2005 Final Report for Manitoba Livestock Manure Management Initiative. Hog Manure on Forages Coarse-textured Soil (Zhoda Fertility Trial)

Transcription

1 25 Finl Report for Mnito Livestock Mnure Mngement Inititive Hog Mnure on Forges Corse-textured Soil (Zhod Fertility Tril) Steve Sger nd Dvid Przednowek* Drft Mrch 23, 25 * This report hs een prepred y Dvid Przednowek on ehlf of Steve Sger of Agriculture nd Agri-Food Cnd, Pririe Frm nd Rehilittion Assocition (AAFC- PFRA). The project ws conducted t Zhod, MB etween 22 nd 24 (lndowner Juergen Schuert), nd ws sponsored y the Sturturn-Piney Agriculturl Development Assocition (SPADA), Mnito Agriculture, Food, nd Rurl Inititives (MAFRI - Peter Petrsh, Roger Berrd, Wlly Hppychuk, Hether Froee), AAFC-PFRA, Elite Swine, Hytek Feeds, Rempel Frms, the Mnito Forge Council, nd the Seine-Rt River Conservtion District. The project ws funded y the Mnito Rurl Adpttion Council (MRAC), the Mnito Livestock Mnure Mngement Inititive, nd AAFC.

2 Tle of Contents Pge 1. Executive Summry Introduction Ojectives Field Monitoring nd Mesurements Site Description Experimentl Design Soil nd Soil Wter Monitoring Forge Hrvesting nd Qulity Anlyses Precipittion nd Groundwter Monitoring Sttisticl Anlyses Results nd Discussion Precipittion nd Soil Wter Monitoring Experiment 1 Results Experiment 2 Results Conclusions References Appendices Appendix A - Comprison of Olson P sttus in the soil profile mong 12N nd control tretments Appendix B Selected forge dt from Experiment Appendix C Monitoring of soil N sttus in Experiment Appendix D - Monitoring of soil P sttus in Experiment Appendix E Summry of results of pn lysimeter study

3 1. Executive Summry Mnito hs experienced drmtic growth in the hog industry. Hog production is lso expnding from trditionl grin-producing res of the province into res primrily involved in forge nd cttle production, such s southestern Mnito nd the Interlke. Some of the forge lnd tht is currently used or destined for receiving hog mnure in the future is considered sndy or corse-textured soil. Such soils tend to hve higher risk of leching of nutrients thn finer textured soils. Currently, there is limited informtion regrding the gronomic nd environmentl impcts of the ppliction of hog mnure to forges grown on corse-textured soils. Studies were initited ner Zhod, MB, to determine the impct of the timing nd rte of hog mnure pplied to forge grown on corse textured soils with high wter tles. Precipittion nd soil groundwter dt were lso collected. In Experiment 1, mnure tretments equivlent to, 6, 9, 12 l N c -1 were pplied commencing in the summer of 22 in summer nd fll fter forge hrvesting; tretment consisting of split ppliction of mnure equivlent to 12 l N c -1 ws lso pplied (6 l c -1 ech in summer nd fll). Four replictes were rrnged in completely rndomized design. In Experiment 2, mnure ws pplied t rtes equivlent to, 1, 2, 3, nd 4 l N c -1 in spring 24 in three replictes in strip plot design. Besides forge yield nd qulity, the distriution of nitrte- N nd phosphorous in the soil profile ws lso monitored in oth experiments. In Experiment 1, evidence of nutrient leching downwrd in the soil profile ws miniml. Depending on conditions during the growing seson nd susequent to mnure ppliction, N losses my hve ccounted for considerle shre of the N tht ws initilly pplied. Given the poor soil fertility t the site, strong yield response to pplied mnure ws lso likely contriuting fctor to minimizing nutrient leching. The evidence suggests tht forges indeed re strong cndidte for mnure ppliction, especilly in circumstnces where inherent soil fertility is poor. Evidence of nutrient leching ws more compelling in Experiment 2. There ws strong evidence of nutrient leching downwrd in the soil profile for the 3N nd 4N tretments. At the lst smpling dte, there ws considerly more nitrte-n t depth in the soil profile for the 4N tretment compred to the other tretments pplied. In oth experiments, residul soil nutrient levels were low to very low, lthough there ws evidence of K ccumultion in oth experiments s mnure ppliction rte incresed. Residul soil N levels met the regultions set out y the Mnito Mnure nd Mortlities Mngement Regultions, nd were low to very low for nitrogen, phosphorous, nd potssium sis the Mnito Soil Fertility Guide. However, the evidence of nutrient leching in Experiment 2 during the growing seson indictes rel thret of downwrd movement of nitrte-n where ppliction rtes re excessive reltive to crop demnd. Forges responded strongly to mnure ppliction with respect to nutrient uptke, nutrient content, nd dry mtter yield. In Experiment 1, dry mtter yields incresed considerly s mnure ppliction rte incresed, s did nutrient uptke. The impct on forge nutrient content ws less consistent cross hrvests, lthough s expected there ws trend in most instnces of incresing nutrient content with incresing mnure ppliction rte. Fll-pplied mnure ppered to produce higher forge yields, possily s result of greter nutrient losses in summer-pplied tretments s well s the lck of nutrient response when dry conditions previled during the summer period. Split N ppliction ws no more effective t incresing forge productivity thn the 12N tretment when considering productivity over production cycle (i.e. fll nd summer hrvest). Tming of nutrient vilility is key considertion in ttempting to mximize forge productivity. In Experiment 2, for exmple, it ws cler tht nutrient vilility ws delyed somewht reltive to ppliction dte, s indicted y dely in the ccumultion of nitrte-n in the upper soil profile. Given the lck of leching oserved in Experiment 1 (up to trget N rte of 12 l c -1 ), incresing mnure ppliction rtes my e fesile reltive to current recommendtions. Splitting mnure ppliction rtes my lso provide nother mens of incresing mnure ppliction rtes without cusing dverse effects to the environment. 2

4 2. Introduction In recent yers, Mnito hs experienced drmtic expnsion in the hog industry. Hog production is lso expnding from the trditionl grin-producing res of the province to res devoted primrily to forge nd cttle production, such s southestern Mnito nd the Interlke. Some of the forge lnd tht is currently used or destined for receiving hog mnure is considered sndy, corse-textured soil, nd hs higher risk of nutrient leching compred to finer textured soils. Furthermore, forges re often grown on inherently infertile soil (Cowell nd Doyle 1993), nd ville soil N is typiclly deficient due to the constnt removl of topgrowth nd crop N use (Johnston et l. 24). Currently, there is limited informtion regrding the gronomic nd environmentl impcts of the ppliction of hog mnure to forges on corse-textured soils. Given the cost of N fertilizer nd the high N demnd of grss hy forge, mny producers see mnure s n opportunity to improve soil fertility nd increse forge yield with little dditionl cost other thn ssocited mnure ppliction costs. Assuming the current cost of N fertilizer is $.43 l -1 N (MAFRI 25) nd n N ppliction rte of 1 l c -1 (the MB Soil Fertility Guide recommends 9-11 l c -1 for estlished stnds of grss hy), fertilizing grss forge to mximize yield would in theory cost $43 c -1, without even considering ppliction costs. In ddition, forges provide series of other enefits with respect to mnure ppliction. Forges provide wider window for mnure ppliction compred to nnul crops; forge lnd provides severl opportunities to pply mnure from spring through fll, wheres mnure ppliction on nnul croplnd trditionlly must e done in erly spring prior to plnting or during the lte fll susequent to hrvesting. Forges re lso hevy users of nutrients, prticulrly nitrogen (N) nd phosphorus (P), nd lso hve deep firous root systems tht hold soil prticles in plce, in turn reducing the risk of soil erosion. The high N requirements of forges mke them n idel cndidte for mnure ppliction in high volumes (Biley et l. 1997). Finlly, forges use lrge mounts of wter during the growing seson, reducing the mount of runoff during rinfll events nd spring snowmelt. For exmple, the verge crop wter demnd of lflf through the end of the second cut t Zhod, MB is 375 to 4 mm, which is comprle to corn nd much higher thn the mm demnd of spring whet (MAFRI 1999). There re numer of producers growing forges in southest Mnito tht pply mnure to corsetextured soils with high wter tle. The chllenge for producers is to increse forge production y pplying mnure without cusing undue risk to the environment. Besides nitrte N, leching of P, potssium (K), nd other solule slts cn occur s result of hevy mnure ppliction (Biley nd Buckley 1999). Akinremi (24) suggested tht the potentil downwrd movement of P nd dissolved orgnic cron re often neglected in leching studies which focus solely on nitrte-n. Interestingly, Simrd et l. (1996) oserved tht the risk of P migrtion from mnure ws greter for forge crops reltive to corn ecuse the greter frequency of soil iopores due to the sence of tillge llowed P to move more freely through the soil profile. Another considertion in the fertiliztion of forges is forge qulity. Forge qulity influences niml performnce y ffecting overll forge consumption nd/or y influencing the efficiency of nutrient consumption (Gozho nd Wittenerg 24). Crude protein content is the primry mesure of forge qulity (Cowell nd Doyle 1993), lthough the sttus of other nutrients is lso considertion. For exmple, excess K consumption cn led to prolems such s milk fever (low lood clcium levels) nd grss tetny (low mgnesium levels in plsm nd cererospinl fluid (Gozho nd Wittenerg 24), the ltter of which cn lso e due to excessive rtes of mmonium fertilizers (Hvlin et l. 1999). Given tht ll of the K in mnure is in orgnic form nd therefore redily ville to the crop, forge production for diry cows is recommended on mnure-free fields in order to mintin low K levels in forge (Green nd Herd 22); K sttus is lso considertion for cow-clf nd feeder cttle opertions. 3

5 At the time this project ws developed, Mnito Conservtion ws in discussions with stkeholders to discuss chnges to the Livestock nd Mortlities regultions. One spect of discussions ws tht lnds identified s eing environmentlly sensitive might e suject to mnure ppliction limittions. As pointed out y Slevinsky et l. (22), 3 T c -1 grss hy crop (1% crude protein) removes 13 l N c -1 on verge, wheres the mximum mnure N ppliction to environmentlly sensitive lnds is 6 l c -1 for nnul crops, leving the cceptle N ppliction rte fr short of wht is required to mximize forge production (MAFRI recommends pplying mximum 15 l c -1 of mnure N to grsses in generl). This project ws developed initilly to monitor the gronomic nd environmentl impcts of 1X, 1.5X nd 2X this rte on corse-textured soil with high wter tle. The following report summrizes the results nd oservtions from series of field trils conducted during the 22, 23, nd 24 growing sesons. 3. Ojectives This project ws designed to provide gronomic nd environmentl informtion regrding the impct of hog mnure ppliction to forges grown on corse-textured soils. The three min ojectives were: 1) To determine the effect of timing of ppliction of hog mnure on forge yield. 2) Monitor the effects of different rtes of hog mnure on forge yield. 3) To monitor the movement of hog mnure nutrients in sndy soil clssified s 4m. 4. Field Monitoring nd Mesurements 4.1 Site Description This tril ws locted on NW E in the RM of L Broquerie. The soil series is Pnsy which is n imperfectly drined Gleyed Eluvited Eutric Brunisol. The texture of this soil tends to e comprised of fine snd throughout the soil profile, while internl dringe is impeded y the presence of high wter tle. The griculturl cpility of this soil is clss 4m, with wter holding cpcity eing limiting fctor to productivity. The forge stnd composition t the site ws primrily orchrdgrss, long with some timothy nd quckgrss. Orchrdgrss is cool seson unchgrss with dense firous root system, nd is common hy nd psture grss in southest Mnito. Orchrdgrss thrives on well-drined soils nd yield is responsive to incresing soil fertility. Timothy is cool seson unchgrss dpted to wetter conditions, nd will tolerte nd thrive mid moderte spring flooding. Timothy hs shllow firous root system nd its yield is lso responsive to incresing soil fertility, while quckgrss is shllow-rooted sodforming grss. 4.2 Experimentl Design Two experiments were initited t the Zhod site. Experiment 1 ws initited in 22 s completely rndomized design with four replictes. Individul plot dimensions were 11 ft (3.4 m) wide X 23 ft (7 m) long. Eight tretments were pplied s follows: 4

6 After 1 st cut After 2 nd cut Mnure Appliction Dtes Tretment l c -1 mnure N pplied N (control) N Fll 6 Oct-8 Oct-2 9N Fll 9 Oct-8 Oct-2 12N Fll 12 Oct-8 Oct-2 6N Summer 6 Jul-28 Jul-3 Jul-15 9N Summer 9 Jul-28 Jul-3 Jul-15 12N Summer 12 Jul-28 Jul-3 Jul-15 12N Split 6 6 Jul-28 Jul-3 Oct-8 Oct-2 Jul-15 Tle 1. Description of Experiment 1 tretments nd mnure ppliction dtes Experiment 2 ws initited in the spring of 24 djcent to Experiment 1 in order to evlute the impct of significntly higher rtes of spring-pplied mnure N on forge yield/qulity nd the distriution of nitrte-n in the soil profile. Trget mnure N rtes were, 1, 2, 3, nd 4 l N c -1 ; mnure ws pplied My 22, 24. Plot dimensions were 2 ft (6.1 m) wide X 23 ft (7 m) long. Given the homogeneity of the plot res, the three individul soil smples collected from ech plot during ech smpling dte were considered individul replictes (G. Crow, personl communiction). Mnure ws surfce pplied using oom spreder pproximtely 6 inches (15 cm) ove the sod surfce. The oom ws constructed of 6 inch (15 cm) PVC piping nd mounted t the rer of domestic septic tnk truck. The pressurized mnure tnk llowed n even ppliction rte of the mnure. A drpe ws mounted over the oom in order to to reduce splshing nd odours during ppliction. The mnure ppliction rte ws clculted using field test mmoni meter results. Mnure smples were susequently nlyzed to verify the ctul mounts of nutrients pplied to the plots. Totl ville N ws clculted s.65*mmoni N +.25* orgnic N. Bsed on estimtes of ville N nd P, the N:P rtio of the mnure rnged etween roughly 2:1 (fll 22) to 8:1 (summer 24). The typicl hog mnure N:P rtio is 4:1, wheres most hy crops utilize N nd P in rtio of 7:1 (Biley nd Buckley 1999). In lmost ll instnces in Experiment 1, the trget N rte ws very close to the ctul rte pplied with the exception of the 6 N nd 9 N tretments pplied in the fll of 22 (Tle 2). Though not drmtic devition from the trget N levels, the consistency of pplying the desired ppliction rte is n issue, especilly considering most producers lck monitoring equipment (Petku nd My 21). Over the course of the experiment, the 6N, 9N, nd 12N tretments received n verge of 168, 245, nd 322 l c -1 of N, respectively. P ppliction rtes for the sme tretments verged 45, 6, nd 82 l c -1, respectively. 5

7 mnure N pplied (l c -1 ) Tretment 22 Summer 22 Fll 23 Summer 23 Fll 24 Summer Totl N (control) 6N Fll N Fll N Fll N Summer N Summer N Summer N Split Tle 2. Mnure N pplied during the course of Experiment 1. mnure P pplied (l c -1 ) Tretment 22 Summer 22 Fll 23 Summer 23 Fll 24 Summer Totl N (control) 6N Fll N Fll N Fll N Summer N Summer N Summer N Split Tle 3. Mnure P pplied during the course of Experiment 1. Nutrient pplied (l c -1 ) Tretment N P K N (control) 1 N N N N Tle 4. Nutrients pplied during the course of Experiment Soil nd Soil Wter Monitoring Deep soil nitrte-n monitoring ws conducted following the ppliction of mnure in order to determine if nitrte-n ws leching through the soil profile. In Experiment 1, smpling ws conducted following rinfll events under the N control, 12N Summer, nd 12N Fll tretments, while smpling ws conducted for ll tretments in Experiment 2. Smpling ws crried out t one-foot (3 cm) increments down to the wter tle; smples were collected s deep s the cm increment during the course of the study. To monitor if nitrtes were leching through the soil profile, pn lysimeters were instlled s prt of Experiment 1. Steel pns 2 ft y 2 ft (.6 m x.6m) were inserted in horizontl position into the soil t depth of.75 m to collect moisture moving through the soil profile. Pns were hydruliclly pushed in from side trench to result in miniml soil disturnce. Moisture ws collected from plstic 2 L pil uried elow nd to the side of the plte. The lysimeters were locted t the est end of the plots nd 6

8 plced under the control nd 12N tretments in two replictes. Sites were smpled following significnt rinfll events; wter ws pumped from the pils using hose nd suction pump. The lysimeters functioned properly in 22 nd collected lechte. However, in 23 nd 24, prolems were encountered with the lysimeters, nmely excess wter eing collected in the pils. We were unsure if the wter tle ws ove the lechte or if the sels of the pils filed nd llowed wter to collect in the pils. Given the difficulties encountered with this spect of the experiment, results re not reported n the min ody of this document for 22, ut re insted reported in Appendix E. 4.4 Forge Hrvesting nd Qulity Anlyses Forges were hrvested in summer nd fll sed on the optimum vegettive stge to chieve mximum forge qulity (lte June nd the end of August). Hrvesting ws conducted with the SPADA plot hrvester in strips of 2.5 ft X 23 ft (.76 m X 7 m). Smples were weighed in order to determine dry mtter yield. Forge nlysis ws conducted sed on individul reps t Norwest ls. Nutrient nlysis ws conducted using NIR. While very suitle for monitoring N sttus, wet chemistry is more desirle for evluting P nd K sttus, lthough for the purposes of this experiment the nlysis ws sufficient. 4.5 Precipittion nd Groundwter Monitoring In 22, wether sttion ws instlled t the site to collect timely precipittion informtion. This informtion ws used to ssess when deep soil smpling nd wter collection would occur. In 23, the wether sttion ws not ville nd rin guges were susequently instlled to provide precipittion informtion for 23 nd 24. A ground wter monitoring well ws instlled t the outset of the study within the experimentl plot re in order to provide informtion on the fluctution of groundwter levels during the growing seson. 4.6 Sttisticl Anlyses Anlysis of soil nitrte-n dt were preceded y log trnsformtion in order to ensure tht vrinces were s homogenous s possile. Slevinsky et l (22) considered there to e evidence of nutrient leching in mnured fields if concentrtions of N nd P were oviously elevted t soil depth of >15 cm in comprison non-mnured fields. This pproch hs een tken y other uthors s well, who hve descried ulge of nitrte N in mnured plots t depth versus control plots tht received no N s evidence of the downwrd movement of nitrte N. In Experiment 1, ANOVA ws used to ssess differences in soil nutrient sttus mong N nd 12N tretments; differences were considered significnt t P <.1. In Experiment 2, single degree of freedom contrsts were used to compre the control tretment ( N) versus the 2N, 3N, nd 4N tretments. 7

9 5. Results nd Discussion 5.1 Precipittion nd Soil Wter Monitoring Prior to the initition of the experiment in the spring nd erly to mid-summer of 22, conditions were generlly drier thn norml. During the course of the experiment, the wter tle fluctuted etween 32 cm (My-31, 24) nd 159 cm (Oct-3, 23), with evidence of decrese in the depth of the wter tle susequent to significnt rinfll events (Fig. 1). In the summer of 22, mnure ws pplied on Jul-28, followed y two hevy rinfll events on 17-Aug (4.2 mm) nd 1-Sep (41.4 mm); no rinfll events of significnce were oserved susequent to the ppliction of mnure on Oct-8. The depth of the wter tle ws lmost 14 cm t the end of Octoer 22, ut recovered to 15 cm y erly April 23. In 23, mnure ws pplied on Jul-3 nd Oct-2. The first rinfll event susequent to mnure ppliction occurred on Jul-7 (1 mm), with no precipittion recorded therefter until Aug-6. The wter tle fluctuted etween 8 nd 12 cm etween erly April nd July 23, nd then rpidly declined s result of the lck of precipittion. These results re not surprising considering the poor wter-holding cpcity of the soil. Comined with the lck of precipittion etween lte June nd lte August 23, tempertures were well ove norml, exceeding 3 degrees Celsius with regulrity during July nd the first hlf of August (dt not presented). The depth of the wter tle recovered only slightly fter hevy rinfll event on Aug-28 (79 mm), nd reched its lowest point during the course of the experiment t the end of Octoer 23 (159 cm). By erly April 24, the wter tle hd recovered drmticlly to roughly 4 cm, thnks to improved precipittion during the lte fll nd winter period. The 24 growing seson rnked s one of the wettest nd coolest on record; four rinfll in excess of 3 mm were recorded during the growing seson, with nother five events in excess of 2 mm. The conditions were idel for vegettive growth, nd the wter tle hd declined to its low point for the growing seson (12 cm) y erly August. Given continued cool, wet conditions throughout the summer nd fll, the wter tle susequently rose, reching 69 mm y the end of the experiment. Mnure ws pplied in 24 on Jul-15; the first rinfll event recorded susequent to ppliction occurred the dy fter ppliction (16 mm). Precipittion (mm) Averge* My 62 n/ n/ 12 June 11 n/ July 89 n/ August Septemer Tle 5. Selected monthly precipittion recorded t the site. Normls re sed on the period for Zhod, MB. Aville t climte_normls/ index_e.html). 8

10 Precipittion (mm) Precipition (mm) nd Wter Tle Depth (cm) Precipittion (mm) Wter Tle Depth (cm) Wter Tle Depth (cm) 1-Apr 22-Apr 13-My 3-Jun 24-Jun 15-Jul 5-Aug 26-Aug 16-Sep 7-Oct 28-Oct -16 Precipittion (mm) Precipition (mm) nd Wter Tle Depth (cm) Precipittion (mm) Wter Tle Depth (cm) Wter Tle Depth (cm) 1-Apr 22-Apr 13-My 3-Jun 24-Jun 15-Jul 5-Aug 26-Aug 16-Sep 7-Oct 28-Oct -16 Precipittion (mm) Precipition (mm) nd Wter Tle Depth (cm) Precipittion (mm) Wter Tle Depth (cm) Wter Tle Depth (cm) 1-Apr 22-Apr 13-My 3-Jun 24-Jun 15-Jul 5-Aug 26-Aug 16-Sep 7-Oct 28-Oct -16 Figure 1. Precipittion nd wter tle depth monitoring in 22, 23, nd 24 t the Zhod site. Dt collection in 22 commenced with the ppliction of mnure (explining the lck of rinfll dt preceding tht period). Precipittion dt collection commenced in My in 23 nd 24, respectively. 9

11 5.2 Experiment 1 Results Nutrient Leching Bsed on soil test results there ws little to no indiction of nitrte-n leching under either tretment (Fig. 2-5). The nitrte-n my hve een tken up y the forge crop, voltilized, or leched through the soil profile efore smpling occurred, depending on the conditions experienced during the growing seson. In 23, for instnce, the potentil for voltiliztion ws very high susequent to summer mnure ppliction, since conditions were hot nd dry; the Mnito Soil Fertility Guide suggests the potentil for voltiliztion losses from unincorported mnure cn e s high s 1% under wrm, dry conditions compred to 4% for cool, wet conditions. At the -3 cm increment in the two smpling dtes following mnure ppliction, the 12N tretment exhiited higher nitrte-n levels compred to the control, lthough differences were not sttisticlly significnt; no significnt differences were oserved elow the -3 cm increment t ny point in the summer of 22. In 23, tretment effects were similr t the - 3 cm depth. The only smpling dte where the 12N tretment exhiited noticely higher nitrte-n levels (though not sttisticlly significnt) t depth occurred on Aug-29 following 76 mm precipittion event, which ws the first significnt rinfll fter the ppliction of mnure Jul-3. In the fll of 23, tretment effects were comprle t the -3 cm depth mong tretments, nd no significnt differences were oserved t depth. In the summer of 24, no significnt differences were oserved t depth mong tretments, while differences mong tretments t the -3 cm depth were much less pronounced with the exception of one smpling dte. Results of soil P monitoring were more vrile (Appendix A), lthough no evidence of nutrient leching ws oserved with the possile exception of the Aug-29 smpling dte (though not significnt the 12N tretment displyed higher P content t the 3-6 cm depth compred to the control). In survey of fields devoted to forge production in southestern Mnito (sndy nd lomy snd soil texture), Slevinsky et l. (22) oserved higher N concentrtion of N nd P to depth of 6 cm in mnured fields versus non-mnured fields, s well s concentrtion of nutrients elow depth of 6 cm in some instnces. Forge Results Additionl tulr forge dt is presented in Appendix B. Differences in verge dry mtter yield mong hrvests strongly reflected growing seson conditions. Among the three fll hrvests nd cross tretments, verge yield ws highest in 24 (849 l c -1 ), compred to 642 l c -1 in 22 nd 415 l c -1 in 23 when conditions were exceedingly dry. Differences were less pronounced mong the two summer hrvests, s yields in 23 nd 24 were 166 nd 264 l c -1, respectively. The limited precipittion during the summer months of 23 resulted in reduced second cut dry mtter yields. The limited wter holding cpcity of the soil during this dry period my hve contriuted to the reduced yields. In ddition, the ove verge tempertures my hve impcted yield, considering tht the stnd is comprised of cool seson grsses. Forge production ws impcted even though the wter tle ws within 12 cm of the soil surfce for most of the growing seson. The poor dry mtter yields exhiited y the control reflect the inherently poor soil fertility of the site, s no hrvest produced yields tht exceeded 8 l c -1 (.36 T c -1 ). Supporting this ssertion is the fct tht control plots hd no more thn 1-2 l nitrte-n c -1 over the course of the study in the top 6 cm of the soil profile. The highest verge yield recorded during the course of the study ws 2726 l c -1 for the 12N fll tretment for the first cut of 24. It is difficult to ttriute the entire enefit of mnure ppliction to the N component of the mnure lone, s mny fertility studies conducted in western Cnd hve indicted tht forge yield response to the ddition of N nd P is often greter thn the ddition of N lone (Cowell nd Doyle 1993; Johnston et l. 24). Given the poor soil fertility oserved t the site, it is plusile tht the ddition of K could hve lso contriuted to yield increses, s K deficiency cn result in significnt yield reductions s well (Johnston et l. 24). 1

12 Figure 2. Comprison of nitrte-n sttus in the soil profile during summer 22 mong 12 N nd control tretments (summer pplied mnure). 9-Aug 13-Aug 29-Aug 17-Sep 2-Sep 3-Oct NO3-N (l c -1 ) Depth (cm) N 15 12N 15 12N 15 12N 15 12N 15 12N Differences considered significnt t P <.1. 11

13 Figure 3. Comprison of nitrte-n sttus in the soil profile during summer 23 mong 12 N nd control tretments (summer pplied mnure). 17-Jul 29-Jul 7-Aug 29-Aug NO3-N (l c -1 ) * Depth (cm) N 15 12N 15 12N 15 12N Differences considered significnt t P <.1 12

14 Figure 4. Comprison of nitrte-n sttus in the soil profile during summer 24 mong 12 N nd control tretments (summer pplied mnure). 14-Jul 22-Jul 29-Jul 31-Aug NO3-N (l c -1 ) Sep Sep Depth (cm) N 15 12N 15 12N 15 12N 15 12N 15 12N Differences considered significnt t P <.1 13

15 Figure 5. Comprison of nitrte-n sttus in the soil profile during fll 22 nd 23 mong 12 N nd control tretments (fll pplied mnure) Oct 1-Oct 21-Oct 31-Oct NO3-N (l c -1 ) NO3-N (l c -1 ) *.582* Depth (cm) 6 9 Depth (cm) N 15 12N 15 12N 15 12N Differences considered siginificnt t P <.1. 14

16 Over the course of the study (i.e. ll five hrvests), significnt differences in dry mtter yield were oserved mong summer nd fll-pplied tretments. No significnt differences were oserved mong the 12N nd SplitN tretments, wheres there ws strong impct of incresing mnure ppliction rte. The 6N nd 9N tretments yielded 2-21% nd % greter dry mtter yield thn the control depending on mnure ppliction timing, compred to % for the 12N/SplitN tretments. Totl cumultive dry mtter yield of the control ws only 2196 l c -1, which indictes very poor soil fertility. While the dynmics of nutrient vilility of mnure re different from tht of fertilizer N, the reltive enefit of spring- versus fll-pplied mnure is of interest, s timing of nutrient vilility is criticl in mximizing forge production. Within this study, evluting the effect of timing of mnure ppliction on productivity cn e conducted y looking t productivity within production cycle (i.e. two consecutive hrvests). A three-wy ANOVA ws conducted on the 6N, 9N, nd 12N summer nd fll tretments using mnure ppliction rte, cycle (two full cycles were completed), nd timing (summer versus fll pplied mnure). Totl mnure N equivlents for fll-pplied 6N, 9N, nd 12N tretments ws 149, 21, nd 238 l N c -1, respectively, compred to 128, 194, nd 256 l N c -1, respectively, for summer-pplied mnure for the 6N, 9N, nd 12N tretments. A second ANOVA ws crried out to evlute differences mong the six tretments of interest, using single degree of freedom contrsts to test for significnt differences etween mnure ppliction timing mong rtes, s well s for rtes comined to vlidte the results of the first ANOVA. Results of the second ANOVA re presented elow in Tle 6. Trget N rte, timing, nd cycle ll hd significnt effect on dry mtter yield; the only significnt interction oserved mong the three fctors ws cycle*timing interction for K uptke. Interestingly, the timing of mnure ppliction hd significnt effect on dry mtter yield (P <.6) nd P uptke (P <.434), ut it ws the fll-pplied mnure tht yielded the higher results. N uptke ws higher for fll-pplied mnure (P <.12), ut not sttisticlly significnt. The gretest difference mong fll versus summer pplied mnure occurred t the 9N rte. Greter voltiliztion losses for summer-pplied mnure my explin some of these effects. DM Yield Nutrient Uptke (l c -1 ) Trget N Timing (l c -1 ) P K N 6 Fll Summer Fll Summer Fll Summer P > F* <.1 <.1 <.1 <.1 Contrsts Fll vs summer Fll vs 6N Fll vs 9N Fll vs 12N CV (%) * Differences considered significnt t P <.5 Tle 6. Comprison of forge productivity mong fll nd summer pplied mnure t trget N rtes of 6, 9, nd 12 l c

17 N uptke responded strongly to mnure ppliction rte cross ll five hrvest periods, nd ws ttriutle to dry mtter yield response. Within production cycles, no significnt differences were oserved in N uptke etween the 12N nd SplitN tretments. Cumultive N uptke rnged from 45 l N c -1 (control) to 163 l c -1 (12N summer) over the course of the study. Forge protein content vried gretly cross hrvests. The verge protein content ws highest for the fll 23 hrvest (19%), while the lowest verge protein content ws oserved for the summer 23 hrvest (11%). Significnt differences in protein content were oserved for summer-pplied tretments in two instnces (fll 22 nd fll 24), wheres the only instnce where significnt differences were recorded mong fll-pplied tretments ws in fll 22. One of the enefits ttriuted to split N pplictions to forges is production of forges with reltively higher crude protein content throughout the seson compred to single N ppliction (MAFRI 22). However, tht ws not the cse in this study, s forge protein content did not differ consistently mong the 12N nd SplitN tretments. Crude protein content levels re of interest to forge producers, s esides indequte forge yield, indequte protein content is the second most prevlent forge production prolem in Mnito (Gozho nd Wittenerg 24). P uptke response ws similr to N uptke response, s significnt differences mong tretments were oserved cross ll five hrvest periods nd P uptke responded strongly to mnure ppliction rte. For summer-pplied tretment comprisons, significnt differences in P content were oserved in two instnces, with the most pronounced differences mong tretments in the fll of 23. As for fll-pplied mnure comprisons, significnt differences mong tretments were oserved in three of five hrvests, lthough in two of those instnces the only difference oserved ws significntly lower P content of the control versus tretments tht received mnure. Cumultive K uptke over the course of the study rnged from 33 l c -1 for the control to 145 l c -1 for the 12N summer-pplied tretment, indicting K uptke responded strongly to mnure ppliction rte given the shrp increses oserved in dry mtter yield. Significnt differences in K uptke were oserved mong tretments cross ll five hrvests for oth summer- nd fll-pplied tretments. No significnt differences etween the 12N nd SplitN tretments were oserved with respect to K uptke within production cycle. K content ws most strongly influenced y mnure ppliction rte in the fll of 22 for summer-pplied tretments; K content incresed from 2.5% in control plots to 3.1% in the 9N tretment. Diry producers need lmost 1% of forge requirements to e less thn 2.5% on dry mtter sis (Green nd Herd 22). Forge hrvest results in the second hrvest following ppliction of mnure re good mesure of residul tretment effects. With respect to summer-pplied nd fll-pplied mnure, tretment effects were pronounced in the second hrvest following mnure ppliction during oth production cycles during the course of the study. However, differences mong tretments ppered to e more pronounced for summer-pplied tretment comprisons with respect to dry mtter yield. 16

18 Yield (l/c) DM Yield (l/c) of Summer nd Split Tretments - Production Cycle 1 c N 6N 9N 12N SplitN Fll 2 Summer 3 Yield (l/c) DM Yield (l/c) of Fll nd Split Tretments - Production Cycle 1 c N 6N 9N 12N SplitN Fll 3 Summer TDN Yield (l/c) of Summer nd Split Tretments - Production Cycle DM Yield (l/c) of Fll nd Split Tretments - Production Cycle 2 Uptke (l/c) d c Uptke (l/c) c 5 5 N 6N 9N 12N SplitN N 6N 9N 12N SplitN Fll 3 Summer 4 Fll 4 Summer 4 Yield (l/c) DM Yield (l/c) of Summer nd Split Tretments - Cumul. Fll/2-Fll/4 Hrvests d c Yield (l/c) DM Yield (l/c) of Fll nd Split Tretments - Cumul. Fll/2-Fll/4 Hrvests d c N 6N 9N 12N SplitN N 6N 9N 12N SplitN Fll 2 Summer 3 Fll 3 Summer 4 Fll 4 Fll 2 Summer 3 Fll 3 Summer 4 Fll 4 Figure 6. Comprison of dry mtter yield mong summer nd fll tretments. 17

19 N Uptke (l/c) of Summer nd Split Tretments - Production Cycle 1 N Uptke (l/c) of Fll nd Split Tretments - Production Cycle Uptke (l/c) c Uptke (l/c) c 1 1 N 6N 9N 12N SplitN N 6N 9N 12N SplitN Fll 2 Summer 3 Fll 3 Summer 3 Uptke (l/c) N Uptke (l/c) of Summer nd Split Tretments - Production Cycle 2 d c Uptke (l/c) N Uptke (l/c) of Fll nd Split Tretments - Production Cycle 2 d c 1 1 N 6N 9N 12N SplitN N 6N 9N 12N SplitN Fll 3 Summer 4 Fll 4 Summer 4 N Uptke (l/c) of Fll nd Split Tretments - Cumul. Fll/2-Fll/4 Hrvests N Uptke (l/c) of Fll nd Split Tretments - Cumul. Fll/2-Fll/4 Hrvests c c Uptke (l/c) e d Uptke (l/c) e d 2 2 N 6N 9N 12N SplitN N 6N 9N 12N SplitN Fll 2 Summer 3 Fll 3 Summer 4 Fll 4 Fll 2 Summer 3 Fll 3 Summer 4 Fll 4 Figure 7. Comprison of nitrogen uptke comprisons mong summer nd fll tretments. 18

20 P Uptke (l/c) of Summer nd Split Tretments - Production Cycle 1 P Uptke (l/c) of Fll nd Split Tretments - Production Cycle 1 Uptke (l/c) c N 6N 9N 12N SplitN Uptke (l/c) c N 6N 9N 12N SplitN Fll 2 Summer 3 Fll 3 Summer 3 P Uptke (l/c) of Summer nd Split Tretments - Production Cycle 2 P Uptke (l/c) of Fll nd Split Tretments - Production Cycle 2 Uptke (l/c) d c N 6N 9N 12N SplitN Uptke (l/c) d c N 6N 9N 12N SplitN Fll 3 Summer 4 Fll 4 Summer 4 Uptke (l/c) P Uptke (l/c) of Summer nd Split Tretments - Cumul. Fll/2-Fll/4 Hrvests c d N 6N 9N 12N SplitN Uptke (l/c) P Uptke (l/c) of Fll nd Split Tretments - Cumul. Fll/2-Fll/4 Hrvests d c N 6N 9N 12N SplitN Fll 2 Summer 3 Fll 3 Summer 4 Fll 4 Fll 2 Summer 3 Fll 3 Summer 4 Fll 4 Figure 8. Comprison of phosphorous uptke comprisons mong summer nd fll tretments. 19

21 K Uptke (l/c) of Summer nd Split Tretments - Production Cycle 1 K Uptke (l/c) of Fll nd Split Tretments - Production Cycle Uptke (l/c) d c c Uptke (l/c) N 6N 9N 12N SplitN N 6N 9N 12N SplitN Fll 2 Summer 3 Fll 3 Summer 3 K Uptke (l/c) of Summer nd Split Tretments - Production Cycle 2 K Uptke (l/c) of Fll nd Split Tretments - Production Cycle Uptke (l/c) c Uptke (l/c) c 1 1 N 6N 9N 12N SplitN N 6N 9N 12N SplitN Fll 3 Summer 4 Fll 4 Summer 4 K Uptke (l/c) of Summer nd Split Tretments - Cumul. Fll/2-Fll/4 Hrvests K Uptke (l/c) of Fll nd Split Tretments - Cumul. Fll/2-Fll/4 Hrvests Uptke (l/c) d c Uptke (l/c) d c 2 2 N 6N 9N 12N SplitN N 6N 9N 12N SplitN Fll 2 Summer 3 Fll 3 Summer 4 Fll 4 Fll 2 Summer 3 Fll 3 Summer 4 Fll 4 Figure 9. Comprison of phosphorous uptke comprisons mong summer nd fll tretments. 2

22 % N Tretment Fll 22 Summer 23 Fll 23 Summer 24 Fll c c 6N N N SplitN c P > F* CV (%) Mens followed y different letter re considered significnt t P <.5. Tle 7. Comprison of forge protein content mong summer-pplied tretments. % N Tretment Fll 22 Summer 23 Fll 23 Summer 24 Fll N N N SplitN P > F* CV (%) Mens followed y different letter re considered significnt t P <.5. Tle 8. Comprison of forge protein content mong fll-pplied tretments. % K Tretment Fll 22 Summer 23 Fll 23 Summer 24 Fll c N N N SplitN P > F* <.1.26 < CV (%) Mens followed y different letter re considered significnt t P <.5. Tle 9. Comprison of forge potssium content mong summer-pplied tretments. % K Tretment Fll 22 Summer 23 Fll 23 Summer 24 Fll c 1.1 c 2. 6N N N SplitN P > F* CV (%) Mens followed y different letter re considered significnt t P <.5. Tle 1. Comprison of forge potssium content mong fll-pplied tretments. 21

23 Residul Soil Nutrient Sttus Soil nutrient sttus t the end of the course of the study ws of interest, especilly with respect to the potentil ccumultion of nutrients t the higher rtes of mnure ppliction. To depth of 6 cm, totl nitrte-n ccumultion ws highest (13 l c -1 ) for the split N ppliction, lthough differences were mrginl mong tretments. Tretment effects were significnt t the -15 cm nd -6 cm depths for fll-pplied comprisons, wheres no significnt differences were oserved for summer-pplied tretments. Totl fll soil nitrte-n to depth of 6 cm less thn 2 l c -1 is considered very low for forge grsses (Mnito Soil Fertility Guide), suggesting efficient crop use of pplied N or N losses such s voltiliztion. Significnt differences in soil P sttus were oserved mong summer nd fll-pplied tretment comprisons. Residul Olsen P (mg kg -1 ) rnged from 4.8 mg kg -1 (N) to 13.3 mg kg -1 (Split N); the ltter is considered moderte level sis MAFRI guidelines. Olson P sttus of summer nd fll 6N, 9N nd 12 N tretments rnged etween 5 nd 1 mg kg -1, which is considered low level sis MAFRI phosphorous recommendtions. Compred to nitrte-n results, the difference etween SplitN nd 12N results ws much stronger for Olson P results. Finlly, soil K sttus ws considered low sis MAFRI guidelines, rnging etween 57 mg kg -1 for the control to 87 mg kg -1 for the SplitN tretment. Like the Olson P results, differences mong tretments were more noticele. Compring mong fll-pplied tretments, there were no significnt differences mong tretments except for the SplitN tretment which exhiited significntly higher K levels. There ws more grdul nd significnt increse in soil K sttus for summer-pplied mnure tretments etween the 6N nd 12N tretment. NO3-N (ls c -1 ) (mg kg -1 ) Tretment -15 cm 15-6 cm -6 cm Olsen P K N c N N N SplitN P > F* CV (%) Mens followed y different letter re considered significnt t P <.1. Tle 11. Comprison of residul soil nutrient sttus mong fll-pplied mnure tretments. NO3-N (ls c -1 ) (mg kg -1 ) Tretment -15 cm 15-6 cm -6 cm Olsen P K N c 56.8 c 6N c 68.8 c 9N c N SplitN P > F* CV (%) Mens followed y different letter re considered significnt t P <.1. Tle 12. Comprison of residul soil nutrient sttus mong summer-pplied mnure tretments. 22

24 5.3 Experiment 2 Results Nutrient Leching Anlyses Experiment 2 ws undertken lrgely s consequence of the lck of significnt differences in soil nitrte- N results mong the N nd 12N tretments oserved in Experiment 1. Significnt vriility in nitrte- N test results ws oserved mong replictes, s demonstrted y high coefficients of vrition (Appendix C). Given the wet conditions during the 24 growing seson nd the frequent nd sometimes hevy rinfll events, nitrte-n leching ws expected. Bsed on the results of single degree of freedom contrsts, strong evidence of nitrte-n leching ws oserved for the 3N nd 4N tretments (Tles 13 nd 14). Significnt differences were expected t rtes exceeding 2N. However, the strong nutrient demnd of the forge stnd my hve resulted in strong nutrient uptke even t this high levels of mnure ppliction, reducing the potentil for downwrd nutrient movement. The potentil for voltiliztion losses my hve lso een contriuting fctor to the lck of downwrd nutrient movement oserved for the 2N tretment. As expected, significnt differences were oserved t the -3 cm depth t the first smpling dte following mnure ppliction t rtes of 2N nd higher, lthough the overll level of nitrte-n ws less thn 5 l N c -1 (less thn 1 l N c -1 to depth of 9 cm). No significnt differences were oserved t the second smpling dte. By the third smpling dte (Jun-4), tretments differences hd ecome much greter, suggesting tht until this point (lmost one month fter mnure ppliction), conversion of mmonium-n to nitrte-n hd een limited. Averge nitrte-n to depth of 9 cm ws etween 6-7 l N c -1 for the control nd 1N tretments, compred to 13, 42, nd 16 l N c -1 for the 2N, 3N, nd 4N tretments, respectively. Differences mong tretments were most pronounced t the -3 cm depth, lthough t the 6-9 cm depth nitrte-n ws significntly higher for the 3N nd 4N tretments versus the control s per single degree of freedom contrsts (lso t 3-6 cm for the 4N tretment. At the fourth smpling dte on Jul-9, the totl mount of nitrte-n in the soil profile incresed cross tretments with the exception of the control. Totl nitrte-n incresed 27% nd 147% for the 3N nd 4N tretments, respectively to 87 nd 157 l N c -1, respectively. The mount of nitrte-n t the 3-6 cm depth incresed in the 3-6 cm depth mrkedly for the 3N nd 4N tretments in prticulr, while the mount of nitrte N t the 6-9 cm depth incresed two- to threefold for the 3N nd 4 N tretments. By Jul-29, significnt differences mong tretments were no longer oserved, while the totl mount of nitrte-n in the soil profile declined, indicting crop N uptke during the period. In the finl three smpling dtes, only the 4N tretment exhiited significntly different nitrte-n levels t depth compred to the control. 23

25 Smpling Dte My-28 Jun-4 Jun-18 Jul-9 Jul-29 Aug-31 Sep-16 Sep-3 Depth (cm) <.1 P vlue < Depth (cm) Degree of significnce -3 * ns **** * ns ** * *** 3-6 ns ns * * ns **** ** * 6-9 ns * ** * ns *** * * 9-12 ns ** * ns, *, **, ***, **** - Not significnt nd significnt t P <.1,.1,.1, nd <.1, respectively Tle 13. Results of single degree of freedom contrsts etween N nd 4N tretments - Experiment 2. Smpling Dte My-28 Jun-4 Jun-18 Jul-9 Jul-29 Aug-31 Sep-16 Sep-3 Depth (cm) P vlue Depth (cm) Degree of significnce -3 ** ns *** * ns * ns ns 3-6 ns ns ns * ns ns ns ns 6-9 ns ns * * ns ns ns ns 9-12 ns, *, **, ***, **** - Not significnt nd significnt t P <.1,.1,.1, nd <.1, respectively Tle 14. Results of single degree of freedom contrsts etween N nd 3N tretments - Experiment 2. Forge Results Becuse plots were hrvested in their entirety, only one replicte of forge hrvest dt ws collected for ech tretment nd s such cnnot e nlyzed sttisticlly. However, numer of oservtions re of interest. Dry mtter yield ws fr higher for the 1N nd 2N tretments versus when compred to the 3N nd 4N tretments for the first cut hrvest, which my e ttriutle to crop smothering y mnure or other deleterious effects of excessive mnure ppliction. Wheres the yield 1N tretment ws lmost doule tht of the control in the first cut, there ws effectively no difference for the second cut, indicting very little residul crryover of N to the second hrvest. However, there ppered to e considerle residul crryover for the 2N, 3N, nd 4N tretments for the second hrvest. Dry mtter yield peked t the 2N rte when the entire production cycle (two cuts) ws considered, while N, P, nd K uptke peked t the 3N rte. As expected, forge nutrient content incresed s mnure ppliction rte incresed. Compred to the control, forge protein content under the 4N tretment ws 4-45% higher, depending on hrvesting period. Forge P content incresed 7-1% etween the control nd 4N tretment, while K content of the 4N tretment incresed 7% (fll) to 28% (summer hrvest) versus the control. Interestingly, forge K content for the 3N nd 4N tretments exceeded 2.5% for oth cuts; diry producers need lmost 1% of forge requirements to e less thn 2.5% on dry mtter sis (Green nd Herd 22). 24

26 28-My 4-Jun 18-Jun 9-Jul NO 3 -N (l c -1 ) Depth (cm) N N 3N 12 4N Figure 1A. Comprison of nitrte-n sttus in the soil profile mong Experiment 2 tretments first hlf of smpling period. 25

27 29-Jul 31-Aug 16-Sep 3-Sep NO 3 -N (l c -1 ) Depth (cm) N 2N N 4N Figure 1B. Comprison of nitrte-n sttus in the soil profile mong Experiment 2 tretments second hlf of smpling period. 26

28 25 2 Dry Mtter Yield (l/c) Comprison - Production Cycle TDN Yield (l/c) Comprison - Production Cycle Yield (l/c) Yield (l/c) N 1N 2N 3N 4N N 1N 2N 3N 4N Summer Fll Summer Fll N Uptke Comprison - Production Cycle P Uptke Comprison - Production Cycle 7 1 l/c l/c N 1N 2N 3N 4N N 1N 2N 3N 4N Summer Fll Summer Fll K Uptke Comprison - Production Cycle l/c N 1N 2N 3N 4N Summer Fll Figure 11. Comprison of forge hrvest results comprisons mong tretments in Experiment 2. 27

29 % N % P % K Tretment Summer Fll Summer Fll Summer Fll N N N N N Tle 15. Forge nutrient content s ffected y mnure ppliction rte in Experiment 2. Residul Soil Nutrient Sttus Differences in residul soil nitrte-n nd Olson P sttus were mrginl mong tretments, while there ws strong indiction of K ccumultion s mnure ppliction rte incresed. The 1N nd 2N tretments exhiited lmost 1.5 times the mount of K in the soil profile versus the control, while the mount of K in the soil profile for the 3N nd 4N tretments ws lmost doule reltive to the control. Bsis MAFRI guidelines, residul soil nutrient levels were considered low to very low. Bsis the Mnito Mnure nd Mortlities Mngement Regultions, residul soil N cn e no greter thn 9 l N c -1 on clss 4 soils witin the top 6 cm of the soil profile. In this study, ll tretments stisfy these regultions. However, considering the results of nutrient movement monitoring presented ove, mnure ppliction t the excessive levels in Experiment 2 hs considerle room to cuse dverse environmentl effects. NO3-N (l c -1 ) mg kg -1 Tretment -15 cm 15-6 cm -6 cm Olsen P K N N N N N Tle 16. Residul soil nutrient sttus t the conclusion of Experiment 2. 28

30 6. Conclusions Mny producers see hog mnure s n opportunity to increse forge production. However, producers require dditionl informtion to ensure mnure ppliction is conducted in n environmentlly sustinle mnner, especilly on environmentlly sensitive lnds. This project ws designed to provide gronomic nd environmentl informtion regrding the impct of hog mnure ppliction to forges grown on corse-textured soils which re considered t high risk of experiencing nutrient leching. In Experiment 1, evidence of nutrient leching downwrd in the soil profile ws miniml. Depending on conditions during the growing seson nd susequent to mnure ppliction, N losses my hve ccounted for considerle shre of the N tht ws initilly pplied. There ws strong tendency for voltiliztion losses for summer-pplied N, especilly in the summer of 23 given the excessively hot, dry conditions susequent to mnure ppliction. Fll-pplied N would hve een suject to denitrifiction nd leching losses s well, lthough the potentil for voltiliztion would hve een reduced reltive to summerpplied mnure. Given the poor soil fertility t the site, strong crop response to pplied mnure ws lso likely contriuting fctor to minimizing nutrient leching. The evidence suggests tht forges re strong cndidte for mnure ppliction, especilly in circumstnces where inherent soil fertility is poor. Evidence of nutrient leching ws more compelling in Experiment 2. There ws strong evidence of nutrient leching for the 3N nd 4N tretments. At the lst smpling dte, there ws considerly more nitrte-n t depth in the soil profile for the 4N tretment compred to the other tretments pplied. In oth experiments, residul soil nutrient levels were low to very low, lthough there ws evidence of K ccumultion in oth experiments. Residul soil N levels met the regultions set out y the Mnito Mnure nd Mortlities Mngement Regultions. However, the evidence of nutrient leching in Experiment 2 during the growing seson indictes rel thret of downwrd movement of nitrte-n where ppliction rtes re excessive reltive to crop demnd. Forges responded strongly to mnure ppliction. In Experiment 1, dry mtter yields incresed considerly s mnure ppliction rte incresed, s did nutrient uptke. The impct on forge nutrient content ws less consistent cross hrvests, lthough s expected there ws trend in most instnces of incresing nutrient content with incresing mnure ppliction rte. Fll-pplied mnure ppered to produce etter forge productivity results, possily s result of greter nutrient losses in summer-pplied tretments. Split N ppliction ws no more effective t incresing forge productivity thn the 12N tretment when considering productivity over production cycle (i.e. fll nd summer hrvest). Tming of nutrient vilility is key considertion in ttempting to mximize forge productivity. In Experiment 2, for exmple, it ws cler tht nutrient vilility ws delyed somewht reltive to ppliction dte, s indicted y dely in the ccumultion of nitrte-n in the upper soil profile. Given the lck of leching oserved in Experiment 1 (up to trget N rte of 12 l c -1 ), incresing mnure ppliction rtes my e fesile reltive to current recommendtions. Splitting mnure ppliction rtes my lso provide nother mens of incresing mnure ppliction rtes without cusing dverse effects to the environment. The results of these trils indicte tht there is significnt opportunity to increse forge productivity on mrginl lnd without cusing undue dmge to the environment if mnure ppliction rtes re within reson. 29