applicatin Figure 6. Assignment f P Nutrient Management Credits. Variables F and G refer t the land use specific P Cre Nn-Nutrient Management BMP applicatin rate multiplier and the P Cre Nutrient Management ESMA BMP applicatin rate multiplier, respectively, as presented in Table 13. Variables H, I and J refer t the land use specific P Rate Supplemental NM BMP lss reductin multiplier, the P Placement Supplemental NM BMP lss reductin multiplier and the P Timing Supplemental NM BMP Lss reductin multiplier, respectively, as presented in Table 15. EOF is edge f field. 11 Review f Literature and Data Gaps 11.1 The Available Science fr N BMPs Crp- and land-use-specific N applicatin rate gal shuld be based n LGU crp fertilizatin recmmendatins, as mdified by the CBP partnership. In an effrt t determine the mst practicable methdlgy fr allcating fertilizer N t satisfy crp- and land-use-specific N applicatin rate gals, the Agriculture Wrkgrup cmpared the mdified LGU recmmendatins fr applicatin f supplemental inrganic N fertilizer t an alternative apprach based n cunty-level redistributin f AAPFCO N fertilizer sales data. This methdlgical cmparisn indicated that there were relatively small differences between the tw methds fr estimating supplemental N fertilizer applicatins, leading the Agriculture Wrkgrup t apprve use f the redistributed AAPFCO fertilizer sales methdlgy in the Phase 6 Mdel. The Panel maintains that LGU recmmendatins shuld cntinue t serve as the fundatin fr crp and land-use-specific N 156