EFFECT OF SOLID CATTLE MANURE AND LIQUID HOG MANURE APPLICATION ON PHOSPHORUS AND NITROGEN IN SOIL, RUN-OFF AND LEACHATE IN SASKATCHEWAN SOILS

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1 EFFECT OF SOLID CATTLE MANURE AND LIQUID HOG MANURE APPLICATION ON PHOSPHORUS AND NITROGEN IN SOIL, RUN-OFF AND LEACHATE IN SASKATCHEWAN SOILS A Disserttion Submitted to the College of Grdute Studies nd Reserch in Prtil Fulfillment of the Requirements for the Degree of Doctor of Philosophy in the Deprtment of Soil Science University of Ssktchewn Ssktoon By Thoms Normn King Copyright Thoms Normn King, September All rights reserved.

2 PERMISSION TO USE In presenting this disserttion in prtil fulfillment of the requirements for Postgrdute degree from the University of Ssktchewn, I gree tht the Librries of this University my mke it freely vilble for inspection. I further gree tht permission for copying of this disserttion in ny mnner, in whole or in prt, for scholrly purposes my be grnted by the professor or professors who supervised my disserttion work or, in their bsence, by the Hed of the Deprtment of Soil Science or the Den of the College of Agriculture nd Bioresources. It is understood tht ny copying or publiction or use of this disserttion or prts thereof for finncil gin shll not be llowed without my written permission. It is lso understood tht due recognition shll be given to me nd to the University of Ssktchewn in ny scholrly use tht my be mde of ny mteril in my disserttion. Requests for permission to copy or to mke other uses of mterils in this disserttion, in whole or prt, should be ddressed to: Hed, Deprtment of Soil Science University of Ssktchewn Ssktoon, Ssktchewn Cnd, S7N 5A8 i

3 DISCLAIMER Reference in this disserttion to ny specific commercil products, process, or service by trde nme, trdemrk, mnufcturer, or otherwise, does not constitute or imply its endorsement, recommendtion, or fvoring by the University of Ssktchewn. The views nd opinions of the uthor expressed herein do not stte or reflect those of the University of Ssktchewn, nd shll not be used for dvertising or product endorsement purposes. ii

4 ABSTRACT Trditionl ppliction methods in which mnure is simply brodcst on the soil surfce re being replced by innovtive methods tht plce the mnure in the soil in bnds, potentilly incresing efficiency of mnure nutrient utiliztion by crops nd reducing losses to the environment. Limited informtion exists on the pools nd mobility of phosphorus (P) nd nitrogen (N) in soils receiving repeted pplictions of niml mnure using different ppliction methods. The overll objective of the thesis reserch is to determine the fte of mnure nutrients pplied using new subsurfce bnding technology, s it ffects crop response nd uptke, residul nutrients in the soil, nd trnsport (lterl nd verticl) by wter off-site. Specific objectives were: 1) to determine yield response to solid cttle mnure (SCM) nd the recovery of SCM nd liquid hog mnure (LHM) P nd N using brodcst mnure plcement nd new subsurfce bnding technology, 2) to determine the mount of soluble rective phosphorus (SRP) nd N tht is trnsported in snowmelt wter moving cross soils receiving different rtes nd methods of ppliction of mnure, nd 3) to determine the mount nd proportion of SRP nd N tht re trnsported downwrd in SCM mended soil profile with leching wter s influenced by mnure rte nd plcement. In-soil plcement of SCM in bnds hd smll impct on improving crop yield nd nutrient uptke in 3 yer crop rottion in est-centrl Ssktchewn compred to brodcst, nd brodcst nd incorporte ppliction strtegies. In-soil plcement of mnure ws lso not effective in reducing P nd N export in snowmelt wter. Export of P nd N downwrd in lechte wter in intct cores ws incresed by in-soil mnure plcement, especilly when plced in bnds. This is ttributed to reduced fixtion of mnure N nd P nd enhnced solubiliztion when mnure is plced in soil in bnds versus brodcst ppliction. Overll, nutrient export ws significntly lower in frozen versus thwing soils, nd export of P in soils receiving liquid hog mnure ws much less thn in soils receiving solid cttle mnure which is ttributed to the higher P content in cttle mnure. iii

5 ACKNOWLEDGEMENTS I wish to thnk my supervisor Dr. Jeff Schoenu for his ccessibility, keen insight, guidnce, inexhustible ptience, commitment to seeing this project completed nd finncil support throughout this reserch project. Jeff s extremely rpid return policy for ppers submitted for review is extremely impressive, unmtched nd we-inspiring quite frnkly. Simply stted, Jeff s dediction towrd not only myself but ll his students is to be both dmired nd emulted. I lso grtefully cknowledge the direction, suggestions nd dvice received from my Advisory Committee: Drs. Jne Elliott, Mike Grevers, Chrles Mule nd Bing Si. Their dherence to diligence nd commitment to qulity control supported nd helped crete this mnuscript. I hve to grciously nd sincerely pprecite their ptience over the lst severl yers to see this reserch through to the end. Mny thnks to Dr. Wole Akinremi for his time nd willingness to be my externl exminer, long with providing criticl feedbck nd suggestions tht improved the disserttion. I would like to express my grtitude to the following for their ssistnce vi provision of reserch funding, scholrship, bursry, or wrd: University of Ssktchewn College of Grdute Studies nd Reserch, University of Ssktchewn Deprtment of Soil Science, College of Agriculture nd the Ssktchewn Ministry of Agriculture. I would like to thnk those people whose efforts in the field nd lbortory ided me in getting the work ccomplished: Brett Ewen, Cory Ftteicher, Burk Ferhtoglu nd Ron Urton. I would especilly like to thnk Ryn Hngs for ll of his invluble help, suggestions nd formtting expertise on this thesis. Ryn s willing rediness to red over thesis drfts for formtting, spelling nd grmmticl errors nd unending help providing formtting solutions leves me indebted to him for the reminder of my life. It looks like I ll be mowing grss nd shoveling the Hngs residence drivewy for the next severl decdes. If I hve missed omitting the help of someone, I pologize for the omission. iv

6 DEDICATION I dedicte this work to my prents Allen nd Jenette King nd to both my brothers Willim nd Colin King. The ssistnce nd ptience fforded me by my fmily over the lst severl yers hve been second to none nd only grdute student s fmily cn remotely empthize with the selfless scrifice of time, energy, nd finnces these fmily members hve mde in support of my cdemic endevors. Although my Mom deprted this world before I begn my Ph.D., it ws her drem tht I embrk on this rduous nd difficult process. I love ll of my fmily immesurbly nd hve been truly grteful for your help, lthough I lwys hd difficult time expressing it. I lso hve to dedicte this Thesis to My Guys, Cudworth nd Muenster. Although they usully did more to hinder the work process thn nything else, their presence nd ntics were tremendous source of stress relief nd lwys brightened my dy no mtter how bogged down on the thesis I hd gotten by the end of the dy. v

7 TABLE OF CONTENTS PERMISSION TO USE... i DISCLAIMER... ii ABSTRACT... iii ACKNOWLEDGEMENTS... iv DEDICATION... v TABLE OF CONTENTS... vi LIST OF TABLES... x LIST OF FIGURES... xii LIST OF ABBREVIATIONS... xii 1. INTRODUCTION Use of Animl Mnure to Fertilize Annully Grown Crops Environmentl Concerns with Soil Nutrients Arising from Animl Mnure Appliction Movement of phosphorus nd nitrogen in spring snowmelt Ph.D. Reserch Description Disserttion Arrngement LITERATURE REVIEW Nutrient Benefits nd Concerns Surrounding Lnd-Applied Animl Mnures Mnure Appliction Method nd Nutrient Retention in Soils Nutrient Movement Associted With Snowmelt Synopsis nd Reltionship to Thesis Reserch Work EFFECT OF SOLID CATTLE MANURE RATE OF APPLICATION AND MANURE PLACEMENT ON CROP YIELD AND SOIL NUTRIENTS IN A BLACK CHERNOZEM IN EAST-CENTRAL SASKATCHEWAN Prefce Abstrct Introduction Mterils nd Methods Site description Generl experimentl setup Mnure chrcteristics Field opertions nd plnt nd soil smpling nd nlysis Mesurement of surfce soil phosphorus nd nitrogen supply rtes Determintion of phosphorus nd nitrogen content nd relese from crop residue vi

8 3.5 Results nd Discussion Crop yer: Rte effects on yield Crop yer: Plcement effects on yield Ot crop nutrient concentrtions nd uptke Soil properties in fll of Crop yer: Rte effects on yield Crop yer: Plcement effect on yield Cnol crop nutrient concentrtions nd uptke Soil properties in fll of Crop yer: Rte effects on yield Crop yer: Plcement effects on yield Ot crop nutrient concentrtions nd uptke Soil properties in fll of Soil phosphorus nd nitrogen supply rtes in the 2009 seson Relese of phosphorus nd nitrogen from cnol residues Conclusion RELATIONSHIP BETWEEN MANURE MANAGEMENT APPLICATION PRACTICES AND PHOSPHORUS AND NITROGEN EXPORT IN SNOWMELT RUN-OFF WATER FROM A BLACK CHERNOZEM Prefce Abstrct Introduction Mterils nd Methods Site description Mnure tretments Soil smpling nd nlysis Snowmelt nd wter run-off simultion on soil slb monoliths Sttisticl nlysis Results nd Discussion Soluble rective phosphorus export in snowmelt wter on thwing solid cttle mnure mended soil Soluble rective phosphorus export in wter moving rpidly cross the surfce of frozen cttle mnure mended soil Soluble rective phosphorus export in thwing snow nd soils from liquid hog mnure mended soil vii

9 4.5.4 Phosphorus export in wter moving rpidly cross the surfce of frozen liquid hog mnure mended soil Dissolved nitrte-nitrogen export in snowmelt wter on thwing solid cttle mnure mended soil Dissolved nitrte-nitrogen export in wter moving rpidly cross the surfce of frozen solid cttle mnure mended soil Dissolved nitrte-nitrogen export in snowmelt wter on thwing liquid hog mnure mended soil Dissolved nitrte-nitrogen in wter moving rpidly cross the surfce of frozen liquid hog mnure mended soil Dissolved mmonium-nitrogen export in snowmelt wter on thwing solid cttle mnure mended soil Dissolved mmonium-nitrogen export in wter moving rpidly cross the surfce of frozen solid cttle mnure mended soil Dissolved mmonium-nitrogen export in snowmelt wter on thwing liquid hog mnure mended soil Dissolved mmonium-nitrogen in wter moving rpidly cross the surfce of frozen soils from liquid hog mnure mended soil Conclusion EFFECT OF SOLID CATTLE MANURE PLACEMENT METHOD ON SOIL CARBON, PHOSPHORUS AND NITROGEN REMOVAL BY LEACHING IN INTACT SOIL CORES Prefce Abstrct Introduction Mterils nd Methods Generl experimentl setup Core collection nd leching experiment Sttisticl nlysis Results nd Discussion Totl orgnic crbon nd nitrogen Orthophosphte-phosphorus nd nitrte-nitrogen Conclusion OVERALL SYNTHESIS AND CONCLUSIONS Summry of Findings nd Their Importnce Documenting the impct of mnure plcement on soil biologicl ctivity nd decomposition in the mnure ppliction zone Investigting nutrient dynmics nd movement t greter soil depth viii

10 6. REFERENCES APPENDIX A. DIXON, SASKATCHEWAN SITE PLOT MAPS APPENDIX B. DIXON, SASKATCHEWAN PLANT, SOIL AND RUNOFF AND/OR LEACHATE CONCENTRATION DATA ix

11 LIST OF TABLES Tble 3.1. Trgeted nitrogen ppliction rte tretments in the solid cttle mnure rte/plcement study ( ) t Dixon, Ssktchewn Tble , 2008 nd 2009 solid cttle mnure composition Tble 3.3. Grin yield in 2007 (ots), 2008 (cnol) nd 2009 (ots) t Dixon, Ssktchewn Tble 3.4. Grin nitrogen concentrtions (µg N g -1 of dry mtter) in 2007 (ots), 2008 (cnol) nd 2009 (ots) t Dixon, Ssktchewn Tble 3.5. Grin phosphorus concentrtions (µg P g -1 of dry mtter) in 2007 (ots), 2008 (cnol) nd 2009 (ots) t Dixon, Ssktchewn Tble 3.6. Soil ph, electricl conductivity nd orgnic crbon (0-15 cm depth) t Dixon, Ssktchewn Tble 3.7. Soil extrctble phosphorus (0-15 cm depth) t Dixon, Ssktchewn Tble 3.8. Soil extrctble nitrte-nitrogen (0-15 cm depth) t Dixon, Ssktchewn Tble 3.9. Soil extrctble mmonium-nitrogen (0-15 cm depth) t Dixon, Ssktchewn Tble 4.1. Rtes of phosphorus, totl N nd mmonium N pplied s mnure from in the solid cttle mnure trils t Dixon, Ssktchewn Tble 4.2. Tretments from , 2008 nd 2009 in the twelve-yer liquid hog mnure study t Dixon, Ssktchewn Tble 4.3. Extrctble soil nutrients (0-15 cm) in the solid cttle mnure trils smpled post-hrvest in 2008 nd 2009 t Dixon, Ssktchewn Tble 4.4. Extrctble soil nutrients (0-30 cm) in the liquid hog mnure trils tht were smpled post-hrvest in 2008 nd 2009 t Dixon, Ssktchewn Tble B.1. Strw biomss (kg h -1 ) in 2007 (ots), 2008 (cnol) nd 2009 (ots) in three-yer solid cttle mnure study t Dixon, Ssktchewn Tble B.2. Strw phosphorus concentrtions (µg P g -1 of dry mtter) in 2007 (ots), 2008 (cnol) nd 2009 (ots) in three-yer solid cttle mnure study t Dixon, Ssktchewn Tble B.3. Strw nitrogen concentrtions (µg N g -1 of dry mtter) in 2007 (ots), 2008 (cnol) nd 2009 (ots) in three-yer solid cttle mnure study t Dixon, Ssktchewn Tble B.4. Soil extrctble phosphorus (kg h -1 ) (15-30 cm depth) in three-yer solid cttle mnure study t Dixon, Ssktchewn x

12 Tble B.5. Soil extrctble nitrte-nitrogen (kg h -1 ) (15-30 cm depth) in three-yer solid cttle mnure study t Dixon, Ssktchewn Tble B.6. Soil extrctble mmonium-nitrogen (kg h -1 ) (15-30 cm depth) in three-yer solid cttle mnure study t Dixon, Ssktchewn Tble B.7. Concentrtions of soluble rective phosphorus (µg P ml -1 ), dissolved nitrte-nitrogen (µg NO3-N ml -1 ) nd dissolved mmonium-nitrogen (µg NH4-N ml -1 ) in snowmelt from thwing soil slb monoliths from three-yer solid cttle mnure field study collected in fll Tble B.8. Concentrtions of soluble rective phosphorus (µg P ml -1 ), dissolved nitrte-nitrogen (µg NO3-N ml -1 ) nd dissolved mmonium-nitrogen (µg NH4-N ml -1 ) in snowmelt from thwing soil slb monoliths from three-yer solid cttle mnure field study collected in fll Tble B.9. Concentrtions of soluble rective phosphorus (µg P ml -1 ), dissolved nitrte-nitrogen (µg NO3-N ml -1 ) nd dissolved mmonium-nitrogen (µg NH4-N ml -1 ) in wter moving rpidly cross the surfce of frozen soil slb monoliths from three-yer solid cttle mnure field study collected in fll Tble B.10. Concentrtions of soluble rective phosphorus (µg P ml -1 ), dissolved nitrte-nitrogen (µg NO3-N ml -1 ) nd dissolved mmonium-nitrogen (µg NH4-N ml -1 ) in snowmelt on thwing soil slb monoliths from twelve-yer liquid hog mnure field study collected in fll Tble B.11. Concentrtions of soluble rective phosphorus (µg P ml -1 ), dissolved nitrte-nitrogen (µg NO3-N ml -1 ) nd dissolved mmonium-nitrogen (µg NH4-N ml -1 ) in wter moving rpidly cross the surfce of frozen soil slb monoliths from twelve-yer liquid hog mnure field study collected in fll xi

13 LIST OF FIGURES Fig Schemtic digrm outlining the study of phosphorus nd nitrogen nutrient export in solid cttle mnure nd liquid hog mnure mended soil Fig Photogrph of portion of the Dixon solid cttle mnure ppliction site, tken on My 10, 2007 fter flgging to mrk plot loctions for tretment ppliction, nd spring nd fll crop nd soil smpling Fig Prototype Pririe Agriculturl Mchinery Institute-University of Ssktchewn solid cttle mnure injector in field Fig Photogrph depicting usge of PRS probes to mesure soil P nd N supply Fig Photogrph depicting frozen crop residues fter soking in wter for 48 h nd then frozen for 72 h Fig Soil phosphte-phosphorus supply rtes mesured in the surfce soil by Plnt Root Simultor nion exchnge membrne probes in 2009 t Dixon, Ssktchewn. Mens followed by the sme letter re not significntly different for tht smpling dte. Error brs denote stndrd devition of the men Fig Soil nitrte-nitrogen supply rtes mesured in the surfce soil by Plnt Root Simultor nion exchnge membrne probes in 2009 t Dixon, Ssktchewn. Mens followed by the sme letter re not significntly different for tht smpling dte. Error brs denote stndrd devition of the men Fig Cnol plnt fter-hrvest residue totl phosphorus concentrtions in 2008 t rte of 60 t h -1 for the brodcst lone, brodcst nd incorported nd subsurfce bnded solid cttle mnure tretments nd rte of 78 kg N h -1 for the ure pplied tretment t Dixon, Ssktchewn. Mens followed by the sme letter re not significntly different t P Error brs denote stndrd devition of the men Fig Cnol plnt fter-hrvest residue totl nitrogen in 2008 t rte of 60 t h -1 for the brodcst lone, brodcst nd incorported nd subsurfce bnded solid cttle mnure tretments nd rte of 78 kg N h -1 for the ure pplied tretment t Dixon, Ssktchewn. Mens followed by the sme letter re not significntly different t P Error brs denote stndrd devition of the men Fig Collection of soil slb monoliths from Dixon three-yer solid cttle mnure nd 12-yer long-term liquid hog mnure study t Dixon, Ssktchewn Fig Simulted snowmelt on thwing soil slb monoliths nd collection of run-off-lechte Fig Export of soluble rective phosphorus (kg P h -1 ) by thwing snow on thwing soil slb monoliths from three-yer solid cttle mnure field study collected in ) fll 2008 nd b) fll xii

14 2009. Mens followed by the sme letter re not significntly (P 0.10) different. Error brs denote stndrd devitions of the mens Fig Export of soluble rective phosphorus (kg P h -1 ) in wter moving rpidly cross the surfce of frozen soil slb monoliths collected in fll 2009 from three-yer solid cttle mnure field study site. Mens followed by the sme letter re not significntly (P 0.10) different. Error brs denote stndrd devitions of the mens Fig Export of soluble rective phosphorus (kg P h -1 ) by thwing snow on thwing soil slb monoliths collected in fll 2009 from 12-yer long-term liquid hog mnure field study site. Mens followed by the sme letter re not significntly (P 0.10) different. Error brs denote stndrd devitions of the mens Fig Export of soluble rective phosphorus (kg P h -1 ) in wter moving rpidly cross the surfce of frozen soil slbs in fll yer long-term liquid hog mnure field study site. Mens followed by the sme letter re not significntly (P 0.10) different. Error brs re stndrd devitions of the mens Fig Export of dissolved nitrte-nitrogen (kg NO3-N h -1 ) by thwing snow on thwing soil slb monoliths from three-yer solid cttle mnure field study collected in ) fll 2008 nd b) fll Mens followed by the sme letter re not significntly (P 0.10) different. Error brs denote stndrd devitions of the mens Fig Export of dissolved nitrte-nitrogen (kg NO3-N h -1 ) in wter moving rpidly cross the surfce of frozen soil slb monoliths collected in fll 2009 from three-yer solid cttle mnure field study site. Mens followed by the sme letter re not significntly (P 0.10) different. Error brs denote stndrd devitions of the mens Fig Export of dissolved nitrte-nitrogen (kg NO3-N h -1 ) by thwing snow on thwing soil slbs collected in fll 2009 from 12-yer long-term liquid hog mnure field study site. Mens followed by the sme letter re not significntly (P 0.10) different. Error brs denote stndrd devitions of the mens Fig Export of dissolved nitrte-nitrogen (kg NO3-N h -1 ) in wter moving rpidly cross the surfce of frozen soil slbs in fll yer long-term liquid hog mnure field study site. Mens followed by the sme letter re not significntly (P 0.10) different. Error brs re stndrd devitions of the mens Fig Export of dissolved mmonium-nitrogen (kg NH4-N h -1 ) by thwing snow on thwing soil slb monoliths from three-yer solid cttle mnure field study collected in ) fll 2008 nd b) fll Mens followed by the sme letter re not significntly (P 0.10) different. Error brs denote stndrd devitions of the mens Fig Export of dissolved mmonium-nitrogen (kg NH4-N h -1 ) in wter moving rpidly cross the surfce of frozen soil slb monoliths collected in fll 2009 from three-yer solid cttle mnure field study site. Mens followed by the sme letter re not significntly (P 0.10) different. Error brs denote stndrd devitions of the mens xiii

15 Fig Export of dissolved mmonium-nitrogen (kg NH4-N h -1 ) by thwing snow on thwing soil slbs collected in fll 2009 from 12-yer long-term liquid hog mnure field study site. Mens followed by the sme letter re not significntly (P 0.10) different. Error brs denote stndrd devitions of the mens Fig Export of dissolved mmonium-nitrogen (kg NH4-N h -1 ) in wter moving rpidly cross the surfce of frozen soil slbs in fll yer long-term liquid hog mnure field study site. Mens followed by the sme letter re not significntly (P 0.10) different. Error brs re stndrd devitions of the mens Fig Photogrph depicting intct soil core leching experiment Fig Totl orgnic crbon removed from intct soil cores receiving two, 5-cm leching events. Tretments evluted re high cttle mnure ppliction rte (60 t h -1 ) pplied using different ppliction methods: brodcst, brodcst nd incorporte nd sub-surfce bnding. Mens followed by the sme letter re not significntly (P 0.10) different. Error brs re stndrd devition of the men Fig Totl nitrogen removed from intct soil cores receiving two, 5-cm leching events. Tretments evluted re high cttle mnure ppliction rte (60 t h -1 ) pplied using different ppliction methods: brodcst, brodcst nd incorporte, nd sub-surfce bnding. Mens followed by the sme letter re not significntly (P 0.10) different. Error brs re stndrd devition of the men Fig Orthophosphte-P removed in two, 5-cm leching events of intct soil cores (0-15 cm) collected from plots receiving high solid cttle mnure ppliction rte (60 t h -1 ). Mens followed by the sme letter re not significntly (P 0.10) different. Error brs re stndrd devition of the men Fig Nitrte nitrogen removed in two, 5-cm leching events of intct soil cores (0-15 cm) collected from plots receiving high solid cttle mnure ppliction rte (60 t h -1 ). Mens followed by the sme letter re not significntly (P 0.10) different. Error brs re stndrd devition of the men Fig. A.1. Three-Yer Solid Cttle Mnure Study Plot Mp nd Tretments Fig. A.2. Twelve-Yer Liquid Hog Mnure Study Plot Mp nd Tretments xiv

16 LIST OF ABBREVIATIONS C LHM LSD MK N NH4-N NO3-N OC OM P PAMI PO4 PO4-P SCM SOC SOM SRP TN TOC Crbon Liquid hog mnure Lest significnt difference Modified Kelown Nitrogen Ammonium-nitrogen Nitrte-nitrogen Orgnic crbon Orgnic mtter Phosphorus Pririe Agriculturl Mchinery Institute Phosphte Phosphte-phosphorus Solid cttle mnure Soil orgnic crbon Soil orgnic mtter Soluble rective phosphorus Totl nitrogen Totl orgnic crbon xii

17 1. INTRODUCTION 1.1 Use of Animl Mnure to Fertilize Annully Grown Crops Lnd ppliction of niml mnures such s solid cttle mnure (SCM) nd liquid hog mnure (LHM) is common prctice in nnully cropped fields, forge nd psture lnds in western Cnd nd other res of the world, to increse soil fertility. Sttistics Cnd estimted there were 2.3 million cttle nd clves nd 1.17 million hed of hogs on Ssktchewn frms s of Jnury 1 st, 2015 (Sttistics Cnd, 2015). The mnure is vlued for its content of orgnic mtter nd constituent nutrients, especilly phosphorus (P) nd nitrogen (N) to increse crop yields (Bernier et l., 2014). The ppliction of SCM nd LHM to lnd is both lower cost nutrient ppliction lterntive to commercil fertilizer, nd mens to dispose of niml wste nd recycle the wste constituents bck into the soil-plnt system. The mnure constituents serve two purposes: the first is to dd orgnic mtter (OM) bck to the soil system, thereby dding to the resident soil OM, which serves to store nd recycle nutrients nd wter, essentil elements for future plnt growth nd longevity; nd second, to return nutrient elements such s P nd N bck to the soil where they my be utilized gin by plnts in future sesons (Cmpbell et l., 1984; Miller et l., 2006; Sommerfeldt et l., 1988). It hs been described tht the ppliction of niml mnure, prticulrly solid cttle mnure, ids not only in supplying nutrients to plnts, but hs indirect effects on plnt root growth by incresing soil ertion nd porosity (Schoenu nd Dvis, 2006). Appliction of niml mnure to provide nutrients for plnt growth hs been long ccepted crop mngement prctice in Cnd nd other regions of the world. Yield responses to the nutrients contined in SCM nd LHM ppliction t severl sites in western Cnd hve been quite fvorble (Mooleki et l., 2004; Mooleki et l., 2002). For exmple, in Ssktchewn soils, prt of the plnt yield response to niml mnure hs been ttributed to the P contined in the mnure (Qin nd Schoenu, 2000) or micronutrients such s zinc nd copper, prticulrly if there is limited plnt vilble soil supply of those nutrients (Lipoth nd Schoenu, 2007; Qin et l., 2003). 1

18 Appliction rtes of mnure to griculturl lnds in the pst hve trditionlly been N bsed (Gburek et l., 2000), owing to this nutrient most often being the mjor limittion in crop production. However, niml mnures such s SCM nd LHM contin significnt mounts of other plnt nutrients like P. The nutrients in niml mnures cn vry in vilbility nd trnsportbility in the soil depending on source (Beuchmp, 1983; Eghbll nd Power, 1999), differences in niml nutrition, differences in niml continment fcilities nd mnure hndling prctices (Mooleki et l., 2004). Any one or combintion of these fctors ct to produce mnure which hs distinct composition relting to the forms, mounts nd behvior of nutrients present in the niml mnure. For exmple, some studies hve shown tht N vilbility in the yer of ppliction cn be low, depending on the niml mnure source (Beuchmp, 1983; Png nd Letey, 2000), especilly for some solid mnures. This is relted to the presence of much of the nutrient in n orgnic form, thus requiring time to be converted into plnt vilble form (Mooleki et l., 2004). In order to meet crop requirements for N, there hs been tendency to pply the mnure in lrge mounts to compenste for this fctor. However, in order to meet plnt requirements for N, other nutrients, specificlly P contined in the mnure, my end up being over-pplied in mounts tht exceed the plnt bility to utilize ll the nutrient (Shrpley et l., 2002). This cn hve dverse environmentl effects, in tht excess nutrient could potentilly be exported from the soil vi wter runoff nd/or leching (Kleinmn et l., 2000). 1.2 Environmentl Concerns with Soil Nutrients Arising from Animl Mnure Appliction The expnsion of the intensive livestock industry in western Cnd hs led to concerns bout the overloding of P nd N in soils receiving niml mnures. In res tht receive high ppliction rtes of niml mnures, elevted trnsport of dissolved nd prticulte P nd N by wter cn be of concern in nutrient overloded soils (Kumrgmge et l., 2011; Shrpley, 1997). For exmple, since the 1990s, soil P levels in Mnitob hve incresed due to mnure ppliction, nd griculturl sources hve been identified in the populr press s responsible for supplying significnt portion of Mnitob s P loding into Lke Winnipeg (Kumrgmge et l., 2011). High P levels in wter bodies cn led to eutrophiction nd lgl blooms. Eutrophiction, which depletes surfce wter bodies of oxygen due to incresed growth of lge nd subsequent decomposition, is ccentuted by the export of P nutrient into the wter nd is identified s mjor 2

19 concern in Mnitob (Kumrgmge et l., 2011). Nitrogen export off-site is lso of concern, s for exmple this cn led to helth effects in humns such s methemoglobinem from consuming wter tht is high in nitrte-n (NO3-N). It is estimted tht P export from nnully cropped fields in Mnitob contribute n estimted 15 % of the P in Lke Winnipeg (Kumrgmge et l., 2011). Appliction of niml mnures tht contin P in rtes tht exceed crop nutrient requirements cn led to n ccumultion of P tht is susceptible to wter export (Ho et l., 2008; Reddy et l., 1999; Withers et l., 2001). Applying niml mnure bsed on crop nutrient requirements nd utiliztion potentil would id in minimizing excess nutrients tht potentilly could be exported from the soil system vi wter medited loss mechnisms such s runoff nd/or leching. The overll mounts, composition of the nutrients contined in niml mnure, soil fctors such s mount of cly nd orgnic mtter (OM), lndscpe nd climte (Klusner et l., 1994) ll contribute to the mount of P nd N nutrients tht cn be exported from field to surfce nd/or subsurfce wter system. Appliction of cttle nd/or hog mnure t excessively high rtes in excess of crop uptke could led to soil buildup nd ccumultion of P nd N nutrients tht ultimtely led to nutrient export nd loss from the field (Bernier et l., 2014). Solid cttle mnure cn be high in both P nd N content, nd there is potentil for vrious orgnic nd inorgnic forms of P nd N in the soil originting from mnure to be trnsported from the field with wter, leding to dverse nutrient enrichment of surfce nd subsurfce wter bodies close to the lnd receiving the mnure (Little et l., 2007). Phosphorus exists in orgnic nd inorgnic forms, both forms of which re trnsportble in solution nd s prticultes in wter moving lterlly nd verticlly in soils (Hy et l., 2006). Orgnic forms of P tht dominte in mny mnure sources re importnt regultors of the biovilbility of soil P. However, the specific composition of soil P pools derived from mnure, long with their turnover nd mobility s ffected by plcement of mnure re only recently being reveled (Kr et l., 2012). Forms of inorgnic N in SCM such s mmonium N (NH4-N) re vilble for plnt uptke but cn lso be trnsported from the soil in run-off wter (Powell et l., 2008) or trnsformed into highly mobile forms like nitrte. Ammonium N cn be voltilized into mmoni gs. Once converted into NO3- N in the nitrifiction process, leching or denitrifiction cn tke plce. (Arrig et l., 2010). Seprtion of mnure P nd soil P into vrious frctions using chemicl extrction (frctiontion) is one of the more commonly used methods to ssess P forms nd mke inferences 3

20 bout the potentil fte of ccumulted P in the soil. In run-off or lechte wter from soils, there re four ctegories of P forms generlly identified including: 1) dissolved rective P (soluble orthophosphte), 2) prticulte rective P (P frction loosely dsorbed on cly, iron, luminum or cly oxides), 3) dissolved unrective P (primrily soluble orgnic P compounds) nd 4) prticulte unrective P, in which the nture of the P compounds is strongly sorbed or precipitted P in minerl nd humic cid complexes (Toor et l., 2006). Considertion of the forms nd distribution of P nd N in Ssktchewn griculturl soils s ffected by mnure mngement prctices such s mnure ppliction rte nd plcement is the first step in ssessing the potentil influence of the prctice on nutrient migrtion. In prticulr, there is need to relte mnure nd soil nutrient forms to nutrient distribution nd mobility ssessments. Fctors ffecting the distribution of P nd N forms prticulrly in the upper 0-5 cm depth of the soil first need to be understood. Soil will retin mjority of P nd N pplied s niml mnure tht is not removed by the crop through trnsformtions such s dsorption, precipittion nd immobiliztion. Soil chrcteristics control the forms in which P is trnsported from the bulk soil to surfce or underground wter systems (Ulen nd Snll, 2007). The P mobility is strongly controlled by its chemicl nd physicl form (Hountin et l., 2000). Furthermore, soil P is ssocited with different size frctions (eg. cly) nd losses from the soil cn come through dissolution or detchment (prticulte nd colloidl P). 1.3 Movement of phosphorus nd nitrogen in spring snowmelt In western Cnd, the primry wter event which cuses nutrient trnsport cross nd into the soil is relted to the increse in temperture in Mrch tht signls the end of winter nd the beginning of the spring nnul snowmelt. Nutrients such s P nd N cn be exported in snowmelt surfce wter runoff nd/or leching in either dissolved or prticulte form, leding to enhnced concentrtions of these nutrients in wter (Lorentz et l., 2008; Lui et l., 2014). Unlike some regions of North Americ where rinfll runoff cn crry significnt nutrient lod in prticulte form due to greter kinetic energy of rindrops creting prticle detchment nd erosion, snowmelt wter runoff nd/or leching hs lower kinetic energy, thus less erosive power nd results in nutrient trnsport primrily in dissolved form (Jensen et l., 2000) over longer distnces. Severl studies in Mnitob nd Albert hve reported tht the mount of P exported in snowmelt runoff ws directly correlted to the concentrtion of lbile P in surfce soils (Little et l., 2007; Slvno 4

21 et l., 2009). Furthermore, where mnure ppliction ws reduced, soil test P ws reduced nd the mount of P moved in runoff ws lso reduced. Recent studies in southwestern Ssktchewn hve shown tht N cn be exported in spring snowmelt from psture s dissolved NH4 (Cde-Menun et l., 2013). It is noted tht in Western Cnd, little informtion exists on nutrient trnsport by snowmelt wter s ffected by bsic mnure mngement prctices like rtes nd methods of ppliction of SCM cultivted fields. There is some recent informtion on P nd N nutrient redistribution in Ssktchewn hummocky lndscpe tht received severl fll pplictions of subsurfce bnded LHM. Priyshnth et l., (2007) reported tht plnt vilble P in these lndscpes ws greter in the footslope lndscpe positions, compred to the shoulder lndscpe position. The uthors lso reported tht NO3-N nd NH4-N concentrtions in the surfce soil in footslope positions ws higher thn the shoulder lndscpe position. Redistribution of mnure nutrients downslope by wter ws believed to be significnt fctor in these lndscpes. (Priyshnth et l., 2007). Wter infiltrtion from snowmelt during the spring seson depends on whether the soil is frozen or in condition of thwing (Srinivsn et l., 2006). Continued freeze-thw during the spring snowmelt could lso crete conditions for more runoff (i.e. when the soil surfce is frozen) to conditions where more wter will infiltrte into thwing soil surfce nd lech downwrd in the soil profile. There re lso conditions tht could exist where soil is in condition of thwing, yet sturted conditions in the unfrozen surfce soil my llow little wter infiltrtion (Ginting et l., 1998). Recently thwed fine textured soil will llow for only low wter infiltrtion (Bker, 1972). Mid-winter melts cn lso led to formtion of surfce ice lens. runoff from snowmelt cn occur in severl wys. Wter infiltrtion will be limited when the soil surfce is frozen. Snowfll prior to freezing in the fll cn serve to insulte the soil surfce llowing more infiltrtion during the spring snowmelt nd leding to sturtion conditions, where excess wter cn move lterlly. Finlly, rinfll received during the spring snowmelt cn led to excess wter being trnsported cross prtilly frozen soil surfce (Srinivson et l., 2006). Studies hve exmined fll pplied mnure tht ws covered with snow, however, inconsistent impcts on run-off nutrient content hve been reported. One study reported higher nutrient concentrtion in runoff (Young nd Mutchler, 1976) while nother study (Klusner et l., 1976), reported tht when lter spring seson snowmelt occurred, nutrient export ws lower. The timing nd durtion of the snowmelt 5

22 period likely hs mjor impct on the mount of nutrient removed from the field during nd immeditely following the snowmelt. 1.4 Ph.D. Reserch Description Limited informtion exists on the movement nd export of inorgnic P nd N in cultivted soils receiving LHM nd especilly SCM pplictions in western Cnd. There re n estimted 2.3 million cttle nd clves in Ssktchewn (Ssktchewn Ministry of Agriculture 2015). New mngement prctices for solid mnures re being developed, including ppliction through bnding. Existing nd new mnure mngement prctices require evlution for their effect on P nd N forms nd distribution in soils, nd in run-off nd leching wter. My overrching hypothesis is tht subsurfce plcement of mnure in bnds will increse the biovilbility but lso the potentil surfce runoff nd/or downwrd mobility of soil P nd/or N nutrients. The objectives of this reserch re: 1. Evlute new subsurfce bnding technology developed for SCM ppliction on the crop yield nd P nd N crop uptke, compred to trditionl ppliction methodologies including brodcst lone nd brodcst nd incorportion. 2. Estimte the mount of soluble rective P (SRP) nd N trnsported offsite s ffected by SCM nd LHM rte nd ppliction methodology, using novel pproch in which intct soil slbs re removed from plots in short nd long term SCM nd LHM field studies in Ssktchewn nd then hve simulted snowmelt conditions pplied in controlled environment room. 3. Address the verticl nutrient trnsport potentil through the soil profile by ssessing the mount of OC, Totl N, SRP nd N tht re trnsported through intct soil cores tht were removed from SCM mended plots in the field nd subjected to leching wter pssed through the cores. The studies tht ddress these objectives will provide new informtion on gronomic nd environmentl implictions of new versus existing mnure mngement prctices in western Cnd tht will be useful in the development of beneficil mngement prctices nd recommendtions for mnure ppliction throughout the region. 6

23 1.5 Disserttion Arrngement Following this introduction (Chpter 1) nd subsequent literture review (Chpter 2), the reserch presented in this disserttion is compiltion of three mnuscripts (Chpters 3-5) nd n (Appendix A) detiling the work tht ws conducted to evlute the effects of different methods nd rtes of SCM ppliction nd their effect on P nd N biovilbility nd mobility in the soil. Specificlly, Chpter 3 covers the results of three yer study in est-centrl Ssktchewn tht compred the crop yield, crop nutrient uptke nd soil vilble P nd N supply in plots treted with SCM using three methods of ppliction (brodcst, brodcst nd incorported, novel subsurfce bnding) t three rtes of ppliction. This study provides comprehensive understnding of the effects of SCM plcement, specificlly subsurfce bnding, on soil nutrient biovilbility nd crop uptke nd utiliztion of SCN nutrient. Chpter 4 investigtes the effect tht the three SCM ppliction methodologies nd two LHM ppliction methodologies hve on the trnsport nd movement of P nd N in simulted snowmelt run-off wter, emphsizing both subsurfce (thwing soil) nd surfce (frozen soil) trnsport. Chpter 5 dels with further investigtion of trnsport of nutrients in wter s ffected by mnure rte nd plcement by determining the mounts of P nd N tht re removed vi verticl leching from wter tht is pplied to the surfce of intct soil cores removed from SCM plots. This study enbled us to determine how the plcement of SCM ffects the export of nutrient from the surfce vi downwrd leching (verticl trnsport) in the soil profile. Therefore, the studies involving snowmelt run-off in Chpter 4 (simulted erly spring) nd infiltrting percolting wter in Chpter 5 (lte spring nd summer) cover the mjor wter-relted trnsport processes tht mnured soils in western Cnd my be expected to experience. In the finl chpter (Chpter 6), the results of ech component of the work re brought together nd integrted, with conclusions drwn nd prcticl recommendtions mde for mnure ppliction best mngement prctices. Also included in the disserttion is Appendix A, which is n ssemblge of plot digrms bsed on the tretment lyout of the study. 7

24 2. LITERATURE REVIEW 2.1 Nutrient Benefits nd Concerns Surrounding Lnd-Applied Animl Mnures Livestock opertions produce lrge mounts of P nd N in mnure from nimls tht re fed plnt mterils nd supplements contining these nutrients. In Cnd, pproximtely 150 million tonnes of mnure re produced nnully which re pplied to bout 3.5 million hectres of lnd in 2005 (Sttistics Cnd, 2006). Benefits to crop production from the ppliction of SCM nd LHM to western Cndin soils to provide P nd N nutrient hve been well documented (Mooleki et l., 2004; Mooleki et l., 2002; Schoenu nd Dvis, 2006), long with other nutrients such s copper nd zinc (Lipoth nd Schoenu, 2007; Qin et l., 2003) if there is limited supply of these micronutrients in the soil. Phosphorus nd N re essentil elements for plnt bove-ground nd below-ground tissue formtion (Hvlin et l., 2013). The ppliction of niml mnures hs primrily been intended s source of N for plnt growth. Nitrogen is primrily utilized by the plnt to form mino cids, proteins nd nucleic cids. Additionlly, N is utilized in the synthesis of chlorophyll which bsorbs light energy for photosynthesis nd ids in vegettive growth (Hvlin et l., 2013). Accordingly, ppliction of niml mnure hs been on n N-bsed pproch, s this is the most widely utilized nd most frequently deficient nutrient in crop production (Gburek et l., 2000). However, niml mnures such s SCM cn contin lrge mounts of P, depending on the source of the mnure nd its hndling nd processing in niml production fcilities (Beuchmp, 1983; Eghbll nd Power, 1999; Mooleki et l., 2004). Phosphorus is utilized by plnts for energy storge nd trnsport nd typiclly is 0.1 to 0.5 % of the dry mtter by weight in plnt mteril (Hvlin et l., 2013). In ttempting to meet the N bsed requirements for plnt growth, producers hve in mny instnces pplied mnure to the point tht there is n overbundnce of P dded to the field, tht exceeds the bility of the crop to utilize the entire mount of mnure P supplied (Shrpley et l., 2015). If the soil is not ble to dequtely dsorb the excess P supply vi the minerl nd orgnic components, the inorgnic nd orgnic 8

25 mnure P constituents tht remin in the soil solution re prone to export off the field site vi wter runoff nd/or subsurfce leching to surfce nd subsurfce wter bodies (Shrpley et l., 2015). Phosphorus nd N contined in niml mnures such s SCM, cn exist in both inorgnic nd orgnic forms. The ppliction of LHM using subsurfce bnding methods nd its positive effect on crop growth in est-centrl Ssktchewn hs been documented by Mooleki et l. (2002). Mooleki et l. (2004) hve lso reported on studies conducted with SCM t rtes of 400 kg N h - 1, which resulted in incresed plnt N vilbility nd crop yields during the yer of ppliction, nd in subsequent yers following ppliction due to the slow minerliztion of mnure orgnic N to plnt vilble inorgnic N. The uthors ttributed the slow relese of N from orgnic forms, nd the low mount of inorgnic N in SCM s lso being responsible for low toxicity to the crop t high rtes of ppliction. They lso reported tht the timing of incorportion, whether immeditely following SCM ppliction or delyed by 24 h, hd no effect on crop yield or on soil N content. A non-nutrient benefit of solid mnures is the significnt ddition of orgnic mtter directly to the soil tht cn improve importnt soil physicl properties like structure nd tilth of the soil (Grevers et l., 2010). With the nutrient nd soil orgnic mtter building benefits ssocited with mnure, intensive livestock opertions lso bring concerns bout the consequences of improper ppliction of niml mnure (Lgue et l., 2006; Snderson nd Jones, 1997). Livestock mnure is recognized s source of orgnic mteril (OM) nd importnt plnt nutrients but there lwys exists concerns bout erosion or leching events removing these nutrients nd trnsporting them off-site to surfce nd/or subsurfce wter bodies (Eghbll nd Power, 1994). Furthermore, ctstrophic events such s flooding cn impct the solubility nd mobility of P in soils (Sclenghe et l., 2014). The rte of decomposition of the mnure orgnic mtter constituents such s fecl mtter nd bedding into soluble, potentilly mobile inorgnic nutrient ions cn vry depending on the mnure type, such s LHM or SCM. The C:N nd C:P rtio of the mnure, the climte zone the soil is locted in nd the conditions in the soil upon which the mnure is being plced (e.g. temperture, moisture) lso influence the degree to which mnure nutrients re rendered rective nd potentilly mobile (Klusner et l., 1994). Beuchmp (1983) nd Png nd Letey (2000) hve reported tht soil N vilbility in the yer of SCM ppliction is low, due to most of the SCM N being in n orgnic form, which tkes time to be converted into plnt vilble inorgnic form, especilly if the C:N rtio is high (Qin nd Schoenu, 2002). Thus, if the rte of SCM is incresed to meet the 9

26 immedite N requirements of the crop due to low short-term vilbility of the N, this cn rpidly led to n excess in soil P (Chng et l., 1991) contributing to run-off nd leching losses. 2.2 Mnure Appliction Method nd Nutrient Retention in Soils Current SCM ppliction technology is limited in tht the rte nd uniformity of mnure ppliction is often not controlled effectively (Lndry et l., 2005). Non-uniform ppliction of SCM cn led to zones in griculturl fields where too little or no SCM is plced while other res in the field hve zones where the mnure is over-pplied. Appliction technologies generlly fit one of severl types: 1) brodcst lone, with no incorportion t time of ppliction; 2) brodcst with incorportion following spreding, 3) ppliction through n irrigtion pivot or 4) subsurfce injection or bnding (Schoenu nd Dvis, 2006). Timing of niml mnure ppliction cn occur during spring pre-seeding, fll post-hrvest or winter ppliction of mnure. The method of ppliction nd/or timing cn profoundly influence the nture nd extent to which nutrients re exported from field. For exmple, N loss through voltiliztion by surfce plcement hs been documented by severl reserchers (Snderson nd Jones, 1997; Zhu et l., 1997). Mooleki et l. (2002) reported on the positive crop yield obtined when subsurfce bnding LHM compred to brodcst nd incorportion, nd the increse in N use efficiency obtined from subsurfce bnding ppliction method versus brodcst nd incorportion. There is tendency to lnd pply niml mnure t high rtes bsed on desire to simply dispose of the product, without considertion for the nutrient content or mkeup of the mnure in reltion to crop needs. This, in turn, cn led to over ppliction of some nutrients contined in the mnure. Considertion of nutrient blnce in mnure is importnt, nd how ppliction method my ffect this. Lrge losses of N during ppliction but retention of P will ggrvte issues with n imblnce of too little N reltive to P in reltion to crop requirements. On the other hnd, retention of both N nd P my ultimtely led to over-ppliction of both, nd increses in soil nitrte-n (NO3-N) concentrtion to the point t which excessive mounts cn be leched downwrd in the root zone to potentilly contminte subsurfce wter (Duden et l., 2004). The ppliction of niml mnure t N-bsed rtes cn result in over-ppliction of other nutrients such s P (Mooleki et l., 2004), which if trnsported off field site cn led to excessive mounts of P in runoff (Pote et l., 1996; Wng et l., 2010) nd in subsurfce wter (Simrd et l., 2000; Sims et l., 1996) which increses the risk of eutrophiction (Shrpley et l., 1994). 10

27 Current SCM ppliction technology is limited in tht the rte nd uniformity of mnure ppliction is not controlled effectively (Schoenu, 2013). Solid niml mnures hve been trditionlly pplied to griculturl fields using box- type spreding mechnism tht cn limit solid mnure spred uniformity, lrgely through limittions in beter design nd lso wer over time. The recent move from horizontl to verticl beters hs improved the distribution to certin extent bsed on personl observtions. Such units lso typiclly provide only limited control of the rte of ppliction, minly by ltering trvel speed (Lgue et l., 2006). The lck of uniform ppliction in surfce pplied SCM nd the potentil for excessive ppliction rtes of the P nd N in zones could led to toxicity risks for the crop nd lso increse the potentil for off field movement nd site contmintion of surfce nd subsurfce wter bodies. This is becuse the zone of over-ppliction my become sturted in terms of its sorption cpcity for the nutrient ion. Subsurfce bnded mnure cn lso crete zones of high nutrient concentrtion (Kovr et l., 2011). Repeted mnure pplictions cn result in P ccumultion in soil, nd this ccumultion cn prtilly or completely sturte soil dsorption sites, depending on OM nd cly content (Qin et l., 1994). Phosphorus tht is not utilized by the crop or dsorbed onto OM or cly minerl components is considered mobile, susceptible to run-off nd leching losses (Eghbll et l., 1996) nd cn be more redily moved ll the wy to surfce nd subsurfce wter bodies (Schroeder et l., 2004; Vds et l., 2005). 2.3 Mnure Appliction Rte nd Appliction Methodology on Nutrient Trnsport in Wter Mny studies exmining trnsport of nutrients in surfce run-off hve emphsized the effect of ppliction rte of niml mnure in comprison to n unmended control (Eghbll et l., 2002; Kleinmn et l., 2002; Kleinmn et l., 2004; Mueller et l., 1984). A few reserchers hve lso reported on the effect tht mnure ppliction methodologies hve on P trnsport in run-off (Volf et l., 2007) (Eghbll nd Gilley, 1999; Kleinmn et l., 2002; Mueller et l., 1984). For exmple, Kleinmn et l. (2002) reported tht with mnure incorportion into soil, there ws decrese in concentrtion of P in run-off nd greter dsorption of P to soil constituents. Depending on soil nd climtic conditions, field mngement nd cropping history, excessive mnure ppliction rtes cn result in high NO3-N ccumultion (Zebrth et l., 1998). Rtes of ppliction of SCM contining mounts of P in excess of crop P uptke cpcity cn increse soil extrctble P levels nd thereby increse the risk of export off field site through runoff (Reddy et l., 1999; 11

28 Shrpley et l., 1994; Withers et l., 2001). Volf et l. (2007) reported tht plots mended with fresh SCM tht ws incorported hd run-off P tht ws not significntly different from plots tht hd received SCM one yer prior. Shrpley et l. (2015) reported tht N-bsed mnure pplictions hve led to n increse in soil P levels tht re in excess of crop requirements. This is especilly noted for cttle mnure, s it is inherently high in P reltive to N (low N:P rtio) (Schoenu nd Dvis, 2006; Stumborg et l., 2007). Studies hve reported tht when cttle feedlot mnure is pplied on P-bsed crop requirement, there is tendency for reduced P in run-off (Eghbll nd Gilley, 1999; Eghbll nd Power, 1999) nd severl reserchers hve reported on the direct reltionship between mnure P ppliction rte, soil P levels nd P in run-off (Dniel et l., 1994; Shrpley nd Rekolinen, 1997). Pote et l. (1996), Schroeder et l. (2004), Lemunyon nd Gilbert (1993) nd Hethwite (1997) reported tht mny vribles such s mount of cly minerl prticles nd subsequently the dsorption cpcity, long with moisture content, clcium crbonte content, climte, lndscpe slope nd mngement prctices ll ffected the mount of P being exported in run-off. Ingrm nd Woolhiser (1980) suggested tht rinfll event intensity, run-off energy nd lndscpe slope ffected the degree of interction between nutrients in the soil nd nutrients trnsported in run-off. Little et l. (2005) stted tht tillge could lso reduce run-off nutrient trnsport by redistributing nutrients deeper in soil profile, while flooding of the soil cn increse P solubility nd ccelerte P loss (Kroger et l., 2012). The ccumultion of nutrients from repeted niml mnure pplictions cn increse or concentrte nutrient mounts ner or t the soil surfce (Set et l., 1993). Eghbll nd Gilley (1999) used rinfll simultor to mesure P nd N in run-off from plots mended with composted nd feedlot mnure. They reported tht there ws little mendment type effect on dissolved P or totl N. Qu et l. (1999), reported tht in plots mended with fresh nd composted diry cttle mnure, totl N concentrtions in the run-off wter ws greter in fresh diry mnure compred to composted diry mnure. In generl, over-ppliction of SCM, nd prolonged yerly pplictions of SCM cn led to non-point source contmintion of surfce nd sub-surfce wter bodies where excess NO3-N nd P re not tken up by the crop or dsorbed onto soil minerl nd orgnic dsorption sites. Prior knowledge on the behvior of P in soil ws tht it ws immobile in soil (Hygrth nd Jrvis, 1999). However, it is now known tht P pplied in fertilizer or niml mnure cn be trnsported to certin extent through overlnd run-off or subsurfce leching (Hrt et l., 2004). 12

29 Soils tht hve lower mounts of OM or cly increses the chnces tht P cn be trnsported vi run-off or downwrd leching through preferentil flow pthwys severl centimeters or more through the soil (Shrpley et l., 1998; Shrpley nd Rekolinen, 1997). Phosphorus trnsport in wter from run-off or leching cn depend on the mnure type being pplied to the soil, the timing (whether it s fll or spring ppliction) (Edwrds nd Dniel, 1993; Shrpley, 1997), the rte of ppliction nd the methodology used to pply the mnure (Withers et l., 2001). Nonpoint source contmintion of surfce nd subsurfce wter bodies from P nd N relesed from niml mnure ppliction is of gret concern. Problems with eutrophiction, where lge growth is incresed due to nutrient enrichment of wter bodies cn cuse problems for qutic nd humn helth (Kumrgmge et l., 2011). The mount of P tht is trnsported by wter from run-off or leching cn be vrible in lnd receiving niml mnure (Shrpley et l., 1998). This literture review hs reveled tht little informtion exists on the mount of P trnsport in run-off nd lechte wter from lnd receiving SCM through subsurfce bnding technology. 2.3 Nutrient Movement Associted With Snowmelt In western Cnd, spring snowmelt is the primry wter movement event nd P nd N nutrients cn be trnsported in dissolved nd prticulte forms, leding to incresed nutrient concentrtions in wter tht reched subsurfce nd/or surfce wter bodies (Jensen et l., 2000). The P dissolved in snowmelt run-off wter cn be trnsported much longer distnces throughout the lndscpe thn prticulte forms. Tiessen et l. (2010) reported tht in exmining snowmelt runoff from two Mnitob wtersheds, snowmelt runoff ccounted for between % of totl nnul runoff. Snowmelt wter hs less soil erosive cpbility, due to the lower kinetic energy ssocited with this type of wter movement, thus more P nd N nutrient movement cn occur in dissolved form (Cde-Menun et l., 2013) nd cn be exported over longer distnces s snowmelt wter trvels longer distnces over fields from higher slope res (Priyshnth et l., 2007) to lower slope positions. Tiessen et l. (2010) reported tht the mjority of prticulte nd dissolved nutrient export from two Mnitob wtersheds occurred during the spring snowmelt runoff. Therefore, the work on P trnsport in run-off described in this thesis ttempts to simulte the trnsport tht my occur in dissolved form in spring snowmelt wter s ffected by mnure mngement prctices. 13

30 Annully cropped griculturl fields hve, in some cses, evolved from serving s n dsorption zone for nutrients such s P nd N to potentil trnsport zone if the plnted crop is unble to use ll the pplied nutrients in single growing seson (Liu et l., 2013; Shrpley nd Wng, 2014). Therefore, with over-ppliction of mnure nd improper plcement, soils cn turn from sink to source of nutrient ions like phosphte to be moved into djcent wter. Phosphorus hs been reported to move from griculturl soil by leching to surfce nd subsurfce wter bodies (Eghbll et l., 1996; Flten et l., 2003). The trnsport of P occurs first through loding process whereby P is relesed to soil solution from the solid phse which cn consist of P dsorbed to soil minerl nd orgnic colloid surfces. A trnsport function occurs where moving wter then trnsloctes the P by movement cross the surfce in run-off or through the soil horizontlly or verticlly with percolting wter (leching) (Jensen et l., 2000). Trnsport of P through the soil profile is enhnced by preferentil flow through soil crcks nd mcropores nd low bundnce of soil dsorption sites (Beuchemin et l., 1996; Culley et l., 1983). Previous reserch conducted in western Cnd hs reported tht soil P losses from spring snowmelt cn be greter thn wht occurs due to run-off from rinfll (Chnsyk nd Woytowich, 1987; Vn Vliet nd Hll, 1991). Wter infiltrtion during the snowmelt period cn depend on whether the soil is in frozen stte, thwing condition (Srinivson et l., 2006) or continuous cycle of freeze nd thw, which cn excerbte conditions more fvorble to runoff thn infiltrtion. The timing nd durtion of spring snowmelt cn lso hve mjor impct on nutrient exported in runoff nd/or in downwrd moving lechte. Severl studies reported conflicting results on the mount of nutrient trnsport in meltwter depending on whether snowmelt ws n erly or lter spring seson event (Klusner et l., 1976; Young nd Mutchler, 1976). Furthermore, snow melting over frozen soil, when spring tempertures begin to increse, cn relese lrge mount of wter tht cn either run off the field site, or else s the soil begins to thw, begin to percolte downwrd in the soil profile (Li et l., 2011). Snowmelt run-off cn exceed rinfll runoff, due to the soil being frozen thus limiting wter infiltrtion (Grnger et l., 1984; Hnsen et l., 2000; Young nd Mutchler, 1976). The lte winter, erly spring period in which snowmelt occurs (e.g. mid-mrch in the southern priries) cn fvor more sturted conditions occurring ner the soil surfce tht cn increse P mobility (Bechmnn et l., 2005; Little et l., 2007; Ontken et l., 2005). 14

31 Snowmelt run-off hs less erosive bility compred to rinfll run-off s the kinetic energy generted by the force of the rindrops contcting the soil surfce cn cuse more soil prticle detchment nd movement thus removing more prticulte forms of nutrients with SOM prticles (Li et l., 2011). Lrge mounts of dissolved forms of nutrients cn be crried off the field with run-off occurring from lrge volumes of snowmelt in western Cnd, especilly when infiltrtion rtes re reduced due to soil surfces tht re frozen in the erlier portion of the spring period (Chnsyk nd Woytowich, 1987; McConkey et l., 1997; Vn Vliet nd Hll, 1991). Glozier et l. (2006) reported tht pproximtely two-thirds of the P nd N removl due to snowmelt run-off in southern Mnitob occurred in dissolved form. Little et l. (2007) reported tht in Albert, over 90 % of the P removed by spring snowmelt ws in dissolved form. Fleming nd Frser (2000) hve reported tht frozen bre soils do not llow infiltrtion of dissolved P nd N. The work described in this thesis emphsizes dissolved ionic forms of P nd N tht re trnsported in wter, owing to the identified importnce of this frction in Western Cnd. 2.4 Synopsis nd Reltionship to Thesis Reserch Work When niml mnure is dded to the soil, there is P nd N nutrient input to the soil. Some of the inorgnic P nd N my be immeditely immobilized into orgnic forms nd retined, or held by dsorption to soil minerl nd OM prticles. Some nutrient ions tht remin in soil solution or tht re mobilized through minerliztion or desorption cn be exported from the soil by wter moving lterlly or verticlly through the soil. A portion of the nutrient will invribly remin in lbile or plnt vilble form t the end of the seson fter hrvest. The reltionships between pplied mnure nutrients, their potentil fte, nd the specific components of the reserch work described in this thesis re shown in Fig 2.1. A significnt spect contributing to the novelty of the thesis work conducted is determining how new subsurfce bnding technology for solid mnure ppliction ffects plnt yield nd nutrient content, soil supply of P nd N, nd the export of dissolved P nd N vi snowmelt run-off nd leching. In Ssktchewn, the mjor wter movement period occurs during erly spring snow melt when melt wter moves cross the soil surfce nd through the upper soil surfce, nd cn crry nutrients in the flow. Thus the ppliction of SCM nd LHM through subsurfce bnding could hve mjor impct on P nd N movement off field compred to surfce ppliction. This is exmined in this thesis through the development of novel method in which intct soil slbs re removed from plots tht hve been treted with 15

32 subsurfce bnded SCM nd LHM, snow cover is pplied nd subsequently llowed to melt under controlled conditions to mesure the mounts of P nd N tht re being trnsported off field site from run-off nd lechte (Fig. 2.1). To ddress the influence of subsurfce bnding on nutrient trnsport with downwrd percolting wter such s from snowmelt or precipittion, intct soil cores were collected nd leched (Fig. 2.1), with the lechte wter collected nd nlyzed for soluble ionic P nd N forms. Becuse defined surfce re is present from which the run-off or leching occurs, the nutrient exports re clculted on kg per h (re bsis). Fig Schemtic digrm outlining the study of phosphorus nd nitrogen nutrient export in solid cttle mnure nd liquid hog mnure mended soil. Overll, review of the literture revels tht gret del of pst reserch work hs been conducted exmining the effect of mnure ppliction rte on crop response nd nutrient loss. Some work hs lso exmined the effect of plcement. However, there is little informtion tht links together mnure plcement effects, prticulrly new bnd plcement technologies, for both gronomic responses nd nutrient trnsport potentil. While crop response nd soil nutrient forms nd mounts cn be ssessed relibly in replicted smll plot studies, run-off ssessments hve trditionlly been mde in seprte lrge scle ctchment bsin or wtershed scle studies. There is need to meld together replicted rndomized block studies of gronomic effects with cpcity 16

33 to study run-off potentil t the sme time. The reserch described in the next three chpters of this thesis helps to ddress this gp. 17

34 3. EFFECT OF SOLID CATTLE MANURE RATE OF APPLICATION AND MANURE PLACEMENT ON CROP YIELD AND SOIL NUTRIENTS IN A BLACK CHERNOZEM IN EAST-CENTRAL SASKATCHEWAN 3.1 Prefce The ppliction of solid cttle mnure (SCM) to griculturl fields is long prcticed method of dding orgnic mtter nd recycling nutrients in groecosystems. Solid cttle mnure hs trditionlly been brodcst pplied to the entire field with mnure spreders t rtes tht re often unknown to the pplictor nd with equipment tht pplies the SCM non-uniformly. Despite the benefits of SCM in dding nutrients to the soil, the inbility to control the rte nd uniformity of ppliction cn led to potentil undesirble gronomic nd environmentl consequences. SCM my be pplied using surfce brodcst lone nd brodcsting followed by incorportion with existing equipment. New technology is lso being developed to pply solid mnure in sub-surfce bnds. Assessing crop yield, soil nd crop residue nutrients s ffected by method of SCM ppliction in pririe soils, including new plcement methods, will id in understnding the effects on soil nutrient vilbility nd crop yield. This chpter covers the gronomic implictions of ppliction of different rtes nd plcement methods of SCM in n ot-cnol rottion t site in est centrl Ssktchewn over three yer period. Subsequent chpters then cover the implictions of mnure mendment on nutrient export in simulted run-off nd leching. A pper hs been published by uthors: Lndry, H., King, T, Schoenu, J.J., Lgue, C. nd J.M. Agnew Development nd evlution of subsurfce ppliction technology for solid orgnic fertilizers. Applied Engineering in Agriculture (Vol. 27: ). This pper incorportes portion of the gronomic work reserched in this chpter. 18

35 3.2 Abstrct Assessing nd quntifying crop nd soil impcts of different rtes nd ppliction methods of solid cttle mnure (SCM) in n nnully cropped system will llow the doption of pproprite mnure mngement prctices tht will enhnce the gronomic benefit of the mnure. The objective of this study ws to evlute the effect of brodcst lone, brodcst nd incorported, nd subsurfce bnding of SCM in n ot-cnol rottion in Blck Chernozem soil locted in est-centrl Ssktchewn. Mnure ppliction incresed yields over the non-mnured, unfertilized controls, but the effect of incresing rte nd plcement methods consisting of brodcst lone, brodcst nd incorported nd subsurfce bnded, ws usully not significnt. Only the subsurfce bnded 20.2, 40.4 nd 60.6 t h -1 SCM tretments incresed cnol grin yields compred to the brodcst lone nd brodcst nd incorported SCM tretments t these three rtes in 2008, nd only when combined with nitrogen (N) ure fertilizer t rte of 78 kg N h -1. This ws ttributed to enhnced supplies of vilble phosphorus (P) from the mnure tht, when limittions on N were removed by ure fertiliztion, resulted in greter yield. Soil supply rtes of orthophosphte-p in the surfce soil, s mesured by PRS resin membrne probe, tended to increse through the 2009 growing seson in ll three SCM 60 t h -1 ppliction tretments. Soil nitrte-nitrogen (NO3-N) supply peked for ll three SCM 60 t h -1 ppliction tretments pproximtely six weeks fter the 2009 ot crop ws seeded, then diminished during the mid nd lte July 2009 smpling periods. However, there ws no significnt impct (P 0.10) of SCM plcement method on supply rtes of phosphte nd nitrte mesured in the surfce soil in the field. The relese of P nd N from collected cnol crop residues in 2008 ws lso mesured. The cnol residue totl P nd N content ws decresed when cnol crop residues were immersed in wter nd frozen. In the cse of P, concentrtions were reduced nerly two-fold, indicting n importnt role of leching in removing nd recycling P from crop residues fter hrvest. However, mnure ppliction rte nd plcement method hd no significnt influence on crop residue P nd N content or relese of nutrient from residue. Overll, the rte of ppliction of SCM ppers to hve more profound effect on soil nd plnt nutrient concentrtions nd yield, especilly P, thn the method of SCM plcement. 19

36 3.3 Introduction The gronomic benefits of ppliction of liquid hog mnure (LHM) in subsurfce bnd versus surfce ppliction re well estblished (Mooleki et l., 2002). Feeding of nimls nd the lnd ppliction of niml mnure recycles the nutrients removed from the soil by plnts nd reduces the need for commercil fertilizer to fulfill future crop nutrient requirements (Jungnitsch et l., 2011). Current ppliction technology vilble for pplying solid cttle mnure (SCM), however, is limited in tht the rte nd uniformity of mnure ppliction is not controlled very effectively (Lndry et l., 2005). Non-uniformity in surfce ppliction of SCM s result of poor spreding cn led to zones where little or no SCM is plced, while other res in the field experience over ppliction of mnure. Furthermore, surfce brodcst pplictions of some mnures re well known to promote potentil dditionl losses of N from voltile mmoni escpe, especilly under wrm nd windy conditions (Hvlin et l., 2014). Surfce plcement without incorportion cn lso strnd nutrients ner the surfce of the soil, reducing their vilbility for root uptke. Incorportion of solid mnure following spreding is commonly prcticed in the northern Gret Plins (Schoenu nd Dvis, 2006) to help retin mnure nutrients, but is not comptible with the no-till system common in western Cnd nd is ssocited with extr cost nd time required for one or more tillge opertions to conduct the incorportion. Prototype subsurfce bnding equipment is vilble tht cn improve the uniformity of ppliction by putting mnure in uniform bnds below the surfce. However, the gronomic benefits of such n pproch to ppliction hve not been evluted. It ws hypothesized tht the crop yield nd nutrient vilbility would differ mong vrious SCM ppliction rtes nd plcement methods. Therefore, the objective of the work described in this chpter ws to evlute the effect of ppliction of SCM pplied nnully t three different rtes using brodcst only, brodcst nd incorported, nd novel subsurfce bnded ppliction method. Effects on crop yield, soil nd crop nd residue nutrients were evluted in three yer experiment conducted on Blck Chernozem soil in est-centrl Ssktchewn ner Dixon, SK. The crop yield, phosphorus nd nitrogen uptke in n ot-cnol rottion ws mesured ech yer, nd comprison of the effects of the tretments on soil nutrient supply rte in the surfce soil nd the nutrient content nd relese from cnol crop residue ws mde. 20

37 3.4 Mterils nd Methods Site description The SCM injection study t Dixon, SK ws estblished in the spring of 2007 before spring seeding opertions commenced, with the first pplictions of SCM (Appendix A). The experiments were initited on the southern hlf of frm field (N ; W ) owned by Mr. Collin Ford. This field is locted pproximtely 6.5 km west of the town of Humboldt; djcent to Ssktchewn Provincil Highwy #5, within the Rurl Municiplity of Humboldt (Figure 3.1). The soil t this site belongs to the Cudworth Assocition nd is Blck Chernozemic soil formed in clcreous, silty, lcustrine prent mterils nd possessing lom surfce texture (Ssktchewn Soil Survey, 1989). The soil t the Dixon field site occurs on gently sloping lnd surfce with few limittions tht hinder griculturl ctivity. Identified limittions include insufficient moisture holding cpcity nd some slinity, which covers 10-20% of the lndscpe, occurring mostly in sloughs nd low lying res (Ssktchewn Soil Survey, 1989). This field site is only slightly stony nd hs low susceptibility to wind nd wter erosion (Ssktchewn Soil Survey, 1989). Crops grown on the Dixon site were ots (Aven stiv) in 2007 nd 2009 nd cnol (Brssic npis) in Fig Photogrph of portion of the Dixon solid cttle mnure ppliction site, tken on My 10, 2007 fter flgging to mrk plot loctions for tretment ppliction, nd spring nd fll crop nd soil smpling. 21

38 3.4.2 Generl experimentl setup The SCM field tril ws set up s rndomized complete block design (four tretment replictes) with plots lid out in April of Within ech block, rte nd method of ppliction tretments were rndomized. Four blocks of tretments were used with lleywys between the blocks to llow for ppliction equipment turning nd ccess to the plots. The size of ech plot ws 3.05 by 6.09 m. There were two control plots for the SCM tril t Dixon, the first consisting of no mnure or fertilizer being pplied nd no disturbnce of the soil. The second control plot hd no mnure or fertilizer pplied but with disturbnce of the soil using the coulter openers of the SCM injector mchine. Solid cttle mnure ws pplied every spring before seeding over the three yers of the study (2007, 2008 nd 2009) using four ppliction procedures: 1) brodcst ppliction; where SCM is pplied on the soil surfce without incorportion, 2) brodcst nd incorported; where SCM is pplied on the soil surfce nd subsequently incorported using disk, 3) subsurfce bnding; where SCM is subsurfce bnded using the PAMI Solid Cttle Mnure Injector Mchine (Fig. 3.2) in six subsurfce trenches using 30 cm coulter openers spced 30 cm prt, pplying SCM product cm in depth with 45 cm closing wheels covering the exposed injection trench with soil, nd 4) subsurfce bnding of SCM with commercil ure fertilizer (46-0-0; t rte of 78 kg N h -1 ) bnded into the soil using smll plot drill prior to the injection of the SCM. Fig Prototype Pririe Agriculturl Mchinery Institute-University of Ssktchewn solid cttle mnure injector in field. 22

39 Tretment 4 ws included s tretment to reflect the low vilbility of N in SCM in the yer of ppliction (Mooleki et l., 2004) tht my be compensted for by the ddition of supplementl commercil N fertilizer. The lowest rte of SCM being pplied (1X) ws equl to 100 kg totl N h -1, t rte of mnure product of 20.2 t h -1, nd my be considered typicl gronomic rte in line with the mount of N tht would be recommended s fertilizer mnure to meet crop requirement. Higher rtes of SCM (2X = 40.4 t h -1, 3X = 60.6 t h -1 ) were considered to be double nd triple the recommended gronomic rtes of N fertilizer ppliction for n ppliction to be mde every yer. The SCM injection trils consisted of 14 tretments (Tble 3.1) tht were replicted in four blocks, rrnged in west to est direction (Appendix A) nd were lid down in rndomized pttern in the spring of 2007 before the producer commenced seeding opertions. The 1X refers to the recommended rte (100 kg N h -1 yr -1 ) of SCM pplied nnully. The 2X nd 3X indicte double nd triple the recommended rte of SCM pplied nnully, respectively. For the SCM subsurfce bnded tretment with ure fertilizer, the 1X, 2X nd 3X rte corresponds to 20.2, 40.4 nd 60.6 t h -1 rte of mnure, with the sme ure fertilizer rte (78 kg N h -1 ) Mnure chrcteristics The SCM pplied in the field tril t Dixon ws obtined from the Poundmker Feedlot, which is locted pproximtely 8 km est of the town of Lnign, SK. The mnure tht ws pplied hd been removed from pens nd stockpiled for pproximtely one yer. The mnure ws pplied to the pproprite plots using the PAMI SCM Mchine. Brodcst pplictions were mde by removing the disc opener component of the mchine nd llowing the mnure to exit the box cross the soil surfce. The brodcst nd incorportion ppliction ws brodcst followed by immedite incorportion to depth of 10 cm using 6 m tndem disc pulled by John Deere hp front wheel ssist trctor. Appliction rtes of the SCM re listed in Tble 3.1. The SCM tretments were pplied prior to seeding of the Dixon site on June 12, 2007 for the 2007 crop yer, on My 10, 2008 for the 2008 crop yer nd on My 19, 2009 for the 2009 crop yer. Mnure sub-smples for the SCM pplictions for ech yer of ppliction were obtined from the ppliction equipment t the time of tretment ppliction in the field plots. 23

40 Tble 3.1. Trgeted nitrogen ppliction rte tretments in the solid cttle mnure rte/plcement study ( ) t Dixon, Ssktchewn. Tretment Sequence N rte Appliction method (t h -1 ) (kg N h -1 ) 0 control 0 with no incorportion 0 control-disturbed 0 with no incorportion, but disturbnce X X X X X X X X X 300 cttle mnure brodcst only cttle mnure brodcst nd incorported cttle mnure subsurfce injected X+U X+U X+U 300 cttle mnure subsurfce injected + ure ure fertilizer U 78 bnded ure fertilizer Appliction rte bsed on wet weight The sequence, 1X for exmple, refers to the rte of mnure ppliction in the crop yer ongoing nnully since 2007 Ure fertilizer The rte of ure fertilizer ppliction plus the corresponding SCM injection rte in the crop yer ongoing nnully since 2007 Smples were stored in 10 L plstic continers nd plced into frozen (-20 C) storge, prior to nlysis for their constituent nutrients. For the SCM smples, individul continers were removed from frozen storge nd thwed t room temperture nd smpled for nutrient content nlysis. After thwing, smples were opened in the lbortory fumehood nd stirred to mix the contents. Totl N nd P were mesured by sulfuric cid peroxide digestion nd soluble mmonium nd phosphte by wter extrction (Thoms et l., 1967). The concentrtions of N nd P in the mnure used in the three yers, long with clculted ppliction rtes re shown in Tble 3.2. The trgeted N rte ws 100 kg N h -1. Soluble, vilble P in the mnure mde up lrger proportion of the 24

41 totl P content. Immeditely vilble N (inorgnic mmonium-nitrogen) (NH4-N) constituted smll portion of the mnure totl N content. Overll, nerly ll of the N in the cttle mnure ws in the orgnic form, with very low concentrtions of NH4-N (Tble 3.2). Tble , 2008 nd 2009 solid cttle mnure composition. Appliction Totl N NH 4 -N Totl P Soluble P Moisture (%) yer µg nutrient g -1 wet mnure (O.D. bsis) Totl N NH 4 -N Totl P Soluble P Appliction rtes of nutrient. Rte: 20 t h -1 (1X) kg h Moisture percentge on n oven dry (O.D.) bsis Field opertions nd plnt nd soil smpling nd nlysis In 2007 nd 2009, ots (Aven stiv, vr Dncer) were seeded (June 18, 2007; My 26, 2009) t rte of 105 kg h -1 using plot seeder with row spcing of 20 cm. On the dy before seeding, plots received n ppliction of glyphoste to control weeds t rte of 0.8 L ctive ingredient h -1. A post emergent ppliction of bromoxnil-mcpa ws mde to control brodlef weeds in erly July. In 2008, cnol (Brssic npus, vr Clerfield) ws seeded on My 18, 2008 t rte of 5.5 kg h -1. An ppliction of imzmox/imzethpyr herbicide to control grssy nd brodlef weeds ws mde on June 10, Plnt smples were collected from the plots in the lst week of August just prior to the producer swthing the ot (2007), cnol (2008) nd ot (2009) crop. Using duplicte 1.0 m 2 qudrts, plnt smples were tken by cutting the stlks pproximtely 5 cm bove the soil surfce, nd returned to the lb where they were dried t 35 C, weighed (totl biomss weight ws recorded), threshed nd clened (seprted into grin nd strw components). The grin nd strw smples were ground using Wiley mill nd 0.25 g smple of ground grin or strw ws digested 25

42 using sulfuric cid-peroxide digestion technique to determine totl P nd totl N concentrtion (Thoms et l., 1967). Soil smples (0-15 cm, cm) were collected from the site in the first week of September of 2007, 2008 nd 2009 following hrvesting opertions nd were obtined using truck-mounted mechnicl soil coring unit. Four seprte cores were tken from ech plot, nd the smples from ech core were bulked ccording to the smpled depth. Smples were extrcted for vilble NO3-N nd NH4-N using 2MKCl (Keeney nd Nelson, 1982) nd vilble P using modified Kelown extrcting solution (Qin et l., 1994) followed by colorimetric ion nlysis using Technicon utomted colorimetry system. Soil ph nd electricl conductivity (EC) were mesured on 2:1 (wter:soil) suspension using Horib meter, nd orgnic crbon (OC) ws mesured using dry combustion method t 840 o C (Wng nd Anderson, 1998) on Leco CR-12 Crbontor Mesurement of surfce soil phosphorus nd nitrogen supply rtes In the 2009 seson, Plnt Root Simultor (PRS ) nion exchnge resin membrne probes were plced into control-disturbed, ure fertilizer, nd 60 t h -1 SCM brodcst lone, brodcst nd incorported nd subsurfce bnded tretment plots over the growing seson from My to August. The first plcement ws mde on My 22, 2009, pproximtely 1-2 dys fter seeding opertions hd been completed in the field. Before the probes were inserted into the soil ech time in the field, deionized wter ws dded to the surfce of the soil (bout 50 ml) to smll re (10 x 10 cm) to bring the surfce of the soil to field cpcity to promote exchnge of ions between soil nd the membrne surfce nd provide consistent moisture content over the mesurement periods (Qin nd Schoenu, 2002). The PRS probes were inserted to encompss depth of soil extending from the surfce to 1 cm below the soil surfce, nd the soil ws re-pcked to obtin good soil to probe contct nd left in situ for 2 h, t which time the probes were removed, bgged, lbeled nd trnsported immeditely bck to the University of Ssktchewn for storge nd nlysis (Fig. 3.3). This procedure ws repeted every two weeks during the growing seson on June 3, June 17, June 30, July 14 nd July 28, After hrvest opertions hd been completed, nother set of nion PRS probes were plced in the designted plots on October 16, Upon rrivl t the lb, the probes were wshed using distilled wter to remove excess soil prticles nd then eluted using 0.5 M HCl (BDH, regent grde). The probe eluent ws then plced in 4 C storge 26

43 until nlysis for the colorimetric determintion of NO3-N nd PO4 P using Technicon utomted colorimetry nlyzer. Fig Photogrph depicting usge of PRS probes to mesure soil P nd N supply Determintion of phosphorus nd nitrogen content nd relese from crop residue Crop residues comprised of stnding stlks nd stlks spred by hrvesting opertions left on the soil surfce fter combine hrvester hd pssed through the plots were collected in October of 2008 from the 60.6 t h -1 SCM rte plcement tretment plots using one squre meter qudrts tht were rndomly plced within ech plot re. The crop residues collected consisted lrgely of cnol residue from the 2008 crop but lso some ot strw residue from The plnt residue smples tht were collected were immeditely frozen nd stored t -20 C. The smples were then thwed, dried nd the biomss ws weighed. A smple of the residue ws retined, dried t 35 C, nd then ground nd digested for totl N nd totl P concentrtion s described for hrvested plnt mteril in section Ech residue smple ws then divided into two seprte portions. One portion ws set side for snow melt leching nd one portion ws set side for wter leching. The crop residues for wter leching were first plced in plstic bg. Then 3.75 L of wter ws dded (equivlent to 7.5 cm of rinwter) nd llowed to sok for 48 hours. After this, the residues were plced in frozen storge t -20 C for 72 h to simulte freeze-thw (Fig. 3.4). After 72 h of frozen conditions, the crop residue smples in the plstic bgs were cut open nd the contents plced into 27

44 plstic collection buckets equipped with plstic colnders to cpture the thwing lechte wter. Fiberglss screen (mesh size 1.40 x 1.10 mm) ws plced between the frozen residue nd the colnder to prevent residue from mixing with the lechte. After thwing, the residues were then dried t 35 o C nd ground nd digested to determine totl N nd P concentrtion s described previously. Fig Photogrph depicting frozen crop residues fter soking in wter for 48 h nd then frozen for 72 h Sttisticl nlysis The three yer SCM study ws nlyzed s rndomized complete block design, with four replictions for crop grin nd strw yield nd nutrient uptke, soil P nd N supply rtes, nd plnt residue totl P nd totl N content. Smple dt ws nlyzed for normlity nd equlity of vrinces using the univrite procedure nd log trnsformed where necessry. Sttisticl comprisons were conducted using the generl liner model procedure using lest significnt difference (LSD,P 0.10) for mens comprison, clculted with SAS Proc GLM (SAS version 9.0, 2008). 28

45 3.5 Results nd Discussion Crop yer: Rte effects on yield In 2007, ots were grown t the Dixon site. There ws significnt (P 0.10) yield response of ots to the ddition of SCM when compring the control tretments to the three SCM ppliction tretments nd the ure fertilizer (Tble 3.3). However, there were no significnt differences in crop yield between the brodcst lone, brodcst nd incorported nd subsurfce bnded SCM tretments. Ot grin yield ws similr in the three SCM tretment brodcst lone, brodcst nd incorported nd subsurfce bnded SCM tretments, verging round 4500 kg h -1. The highest grin yields were observed t the high rte of cttle mnure ddition (3X or 60.6 t h -1 rte) (Tble 3.3). Compred to ure lone, the ddition of cttle mnure lone or in combintion with ure produced similr yield t high rtes of mnure. Tble 3.3. Grin yield in 2007 (ots), 2008 (cnol) nd 2009 (ots) t Dixon, Ssktchewn. Appliction rte ( t h -1 ) (kg h -1 ) Control (1353) 543 (342) 1753 (657) Control-Disturbed (1116) 452 (324) 1846 (551) Brodcst lone Brodcst nd incorported Subsurfce bnded Subsurfce bnded + ure (375) 851 (435) 2614 (362) (347) 857 (277) 2762 (334) (1573) 902 (408) 3594 (535) (929) 995 (426) 2742 (594) (366) 858 (292) 3036 (710) (512) 1171 (313) 3643 (349) (549) 660 (160) 3111 (590) (257) 730 (317) 3848 (542) (709) 1253 (382) 3505 (389) ure 5103 (343) 2014 (362) 3623 (525) ure 4853 (854) 2185 (472) 3908 (342) ure 4909 (570) 1964 (223) 3550 (344) Ure 78 kg N h (281) 1401 (401) 3784 (475) LSD (0.10) Mens in the first column Stndrd devition (±) of the mens in the second column Lest significnt difference t P 0.10 Adding 78 kg N h -1 of ure long with the solid cttle mnure gve the highest yield t the 1X rte (20.2 t h -1 ). Therefore, supplementtion with ure to ccount for the low N vilbility 29

46 of SCM in the yer of ppliction would seem to be good option if one desires to use low rte of SCM to void P loding. Chng nd Jnzen (1996) reported tht even fter 20 yers of nnul SCM pplictions, only 56 % of the totl N pplied with the mnure hd been minerlized, which suggests tht mny pplictions of SCM over very long time period would be necessry to produce significnt effect on crop yield due to reltively low vilbility of the cttle mnure N in the initil yers of ppliction. There were no significnt (P 0.10) differences in ot crop grin yield between the three rte tretments of 20.2, 40.4 nd 60.6 t h -1 of brodcst lone, brodcst nd incorported nd subsurfce bnded SCM tretments dded to the tretment plots (Tble 3.3). Strw biomss in the 2007 ots crop ws significntly (P 0.10) greter in the subsurfce bnded plus ure tretments compred to the control tretments (Appendix B. Tble B.1). Ots through its extensive nd root development cn ccess soil nutrients t greter depths (Mlhi et l., 2002; Mlhi et l., 2006), explining the generl overll lck of lrge response to mnure nd fertilizer ppliction Crop yer: Plcement effects on yield Compring brodcst without incorportion ppliction to brodcst nd incorportion ppliction, the only significnt difference in yield ws observed t the high rte of SCM, with the brodcst without incorportion tretment surprisingly hving higher yield. This my be relted to hot nd dry conditions encountered during the summer of 2007 in which the mount of mnure persisting on the surfce s result of no incorportion my hve reduced surfce tempertures nd helped reduce evportion. Lck of generl benefit of incorportion is lso explined by the low mmonium content of the mnure (Tble 3.2) nd therefore low potentil for voltiliztion losses of the N contined in the mnure. For the sme rte of ppliction, the bnd subsurfce bnded SCM ws not significntly different in yield from the brodcst nd incorporte, or brodcst pplictions Ot crop nutrient concentrtions nd uptke Grin N concentrtions incresed with incresing rte of SCM for the brodcst nd incorported, nd subsurfce bnded tretment, but not for the brodcst without incorportion tretment (Tble 3.4) Higher concentrtions of nutrient in plnt mteril re reflective of greter nutrient vilbility in the soil (Hvlin et l., 2014). Lower plnt N concentrtions for the brodcst 30

47 without incorportion thn the other tretments indictes lower N recovery for SCM when brodcst thn when incorported or subsurfce bnded. The subsurfce bnded SCM hs grin N nd strw N concentrtions (Appendix B. Tble B.3), tht re similr or slightly bove the brodcst nd incorporte tretments, nd significntly higher thn the brodcst without incorportion. A similr trend ws noted for P concentrtion in grin nd strw (Appendix B, Tble B.2), with highest P concentrtion in the grin from the subsurfce bnded tretment (Tble 3.5). Overll, there were not lrge differences in grin nd strw nutrient concentrtions between brodcst nd incorported nd the subsurfce bnded tretments. The highest grin nd strw N (Appendix B, Tble B.3) concentrtions were found in tretments where ure ws dded long with the SCM. Tble 3.4. Grin nitrogen concentrtions (µg N g -1 of dry mtter) in 2007 (ots), 2008 (cnol) nd 2009 (ots) t Dixon, Ssktchewn. Appliction rte ( t h -1 ) (µg g -1 ) Control (853) (2857) (646) Control-disturbed (638) (7433) (1023) Brodcst lone Brodcst nd incorported Subsurfce bnded Subsurfce bnded + ure (805) (2393) (1122) (224) (2269) (448) (597) (6002) (1813) (945) (641) (792) (835) (3543) (1246) (1344) (5938) (1018) (1156) (1824) (794) (1512) (743) (912) (1249) (788) (1657) ure (1325) (4750) (1657) ure (1190) (1619) (898) ure (908) (4090) (475) Ure 78 kg N h (1001) (1835) (700) LSD (0.10) Mens in the first column Stndrd devition (±) of the mens in the second column Lest significnt difference t P

48 Tble 3.5. Grin phosphorus concentrtions (µg P g -1 of dry mtter) in 2007 (ots), 2008 (cnol) nd 2009 (ots) t Dixon, Ssktchewn. Appliction rte ( t h -1 ) (µg g -1 ) Control (244) 6367 (164) 3832 (731) Control-disturbed (150) 6638 (265) 3337 (225) 2009 Brodcst lone Brodcst nd incorported Subsurfce bnded Subsurfce bnded + ure (300) 6584 (243) 3598 (154) (108) 7117 (234) 3576 (51) (377) 7168 (560) 3616 (270) (287) 6927 (149) 3429 (129) (410) 6985 (142) 3649 (145) (300) 7121 (224) 3612 (136) (450) 6635 (286) 3433 (158) (287) 7004 (241) 3562 (228) (377) 7061 (122) 3604 (140) ure 3825 (150) 6642 (574) 3742 (148) ure 4050 (173) 7192 (177) 3660 (149) ure 3975 (287) 7527 (450) 3697 (153) Ure 78 kg N h (150) 5715 (352) 3425 (130) LSD (0.10) Mens in the first column Stndrd devition (±) of the mens in the second column Lest significnt difference t P Soil properties in fll of 2007 Cttle mnure ddition cused some smll but non-significnt increses in EC (slinity) t the 0-15 cm depth (Tble 3.6). There ws no significnt effect of ppliction method on the EC. The soil ph (0-15 cm depth) ws not significntly ffected by tretment (Tble 3.6). The OC concentrtion in the 0-15 cm depth incresed with ppliction of mnure, for ll methods of ppliction nd ure fertilizer ppliction. However, there ws no significnt effect of mnure plcement on soil OC (Tble 3.6). 32

49 Tble 3.6. Soil ph, electricl conductivity nd orgnic crbon (0-15 cm depth) t Dixon, Ssktchewn. Appliction rte ph Electricl conductivity Orgnic crbon ( t h -1 ) (ms cm -1 ) (%) Control Control-disturbed Brodcst lone Brodcst nd incorported Subsurfce bnded Subsurfce bnded + ure ure ure ure Ure 78 kg N h The Modified Kelown (MK) extrctble P (0-15cm) ws significntly incresed by the single cttle mnure ppliction (Tble 3.7). The MK extrctble P incresed from bout 14 kg P h -1 to greter thn 60 kg P h -1 t the highest rtes of ppliction. Below 15 cm, no significnt increses in extrctble P were observed (Appendix B. Tble B.4). The lrge increse in soil test P from single ppliction is consistent with the high P content of this mnure which hd greter impct on vilble P thn tht observed on similr soil from single ppliction of LHM with lower P content (Qin nd Schoenu, 2000). For the sme rte of ppliction, the brodcst lone nd brodcst with incorportion tretments resulted in very similr MK extrctble P vlues in the 0-15 cm depth. Of note is tht the high rte (3X or 60.6 t h -1 ) of subsurfce bnded SCM produced significntly higher MK extrctble P thn the high rte of brodcst without, nd with, incorportion. This suggests tht there my be better soil dsorption of P with subsurfce bnded SCM when pplying t high rtes. 33

50 Tble 3.7. Soil extrctble phosphorus (0-15 cm depth) t Dixon, Ssktchewn. Appliction rte ( t h -1 ) (kg h -1 ) Control (5.0) 23.4 (20.0) 18.3 (11.8) Control-disturbed (3.2) 23.5 (9.6) 19.8 (6.6) 2009 Brodcst lone Brodcst nd incorported Subsurfce bnded Subsurfce bnded + ure (10.2) 42.3 (21.4) 62.3 (26.7) (12.8) 77.0 (23.2) (66.4) (17.6) (51.1) (36.8) (5.1) 68.4 (21.1) 70.0 (27.4) (8.5) 93.4 (37.0) (58.3) (18.0) 93.3 (73.7) (20.6) (5.4) 26.3 (10.1) 42.3 (16.7) (42.4) (109.6) (122.4) (79.1) (73.6) (127.3) ure 21.7 (7.3) 50.1 (30.6) (91.6) ure 26.2 (15.3) 46.7 (11.4) (98.1) ure 85.3 (60.4) 75.0 (27.6) (78.5) Ure 78 kg N h (2.6) 38.3 (52.4) 30.4 (19.1) LSD (0.10) Mens in the first column Stndrd devition (±) in the second column Lest significnt difference t P 0.10 The residul soil nitrte in the fll of 2007 ws generlly low, with not much difference between the mnured tretments, except for the 60.6 t h -1 rte subsurfce bnded nd subsurfce bnded plus ure tretments (Tble 3.8). There ws significnt (P 0.10) differences between the control tretment nd high (60 t h -1 ) rte SCM tretments, reflecting low relese of vilble N from 20.2 t h -1 rte SCM tretments in the yer of ppliction. There ws no significnt rte effect nd little difference in residul soil NO3-N (Tble 3.8) nd NH4-N (Tble 3.9) content mong plcement methods. There ws no significnt rte effect nd little difference in residul soil NO3- N (Tble 3.8) nd NH4-N (Tble 3.9) content mong plcement methods in the cm depth (Appendix B. Tble B.5 nd Tble B.6). Overll, the highest residul nitrte contents were observed in the high rte of subsurfce bnded cttle mnure plus ure tretment. 34

51 Tble 3.8. Soil extrctble nitrte-nitrogen (0-15 cm depth) t Dixon, Ssktchewn. Appliction rte ( t h -1 ) (kg h -1 ) Control (2.1) 5.7 (2.3) 6.6 (2.0) Control-disturbed (1.1) 5.5 (1.7) 4.6 (0.4) Brodcst lone Brodcst nd incorported Subsurfce bnded Subsurfce bnded + ure (2.6) 6.9 (4.3) 7.6 (2.5) (1.5) 7.3 (1.2) 9.5 (3.0) (1.7) 11.1 (1.9) 10.3 (1.6) (1.3) 10.7 (2.7) 6.5 (1.3) (1.6) 9.9 (2.4) 7.3 (0.9) (1.7) 9.1 (5.2) 9.0 (1.7) (0.8) 6.3 (1.3) 5.9 (0.7) (0.4) 7.9 (3.3) 7.8 (1.9) (3.5) 9.7 (4.3) 11.4 (3.5) ure 8.2 (1.7) 10.5 (1.7) 8.5 (1.5) ure 11.5 (3.4) 11.4 (3.0) 12.7 (3.2) ure 17.0 (4.6) 15.5 (1.4) 15.0 (7.3) Ure 78 kg N h (5.5) 11.2 (3.7) 7.5 (1.4) LSD (0.10) Mens in the first column Stndrd devition (±) in the second column Lest significnt difference t P

52 Tble 3.9. Soil extrctble mmonium-nitrogen (0-15 cm depth) t Dixon, Ssktchewn. Appliction rte ( t h -1 ) (kg h -1 ) Control (2.8) 12.7 (2.7) 7.6 (2.3) Control-disturbed (3.5) 13.1 (3.8) 8.3 (1.2) 2009 Brodcst lone Brodcst nd incorported Subsurfce bnded Subsurfce bnded + ure (2.3) 10.9 (2.5) 7.7 (3.4) (3.6) 15.0 (6.2) 7.7 (1.6) (1.6) 10.6 (3.3) 7.1 (1.7) (1.9) 11.8 (2.7) 7.5 (2.0) (2.6) 10.9 (3.7) 6.6 (1.1) (2.1) 10.9 (3.2) 8.2 (1.9) (2.9) 11.9 (3.0) 6.3 (0.8) (3.1) 8.2 (3.9) 7.7 (1.6) (1.4) 12.7 (1.5) 9.5 (4.2) ure 5.9 (1.9) 11.5 (4.3) 7.5 (1.7) ure 7.5 (2.8) 13.2 (1.9) 7.4 (2.2) ure 7.2 (3.8) 10.6 (4.2) 7.0 (1.1) Ure 78 kg N h (2.3) 15.7 (1.6) 8.5 (1.0) LSD (0.10) Mens in the first column Stndrd devition (±) in the second column Lest significnt difference t P Crop yer: Rte effects on yield In 2008, cnol ws grown t the site. Compred to the non-mnured, unfertilized control tretments, mnure nd ure ddition incresed cnol grin yield (Tble 3.3). The 60.6 t h -1 subsurfce bnded rte tht produced significntly (P 0.10) higher yield thn the 20.2 nd 40.4 t h -1 in the brodcst nd incorported subsurfce bnded tretments. The gretest tretment effect ws observed for the combintion of ure plus subsurfce bnded solid cttle mnure. The greter response of cnol yield to tretments observed in 2008 s compred to ot yield in 2007 could be explined by the greter N nutrient requirement of cnol compred to ots (Mlhi et l., 2008). The tretments of 78 kg N h -1 s ure plus subsurfce bnded cttle mnure resulted in significntly higher cnol yields thn the other tretments, including ure lone. The benefit of the combined SCM nd ure is ttributed to ure providing dditionl plnt vilble N, long with other nutrients tht the SCM supplies such s P nd sulfur. Cnol strw biomss ws significntly (P 0.10) greter in the subsurfce bnded plus ure fertilizer tretments compred to the 36

53 brodcst lone, brodcst nd incorported SCM tretments nd the control tretment (Appendix B. Tble B.1). Mooleki et l. (2004) reported tht spring ppliction of SCM t different rtes using brodcst nd incorportion ppliction, on Blck Chernozemic soil t Humboldt, Ssktchewn, resulted in no significnt yield increse for the cnol crop. The uthors reported tht the SCM in their study contined limited vilble NH4-N nd high C:N rtio tht restricted minerliztion potentil in the yer of ppliction. Subsequent yers of SCM ppliction did result in n increse in cnol grin yield which the uthors ttributed to relese of vilble N over time (Mooleki et l., 2004). In the second yer of the current study with only one previous ppliction of SCM, there would hve been little residul vilble N for the cnol crop to utilize. When SCM ws subsurfce bnded with ure, the vilble N in the fertilizer llowed for greter cnol crop yield response, compred to the brodcst lone, brodcst nd incorported nd subsurfce bnded SCM tretments in 2008 (Tble 3.3). The plcement of SCM in concentrted bnd with ure my potentilly enhnce microbil ctivity to relese more nutrient contined in the mnure to increse the cnol crop yield. When compred to the crop yield obtined with the ure fertilizer lone, the ddition of SCM, despite there being no rte effect, did increse grin yield (Tble 3.3) Crop yer: Plcement effect on yield There ws n impct in 2008 of the SCM plcement on cnol yield with in-soil plcement (brodcst nd incorporte, subsurfce bnded) hving higher yield thn brodcst t the 60.6 t h -1 ppliction rte (Tble 3.3). However t lower rtes there ws no significnt influence of plcement method. The subsurfce bnded tretment when combined with redily vilble N from the ure fertilizer significntly (P 0.10) incresed cnol grin yield. As in 2007, the lck of benefit of SCM incorportion or subsurfce bnding is likely relted to the low NH4 content of the SCM nd low potentil for voltiliztion losses of the N contined in the mnure. The high 60.6 t h -1 SCM rte in the brodcst nd incorported, subsurfce bnded produced higher grin yields while ll three SCM ppliction rtes in the subsurfce bnded plus ure ppliction method tretments produced the highest overll grin yields (Tble 3.3). 37

54 Cnol crop nutrient concentrtions nd uptke Cnol grin N content ws only slightly incresed by cttle mnure ppliction, reflecting the reltively low vilbility of N contined in the SCM (Tble 3.4). Both grin P nd strw P (Appendix B. Tble B.2) were significntly incresed, reflecting the significnt contribution of SCM P to plnt vilble P in the soil (Tble 3.7) (Qin nd Schoenu, 2000). At the 20.2 t h -1 SCM rte, grin nd strw N (Appendix B. Tble B.2) concentrtion tended to be higher for brodcst nd incorported nd subsurfce bnded SCM tretments thn brodcst only tretment, indicting greter recovery of N from in-soil plcement, s hs been observed in previous trils with liquid swine mnure (Mooleki et l., 2002). This trend ws lso observed in This effect however, ws not observed t higher rtes. The 40.4 nd 60.6 t h -1 SCM rte for brodcst lone, brodcst nd incorported, subsurfce bnded nd subsurfce bnded plus ure tretment hd the highest plnt P concentrtions while the subsurfce bnded SCM plus ure tretment produced the highest plnt N concentrtions (Tble 3.4) Soil properties in fll of 2008 As in 2007, soil ph nd slinity in 2008 were not significntly ffected by SCM rte or plcement (Tble 3.6). As well, similr to the previous yer, the OC concentrtion in the 0-15 cm ws ffected by SCM ppliction, ppliction rte nd method of plcement (Tble 3.6). Mnure ppliction resulted in significnt increses in MK extrctble P gin in the fll of 2008 (Tble 3.7). After two successive mnure pplictions, the generl trend for soil test P vlues ws to increse compred to fll of 2007, with vlues of ~150 kg extrctble P h -1 present in the 3X tretments. There were no discernible effects of plcement. Of the 60.6 t h -1 tretments, the brodcst nd the subsurfce bnded tretments hd higher soil test P thn the brodcst nd incorported in the 0-15 cm depth (Tble 3.7). Adding ure to the subsurfce bnded mnure reduced the soil test P levels in the fll, presumbly due to greter yield nd mnure P utiliztion by the crop. Extrctble potssium levels were lso nerly doubled. The soil NO3-N levels in the fll of 2008 tended to increse slightly with ppliction rte, nd, s in 2007, they were generlly low. Also, gin plcement hd no significnt effect on soil NO3-N (Tble 3.8) nd tended to depress NH4-N (Tble 3.9) in the 0-15 cm depth. Soil NO3-N level in the subsurfce bnded plus ure 60.6 t h -1 SCM tretment ws significntly (P 0.10) 38

55 greter thn the control, brodcst lone nd brodcst nd incorported tretments in the cm depth (Appendix B. Tble B.4) Crop yer: Rte effects on yield As in 2007 nd 2008, SCM ppliction tretments were mde on the plots in spring of 2009 nd ots were grown. A significnt (P 0.10) ot grin yield response to mnure ddition tretments compred to the non-mnured, unfertilized control tretments ws observed gin in 2009 (Tble 3.3), s for the crops in previous yers. Unlike in 2007 nd 2008, there ws rte effect in ot yield response in 2009, with the 3X (60.6 t h -1 ) mnure tretments producing significntly (P 0.10) higher ot yield thn the 20 t h -1 low rte (Tble 3.3). There ws response to the supplementl ddition of ure t the 20.2 t h -1 (1X) rte of mnure, but not t the 40.4 t h - 1 (2X) or 60.6 t h -1 (3X) rtes. Since 2009 represents the third consecutive yer on which mnure ws pplied t these rtes, it ppers tht greter minerliztion of ccumulted orgnic N in the soil is now tking plce t the 40.4 nd 60.6 t h -1 mnure rtes to meet the crop nutrient requirements, especilly t the 60.6 t h -1 rte of ddition. The 20 t h -1 mnure tretments continue to yield less thn the ure tretments, suggesting tht the supply of N from the nnul ppliction of 20.6 t h -1 for 3 yers is not yet sufficient to meet crop N requirements Crop yer: Plcement effects on yield For the effects of plcement on ot grin yield in the lst yer of the study, 2009, the surfce brodcst nd the brodcst nd incorportion tretments t the sme rte of cttle mnure hd similr yield (Tble 3.3). However, there ws trend for the subsurfce bnded mnure to yield slightly higher thn the brodcst lone, nd brodcst nd incorporte tretments, especilly t the 40 t h -1 SCM rte (2X) of mnure ddition. In previous yers (2007 nd 2008), there ws no pprent benefit to subsurfce bnding (Tble 3.3). A possible reson for benefit tht ppers in yer three of the experiment is tht the subsurfce bnding hs hstened the decomposition nd relese of vilble nutrients through minerliztion. Plcement of crop residues in contct with soil is well known to enhnce decomposition rtes (Cmpbell et l., 2007) nd the lower degree of surfce strtifiction of nutrient in the subsurfce bnded tretment, s the mnure is concentrted 39

56 in bnd cm below the surfce, my lso be fvorble in reducing voltile losses of gseous N to the tmosphere s mmoni during mnure decomposition Ot crop nutrient concentrtions nd uptke Grin nd strw N concentrtions were incresed by ppliction of cttle mnure, s observed in the previous two yers (Tble 3.4). The grin N concentrtions in the bnded tretment tended to be higher or similr to the brodcst nd the brodcst nd incorporte tretments, following trends observed in 2007 nd The higher plnt N concentrtions long with the higher yields noted for subsurfce bnding, especilly t the 1X (20.2 t h -1 ) rte, indicte tht injection is providing some benefit in enhncing crop uptke nd recovery of mnure N, possibly by reducing mmoni voltiliztion losses or enhncing decomposition to vilble forms. The plnt P concentrtions were less ffected by mnure ppliction thn in 2008, likely result of the greter bility of ots to scvenge soil P compred to cnol (Tble 3.5) Soil properties in fll of 2009 Some smll increses in EC were noted with mnure ppliction, reflecting the slts dded in the mnure, but there ws no evidence of ny slinity build-up (Tble 3.6) tht would cuse injury to ny crop, s EC vlues > 1 ms cm -1 re generlly required to be of concern in mnured soils (Jpp, 2007). As well, similr to the previous two yers in this study, the OC concentrtion in the 0-15 cm depth incresed with ppliction rte for brodcst lone nd brodcst nd incorported SCM methods of ppliction (Tble 3.6). There ws no significnt effect of plcement on ph, EC or OC concentrtion in the 0-15 cm depth (Tble 3.6). The soil test MK P incresed from 18.3 kg P h -1 t the 0-15 cm depth in the unfertilized control to > 200 kg P h -1 in the 3X (60.6 t SCM h -1 ) tretment (Tble 3.7). This is explined by the lrge mount of mnure P, clculted to be ~ 500 kg P h -1, tht ws dded to the soil in this tretment over the three yers. These results gin demonstrte tht build-up of soil P cn occur with cttle mnure ddition even over reltively short time periods when nnul ppliction rtes re high. Mnure plcement method ppered to hve reltively little influence on extrctble P in the 0-15 cm depth (Tble 3.7). The significntly greter extrctble P level in the cm depth t high ppliction rtes, could be due to smll mount of P moving below the 0-15 cm depth into the cm depth by leching (Appendix B. tble B.4). 40

57 The soil NO3-N levels in the 0-15 cm depth incresed with mnure ppliction, nd generlly incresed with incresing rte (Tble 3.8), however, the mount of nitrte in the soil, even t the 60.6 t h -1 yr -1 rte, ws still low (< 15 kg NO3-N h -1 ). Also there ws no evidence of significnt movement of nitrte below the 15 cm depth into the cm (Appendix B. Tble B.5), except for slight elevtion t the high rtes of the subsurfce bnded mnure plus ure tretment. The lrgest impct of mnure ddition observed in this study ws on soil extrctble P levels. These were gretly incresed by ddition of mnure (Tble 3.7) Soil phosphorus nd nitrogen supply rtes in the 2009 seson Soil PO4-P nd NO3-N supply rtes were mesured during the growing seson from the beginning of June to the end of July, 2009 in the surfce lyer of soil using PRS probes. Soil P nutrient supply ws ssessed in the control tretment nd the 60.6 t h -1 (high rte) SCM brodcst lone, brodcst nd incorported, nd subsurfce bnded SCM tretment plots nd the ure fertilizer lone tretment (Fig. 3.5). Soil PO4-P supply rtes were significntly (P < 0.10) higher in mnure mended soils thn in the control tretment for ll mesurement periods (Fig. 3.5). Ure lone tretment lso hd slightly higher supply rtes of PO4-P thn the control, which ws significnt t two mesurement times. This my reflect some stimulted biologicl ctivity induced by the ure. Sustined soil PO4-P supply rtes in the top 1cm of soil throughout the smpling period to the end of July suggests continued P mobiliztion from the mnure but my lso reflect limited plnt removl of P from the top 1 cm of soil by roots. The soil P supply rte ws significntly ffected by SCM plcement method (Figure 3.5). Significntly higher soil P supply rtes were observed for surfce brodcst plcement thn for brodcst nd incorportion nd subsurfce bnding. 41

58 Control-disturbed Brodcst lone 60 t h-1 Brodcst nd incorported 60 t h-1 Subsurfce bnded 60 th-1 Ure 78 kg N h-1 Control-disturbed Brodcst lone 60 t h-1 Brodcst nd incorported 60 t h-1 Subsurfce bnded 60 th-1 Ure 78 kg N h-1 Control-disturbed Brodcst lone 60 t h-1 Brodcst nd incorported 60 t h-1 Subsurfce bnded 60 th-1 Ure 78 kg N h-1 Control-disturbed Brodcst lone 60 t h-1 Brodcst nd incorported 60 t h-1 Subsurfce bnded 60 th-1 Ure 78 kg N h-1 Control-disturbed Brodcst lone 60 t h-1 Brodcst nd incorported 60 t h-1 Subsurfce bnded 60 th-1 Ure 78 kg N h-1 Phosphte supply (ug cm -2 ) d bc b c d bc b cd c b b d b b c June 3 LSD (0.10) = 0.27 June 17 LSD (0.10) = 0.28 June 30 LSD (0.10) = 0.30 July 14 LSD (0.10) = 0.25 July 28 LSD (0.10) = 0.55 d b c d Jun-03 Jun-17 Jun-30 Jul-14 Jul-28 Tretment & smpling dte Fig Soil phosphte-phosphorus supply rtes mesured in the surfce soil by Plnt Root Simultor nion exchnge membrne probes in 2009 t Dixon, Ssktchewn. Mens followed by the sme letter re not significntly different for tht smpling dte. Error brs denote stndrd devition of the men. Subsurfce bnding tretment hd the lowest soil PO4-P supply rtes in the surfce soil t the middle nd end mesurement times. This could be due to the SCM P tht ws bound in the subsurfce bnd, mking it less vilble for plnt P supply. The soil supply of PO4-P in the brodcst lone SCM tretment is ttributed to the SCM in this tretment being pplied on the soil surfce without incorportion. By the lst smpling dte of July 28 th, soil supply of PO4-P in the brodcst nd incorported nd subsurfce bnded tretments hd incresed compred to the mounts mesured in the four erlier smpling dtes (Fig. 3.5). This could reflect the brekdown nd decomposition of the SCM potentilly due to n increse in soil temperture nd the relese of the P nutrient contined in the mnure into exchngeble orthophosphte forms s noted with LHM in previous study (Qin nd Schoenu, 2000). The surfce soil NO3-N supply diminished s the crop yer progressed into summer (Fig. 3.6). 42

59 Control-disturbed Brodcst lone 60 t h-1 Brodcst nd incorported 60 t h-1 Subsurfce bnded 60 th-1 Ure 78 kg N h-1 Control-disturbed Brodcst lone 60 t h-1 Brodcst nd incorported 60 t h-1 Subsurfce bnded 60 th-1 Ure 78 kg N h-1 Control-disturbed Brodcst lone 60 t h-1 Brodcst nd incorported 60 t h-1 Subsurfce bnded 60 th-1 Ure 78 kg N h-1 Control-disturbed Brodcst lone 60 t h-1 Brodcst nd incorported 60 t h-1 Subsurfce bnded 60 th-1 Ure 78 kg N h-1 Control-disturbed Brodcst lone 60 t h-1 Brodcst nd incorported 60 t h-1 Subsurfce bnded 60 th-1 Ure 78 kg N h-1 Nitrte-nitrogen supply rte (ug cm -2 ) June 3 LSD (0.10) = 0.45 June 17 LSD (0.10) = 0.68 June 30 LSD (0.10) = 2.02 July 14 LSD (0.10) = 0.36 July 28 LSD (0.10) = c bc b c b b b b b b b b b b b b b Jun-03 Jun-17 Jun-30 Jul-14 Jul-28 Tretment nd smpling dte Fig Soil nitrte-nitrogen supply rtes mesured in the surfce soil by Plnt Root Simultor nion exchnge membrne probes in 2009 t Dixon, Ssktchewn. Mens followed by the sme letter re not significntly different for tht smpling dte. Error brs denote stndrd devition of the men. This reflects the consumption of nitrte by the crop, s nitrte is mobile nd will move with wter by mss flow to roots t depth. The spike in NO3-N supply on June 30 my be explined by lrge rin event prior to the June 30 th smpling dte tht my hve enhnced minerliztion nd nitrifiction of the SCM orgnic nitrogen (Fig. 3.6). For the most prt, erly on in the growing seson the mnure nd ure tretments hd significntly higher NO3-N supply rtes thn the nonmnured, unfertilized control. In-soil plcement tretments tended to hve lower nitrte supply erly on in the seson but by the end the subsurfce bnded hd slightly but significntly higher nitrte supply rte in the surfce soil (Fig. 3.6). The high C:N rtio of SCM would slow minerliztion potentil initilly, however, greter moisture nd microbil decomposition rising from plcement in the soil my ccelerte the immobiliztion reminerliztion (Dorn, 1980). 43

60 Residue totl phosphorus (ug g -1 ) Relese of phosphorus nd nitrogen from cnol residues Above ground cnol plnt residue collected fter hrvest opertions ws not significntly (P 0.10) different mong tretments in totl P concentrtion. This ws the cse for both unleched nd leched (residue immersed in wter nd frozen for 24 hours) residues (Fig. 3.7). There ws found to be decrese in totl P concentrtion s result of the leching-freezing tretment of the residue in ll tretments bsed on comprison of the unleched to the leched plnt residues (Fig. 3.7) LSD (0.10) Leched = LSD (0.10) Unleched = A A A A A Leched Unleched Leched Unleched Leched Unleched Leched Unleched Leched Unleched Control-disturbed Brodcst lone Brodcst nd incorported Subsurfce bnded Ure Tretment Fig Cnol plnt fter-hrvest residue totl phosphorus concentrtions in 2008 t rte of 60 t h -1 for the brodcst lone, brodcst nd incorported nd subsurfce bnded solid cttle mnure tretments nd rte of 78 kg N h -1 for the ure pplied tretment t Dixon, Ssktchewn. Mens followed by the sme letter re not significntly different t P Error brs denote stndrd devition of the men. Unlike the strw nd grin P concentrtions in the hrvested cnol smples, the P concentrtions in the residue collected from the mnure tretments ws not significntly higher thn the non-mnured control. This suggests tht some P my lredy hve been lost from the 44

61 residue in the time period from hrvest t the end of August to the time of residue collection in October. As such, there ws lck of detectble mnure plcement effect on cnol residue P content. Similr to P, there were no significnt (P 0.10) differences in residue totl N contents mong tretments for both unleched nd leched (immersed in wter nd frozen for 24 h) residues (Fig. 3.8). The leched nd frozen residues hd pprently lost the equivlent of bout 1000 µg g - 1 totl N in the three SCM tretments s result of the leching nd freezing. Overll the mgnitude of reduction in N content of the residues ws less thn observed for P. This is explined by higher proportion of P in wter soluble form in crop residue s compred to N, where more of the N is bound in orgnic forms tht re not esily removed by wter (Qin nd Schoenu, 1995). In corn, soyben nd whet residue leching study conducted on Nebrsk field receiving niml mnure, residues tht were collected nd subjected to ddition of wter in lb over period of time reveled tht type of residue nd residue/wter contct time ffected the leching nd sorption of P nd N (Cermk et l., 2004; Schnepf nd Cox, 2006). 45

62 Residue totl nitrogen (ug g -1 ) LSD (0.10) Lecxhed = LSD (0.10) Unleched = A A A A A Leched Unleched Leched Unleched Leched Unleched Leched Unleched Leched Unleched Control-disturbed Brodcst lone Brodcst nd incorported Subsurfce bnded Ure Tretment Fig Cnol plnt fter-hrvest residue totl nitrogen in 2008 t rte of 60 t h -1 for the brodcst lone, brodcst nd incorported nd subsurfce bnded solid cttle mnure tretments nd rte of 78 kg N h -1 for the ure pplied tretment t Dixon, Ssktchewn. Mens followed by the sme letter re not significntly different t P Error brs denote stndrd devition of the men. The uthors reported tht whet residues sorbed PO4-P t greter rtes, s the time of immersion in wter incresed, while for corn nd soyben residues the PO4-P leching incresed s immersion time incresed. Although there ws no differences between SCM tretments in mount of P nd N in cnol plnt residues tht were subjected to leching, the N nd especilly P content in leched residues ws lower thn unleched residues, indicting tht the fresh residues relesed considerble mounts of these nutrients fter being subjected to one time leching event. 46

63 3.6 Conclusion Rte of mnure ppliction nd ppliction method hd limited effect on enhncing crop yields nd nutrient uptke over the 2007, 2008 nd 2009 growing sesons t the Dixon site. Mnure ppliction incresed yields over the non-mnured, unfertilized controls, but the effect of incresing rte nd plcement methods ws usully not significnt. In-soil plcement through incorportion or subsurfce bnding resulted in higher cnol yield thn brodcst lone in 2008 nd in the finl yer of the study in 2009, subsurfce bnding produced higher ot yield thn other plcement methods but only t the 40.4 t h -1 rte. Addition of ure fertilizer long with mnure resulted in the gretest yield benefits. The high content of orgnic N nd very low plnt vilble NH4-N kept more of the N in plnt unvilble form. Overll, while SCM ppliction cn enhnce crop yields t the rtes tht were evluted, better responses my be nticipted for high nutrient requiring crops like cnol when the mnure is combined with commercil N fertilizer. A lck of crop removl of P nd N could potentilly increse the potentil for lterl nd/or verticl movement of these nutrients. Subsurfce bnding of SCM or incorportion of brodcst mnure did not generlly produce lrge significnt gronomic benefits in yield nd nutrient content compred to brodcsting lone. Although no economic nlysis ws conducted regrding subsurfce bnding, it likely to be more expensive to subsurfce bnd SCM s opposed to brodcst lone nd/or brodcst nd incorporte. Mnure mendment nd plcement method hd more pronounced effect on soil P thn N, consistent with its higher content of P, prticulrly soluble P. Soil P supply ws gretly incresed by SCM mendment nd t the end of the three-yer period surfce soil P supply rtes mesured over the seson were significntly higher in brodcst lone tretments compred to in soil plcement vi incorportion or subsurfce bnding. Observed loss of P from crop residues by wter leching could be significnt mechnism tht my lso influence the degree to which P is trnsported off site. However, the ppliction of mnure nd its plcement did not ffect the mount of P or N removed from post-hrvest cnol crop residue in simulted leching. It would seem tht perhps the interction of the run-off wter with the minerl soil itself, s simulted in the PRS probe mesurement, could be more importnt potentil influence of plcement. The impct of mnure ppliction nd plcement on trnsport in wter is covered in subsequent chpters in this thesis. 47

64 4. RELATIONSHIP BETWEEN MANURE MANAGEMENT APPLICATION PRACTICES AND PHOSPHORUS AND NITROGEN EXPORT IN SNOWMELT RUN-OFF WATER FROM A BLACK CHERNOZEM 4.1 Prefce Appliction of niml mnures to griculturl fields ws shown to be n effective prctice for incresing soil fertility nd crop yield s reveled in the study reported on in Chpter 3. However, the environmentl effects of repeted mnure pplictions on surfce nd groundwter qulity cn be detrimentl if excessive mounts of mnure-derived phosphorus (P) nd nitrogen (N) re trnsported by overlnd flow or leched s result of high moisture events such s spring snowmelt. Excess nutrients contined in the niml mnure pplied tht re not tken up by the growing crop or dsorbed to soil constituents cn become non-point source pollutnt for surfce nd/or subsurfce wter bodies. The reserch conducted in this chpter (Chpter 4) ddresses specificlly the reltionship between mnure mngement prctices nd the mount of phosphorus nd nitrogen trnsported off the soil in simulted snowmelt run-off. Plcement of solid cttle mnure (SCM) in concentrted subsurfce bnd my reduce potentil for surfce runoff trnsport due to positioning of the mnure nutrient further wy from the surfce flow. However, this effect my be offset by enhnced decomposition of the SCM nd relese of soluble rective phosphorus (SRP), s well s providing subsurfce chnnel for lterl movement of nutrient below the surfce. The reserch described in this chpter uses novel method of simulting snowmelt wter trnsport s ffected by mnure plcement (brodcst, brodcst nd incorporte, subsurfce bnd), type such s SCM nd liquid hog mnure (LHM) nd rte tretments imposed in smll plot replicted trils in est-centrl Ssktchewn. An intct slb of soil is removed nd exposed to simulted snowmelt run-off under controlled environment conditions, with two common spring melting regimes exmined: thwing nd frozen soil surfce. 48

65 4.2 Abstrct In Ssktchewn, soil nutrients relesed from lnd-pplied solid cttle mnure (SCM) nd liquid hog mnure (LHM) could be subject to off-field export vi spring surfce run-off wter nd/or subsurfce leching from melting snow. The objective of this study ws to determine how the plcement of SCM nd LHM using surfce nd subsurfce ppliction methods ffects the mounts of soluble rective phosphorus (SRP), nitrte-nitrogen (NO3-N) nd mmonium nitrogen (NH4-N) exported in simulted snowmelt run-off. Intct soil slbs were collected post-hrvest in Oct nd Oct from n nnully cropped Blck Chernozem in est-centrl Ssktchewn hving tretments of: 1) control, with no SCM or ure fertilizer dded nd 2) SCM pplied t rte of 60.6 t h -1 for 2 yers s: surfce brodcst, brodcst nd incorported nd subsurfce bnded. For comprison purposes, intct soil slb monoliths were collected post-hrvest in Oct from n nnully cropped Blck Chernozem in est-centrl Ssktchewn hving tretments of: 1) control, with no LHM or ure fertilizer dded; 2) LHM brodcst nd incorported t rte of 37,000 L h -1 for 12 yers; nd 3) LHM subsurfce bnded t rtes of 37,000 L h -1 nd 148,000 L h -1 for 12 yers. Run-off wter nd lechte were collected under two different simulted pririe spring melt conditions: 1) thwing soil slbs contining snow tht slowly melted on the surfce; nd 2) frozen soil slbs with run-off wter pplied to the surfce nd llowed to run-off cross the frozen soil surfce. Export of SRP in the thwing soil slbs tht hd SCM pplied in subsurfce bnds ws 0.51 kg P h -1 nd ws significntly higher thn the non-mnured control (0.07 kg P h -1 ). Dissolved NO3-N exported in wter running cross the frozen soil slbs ws highest in the brodcst nd incorported tretment (0.30 kg N h -1 ). All SCM mnured tretments hd higher export of nitrte ( kg NO3-N h -1 ) compred to the non-mnured control (0.07 kg h -1 ). There ws no significnt (P 0.10) effect of plcement method on SRP, NO3-N nd NH4- N export on thwing or frozen SCM soil slbs. Export of SRP ws less in LHM tretments thn SCM tretments. In thwing soil slbs with 148,000 L h -1 LHM tretment, the P export ws 0.05 kg P h -1 nd ws greter thn the control tretment (0.01 kg h -1 ). Rte of ppliction nd mnure type ppers to be more importnt thn method of plcement in influencing P nd N trnsport in melt wter on these soils. 49

66 4.3 Introduction Appliction of niml mnure for its nutrient content nd bility to id in building soil orgnic mtter is common prctice in western Cnd in loctions where niml mnures re bundnt. Nutrients such s phosphorus (P) nd nitrogen (N) in mnures cn be effectively utilized for crop production. However, in soils receiving lrge ppliction rtes of niml mnures, elevted trnsport of dissolved nd prticulte P nd N off-field by wter cn be of concern in soils tht become overloded in these nutrients. For exmple, since the 1980s; the helth of Lke Winnipeg hs decresed due to excessive dissolved P nd N loding from non-point sources including nturl ecosystems, urbn sources, tmospheric deposition s well s surrounding griculturl systems (Lke Winnipeg Stewrdship Bord, 2006). Beneficil mngement prctices hve been identified in n ttempt to reduce the excess nutrients exported offsite to surfce nd subsurfce wter bodies (Schnepf nd Cox, 2006). Much ttention hs been directed towrds controlling point source contmintion of surfce nd subsurfce wter bodies; however, non-point source contmintion, such s off-field movement of nutrients from golf courses, urbn lwns nd griculturl fields, into surfce nd subsurfce wter bodies is difficult to identify nd control (Shrpley et l., 2001). Some griculturl fields hve evolved from serving s sinks for nutrients such s P nd N, to nutrient sources due to fertilizer ppliction beyond crop nutrient demnd (Shrpley et l., 2001). The desired P nd N nutrient mngement in griculture is to meet crop nutrient demnd with little residul nutrient tht is susceptible to loss mechnisms such s leching, denitrifiction or export from the field in wter. Prcticing no-till soil conservtion hs been identified s one mngement method tht reduces the mount of prticulte nutrients crried by eroding sediment tht is removed from griculturl fields, nd this prctice hs been widely dopted by growers on the Cndin priries. However, it ws reported erly on tht dissolved nutrients cn be more esily exported vi surfce nd subsurfce wter in these miniml low disturbnce (Bker nd Lflen, 1983; Lngdle et l., 1985; Shrpley nd Smith, 1994; Zho et l., 2001). There hs been desire to more closely monitor nd control the dissolved P movement off fields receiving nnul or semi-nnul pplictions of niml mnure (Shrpley et l., 2005). Agriculturl fields tht re under no-till mngement hve been documented s hving greter dissolved P losses in surfce run-off, compred to conventionl tilled fields due to the strtifiction of P with depth (Mueller et l., 1984; Shrpley nd Smith, 1994), with greter mount of P being 50

67 concentrted in the upper surfce portion of the soil (Butler nd Cole, 2005; Guertl et l., 1991; Tiessen et l., 2010). Shrpley et l. (2005) observed strong correltion between P losses in runoff wter nd soil P vilbility t the cm depth; nmely s soil P incresed in this zone, the greter the observed potentil for soil relese of P to run-off wter which hs lso been reported elsewhere (Vds et l., 2005). Phosphorus nd N export in run-off wter cn be ffected by the rte, method nd sesonl timing of mnure ppliction. Phosphorus nd N in mnures such s SCM or LHM tht re directly pplied to the soil surfce without incorportion, my not interct with soil prticles tht would otherwise help to retin them through dsorption nd formtion of insoluble complexes (Vds et l., 2004). Mooleki et l. (2002) reported greter crop yields nd lrger N recovery when LHM ws subsurfce bnded compred to brodcst pplictions. Some studies hve reported tht the timing of niml mnure ppliction influences the forms nd/or mounts of nutrients exported offsite. Klusner et l. (1976) suggested tht fll pre-snowfll ppliction of mnure reduces N nutrient loss compred to winter mnure ppliction. When mnure is pplied during the spring prior to field opertions (e.g., tillge, seeding nd hrrowing) the mnure P is incorported into the soil, which is commonly believed to reduce the mount of P exported vi run-off. A lrge portion of the nutrient loss reserch hs been conducted in res of Cnd or the United Sttes where run-off from rinfll events ccounts for the mjority of nutrient export. Previous reserch conducted in western Cnd hs reported tht soil losses from spring snowmelt cn be greter thn erosion from rinfll (Chnsyk nd Woytowich, 1987; McConkey et l., 1997; Vn Vliet nd Hll, 1991). In regions of the northern Gret Plins such s Ssktchewn, spring snowmelt is the mjor moisture rechrge event of the yer. Snowfll cn ccount for s much s 30 % of the nnul precipittion received (Cutforth et l., 1999) nd ccumultes through severl months, subsequently melting nd running over thwing nd frozen soil when spring tempertures begin to increse (Li et l., 2011). Snowmelt run-off cn exceed rinfll run-off due to frozen soils with limited wter infiltrtion (Grnger et l., 1984; Hnsen et l., 2000; Young nd Mutchler, 1976). The prolonged period in which snowmelt occurs fvors more sturted conditions within the soil surfce, which enhnces the relese of dissolved nutrient forms (Bechmnn et l., 2005; Little et l., 2007; Ontken et l., 2005). Snowmelt run-off hs less erosive bility compred to run-off from rinfll. The kinetic energy generted by the force of rindrops contcting the soil surfce cn cuse more ggregte 51

68 brekdown, soil prticle detchment nd movement of prticles with the run-off wter (Li et l., 2011). Glozier et l. (2006) reported tht pproximtely two-thirds of the N nd P removl due to run-off from snowmelt in southern Mnitob occurred in dissolved inorgnic form. Little et l. (2007) reported tht in Albert, Cnd, over 90 % of the P removed by spring snowmelt ws in dissolved inorgnic form. Fleming nd Frser (2000) hve reported tht frozen or unthwed bre soils do not llow infiltrtion of nutrients such s P nd N. Reserch hs lso been conducted into subsurfce pthwys for P loss (Sims et l., 1998). Jensen et l. (1998) nd Stmm et l. (1998) hve reported tht most of the P leching is likely through shllow mcropore preferentil flow. In soils tht re thwing t the surfce but remin frozen underneth in erly spring, much of the flow below the soil surfce my be lterl flow bove the frozen lyer. Despite severl studies tht hve exmined wter trnsport pthwys in generl, it is evident tht limited informtion exists specificlly on the nture nd extent of SRP nd N trnsport in snowmelt wter in soils receiving niml mnure pplictions in western Cnd. Even less informtion exists regrding multi-yer niml mnure pplictions t different rtes nd the effect of different ppliction methods. Subsurfce injection or bnding of mnure cn be beneficil to crop, such s incresed plnt nutrient uptke, incresed biovilbility of soil nutrients nd enhnced crop growth (see Chpters 2 nd 3). However the effects on nutrient export in snowmelt run-off hve not been evluted in western Cndin soils. Therefore the objective of the reserch in this chpter ws to determine the effect of surfce nd subsurfce wter flow rising from snowmelt on the nutrient export from soils with different mnure mngement histories. A novel methodology ws developed for collecting intct soil slb monoliths from replicted field plots. This ws followed by the development of technique for simulting melting snow conditions nd run-off under two common spring scenrios: 1) where snowmelt wter is llowed to infiltrte nd move lterlly below the soil surfce in thwing soil nd 2) condition in which melt wter moves rpidly cross frozen surfce. It ws hypothesized tht P nd N movement from soil mended with mnure would be enhnced compred to unmended controls, tht in-soil plcement would reduce nutrient export in surfce run-off, greter export of P would occur from SCM mended soil, nd tht export would be greter from snow melting on thwing soil tht llows the snowmelt wter to interct with the soil compred to melt wter rpidly pssing cross frozen soil.. 52

69 4.4 Mterils nd Methods Site description The SCM nd LHM studies were conducted ner Dixon, Ssktchewn (Dixon site) on two djcent res of the sme field (legl loction NW W2) within the Rurl Municiplity of Humboldt. The site description hs been provided previously in section The soil t the site belongs to the Cudworth Assocition nd is Blck Chernozemic soil formed in clcreous, silty, lcustrine prent mterils nd hving lom surfce texture (Ssktchewn Soil Survey 1989). The soil t this site occurs on gently sloping lnd surfce nd hs few limittions tht hinder griculturl ctivity. Identified limittions include insufficient moisture holding cpcity nd some slinity (covering 10-20% of the lndscpe), occurring mostly in sloughs nd low lying res (Ssktchewn Soil Survey, 1989). Soil ph in the 0-15 cm depth is 7.9, electricl conductivity is 0.1 ds m -1 nd soil orgnic crbon is 2.5%. This field site is only slightly stony nd hs low susceptibility to wind nd wter erosion (Ssktchewn Soil Survey, 1989) Mnure tretments The SCM injection study t Dixon ws estblished before spring seeding opertions commenced in June 2007, with SCM pplied using Pririe Agriculturl Mchinery Institute s (PAMI) SCM subsurfce bnding pplictor mchine s described in Chpter 3. The SCM field tril plots (3.05 x 6.09 m) were set up s rndomized complete block design, replicted four times. The SCM tretments were pplied in June 2007, My 2008 nd My A description of field seeding of crops nd dtes seeded ws previously described in section Tretments included n undisturbed control plot with no mnure or fertilizer pplied, nd nother control with no mnure or fertilizer pplied but with disturbnce of the soil using the coulter openers of the SCM injector mchine. The SCM ws pplied using three ppliction procedures; 1) brodcst ppliction where SCM ws pplied on the soil surfce (no incorportion), 2) brodcst nd incorported where SCM ws pplied on the soil surfce nd then incorported using disk, 3) subsurfce bnding, where SCM ws subsurfce plced in bnds using the PAMI SCM bnder mchine (in six subsurfce trenches with 60 cm coulter openers spced 30 cm prt, pplying the SCM product in bnds cm in depth). Twenty cm closing wheels covered the exposed or bnded trench with soil. The rte of SCM pplied ws equl to 300 kg totl N h -1, t rte of 53

70 pproximtely 60.6 t h -1, nd my be considered triple the rte of nnully pplied N (pproximtely 100 kg N h -1 ) tht would be recommended s commercil fertilizer to meet typicl crop requirements in the cnol-ot rottion. The SCM pplied in the three-yer field tril ws obtined from the Poundmker Feedlot, which is locted pproximtely 8 km est of the town of Lnign, SK. Phosphorus nd N contents of the SCM pplied in 2007, 2008 nd 2009 re listed in Tble 4.1. Due to vrition in mnure P content over the yers, the P pplied in the SCM tretments rnged from 150 kg P h -1 in 2008 to 213 kg P h -1 in Applied Totl N in the SCM rnged from 180 kg N h -1 in 2008 to 561 kg N h -1 in Applied mmonium-nitrogen (NH4-N) in the SCM ws 0.15 kg NH4-N h -1 in 2007 nd 2008, nd 0.18 kg NH4-N h -1 in The LHM trils tht were smpled for comprison purposes were estblished in October of In this tril, ech yer fter hrvesting opertions were completed, ppliction of LHM ws mde using PAMI s LHM subsurfce injector pplictor truck s described by Mooleki et l. (2002). Soil slb monolith collection ws conducted in Oct prior to ppliction of LHM. The LHM field tril plots (3.05 x m) were set up s rndomized complete block design nd replicted four times. Tretments were pplied in October, post-hrvest, every yer for the durtion of the 12-yer long-term LHM study. The field ws seeded to cnol in lte My of 2008, nd to brley (Hordeum vulgre) in erly June Tretments included control plot with no mnure or fertilizer being pplied nd disturbnce of the soil using the coulter openers of the PAMI LHM subsurfce injection pplictor truck. Liquid hog mnure ws pplied using two ppliction procedures; 1) subsurfce injection where LHM ws subsurfce bnded nd plced in bnd using the PAMI LHM subsurfce injection mchine in six subsurfce bnds using 60 cm dimeter coulter openers spced 30 cm prt pplying the LHM cm deep, nd 2) brodcst of LHM cross the soil surfce followed by incorportion fter 24 hr. 54

71 Tble 4.1. Rtes of phosphorus, totl N nd mmonium N pplied s mnure from in the solid cttle mnure trils t Dixon, Ssktchewn. Yer of Appliction Tretment Totl P Totl N NH 4 -N Appliction method (t h -1 ) (kg h -1 ) with no incorportion, but disturbnce # brodcst only brodcst nd incorported subsurfce bnded with no incorportion, but disturbnce # brodcst only brodcst nd incorported subsurfce bnded with no incorportion, but disturbnce # brodcst only brodcst nd incorported Appliction rte bsed on wet weight Totl phosphorus from 3 yers of solid cttle mnure ppliction Totl nitrogen from 3 yers of solid cttle mnure ppliction Ammonium nitrogen from 3 yers of solid cttle mnure ppliction # No ppliction of mnure nd soil disturbnce with PAMI mnure pplictor coulters inserted in soil subsurfce bnded Mnure sub-smples for both the SCM nd LHM pplictions for ech yer of ppliction were obtined from the ppliction equipment t the time of tretment ppliction in the field plots. From , the nnul ppliction rtes of LHM were pproximtely 90 (37, 000 L h -1 ) nd 55

72 350 (148,000 L h -1 ) kg totl N h -1 per yer, nd 6 kg totl P h -1 nd 25 kg totl P h -1 per yer on the low nd high rte tretments respectively (Tble 4.2). Tble 4.2. Tretments from , 2008 nd 2009 in the twelve-yer liquid hog mnure study t Dixon, Ssktchewn. Yer of Appliction Tretment P rte Totl N rte (L h -1 ) (kg h -1 ) , , , NH 4 -N rte , , , Appliction method with no incorportion, but disturbnce # hog mnure subsurfce injected hog mnure brodcst nd incorported with no incorportion, but disturbnce # hog mnure subsurfce injected hog mnure brodcst nd incorported , , , with no incorportion, but disturbnce hog mnure subsurfce injected hog mnure brodcst nd incorported fter 24 h Appliction rte bsed on wet weight Totl phosphorus from 12 yers of liquid hog mnure ppliction Totl nitrogen from 12 yers of liquid hog mnure ppliction Ammonium nitrogen from 12 yers of liquid hog mnure ppliction # No ppliction of mnure nd soil disturbnce with PAMI mnure pplictor coulters inserted in soil The totl N tht ws pplied in the 12-yer long-term LHM tril in the yers tht encompssed this study (2008 nd 2009) slightly rnged from 68 kg N h -1 in the 2008 low ppliction rte tretment to 79 kg N h -1 in 2009, while totl P rnged from 4 kg P h -1 to 7 kg P h -1 in the sme tretments 56

73 (Tble 4.2). Phosphorus tht ws dded over the 12 yers in the LHM tretments t the 37,000 L h -1 rte ws 73 kg P h -1 nd dded t the 148,000 L h -1 rte ws 292 kg P h Soil smpling nd nlysis Soil smples from the SCM study nd 12 yer long-term LHM study were obtined from ech of the tretment plots post-hrvest in Oct nd Oct using truck mounted soil smpling coring device. Soil smples were nlyzed for vilble nitrte-nitrogen (NO3-N) nd NH4-N by extrcting with 2 M potssium chloride nd mesuring the ion concentrtions colorimetriclly using Technicon Autonlyzer II (Keeney nd Nelson, 1982). Soil extrctble P ws determined by modified Kelown method (Qin et l., 1994). The extrctble P mesured in the 0-15 cm depth post-hrvest t the 3 yer SCM site incresed to over 170 kg P h -1 in the three mnure tretments by fll 2009 compred to bout 20 kg P h -1 in the unmnured control plots (Tble 4.3), reflecting the high mount of P dded in the cttle mnure. Only smll mount of inorgnic N ccumulted in the soil from the ppliction of SCM, nd soil extrctble NO3-N levels in the SCM site were 9-11 kg NO3-N h -1 in the three mnure tretments in both the fll of 2008 nd 2009 (Tble 4.3). Soil extrctble NH4-N decresed slightly from 10 kg NH4-N h -1 in the three tretments in 2008 to less thn 9 kg NH4-N h -1 in 2009 (Tble 4.3). Low ccumultions of mmonium nd nitrte in the soil re nticipted with SCM due to low mmonium content nd lrge mount of orgnic N tht minerlizes only very slowly, s discussed in Chpter 3. Soil extrctble P mesured in the 0-30 cm depth post-hrvest t the 12 yer LHM site, prior to LHM ppliction in fll 2008 nd 2009 ws similr mong tretments in 2008 nd In 2008, MK-P rnged from 20.7 kg P h -1 in the low rte brodcst nd incorported to 31.3 kg P h -1 in the high rte subsurfce bnded versus 24.6 kg P h -1 in the unmnured control (Tble 4.4). Soil extrctble P levels in the LHM tretments in the fll of 2009 were similr, nd slightly lower thn in the fll of Lck of lrge influence of long-term ppliction of LHM on soil extrctble P content is consistent with mounts of P dded in LHM over the yers (5 to 25 kg P h -1 yr -1 ) tht re similr to P removed in crop hrvest ech yer. Soil extrctble NO3-N levels in fll of 2008 in the 0-30 cm depth t the LHM site were 9 kg NO3-N h -1 in the control, 12 kg NO3-N h -1 in the low rte brodcst nd incorporte, 51 kg NO3-N h -1 in the low rte subsurfce bnded nd 266 kg NO3-N h -1 in the high rte subsurfce bnded tretment (Tble 4.4). Soil extrctble NH4-57

74 N in the 0-30 cm depth ws kg NH4-N h -1 in three LHM tretments nd the control in In fll 2009 smples, soil extrctble NO3-N levels were gin bout four times higher in the high rte subsurfce bnded soils compred to the lower rte treted plots (Tble 4.4). Accumultion of nitrte rther thn phosphte in the LHM soil is expected with 12 yers of nnul ddition of bout 300 kg N h -1, which is n mount tht gretly exceeds removl in crop hrvest. Tble 4.3. Extrctble soil nutrients (0-15 cm) in the solid cttle mnure trils smpled posthrvest in 2008 nd 2009 t Dixon, Ssktchewn. Yer of Appliction 2008 Tretment MKP NO 3 -N NH 4 -N Appliction method (t h -1 ) (kg h -1 ) (9.6) 5.5 (1.7) 13.1 (3.8) with no incorportion, but disturbnce # (51.1) 11.1 (1.9) 10.6 (3.3) brodcst only (73.7) 9.1 (5.2) 10.9 (3.2) brodcst nd incorported (73.6) 9.7 (4.3) 12.7 (2.7) subsurfce bnded LSD (0.10) (6.6) 4.6 (0.4) 8.3 (1.2) (36.8) 10.3 (1.6) 7.1 (1.7) (20.6) 9 (1.7) 8.2 (1.9) (127.3) 11.4 (3.5) 9.5 (4.2) LSD (0.10) with no incorportion, but disturbnce # cttle mnure brodcst only cttle mnure brodcst nd incorported cttle mnure subsurfce bnded Appliction rte bsed on wet weight Modified Kelown extrctble P Mens in the first column Stndrd devitions (±) of the men in the second column # No ppliction of mnure nd soil disturbnce with PAMI mnure pplictor inserted in soil Lest significnt difference (P 0.10) 58

75 Tble 4.4. Extrctble soil nutrients (0-30 cm) in the liquid hog mnure trils tht were smpled post-hrvest in 2008 nd 2009 t Dixon, Ssktchewn. Yer of Appliction Tretment MKP NO 3 -N NH 4 -N Appliction method (L h -1 ) (kg h -1 ) (15.0) 9.3 (1.8) 26.4 (5.4) 37, (12.9) 50.7 (16.5) 25.0 (8.5) 148, (16.4) (231.6) 26.4 (5.8) 37, (8.3) 11.7 (4.5) 24.3 (5.5) LSD (0.10) with no incorportion, but disturbnce # hog mnure subsurfce injected hog mnure brodcst nd incorported (8.6) 12.6 (4.6) 16.9 (9.6) 37, (5.7) 28.0 (10.0) 39.2 (38.2) 148, (8.0) (78.3) 17.5 (9.6) 37, (3.2) 11.3 (0.9) 30.8 (11.8) LSD (0.10) Appliction rte bsed on wet weight Modified Kelown extrctble P Stndrd devitions of the men No ppliction of mnure nd PAMI mnure pplictor coulters inserted in soil # Lest significnt difference (P 0.10) with no incorportion, but disturbnce # hog mnure subsurfce injected hog mnure brodcst nd incorported Snowmelt nd wter run-off simultion on soil slb monoliths Soil slb monolith smples for the thwing soil slb snowmelt portion of the study were collected t rndom positions within ech tretment plot in mid-oct nd mid-oct. 2009, fter hrvest opertions hd concluded for ech of those crop yers in the SCM study, nd in mid-oct fter hrvest opertions hd concluded in the 12- yer long-term LHM study. Single soil slb monolith smples for the frozen soil slb wter run-off portion of the SCM study were collected in mid-oct fter hrvest opertions hd been completed for tht crop yer. Soil slb monolith smples for the frozen soil slb wter run-off portion of the 12-yer longterm LHM study were collected in mid-oct fter hrvest opertions were complete. A single 59

76 soil slb monolith ws collected from ech of the four replictes for every tretment in the SCM nd LHM studies. In the soil slb monolith collection process, in ech tretment plot smll trench ws excvted to depth of pproximtely cm in rectngle to expose 30 x 40 cm section of soil. A crosscut hnd sw ws then used to horizontlly cut 30 by 40 cm soil cross section slb t n pproximte depth of cm (Fig. 4.1). Once the soil slb section plus the ccompnying crop residues hd been severed from the surrounding soil, plstic plexiglss sheet ws inserted into the severed section in order to keep the slb section intct, nd to ensure tht the slb ws not frctured during removl. The soil slb section ws then wrpped in shipping tpe to prevent frcture nd brekup during trnsport to the lbortory, plced in plstic storge continer nd then immeditely plced in freezer where they were stored t -20 C until the simulted snowmelt tretment. Fig Collection of soil slb monoliths from Dixon three-yer solid cttle mnure nd 12- yer long-term liquid hog mnure study t Dixon, Ssktchewn. In Februry of 2009 nd 2010, undisturbed unblown snow tht hd recently (within 48 h) fllen ws collected from field t the Goodle Frm (field legl loction SE W3) locted pproximtely 20 km south-est of Ssktoon, SK. The undisturbed snow ws collected from the field t pproximtely m distnce from the rod to minimize ny contmintion of the snow from foreign rodside debris. For mesuring snow melt run-off nd leching over thwing soil, the frozen soil slb monoliths were plced inside insulted plywood boxes designed to slow the rpid thwing of the soil slb so s to mimic snowmelt s it occurs in the spring, but lso to llow the dded snow cover to infiltrte into the subsurfce of the soil nd not simply run off the soil surfce (Fig. 4.2). Approximtely 2 kg of snow (representing 7.5 cm of snow cover in field, equivlent 60

77 to 1.67 cm of wter), ws dded to the soil slb monolith section surfce. The rer of the insulted plywood boxes ws elevted to position of five degrees to llow lechte nd run-off to occur. The boxes were lined with plstic sheets to fcilitte snowmelt lechte nd run-off collection. Lbortory room temperture ws ltered for the first 48 h of the experiment to simulte spring dy conditions. Specificlly, temperture ws ltered from - 8 C (night), to 0 C mid-dy, 5 C in lter portions of the dy nd bck to -8 C t night which llowed more grdul thwing of the soil slb monolith, llowing greter infiltrtion of the snowmelt wter into the soil slb. Fig Simulted snowmelt on thwing soil slb monoliths nd collection of run-offlechte. Additionlly, soil slb monoliths were used to simulte nd mesure nutrient movement in surfce wter run-off pssing quickly cross frozen soil. This experiment ws conducted to simulte wrm Cndin pririe spring dy in which snow hs melted nd wter is moving rpidly cross field while the soil surfce remins in predomintely frozen or unthwed stte. A set of -20 ⁰C frozen soil slbs smpled from the tretments obtined in Oct were plced in elevted boxes s described bove. Two kg of wter t 2 C ws poured over 60-second time period from plstic bucket directly nd rpidly t distnce of 2 cm from the slb surfce strting from the elevted portion of the frozen soil slb surfce nd wter ws collected t the lower portion of the elevted box s described previously. The lechte nd run-off from the thwing soil slb monoliths nd the frozen soil slbs ws collected, the volume collected ws mesured, recorded nd smples immeditely frozen nd stored t -20 C until the smples were thwed nd filtered using Millipore 45 µm glss filters. All of the filtered smples were nlyzed for SRP, NO3-N nd NH4-N using Technicon II utomted colorimetry nlyzer (Americn Public Helth Assocition 2005). A sub-smple of collected snow 61

78 ws melted seprtely, filtered nd nlyzed to determine the bckground levels of the bove nutrients, which ws subtrcted from the tretment run-off concentrtions Sttisticl nlysis Dt from both the three-yer SCM nd 12-yer long-term LHM studies were nlyzed s rndomized complete block design, replicted four times for ll field experiments t the SCM Ssktchewn site for SRP, NO3-N nd NH4-N with two fctors for the SCM ppliction: rte of SCM tretment mendment nd method of SCM ppliction. The 12 yer long-term LHM study ws nlyzed s rndomized complete block design, replicted four times for ll field experiments for SRP, NO3-N nd NH4-N with two fctors for the LHM ppliction: rte of LHM tretment mendment nd method of LHM ppliction. Dt from the SCM nd LHM sites were nlyzed independently. Smple dt ws nlyzed for normlity nd equlity of vrinces using the univrite procedure nd trnsformed where necessry. Mens seprtion comprisons for ll vribles were conducted using the generl liner model procedure using lest significnt difference (LSD) of (P 0.10) clculted with SAS Proc GLM (SAS version 9.0, 2008). 4.5 Results nd Discussion Soluble rective phosphorus export in snowmelt wter on thwing solid cttle mnure mended soil In the SCM soil slbs collected in the fll of 2008, the SRP exported in run-off nd lechte from snowmelt ws observed to be significntly (P 0.10) higher in the brodcst nd incorported nd subsurfce bnded tretments thn the 0.02 kg P h -1 exported in the unmended control (Fig. 4.3). Soluble rective P concentrtions for fll 2008 re reported in Appendix Tble B.7. As ws observed in the 2008 thwing snow nd soil slbs, the SRP exported in the SCM tretments in 2009 ws significntly greter thn the 0.03 kg SRP h -1 exported in the control tretment (Fig. 4.3b). Soluble rective P concentrtions for fll 2009 re reported in Appendix Tble B.8. In 2008 nd 2009, the mnured tretments were found to be significntly (P 0.10) higher in SRP export thn the disturbed-control tretment. Amounts of P exported in mnured tretments rnged from bout 0.1 kg P h -1 in the brodcst SCM tretment in 2008 to bout 0.5 kg P h -1 in the subsurfce bnded tretment in The mounts of P removed from the SCM treted soils re 10 times 62

79 higher thn in the non-mnured controls. These findings re in greement with Smith et l. (2011) who reported tht SRP concentrtions in spring snowmelt wter from cttle overwintering sites in est-centrl Ssktchewn were over 10.0 mg PO4-P L -1, which ws 20 times greter thn the P concentrtion in the control bsin wter run-off (0.47 mg PO4-P L -1 ). Olsen et l. (2010) hs reported greter mounts of P nd N in wter runoff from cttle mnured soil fter the first yer of ppliction in multi-yer study in Albert, but with reduced P nd N in runoff in subsequent yers. This ws not the cse in the present study, s the mount of SRP exported incresed from 2008 to 2009, but is consistent with greter mount of P pplied in the SCM tretments in 2009 (Tble 4.1) nd the higher soil test extrctble P in the fll of 2009 (Tble 4.3). Immobiliztion of P in SCM in orgnic forms nd slow minerliztion (Stumborg nd Schoenu, 2008) could explin why overll SRP export ws less thn 1 kg SRP h -1 for ll three SCM ppliction methods. As well, the brief soil-wter interction time my not hve been sufficient to mobilize much P. Converse et l. (1976) nd Kongoli nd Blnd (2002) hve noted tht removl of nutrients with run-off wter fter winter pplictions of mnure vries with the nture of the mnure. Specificlly solid niml mnures contining greter mounts of bedding nd strw, such s the mnure used in this study, cn serve s mulch pltform tht limits or reduces the mounts of nutrients tht cn be removed by snowmelt run-off wter. The less thn 1 kg SRP h -1 export for ll three SCM ppliction methods is negligible compred to the 150 kg P h -1 dded in the brodcst lone, brodcst nd incorported nd subsurfce bnded, respectively, SCM tretments in This could be ccounted for by the low solubility of P in SCM nd sorption to soil constituents, leding to its decresed mobility (Shrpley nd Moyer, 2000). If the mount of P pplied is greter thn the P sorption cpcity of soil nd exceeds the bility of plnts to tke up vilble supplies of P then more P is predicted to be exported by wter (Brye et l., 2002), especilly if there re preferentil conduit modes of trnsport, which could explin the greter mount of SRP trnsported in the subsurfce bnded SCM tretment. The plcement of SCM in concentrted mnure bnd could potentilly overlod soil minerl nd orgnic dsorption sites which, combined with the deep horizontl bnding (10-13 cm), cretes more opportunity for preferentil flow movement. 63

80 Runoff-lechte soluble rective phosphorus (kg SRP h -1 ) Runoff-lechte soluble rective phosphorus (kg SRP h -1 ) ) b LSD (0.10) = 0.1 b) b Control-Disturbed Brodcst lone Tretment Brodcst & incorported LSD (0.10) = 0.2 Subsurfce bnded Fig Export of soluble rective phosphorus (kg P h -1 ) by thwing snow on thwing soil slb monoliths from three-yer solid cttle mnure field study collected in ) fll 2008 nd b) fll Mens followed by the sme letter re not significntly (P 0.10) different. Error brs denote stndrd devitions of the mens Soluble rective phosphorus export in wter moving rpidly cross the surfce of frozen cttle mnure mended soil In snowmelt conditions of wter pssing rpidly over frozen soil monoliths obtined from the SCM site in mid-oct. 2009, the SRP exported in the three mnure tretments ws significntly (P 0.10) higher thn the 0.03 kg SRP h -1 exported in the control tretment (Figure 4.4). Soluble rective P concentrtions for fll 2009 re reported in Appendix Tble B.9. Overll, SRP export in wter running rpidly cross the surfce of SCM tretment frozen soil slbs ws pproximtely 64

81 Runoff-lechte soluble rective phosphorus (kg SRP h -1 ) 0.15 kg SRP h -1, which is less thn one-hlf of tht in the thwing snow nd soil. This is expected due to lower degree of interction between wter nd soil when the soil surfce is frozen. The longer time durtion ssocited with the snowmelt run-off nd leching on the thwing soil slbs contrsts with the shorter time durtion of the simultion of wter running cross the frozen surfce of soil. This difference in time nd frozen soil conditions which prevents infiltrtion of wter mens reduced degree of soil-wter interction. It ppers tht the nture of the thw nd run-off such s thwing versus frozen soils cn considerbly influence the mount of nutrient ion tht my be exported off the field 1.0 LSD (0.10) = b 0.0 Control- Disturbed Brodcst lone Brodcst & incorported Subsurfce bnded Fig Export of soluble rective phosphorus (kg P h -1 ) in wter moving rpidly cross the surfce of frozen soil slb monoliths collected in fll 2009 from three-yer solid cttle mnure field study site. Mens followed by the sme letter re not significntly (P 0.10) different. Error brs denote stndrd devitions of the mens Soluble rective phosphorus export in thwing snow nd soils from liquid hog mnure mended soil As expected, the mounts of SRP exported vi run-off nd lechte from thwing snow nd soil slb monoliths collected from the long-term (12 yers of ppliction) LHM field study site ws incresed with LHM ppliction (Fig. 4.5). The SRP removed in the nnul ppliction rte of 148,000 L h -1 (Fig. 4.5) of bout 0.05 kg P h -1 ws significntly (P 0.10) greter thn the control-disturbed tretment but ws not significntly (P 0.10) different from the other tretments, which themselves were not significntly different from the control tretment. Soluble rective P 65

82 Runoff-lechte soluble rective phosphorus (kg SRP h -1 ) concentrtions for fll 2009 re reported in Appendix Tble B.10. Overll, the LHM SRP exports from 12 yers of LHM ppliction re bout 10% of the SCM exports from two yers of SCM ppliction (Fig. 4.3), despite only slightly lower mounts of P dded s LHM over 12 yers in the 148,000 L h -1 rte tretments s dded in two yers of SCM ppliction t 60 t h -1. This cn be explined in prt by crop uptke nd removl of the P dded in the LHM tretments over the 12 yers (Stumborg nd Schoenu, 2008). This resulted in smller P surplus for the LHM fieldstudy compred to the SCM study nd much lower soil test extrctble P contents in the soil of the LHM (Tble 4.4) compred to the SCM (Tble 4.3). The P in the LHM would hve hd more time to rect with the soil (12 yrs ppliction period) compred to the shorter ppliction period in the SCM tretments (3 yrs). Cmpbell et l. (1984) hs described how the P concentrtion in the soil solution is typiclly low nd it is known tht P dded s fertilizer cn trnsform into insoluble forms over time, which cn retrd the vilbility nd movement of P in the soil solution. Conversion of mnure P into less soluble forms my lso be occurring in the LHM mended soils over the 12 yers of ppliction. The mount of P dded in the LHM (Tble 4.2) in Oct nd Oct ws quite low compred to the P dded in the SCM (Tble 4.1) b Control- Disturbed b Brodcst nd incorportion L/h Tretment Subsurfce bnded 37000L/h LSD (0.10) = 0.02 Subsurfce bnded L/h Fig Export of soluble rective phosphorus (kg P h -1 ) by thwing snow on thwing soil slb monoliths collected in fll 2009 from 12-yer long-term liquid hog mnure field study site. Mens followed by the sme letter re not significntly (P 0.10) different. Error brs denote stndrd devitions of the mens. b 66

83 Runoff-lechte soluble rective phosphorus (kg SRP h -1 ) Wter soluble P in mnure ws reported by Kumrgmge et l. (2011) to be 3.4 kg t -1 in LHM compred to 0.8 kg t -1 in SCM. A greter solubility of P in LHM would be expected to result in greter mounts of exportble SRP in runoff nd/or lechte from LHM mended soil compred to SCM mended per unit of P dded in fresh mnure. However, crop uptke nd removl of lbile, redily vilble P dded over the yers in the LHM tretments, low mount of P dded with the LHM, long with conversion to less soluble forms once in the soil would msk ny effect in the current study Phosphorus export in wter moving rpidly cross the surfce of frozen liquid hog mnure mended soil The SRP exported in wter moving rpidly cross the frozen surfce of the LHM soil slbs (Fig. 4.6) ws pproximtely one-tenth of the mount of SRP export in wter moving rpidly cross the frozen soil surfce fter two yers of mnure ppliction t the SCM site. This my be explined by the mount of P dded, s the mount of P dded over 12 yers of LHM (Tble 4.2) ppliction t the 37,000 L h -1 rte ws much smller thn the mount of P dded in SCM t the 60 t h -1 rte over 3 yers (Tble 4.1) LSD (0.10) = b 0.01 b b 0.00 Control-Disturbed Brodcst nd incorportion L/h Subsurfce bnded 37000L/h Tretment Subsurfce bnded L/h Fig Export of soluble rective phosphorus (kg P h -1 ) in wter moving rpidly cross the surfce of frozen soil slbs in fll yer long-term liquid hog mnure field study site. Mens followed by the sme letter re not significntly (P 0.10) different. Error brs re stndrd devitions of the mens. 67

84 The mount of P dded over 12 yers of LHM (Tble 4.2) ppliction t the 148,000 L h -1 rte ws four times greter thn the mount of P dded t the 37,000 L h -1 rte. Soluble rective P export ws found to be much less thn the SRP export in the SCM tretments. Soluble rective P concentrtions for fll 2009 re reported in Appendix Tble B.11. The LHM subsurfce bnded high rte 148,000 l h -1 produced significntly (P 0.10) greter mount of exported SRP in runoff moving cross frozen soil surfce, compred to the lower 37,000 h -1 subsurfce bnded LHM tretment nd the control tretment. Of the different mnure type (SCM nd LHM) nd snowmelt (thwing nd frozen soil surfce) scenrios exmined, the rpid flow of wter movement cross the frozen surfce of LHM mended soil resulted in the lowest SRP export from the soil, round 0.01 kg P h Dissolved nitrte-nitrogen export in snowmelt wter on thwing solid cttle mnure mended soil In the SCM thwing soil slbs from fll of 2008, the mounts of dissolved NO3-N in runoff nd lechte snowmelt derived wter were similr mong mnured tretments (~0.4 kg NO3- N h -1 ) nd were not significntly different (P 0.10) from the control-disturbed tretment (Fig. 4.7). Dissolved NO3-N concentrtions for fll 2008 re reported in Appendix Tble B.7. This grees with observtions by Smith et l. (2011), where little NO3-N in run-off wter ws observed from winter snowmelt fter the first yer of mnure ppliction in winter-feeding field locted in est-centrl Ssktchewn. Export of dissolved NO3-N in the 2009 run-off nd lechte ws lso similr mong mnured tretments (~ kg NO3-N h -1 ) nd were not significntly different (P 0.10) from the control-disturbed tretment (Fig. 4.7b). Dissolved NO3-N concentrtions for fll 2009 re reported in Appendix Tble B.8. Smith et l. (2011) reported verge NO3-N concentrtions in wter smples from cttle overwintering sites of 0.25 mg NO3-N L -1 compred to 0.19 mg NO3-N L -1 in control sites. The microbil conversion of orgnic N nd NH4-N contined in the mnure to NO3-N cn be slowed by cold tempertures (Strk nd Firestone, 1996), nd the SCM in this study contined reltively little inorgnic N. Additionlly, most of the inorgnic N would hve been utilized by the crop in the first yer fter ppliction. Moreover, the vilbility of N dded in SCM cn be very low due to cttle pen bedding mteril contining strw nd/or wood chips, which cn hve high C:N 68

85 Runoff-lechte dissloved nitrtenitrogen (kg NO 3 -N h -1 ) Runoff-lechte dissolved nitrtenitrogen (kg NO 3 -N h -1 ) rtio, subsequently limiting minerliztion nd relese of inorgnic N (Schoenu nd Dvis, 2006), s discussed in Chpter 3. ) 6.0 LSD (0.10) = b) LSD (0.10) = Control- Disturbed Fig Export of dissolved nitrte-nitrogen (kg NO3-N h -1 ) by thwing snow on thwing soil slb monoliths from three-yer solid cttle mnure field study collected in ) fll 2008 nd b) fll Mens followed by the sme letter re not significntly (P 0.10) different. Error brs denote stndrd devitions of the mens Dissolved nitrte-nitrogen export in wter moving rpidly cross the surfce of frozen solid cttle mnure mended soil Brodcst lone Tretment Brodcst & incorported Subsurfce bnded Dissolved NO3-N removl in run-off from wter moving rpidly cross frozen soil slb monoliths in the SCM brodcst nd incorported tretment ws significntly (P 0.10) higher 69

86 Runoff-lechte dissolved nitrtenitrogen (kg NO 3 -N h -1 ) thn the control tretment (Fig. 4.8). Dissolved NO3-N concentrtions for fll 2009 re reported in Appendix Tble B.9. The mount of nitrte removed ws bout hlf of the NO3-N removed vi snowmelt run-off nd lechte in the 2008 thwing snow nd soil slbs, nd it ws 10% of the dissolved NO3-N removed in the 2009 thwing snow nd soil slbs (Fig. 4.7b). 0.5 LSD (0.10) = b b b 0.0 Control-Disturbed Brodcst lone Brodcst & incorported Subsurfce bnded Fig Export of dissolved nitrte-nitrogen (kg NO3-N h -1 ) in wter moving rpidly cross the surfce of frozen soil slb monoliths collected in fll 2009 from three-yer solid cttle mnure field study site. Mens followed by the sme letter re not significntly (P 0.10) different. Error brs denote stndrd devitions of the mens Dissolved nitrte-nitrogen export in snowmelt wter on thwing liquid hog mnure mended soil There were no significnt (P 0.10) differences in dissolved NO3-N export in wter from thwing snow nd soil slb monoliths collected in fll of 2009 mong the three tretments nd the non-mnured control (Fig. 4.9). Dissolved NO3-N concentrtions for fll 2009 re reported in Appendix Tble B.10. For the low rte of ppliction, the subsurfce bnding tended to result in greter export thn brodcst nd incorporte, nd export incresed with rte. The mounts removed (bout 1-4 kg NO3-N h -1 ) were similr to the mounts of nitrte removed in the SCM fll 2009 soils, despite lower fll soil nitrte contents in the SCM mended soils compred to the LHM mended soils. The reson for this is not known, but might reflect greter interction of snowmelt wter with the soil in the SCM mended soil compred to the LHM mended soil. 70

87 Runoff-lechte dissolved nitrtenitrogen (kg NO 3 -N h -1 ) LSD (0.10) = Control- Disturbed Brodcst nd incorportion L/h Tretment Subsurfce bnded 37000L/h Subsurfce bnded L/h Fig Export of dissolved nitrte-nitrogen (kg NO3-N h -1 ) by thwing snow on thwing soil slbs collected in fll 2009 from 12-yer long-term liquid hog mnure field study site. Mens followed by the sme letter re not significntly (P 0.10) different. Error brs denote stndrd devitions of the mens Dissolved nitrte-nitrogen in wter moving rpidly cross the surfce of frozen liquid hog mnure mended soil Dissolved NO3-N export in wter pssing over frozen soil slb monoliths ws not significntly different mong the LHM tretments (Fig. 4.10). Dissolved NO3-N concentrtions for fll 2009 re reported in Appendix Tble B.11. As for phosphte, mounts of NO3-N removed in wter pssing over the frozen surfce were considerbly less thn for snow melting on thwing soil. Soil texture, wter infiltrtion rtes nd redistribution of crop residues vi tillge opertions cn ll hve n effect on the mount of NO3-N tht is retined ner the soil surfce (Stumborg et l., 2007). The subsurfce flow of snowmelt wter through thwing soil often results in much greter NO3-N removl (Li et l., 2011). 71

88 Runoff-lechte dissolved nitrtenitrogen (kg NO 3 -N h -1 ) LSD (0.10) = Control-Disturbed Brodcst nd incorportion L/h Subsurfce bnded 37000L/h Tretment Subsurfce bnded L/h Fig Export of dissolved nitrte-nitrogen (kg NO3-N h -1 ) in wter moving rpidly cross the surfce of frozen soil slbs in fll yer long-term liquid hog mnure field study site. Mens followed by the sme letter re not significntly (P 0.10) different. Error brs re stndrd devitions of the mens Dissolved mmonium-nitrogen export in snowmelt wter on thwing solid cttle mnure mended soil The dissolved NH4-N export ws not significntly (P 0.10) different between the disturbed-control tretment, brodcst lone, brodcst nd incorported nd subsurfce bnded SCM tretments (Fig. 4.11). Strong dsorption to soil prticles could explin the low mount of NH4-N extrcted by wter pssing cross nd through the soil. Mnure NH4-N is redily dsorbed nd held on the soil ction-exchnge sites nd is not esily extrcted from the soil with wter. In this study, the NH4-N relesed from mnure could lso hve been rpidly utilized by plnts during the growing seson nd/or nitrified thus leving little residul NH4-N (Stumborg et l., 2007). In greement with this, soil NH4-N contents in the fll were low (Tble 4.3), nd re consistent with low (round 0.02 kg NH4-N h -1 ) mounts of NH4-N exported in the run-off nd lechte wter collected from the melting snow on the slbs. The mounts of NH4-N exported re bout 50 times lower thn the mounts of NO3-N (Fig. 4.10). Dissolved NH4-N concentrtions for fll 2008 nd fll 2009 re reported in Appendix Tbles B.7 nd B.8. 72

89 Runoff-lechteDissolved mmoniumnitrogen (kg NH 4 -N h -1 ) Runoff-lechte dissolved mmoniumnitrogen (kg NH 4 -N h -1 ) ) LSD (0.10) = b) 0.05 LSD (0.10) = Control-Disturbed Brodcst lone Fig Export of dissolved mmonium-nitrogen (kg NH4-N h -1 ) by thwing snow on thwing soil slb monoliths from three-yer solid cttle mnure field study collected in ) fll 2008 nd b) fll Mens followed by the sme letter re not significntly (P 0.10) different. Error brs denote stndrd devitions of the mens Dissolved mmonium-nitrogen export in wter moving rpidly cross the surfce of frozen solid cttle mnure mended soil Tretment Brodcst & incorported The mnure tretments nd nture of run-off hd reltively little effect on NH4-N export in wter running rpidly cross frozen soil surfce in this study (Fig. 4.12). Dissolved NH4-N concentrtions for fll 2009 re reported in Appendix Tble B.9. The NH4-N is bound to soil colloids, which limits its interction nd relese to wter pssing through. The frozen condition of the surfce soil would further limit interction. However, others hve noted tht NH4-N export cn still occur depending on ice content in the pores (Steenhuis et l., 1981). Subsurfce bnded 73

90 Runoff-lechte dissolveed mmonium-nitrogen (kg NH 4 -N h -1 ) As noted previously, there ws very little NH4-N dded with the SCM, which could lso ccount for the smll mount of run-off nd lechte NH4-N. In 2009, NH4-N exports were not enhnced in mnure tretments compred to the control tretment. Infiltrtion of the soil micropores by wter from snowmelt cn be prevented if ice content is blocking the pore system (Ginting et l., 1998; Zuzel nd Pikul, 1987). Given the low NH4-N content in soils receiving SCM s consequence of plnt uptke nd rpid nitrifiction, nd the retention by dsorption to clys nd OM, it is not surprising tht the mnure tretment hd miniml influence on NH4-N export (Fig. 4.12), nd there ws little difference in export on thwing nd frozen soils LSD (0.10) = Fig Export of dissolved mmonium-nitrogen (kg NH4-N h -1 ) in wter moving rpidly cross the surfce of frozen soil slb monoliths collected in fll 2009 from three-yer solid cttle mnure field study site. Mens followed by the sme letter re not significntly (P 0.10) different. Error brs denote stndrd devitions of the mens Dissolved mmonium-nitrogen export in snowmelt wter on thwing liquid hog mnure mended soil Control-Disturbed Brodcst lone Tretment Brodcst & incorported Subsurfce bnded There were no significnt differences in NH4-N export in wter mong the three LHM tretments t the 12-yer long-term site (Fig. 4.13). Dissolved NH4-N concentrtions for fll 2009 re reported in Appendix Tble B.10. With similr cly content t both the SCM nd LHM field sites (they re locted djcent to ech other), ction dsorption would be similr. More NH4-N ws dded with the LHM compred to the SCM, however run-off nd lechte NH4-N 74

91 Runoff-lechte dissolved mmonium-nitrogen (kg NH 4 -N h -1 ) concentrtions were similr, which could be ttributed to utiliztion of the LHM NH4-N by the crops long with nitrifiction from the time of ppliction in spring to smpling time in the fll LSD (0.10) = Control-Disturbed Brodcst nd incorportion L/h Subsurfce bnded 37000L/h Subsurfce bnded L/h Fig Export of dissolved mmonium-nitrogen (kg NH4-N h -1 ) by thwing snow on thwing soil slbs collected in fll 2009 from 12-yer long-term liquid hog mnure field study site. Mens followed by the sme letter re not significntly (P 0.10) different. Error brs denote stndrd devitions of the mens Dissolved mmonium-nitrogen in wter moving rpidly cross the surfce of frozen soils from liquid hog mnure mended soil Similr to the results from the SCM tretments, the mount of NH4-N exported in ll three of the LHM tretments for wter running cross frozen soils ws similr nd not significntly (P 0.10) different from the control tretment (Fig. 4.14), nd lso similr to the mount of NH4-N collected in run-off nd lechte from thwing snow nd soil slbs (Fig. 4.13). Dissolved NH4-N concentrtions for fll 2009 re reported in Appendix Tble B.11. The lck of tretment effects of LHM on NH4-N export is similr to the lck of tretment effects for SCM. There ws less NH4-N dded in the SCM compred to the NH4-N dded in the LHM. The observed lck of difference mong LHM tretments my be ttributed to the rpid conversion of NH4-N to NO3-N in the nitrifiction process following mnure ppliction nd over the subsequent growing sesons, leving little N ccumulted in the soil s NH4-N by the time of slb removl fter hrvest in the fll. Also, ny residul removl of NH4-N by wter could be reduced due to retention of NH4-N on soil ction exchnge sites. Tretment 75

92 Runoff-lechte dissolved mmoniumnitrogen (kg NH 4 -N h -1 ) 0.05 LSD (0.10) = Control-Disturbed Brodcst nd incorportion L/h Subsurfce bnded 37000L/h Subsurfce bnded L/h Fig Export of dissolved mmonium-nitrogen (kg NH4-N h -1 ) in wter moving rpidly cross the surfce of frozen soil slbs in fll yer long-term liquid hog mnure field study site. Mens followed by the sme letter re not significntly (P 0.10) different. Error brs re stndrd devitions of the mens. 4.6 Conclusion Tretment The ddition of SCM using brodcst lone, brodcst nd incorported nd subsurfce bnding techniques significntly incresed SRP export in thwing snow nd soil slb monoliths. However, there ws no significnt (P 0.10) effect of SCM plcement method on SRP export in snowmelt run-off nd lechte in the soil slbs obtined from the SCM treted plots. This suggests tht incorportion of mnure or subsurfce bnding my not be effective in reducing trnsport. While in-soil plcement my reduce mnure contct with wter during spring melt, it my lso enhnce the process of mnure decomposition nd production of SRP s well s provide chnnels for preferentil flow of wter. The ddition of SCM using ll three plcement methodologies significntly incresed SRP export in run-off collected from wter flowing rpidly cross the frozen surfce of soil slb. However, the mounts exported by wter running cross frozen soil were bout one hlf of tht exported from snowmelt running off nd percolting through thwing soil. Compred to three yers of SCM ppliction, pplying LHM for 12-yers resulted in smller mounts (bout ten times less) of SRP exported in wter from soil slb monoliths. This my be explined by crop removl nd lower mnure P input over the durtion of the 12-yer long-term LHM study. Reduction in the solubility of the P with ging could lso be fctor. Chemicl nd 76

93 spectroscopic ssessments of phosphorus species present in the soils would help confirm this spect. There ws no significnt effect of mnure ppliction rte or method on NO3-N export, except for the brodcst nd incorporte SCM tretment which hd higher NO3-N export in wter flowing cross the frozen soil surfce compred to the unmended control. Overll greter vribility ws encountered in NO3-N export compred to SRP. Similr to phosphte export, the NO3-N export ws lower in wter running cross frozen soil surfces compred to snowmelt occurring on thwing soils. Interestingly, NO3-N export ws similr between SCM nd LHM mended soils, despite the LHM soils hving higher NO3-N content. There ws trend for the high LHM ppliction rte which cused ccumultion of NO3-N in the soil to hve the highest NO3-N export in snowmelt wter. Mnure tretment hd no significnt (P 0.10) effect on NH4- N export in the soils, regrdless of type of pplied niml mnure. This my be ttributed to the predominnce of NO3-N over NH4-N, likely due to rpid nitrifiction of the NH4-N, especilly fter severl yers of mnure ppliction. Nitrifiction, N uptke by the crop, nd dsorption of NH4-N to soil ction exchnge sites could explin the observed smll mounts of NH4-N removed by wter in the mnure tretments. 77

94 5. EFFECT OF SOLID CATTLE MANURE PLACEMENT METHOD ON SOIL CARBON, PHOSPHORUS AND NITROGEN REMOVAL BY LEACHING IN INTACT SOIL CORES 5.1 Prefce The ppliction of niml mnures to griculturl soil is common method of returning phosphorus (P) nd nitrogen (N) tht is removed from fields vi plnt uptke nd hrvest, nd subsequently consumed by nimls. Upon incorportion into the soil through tillge nd/or seeding opertions, microbil brekdown nd solubiliztion of nutrient-contining mnure constituents cn serve s P nd N nutrient source for plnts nd build soil orgnic mtter. Nutrient movement offsite from run-off nd/or leching cn led to non-point source contmintion of surfce nd subsurfce wter bodies. Chpter 4 covered series of experiments in which soluble rective inorgnic P nd inorgnic N trnsport ws ssessed in simulted snowmelt run-off from mnure mended soils. This chpter (Chpter 5) covers study in which the verticl trnsport of orgnic nd inorgnic forms of nutrient ws ssessed in mnure mended soils. This ws ccomplished vi the collection of intct soil cores from mnured field plots followed by collection of lechte from the bottom of the cores. In this study, cttle mnure tretments were utilized nd becuse of the dominnt presence of orgniclly bound N for cttle mnure identified in Chpters 3 nd 4, both orgnic nd inorgnic forms of crbon (C) nd N were mesured long with phosphte nd nitrte in the lechte. 78

95 5.2 Abstrct Spring snowmelt in Ssktchewn cn trnsport nutrients such s phosphorus (P) nd nitrogen (N) from the soil surfce s well s lech nutrients situted on the soil surfce or upper surfce (0-5 cm depth) downwrd in the soil profile. Rinfll events during the spring nd summer cn lso induce net downwrd leching. The objective of this study ws to determine how the plcement of solid cttle mnure (SCM) ffects the export of totl orgnic crbon (TOC), totl N, orthophosphte (PO4-P) nd nitrte-nitrogen (NO3-N) from the surfce vi downwrd leching in the soil profile using intct soil columns (0-15 cm) collected from mnured plots in the field. Tretments in which the SCM ws pplied using the subsurfce bnded ppliction method showed greter export of ll nutrients compred to the SCM brodcst lone tretment. Totl OC export during the first leching event in the subsurfce bnded high rte (60.6 t h -1 ) SCM tretment ws 13.5 kg C h -1 nd ws bout double the export (6.4 nd 7.6 kg C h -1 ) in the brodcst lone nd brodcst nd incorported tretments, respectively. Totl N export out of the core in the subsurfce bnded tretment ws 3.5 nd 3.9 kg totl N h -1 fter the first nd second soil core leching, nd ws significntly higher thn the totl N leched in the brodcst lone nd brodcst nd incorported tretments. Orthophosphte-P leched out of the intct soil cores from the subsurfce bnded tretment ws 1.9 kg P h -1 during the first leching event nd ws significntly greter thn the orthophosphte-p leched out of the brodcst lone nd brodcst nd incorported SCM tretments. A higher content of soluble P forms t depth in the soil such s originting from residul bnd of mnure could explin the greter mount of P removed from the 0-15 cm depth in the subsurfce bnded SCM tretment, compred to the other two SCM tretments. Nitrte-N exported from the soil core ws greter in the subsurfce bnded (0.93 kg NO3-N h -1 ) nd brodcst nd incorported (0.92 kg NO3-N h -1 ) SCM tretments, compred to brodcst lone tretment. Subsurfce bnding of SCM t the cm depth would decrese the contct with soil minerl nd orgnic dsorption sites nd lso potentilly increse microbil decomposition nd minerliztion compred to brodcsting, llowing for greter element leching from the surfce horizons. 79

96 5.3 Introduction The downwrd trnsport from the surfce following high rtes of mnure ppliction cn serve s nutrient input to subsoil horizons (Ashjei et l., 2010), ffecting trnsformtions nd fte of nutrient in both the surfce nd subsurfce horizons. Phosphorus tht is trnsported to surfce nd subsurfce wter bodies cn cuse environmentl problems such s eutrophiction, while contmintion from N cn cuse humn helth problems. The wter pssing through the soil, termed lechte, my flow lterlly or verticlly. Export in surfce run-off nd shllow subsurfce lterl flow from simulted snowmelt conditions ws exmined in the previous chpter (Chpter 4). Due to the higher mount of N in the orgnic form in SCM nd the C content present in the SCM fecl mtter nd strw bedding, the mount of N relesed through minerliztion cn be quite low, especilly in the yer of SCM ppliction (Qin nd Schoenu, 2002b). Beef cttle feedlot mnure contins bout ~15 % C nd dds considerble mounts of orgnic mtter (OM) to the soil (Eghbll nd Gilley, 1999), nd portion of this C is mobile in wter nd cn potentilly ffect trnsformtions of P nd N in the subsoil (Konschu, 2013). Therefore, it is lso importnt to consider C in lechte wter. Depending on spring time soil moisture nd temperture conditions, NO3-N cn be exported from field site by surfce runoff nd/or subsurfce downwrd leching movement (Krmnos et l., 2007). In the soil itself, phosphorus (P) is thought to be reltively immobile nutrient, due to the bility of the soil to remove P from solution nd retin the phosphte ion vi dsorption nd precipittion rections (Hygrth nd Jrvis, 1999). Solid cttle mnure contins P in both orgnic nd inorgnic forms. Soil nutrients relesed from pplied niml mnure re subject to off-field export vi surfce run-off wter nd subsurfce lechte from melting snow, s well s rinfll events (Chnsyk nd Woytowich, 1987; McConkey et l., 1997; Vn Vliet nd Hll, 1991). Depending on soil moisture nd temperture conditions during spring snowmelt, orgnic P cn be mobilized nd minerlized, nd is rendered vilble for leching export (Sims nd Shrpley, 2005). The mount of P tht cn be leched in soil from SCM is greter if the soil hs higher vilble soil P content (Ashjei et l., 2010) nd if the soil hs received lrge mounts of SCM nd/or received SCM for long time period (Eghbll et l., 1996). Ashjei et l. (2010) reported tht fter eight yers of 400 kg N h -1 SCM ppliction rtes, wter soluble P removed in soil columns by leching ws significntly greter thn unmended controls. Eghbll (2003) observed 80

97 in Nebrsk soil tht when SCM ws pplied on crop N requirement bsis, P ccumulted in the upper 15 cm nd more leching of P ws observed t 30 cm depth. Along with ffecting P trnsport in wter moving overlnd, the overloding of P sorption sites seems likely to llow non-sorbed P to move downwrd from the surfce horizon in the soil profile with percolting wter from nnul events such s spring snowmelt in the Cndin priries, s well s intense rinfll events throughout the seson. Nitrte-N leching in soil receiving SCM is dependent on the composition of the mnure N nd environmentl conditions. Nitrogen in mnure tht is in either n orgnic form or NH4-N will not be highly mobile (Ashjei et l., 2010). In SCM, most of the N is comprised of orgnic N, with smll mounts of NH4-N nd little or no NO3-N (see Chpter 3). Nitrte is the soluble, most mobile form of N. The degree of minerliztion nd nitrifiction of NH4-N to NO3-N, enhnced by wrm, moist soil conditions, will gretly influence the overll leching potentil of N dded to soils in SCM (Eghbll nd Power, 1999). The fte of soluble P nd N will lso be ffected by OC in the soil solution, s it is redily decomposble substrte for promoting microbil growth nd trnsformtions. In Chpter 4, the effect of mnure plcement on the horizontl surfce nd lterl subsurfce trnsport of rective inorgnic PO4-P, NO3-N nd NH4-N by snowmelt wter ws detiled. These ions were investigted becuse of their direct nd immedite importnce s sources of nutrient for qutic growth orgnism such s lge when entering into surfce wter bodies directly from run-off. However, wter pssing through soil hs greter opportunity to interct with the soil nd remove other forms of nutrients importnt in cycling, especilly in cttle mnure mended soils which dd considerble mounts of OM directly to the minerl soil when incorported or bnded. Previous studies hve exmined leching processes in soil using columns of soil tht re mde by pcking with dried nd ground soil removed from the field, it ws felt tht use of this pproch in this study would crete too mny rtifcts (Trklson nd Leytem, 2009; Ojekmi et l., 2011). The mobility of P nd N forms from ppliction of high rtes of SCM ppliction s ffected by method of ppliction (e.g., brodcst lone versus brodcst nd incorported versus subsurfce bnded ppliction methods) hs not been documented, yet is importnt when mking decisions for best plcement of mnure to mximize plnt recovery nd minimize losses. Therefore in this study the pproch ws to use intct soil cores collected directly from the field soil so s to preserve the crop residue nd mnure distribution s well s the soil mcro nd 81

98 micro structure tht is importnt in wter flow through the soil nd interction of the wter with the soil. One considertion of the soil core method is tht it is n indirect mesurement of soil NO3- N leching from the surfce (0-15 cm) depth. The leching is time dependent nd sptilly vrible cused by vrying N concentrtions in SCM nd fctors controlling rtes of minerliztion nd distribution in brodcst lone, brodcst nd incorported nd subsurfce bnded ppliction methodologies. In-situ pproches to leching ssessment like lysimeters my not be most pproprite for mnure plcement studies with high nticipted vribility cross the plot re such s this, due to the lrge number of units tht my be required to be instlled per plot. The objective of this experiment ws to collect intct soil cores nd conduct leching ssessments to determine how the plcement of SCM in brodcst lone, brodcst nd incorported nd subsurfce bnded methods ffects the leching of soluble orgnic C nd N, long with PO4-P nd NO3-N in the top lyer of the soil. 5.4 Mterils nd Methods Generl experimentl setup A detiled description of the Dixon SCM field study site ws previously provided in Chpter 3, specificlly, section The SCM field tril soil core leching study ws set up s rndomized complete block design, nd tretments were replicted four times. The Dixon site ws estblished in the spring of 2007 when SCM ws pplied to the plots mesuring 3.05 x 6.09 m. There re two control tretments for the SCM tril t Dixon, the first consisting of no mnure or fertilizer being pplied nd no disturbnce of the soil (unmended, undisturbed control), the second control tretment consisting of no mnure or fertilizer being pplied but with disturbnce of the soil using the coulter openers of the SCM injector mchine. Solid cttle mnure ws pplied using three ppliction procedures; 1) brodcst ppliction where SCM ws pplied on the soil surfce (no incorportion), 2) brodcst nd incorported where SCM is pplied on the soil surfce nd then incorported using disk, 3) subsurfce injection, where SCM is subsurfce bnded using the PAMI SCM Injector Mchine in six subsurfce trenches using 60 cm coulter openers spced 30 cm prt, pplying SCM product t depth of cm. Closing wheels of 45 cm dimeter covered the exposed injection trench contining the mnure with soil. 82

99 5.4.2 Core collection nd leching experiment The experimentl site description nd mnure tretments t Dixon, SK used for this experiment re described in section 3.4 of this thesis nd will not be repeted here. Three intct soil cores were removed from ech of the four replicte plots of the disturbed-control tretment, brodcst lone, brodcst nd incorported nd subsurfce bnded SCM mnure tretments. Intct soil cores were collected from the experimentl tretment plots using polyvinyl chloride (PVC) pipe tubes mesuring 10.0 cm inside dimeter by 15.0 cm in overll length were inserted into ech of the four high SCM rte (60.6 t h -1 ) replicte plots, pplied s 1) brodcst lone, 2) brodcst nd incorported, nd 3) subsurfce bnded ppliction of mnure completed in My of The intct soil cores were inserted to depth of 15 cm nd collected using hnd held core pounder device in mid-oct. 2007, fter hrvest opertions on the field site hd been completed. Three cores were collected from ech plot t rndom. The intct soil PVC pipe, with ccompnying surfce crop residues were excvted, plced in plstic bgs nd frozen t -20 C to represent winter conditions. For the leching study, the frozen cores were first removed from the freezer nd llowed to slowly thw nd wrm to 20 o C. A leching system ws developed nd is described s follows. To enble collection of the lechte from the intct soil PVC cores, the bottom of the intct soil cores ws covered with perforted wshed cloth screen. The cloth ws pre-wshed nd rinsed with deionized wter four times beforehnd nd used to prevent ny prticulte mteril tht might be loosened from the bottom of the core from entering into the lechte collection vessel (Fig. 5.1). Another PVC core ws plced on top of the soil PVC core with the sem wrpped in prfilm nd duct tped to prevent wter lekge. All core were brought to field cpcity by dding 200 ml of deionized wter nd then llowed to equilibrte for 48 hours. Any smll mount of excess wter tht ws noted to hve leched through the soil cores during this period were collected nd poured bck onto the core. Once field cpcity ws chieved nd the core hd equilibrted, two seprte leching opertions ws conducted. In ech leching event, the intct soil cores were leched with 392 ml of deionized wter, dded to the surfce representing 5 cm leching event, clculted using the volume nd core dimeter of the cylinder. After one week, nother 392 ml of deionized wter ws dded to the soil cores. All lechte wter ws collected over 24 h period nd mesured, with evportion prevented by covering the collection vessel with plstic. The lechte wter ws immeditely frozen nd stored in freezer t -20 C until nlysis. After thwing to 20 83

100 o C, smples were filtered by pssing the lechte volume through Millipore TM 45 µm glss filters. The filtered smples were then immeditely nlyzed for: totl orgnic crbon (TOC) nd totl N using Shimdzu TOC-V nlyzer. The NH4-N, NO3-N nd orthophosphte P (soluble rective P; SRP) were mesured colorimetriclly using using Technicon utomted colorimetry nlyzer s described in Chpter 4. Fig Photogrph depicting intct soil core leching experiment Sttisticl nlysis Dt were nlyzed s rndomized complete block design, replicted four times using three smples collected per tretment for ll field experiments t the SCM Ssktchewn site for TOC, TN, orthophosphte-p nd NO3-N nd NH4-N with one fctor for the method of SCM ppliction. Smple dt ws nlyzed for normlity nd equlity of vrinces using the univrite procedure nd log trnsformed where necessry. Mens seprtion comprisons for ll vribles were conducted using the generl liner model procedure using lest significnt difference (LSD) (P 0.10) clculted with SAS Proc GLM (SAS version 9.0, 2008). 84