CROP RESIDUE EFFECTS ON RUNOFF NUTRIENT CONCENTRATIONS FOLLOWING MANURE APPLICATION

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1 CROP RESIDUE EFFECTS ON RUNOFF NUTRIENT CONCENTRATIONS FOLLOWING MANURE APPLICATION J. E. Nicolisen, J. E. Gilley, B. Eghll, D. B. Mrx ABSTRACT. Mnure is pplied to croplnd res mnged under diverse conditions, resulting in vrying mounts of residue cover. The ojective of this study ws to mesure the effects of crop residue on nutrient concentrtions in runoff from res where eef cttle or swine were recently pplied ut not incorported. Plots.75 m wide y m long were estlished t the study site. Existing residue mterils were removed, nd corn, soyen, or winter whet residue ws dded t rtes of,, or 8 Mg h. Mnure ws then pplied t rtes required to meet estimted nnul nitrogen requirements for corn. Control plots with ut no residue, nd plots with no residue nd no were lso estlished. Three 3 min simulted rinfll events, seprted y h intervls, were conducted t n intensity of pproximtely 7 mm h. Dissolved phosphorus (DP), totl phosphorus (TP), NO 3 N, NH N, totl nitrogen, runoff, nd soil loss were mesured for ech rinfll event. When eef cttle or swine ws pplied to plots contining residue mterils, nutrient concentrtions in runoff were not ffected y the mount of crop residue on the soil surfce. Concentrtions of DP nd NO 3 N in runoff from the plots with eef cttle were significntly greter on the plots with residue thn on the no-residue tretments. No significnt differences in runoff nutrient concentrtions were found etween the residue nd no-residue tretments with swine. Concentrtions of DP nd TP were significntly less on the no-residue/no- tretment thn on the plots with eef cttle or swine. Keywords. Crop residue, Lnd ppliction, Mnure mngement, Mnure runoff, Nitrogen movement, Nutrient losses, Phosphorus, Residue mngement, Runoff, Wter qulity. Mnure contins nutrients tht cn serve s sustitute for inorgnic fertilizer nd orgnic mtter tht cn improve soil chrcteristics including infiltrtion, porosity, nd wter holding cpcity. However, nutrients in runoff from griculturl res my cuse dverse environmentl impcts (Shrpley et l., 99, ; Andrski nd Bundy, 3). Source fctors such s or fertilizer ppliction method, loding rte, nd soil nutrient test level ffect runoff nutrient concentrtions (Sims, 993; Dniel et l., 99; McDowell et l., ). Trnsport fctors including runoff nd erosion my influence nutrient delivery y surfce runoff (Lemunyon nd Gilert, 993; Gilley et l., ). The length of time tht hs elpsed since ppliction cn lso ffect runoff nutrient concentrtions (Gilley nd Eghll, ). Soil nutrient vlues my not significntly impct runoff nutrient con- Sumitted for review in Novemer 6 s mnuscript numer SW 6739; pproved for puliction y the Soil & Wter Division of ASABE in Mrch 7. This rticle is contriution from the USDA-ARS in coopertion with the Agriculturl Reserch Division, University of Nersk, Lincoln, nd is pulished s Journl Series No The uthors re Jeffrey E. Nicolisen, Stff Engineer, Environmentl Resource Mngement, Inc., Appleton, Wisconsin; John E. Gilley, ASABE Memer Engineer, Agriculturl Engineer, USDA-ARS, University of Nersk, Lincoln, Nersk; Bhmn Eghll, Soil Scientist (decesed), USDA-ARS, Lincoln, Nersk; nd Dvid B. Mrx, Professor, University of Nersk, Lincoln, Nersk. Corresponding uthor: John E. Gilley, USDA-ARS, Room 5, Chse Hll, University of Nersk, Lincoln, NE ; phone: ; fx: ; e-mil: John.Gilley@rs.usd.gov. centrtions when rinfll occurs soon fter ppliction (Eghll et l., ). Reduced tillge systems help to mintin crop residue on the soil surfce. Dorn nd Linn (99) cite severl enefits of no-till frming systems including soil protection from erosion losses, conservtion of soil wter y incresed infiltrtion nd decresed evportion, greter use of lnd too steep for conventionl tillge, nd reduction in fuel, lor, nd mchinery costs. The ppliction of to no-till system without incorportion cn result in DP concentrtions in runoff tht exceed estlished wter qulity stndrds (Eghll nd Gilley, 999). Mintennce of residue cover is n importnt concern when reduced tillge systems re used. There hve een few studies exmining the effects of crop residue on runoff nutrient concentrtions from sites on which ws recently dded. The ojective of this study ws to mesure the effects of crop residue on nutrient concentrtions in runoff from res where eef cttle or swine were recently pplied ut not incorported. MATERIALS AND METHODS STUDY SITE CHARACTERISTICS AND EXPERIMENTAL DESIGN This field study ws conducted from My to August t the University of Nersk Rogers Memoril Frm locted out 8 km est of Lincoln, Nersk, in Lncster County. The Shrpsurg silty cly lom soil (fine, smectitic, mesic Typic Argiudoll) t the site contined % snd, 5% silt, nd 35% cly, nd 8.5 g kg orgnic C in the top 5 cm of soil. The soil formed from loess under pririe vegettion nd hd Trnsctions of the ASABE Vol. 5(3): Americn Society of Agriculturl nd Biologicl Engineers ISSN

2 Soil Depth (cm) Tle. Soil chrcteristics efore ppliction. WSP [] (mg kg ) BKP [] (mg kg ) NO 3 N (mg kg ) NH N (mg kg ) EC [] (d S m ) ph [] WSP = wter solule P, nd BKP = Bry nd Kurtz No. phosphorus. [] EC = electricl conductivity. EC nd ph were determined in : soil/ wter rtio (Smith nd Dorn, 996). men slope of 7%. Soil chrcteristics t the study site re shown in tle. The site hd een cropped using grin sorghum (Sorghum icolor (L.) Moench), soyen (Glycine mx (L.) Merr.), winter whet (Triticum estivum L. cv. Pstiche) rottion, under no-till mngement system, nd ws left undistured following soyen hrvest in the fll of. Hericide ws pplied immeditely efore nd midwy through the study to prevent weed growth. Tests using eef cttle (Bos turus) nd swine (Sus scrof) were conducted on seprte locks ech contining 33 plots. The types nd mounts of crop residue pplied within ech lock vried in rndomized design. Ech lock included three replictions of corn (Ze mys L.), soyen, or winter whet residue pplied t rtes of,, or 8 Mg h (7 plots). In ddition, tretment without crop residue ut with (3 plots) nd tretment without crop residue or (3 plots) were included in the 33 plots contined in ech lock. Thus, totl of 66 plots were exmined during this study. Corn nd soyen residue used in this investigtion were collected in My t the Rogers Memoril Frm. The winter whet strw ws otined from commercil source nd ws iled soon fter hrvest. The crop residue mterils were dried in n oven t 6 C nd then stored for future use. The drying process llowed the residue mterils to e pplied on uniform dry weight sis. Equtions hve een developed tht llow surfce cover to e estimted from residue mss. A residue mss of,, or 8 Mg h provides pproximtely the following surfce cover: %, 37%, nd 6% with corn (Gilley et l., 986); %, %, nd 66% with soyen (Gilley et l., 986); nd 63%, 86%, nd 98% with whet (Gregory, 98). Decomposition, residue wethering, nd tillge cuse residue cover to decrese. The residue rtes used in this study (which include no-residue condition) re representtive of rod rnge of tillge nd mngement conditions found on croplnd res. MANURE CHARACTERISTICS Beef cttle ws collected in My from privte confined livestock opertion ner Wterloo, Nersk. To provide greter ppliction uniformity, lrger-size mterils were roken y hnd nd the ws sieved through screen with mm openings. The eef cttle ws then plced in plstic gs nd stored t C until it ws pplied. Swine ws otined in June from the University of Nersk Agriculturl Reserch nd Development Center ner Ithc, Nersk. The liquid swine ws collected from pit locted elow sltted floor nd ws stored in 9 L plstic pils. The plstic pils with lids were kept t ir temperture in shed until they were needed. The production unit hd een in opertion for two months nd contined swine weighing 36 to 5 kg tht were fed corn-soyen diet. Beef cttle nd swine were pplied t rtes of 3.3 nd 66.5 Mg h, respectively, the pproximte mounts required to meet estimted corn N requirements. Appliction rtes were determined using % N vilility for eef cttle (Eghll nd Power, 999) nd 7% N vilility for swine (Gilertson et l., 979). Tle lists chrcteristics reported from replicted smples sent to commercil lortory, nd ppliction rtes of nitrogen (N) nd phosphorus (P). RAINFALL SIMULATION PROCEDURES Wter used in the rinfll simultion tests ws otined from n irrigtion system. Mesured men concentrtions of DP, TP, NO 3 N, NH N, nd totl N (TN) in the irrigtion wter were:.,., 7.8,., nd 7.8 mg L, respectively. The irrigtion wter hd men EC vlue of.73 ds m nd ph of 7.6. Reported nutrient concentrtions represent the difference etween runoff mesurements nd concentrtions in the irrigtion well wter. Pired.75 m wide y m long plots were estlished. The plots were rked, nd ny remining plnt mteril ws removed y hnd. Burlp mteril ws plced on the plots to reduce surfce disturnce during the prewetting process. To provide more uniform ntecedent soil wter conditions etween tretments, wter ws pplied to the plots with hose until runoff egn. Crop residue nd then were dded y hnd following the pre-wetting process. Rinfll simultion procedures dopted y the Ntionl Phosphorus Reserch Project (NPRP) were employed in this study (Shrpley nd Kleinmn, 3). Two rin guges were plced long the outer edge of ech plot, nd one rin guge ws locted etween the pired plots. A portle rinfll simultor sed on the design y Humphry et l. () ws used to pply rinfll for 3 min t n intensity of pproximtely 7 mm h. Two dditionl rinfll simultion runs were conducted t pproximtely h intervls. Plots were covered with trps etween simultion events to prevent the input of nturl rinfll. Sheet metl orders chnneled runoff into collection trough. The trough extended cross the ottom of ech plot nd diverted runoff into luminum wshtus. Runoff ws gitted to mintin suspension of solids nd then smpled. Mnure NO 3 N (g kg ) Tle. Mnure chrcteristics nd ppliction rtes of nitrogen nd phosphorus. Concentrtions [] NH N (g kg ) Totl N (g kg ) Totl P (g kg ) Wter Content (g kg ) EC [] (d S m ) ph Totl N (kg h ) Applied Totl P (kg h ) Beef cttle Swine [] Nutrient concentrtions of the eef cttle nd swine were determined on dry nd wet sis, respectively. [] EC = electricl conductivity. EC nd ph for eef cttle were determined in :5 /wter rtio; EC nd ph for swine were mesured without dilution. 9 TRANSACTIONS OF THE ASABE

3 Tle 3. Anlysis of vrince (PR > F) showing the effects of residue type, residue mount, nd ppliction on wter qulity, runoff nd erosion chrcteristics. Vrile DP Totl P NO 3 N NH N Totl N Runoff Erosion Beef cttle Residue type Residue mount Residue type mount No residue No residue no Swine Residue type Residue mount Residue type mount No residue No residue no Centrifuged nd filtered runoff smples were nlyzed for DP (Murphy nd Riley, 96), NO 3 N, nd NH N using Lcht system (Zellweger Anlytics, Milwukee, Wisc.). Non-centrifuged smples were nlyzed for TP (Johnson nd Ulrich, 959) nd TN (Tte, 99). Runoff smples were dried in n oven t 5 C nd weighed to determine sediment content. STATISTICAL ANALYSES Physicl nd chemicl chrcteristics of the eef cttle nd swine were sustntilly different. As result, seprte sttisticl nlyses were preformed on dt collected from the eef cttle nd swine tretments. Mesurements from the three rinfll simultion runs were treted s repeted mesures. Anlysis of vrince ws performed to identify the effects of residue type, residue mount, nd ppliction on selected wter qulity, runoff, nd erosion chrcteristics. The lest significnt difference test ws used to determine sttisticl significnce mong tretment mens. A proility level <.5 ws considered significnt. RESULTS AND DISCUSSION BEEF CATTLE MANURE TREATMENTS The residue type residue mount interction ws not significnt for ny of the wter qulity, runoff, or erosion chrcteristics mesured on the plots with eef cttle (tle 3). For the plots contining residue nd, the mount of residue on the soil surfce did not significntly ffect nutrient concentrtions in runoff (tle 3). However, significnt differences in concentrtions of DP nd NO 3 N were found etween the residue nd no-residue tretments with eef cttle (figs. nd c). Concentrtions of DP, TP, nd NO 3 N in runoff were significntly less on the plots with no residue nd no thn the tretments with eef cttle (figs.,, nd c). Runoff concentrtions of NH N nd TN for the 33 plots on the eef cttle experimentl lock verged.7 nd 55.3 mg L, respectively. Hydrulic roughness coefficients re greter on res contining crop residue (Gilley et l., 99). As result, overlnd flow runoff velocities my e reduced on sites with sustntil residue cover. In ddition, smll ponds creted y crop residue serve to store wter on uplnd res (Gilley nd Kottwitz, 99). The cumultive volume of wter generted y lrge numer of ponds cn e sustntil. The reduced runoff velocity nd ponding of wter cused y crop residue could hve incresed leching of DP nd NO 3 N from the eef cttle. Wter ws dded to the plots efore initition of the rinfll simultion tests to provide more uniform ntecedent soil wter conditions mong plots. Since soil ner the surfce ws close to sturtion when the rinfll simultion tests were initited, no significnt differences in totl runoff were mesured etween the residue nd no-residue tretments (tle 3). Consequently, results relted to nutrient concentrtion should lso e pplicle to nutrient lod. A men runoff vlue of 8 mm ws mesured for the 33 plots on the eef cttle experimentl lock. No significnt differences in soil erosion mesurements were found mong the experimentl tretments on the eef cttle experimentl lock. The reduced erodiility expected under no-till conditions ppers to hve een mintined even fter the existing residue mterils hd een removed. For the 33 plots on the eef cttle experimentl lock, men soil erosion vlue of.9 Mg h ws mesured. Gilley nd Eghll (998) lso found tht runoff nd erosion from simulted rinfll were not significntly influenced y the single ppliction of eef cttle. SWINE MANURE TREATMENTS For the plots with swine, the residue type residue mount interction ws not significnt for ny of the mesured wter qulity, runoff, or erosion chrcteristics (tle 3). The mount of residue on the soil surfce did not significntly ffect nutrient concentrtions in runoff on the plots contining residue nd (tle 3). No significnt differences in nutrient concentrtions were found etween the residue nd no-residue tretments with swine (tle 3, figs. through d). Concentrtions of DP, TP, nd NH N in runoff were significntly less on the plots with no residue nd no (figs.,, nd c). For the 33 plots on the swine experimentl lock, men concentrtions of NO 3 N nd TN were.55 nd 6 mg L, respectively. No significnt differences in totl runoff mounts were mesured etween the residue nd no residue tretments (tle 3) on the swine experimentl lock. A men runoff vlue of mm ws mesured. For the plots with residue nd, men erosion vlue of.8 Mg h ws otined, compred to.95 nd.68 Mg h on the no Vol. 5(3):

4 Dissolved phosphorus (mg L ) c No Dissolved phosphorus (mg L ) No Figure. Dissolved phosphorus in runoff s ffected y crop residue nd cttle. Verticl rs re stndrd errors. The letter ove ech r indictes sttisticl significnce t P <.5 using the lest significnt Figure. Dissolved phosphorus in runoff s ffected y crop residue nd swine. Verticl rs re stndrd errors. The letter ove ech r indictes sttisticl significnce t P <.5 using the lest significnt Totl phosphorus (mg L ) No Totl phosphorus (mg L ) 8 6 No Figure. Totl phosphorus in runoff s ffected y crop residue nd cttle. Verticl rs re stndrd errors. The letter ove ech r indictes sttisticl significnce t P <.5 using the lest significnt Figure. Totl phosphorus in runoff s ffected y crop residue nd swine. Verticl rs re stndrd errors. The letter ove ech r indictes sttisticl significnce t P <.5 using the lest significnt 5 Nitrte (mg L ) c No Ammonium (mg L ) No Figure c. Nitrte in runoff s ffected y crop residue nd cttle. Verticl rs re stndrd errors. The letter ove ech r indictes sttisticl significnce t P <.5 using the lest significnt Figure c. Ammonium in s ffected y crop residue nd swine. Verticl rs re stndrd errors. The letter ove ech r indictes sttisticl significnce t P <.5 using the lest significnt residue/ nd no residue/no tretments, respectively (fig. d).. ADDITIONAL CONSIDERATIONS The rinfll simultion nd dt collection protocols dopted y the NPRP (Shrpley nd Kleinmn, 3) were used in this study. However, it is recognized tht these procedures represent n extreme condition. Three consecutive high-intensity storms, ech of 3 min durtion, would not e expected to occur over 7 h period under nturl rinfll conditions. Adding wter to the plots prior to the tests to provide more uniform ntecedent soil wter conditions enhnced the opportunity for runoff. Rinfll simultion tests were conducted soon fter ws pplied. In this study, ws not incorported Erosion (Mg h ) No Figure d. Erosion s ffected y crop residue nd swine. Verticl rs re stndrd errors. The letter ove ech r indictes sttisticl significnce t P <.5 using the lest significnt 9 TRANSACTIONS OF THE ASABE

5 or injected. The incorportion of following ppliction cn significntly reduce the concentrtion of nutrients in runoff (Eghll nd Gilley, 999). Little informtion is currently ville concerning temporl chnges in nutrient trnsport following the ddition of eef cttle or swine to croplnd res. Mnure hs een effectively used to improve crop production nd soil properties ecuse it contins nutrients nd or gnic mtter. In this study, runoff nd erosion were mesured soon fter ppliction. For selected loctions on which ws dded nnully, runoff ws reduced from % to 6%, nd soil loss decresed from 5% to 65% compred to non-d sites (Gilley nd Risse, ). Crop residues on the soil surfce sujected to rinfll hve een found to e significnt source of solule nutrients in griculturl runoff (Schreier, 985). As residue decomposed, the frction of wter-solule NO 3 N in plnt mteril tht ws leched under rinfll ws reported to increse (Hvis nd Alerts, 993). Significnt mounts of PO P nd NH N were lso found in lechte from corn residue (Schreier, 999). Nutrient concentrtions in lechte were greter t lower rinfll intensities nd higher corn residue loding rtes. For individul storms, NO 3 N concentrtions in lechte rpidly decresed with either time or cumultive lechte volume to ner constnt vlue. Little informtion is currently ville concerning temporl chnges in the leching of nutrients from crop residue mterils. Concentrtions of humn helth-relted microorgnisms in runoff from the experimentl plots estlished in this study were lso mesured. Additionl detils concerning the microil tests re provided y Thurston-Enriquez et l. (5). CONCLUSIONS The mount of crop residue found on site cropped under no-till conditions did not significntly ffect nutrient concentrtions in runoff on the tretments with residue nd eef cttle pplied directly on the surfce. However, significnt differences in concentrtions of DP nd NO 3 N were found etween the residue nd no-residue tretments with eef cttle. Concentrtions of DP, TP, nd NO 3 N in runoff were significntly less on the plots with no residue nd no thn the tretments with eef cttle. Runoff concentrtions of NH N nd TN for the 33 plots on the eef cttle experimentl lock verged.7 nd 55.3 mg L, respectively. On the plots contining residue nd swine nd cropped under no-till conditions, the mount of residue on the soil surfce did not significntly ffect nutrient concentrtions in runoff. No significnt differences in nutrient concentrtions were found etween the residue nd no-residue tretments with swine. Concentrtions of DP, TP, nd NH N in runoff were significntly less on the plots with no residue nd no. For the 33 plots on the swine experimentl lock, men concentrtions of NO 3 N nd TN were.55 nd 6 mg L, respectively. REFERENCES Andrski, T. W., nd L. G. Bundy. 3. 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6 Schreier, J. D Nutrient leching from corn residues under simulted rinfll. J. Environ. Qul. 8(6): Shrpley, A. N., nd P. J. A. Kleinmn. 3. Effect of rinfll simultor nd plot scle on overlnd flow nd phosphorus trnsport. J. Environ. Qul. 3(6): Shrpley, A. N., S. C. Chpr, R. Wedepohl, J. T. Sims, T. C. Dniel, nd K. R. Reddy. 99. Mnging griculturl phosphorus for protection of surfce wters: Issues nd options. J. Environ. Qul. 3(3): Shrpley, A. N., B. H. Foy, nd P. J. A. Withers.. Prcticl nd innovtive mesures for the control of griculturl phosphorus losses to wter: An overview. J. Environ. Qul. 9(): -9. Sims, J. T Environmentl soil testing for phosphorus. J. Prod. Agric. 6(): Smith, J. L., nd J. W. Dorn Mesurement nd use of ph nd electricl conductivity for soil qulity nlysis. In Methods for Assessing Soil Qulity, J. W. Dorn nd A. J. Jones, eds. SSSA Spec. Pul. 9. Mdison, Wisc.: SSSA. Tte, D. F. 99. Determintion of nitrogen in fertilizer y comustion: Collortive study. J. AOAC Intl. 77(): Thurston-Enriquez, J. A., J. E. Gilley, nd B. Eghll. 5. Microil qulity of runoff following lnd ppliction of cttle nd swine slurry. J. Wter Helth 3(): TRANSACTIONS OF THE ASABE