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RESEARCH ARTICLE

A new model for dung decomposition and phosphorus transformations and loss in runoff

P. A. Vadas A E , S. R. Aarons B , D. M. Butler C and W. J. Dougherty D
+ Author Affiliations
- Author Affiliations

A USDA-ARS, U.S. Dairy Forage Research Center, 1925 Linden Drive West, Madison, WI 53706, USA.

B Ellinbank Research Institute, Department of Primary Industries, Hazeldean Rd, Ellinbank, Vic. 3821, Australia.

C 2431 Joe Johnson Dr., University of Tennessee, Knoxville, TN 37996-4561, USA.

D Department of Primary Industries, Industry and Investment New South Wales, Locked Bag 4, Richmond, NSW 2753, Australia.

E Corresponding author. Email: peter.vadas@ars.usda.gov

Soil Research 49(4) 367-375 https://doi.org/10.1071/SR10195
Submitted: 14 September 2010  Accepted: 19 November 2010   Published: 19 May 2011

Abstract

Non point-source pollution of fresh waters by agricultural phosphorus (P) can accelerate eutrophication of surface waters and limit their use for drinking, recreation, and industry. An important pathway of agricultural P transport is surface runoff, to which unincorporated dung from grazing cattle can be a significant contributor. Computer models commonly used to identify agricultural areas with a high potential for P export do not adequately simulate dung application to the soil surface, dung disappearance, and dung P loss to runoff. We developed a new model to simulate these processes for grazing cattle dung. The model simulates dung organic matter decomposition and assimilation into soil by bioturbation as a function of air temperature and dung moisture. We validated that the model can accurately predict rates of dung disappearance, using data from 12 published studies. The model also simulates four pools of inorganic and organic P, P mineralisation to water-extractable P, leaching of dung water-extractable P into soil by rain, and loss of dissolved inorganic P in runoff. We validated the ability of the model to reliably simulate these P processes, using data from six published dung P transformation studies and six runoff studies. Overall, the model represents a novel approach for assessing the environmental impact of grazing dairy and beef cattle. Research should investigate the impact of dung deposition rate as a function of time and animal diet and type, where deposition occurs relative to runoff movement, weather conditions, and the ability of dung pad crusting to reduce P release to runoff.

Additional keywords: dung, phosphorus, runoff, model.


References

Aarons SR, O’Connor CR, Gourley CJP (2004) Dung decomposition in temperate dairy pastures. I. Changes in soil chemical properties. Australian Journal of Soil Research 42, 107–114.
Dung decomposition in temperate dairy pastures. I. Changes in soil chemical properties.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD2cXht1ahsbw%3D&md5=ce3700fdc5da0184c7772330b6783b74CAS |

Aarons SR, O’Connor CR, Hosseini HM, Gourley CJP (2009) Dung pads increase pasture production, soil nutrients and microbial biomass carbon in grazed dairy systems. Nutrient Cycling in Agroecosystems 84, 81–92.
Dung pads increase pasture production, soil nutrients and microbial biomass carbon in grazed dairy systems.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD1MXksF2hur8%3D&md5=f6e6abd6617f4333963a49a00e05da71CAS |

Barth D (1993) Importance of methodology in the interpretation of factors affecting degradation of dung. Veterinary Parasitology 48, 99–108.
Importance of methodology in the interpretation of factors affecting degradation of dung.Crossref | GoogleScholarGoogle Scholar | 1:STN:280:DyaK3szkvVOnsQ%3D%3D&md5=0a324b8017c0f6d47c0bbbd54e32e8aaCAS | 8346653PubMed |

Bourke D, Jeffrey DW, Dowding PD, Tunney HT, Kurz I (2008) Phosphorus dynamics in a grazed grassland ecosystem. Final Report. Environmental Protection Agency, Johnstown Castle, Wexford, Ireland.

Butler DM, Franklin DH, Ranells NN, Poore MH, Green JT (2006) Ground cover impacts on sediment and phosphorus export from manured riparian pasture. Journal of Environmental Quality 35, 2178–2185.
Ground cover impacts on sediment and phosphorus export from manured riparian pasture.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD28Xht1yltrnP&md5=a331d06db48a77ae49784c2d27624b3bCAS | 17071887PubMed |

Butler DM, Ranells NN, Franklin DH, Poore MH, Green JT (2008) Runoff water quality from manured riparian grasslands with contrasting drainage and simulated grazing pressure. Agriculture, Ecosystems & Environment 126, 250–260.
Runoff water quality from manured riparian grasslands with contrasting drainage and simulated grazing pressure.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD1cXkvVOlurs%3D&md5=0cb7064183a5fde75b65551b869cf050CAS |

Capece JC, Campbell KL, Bohlen PJ, Graetz DA, Portier KM (2007) Soil phosphorus, cattle stocking rates, and water quality in subtropical pastures in Florida, USA. Rangeland Ecology and Management 60, 19–30.
Soil phosphorus, cattle stocking rates, and water quality in subtropical pastures in Florida, USA.Crossref | GoogleScholarGoogle Scholar |

Carpenter SR, Caraco NF, Correll DL, Howarth RW, Sharpley AN, Smith VH (1998) Nonpoint pollution of surface waters with phosphorus and nitrogen. Ecological Applications 8, 559–568.
Nonpoint pollution of surface waters with phosphorus and nitrogen.Crossref | GoogleScholarGoogle Scholar |

Dao TH, Schwartz RC (2010) Mineralizable phosphorus, nitrogen, and carbon relationships in dairy manure at various carbon-to-phosphorus ratios. Bioresource Technology 101, 3567–3574.
Mineralizable phosphorus, nitrogen, and carbon relationships in dairy manure at various carbon-to-phosphorus ratios.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC3cXhvFyjtL4%3D&md5=b651897420bcb8d8a2567d370b1f7233CAS | 20080400PubMed |

Daverede IC, Kravchenko AN, Hoeft RG, Nafziger ED, Bullock DG, Warren JJ, Gonzini LC (2004) Phosphorus runoff from incorporated and surface-applied liquid swine manure and phosphorus fertilizer. Journal of Environmental Quality 33, 1535–1544.
Phosphorus runoff from incorporated and surface-applied liquid swine manure and phosphorus fertilizer.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD2cXmtFKhtLg%3D&md5=bc8fa84941326fdaa72a082f46b1a8b5CAS | 15254136PubMed |

DeLaune PB, Moore PA, Carman DK, Sharpley AN, Haggard BE, Daniel TC (2004a) Development of a phosphorus index for pastures fertilized with poultry litter – Factors affecting phosphorus runoff. Journal of Environmental Quality 33, 2183–2191.
Development of a phosphorus index for pastures fertilized with poultry litter – Factors affecting phosphorus runoff.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD2cXhtVegs7jE&md5=3db6a6934c9472142576224046302276CAS | 15537941PubMed |

DeLaune PB, Moore PA, Carman DK, Sharpley AN, Haggard BE, Daniel TC (2004b) Evaluation of the phosphorus source component in the phosphorus index for pastures. Journal of Environmental Quality 33, 2192–2200.
Evaluation of the phosphorus source component in the phosphorus index for pastures.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD2cXhtVegs7jF&md5=80fb0728fb1139991b1e8fb6161147e6CAS | 15537942PubMed |

Dickinson CH, Craig G (1990) Effects of water on the decomposition and release of nutrients from cow pats. New Phytologist 115, 139–147.
Effects of water on the decomposition and release of nutrients from cow pats.Crossref | GoogleScholarGoogle Scholar |

Dickinson CH, Underhay VSH, Ross V (1981) Effect of season, soil fauna and water-content on the decomposition of cattle dung pats. New Phytologist 88, 129–141.
Effect of season, soil fauna and water-content on the decomposition of cattle dung pats.Crossref | GoogleScholarGoogle Scholar |

Dimander SO, Hoglund J, Waller PJ (2003) Disintegration of dung pats from cattle treated with the ivermectin anthelmintic bolus, or the biocontrol agent Duddingtonia flagrans. Acta Veterinaria Scandinavica 44, 171–180.
Disintegration of dung pats from cattle treated with the ivermectin anthelmintic bolus, or the biocontrol agent Duddingtonia flagrans.Crossref | GoogleScholarGoogle Scholar | 1:STN:280:DC%2BD2c7nvF2juw%3D%3D&md5=a2e910a044684d178bcbaf8601d41f5dCAS | 15074630PubMed |

Dougherty WJ, Milham PJ, Havilah EJ, Lawrie RA (2008) Phosphorus fertilizer and grazing management effects on phosphorus in runoff from dairy pastures. Journal of Environmental Quality 37, 417–428.
Phosphorus fertilizer and grazing management effects on phosphorus in runoff from dairy pastures.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD1cXjsVWksbo%3D&md5=0d7b41da87eb141848022eb86cba46afCAS | 18268305PubMed |

Edwards DR, Hutchens TK, Rhodes RW, Larson BT, Dunn L (2000a) Quality of runoff from plots with simulated grazing. Journal of the American Water Resources Association 36, 1063–1073.
Quality of runoff from plots with simulated grazing.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD3cXot1Sls7o%3D&md5=b43fbf2897fcc7b86c5055b84bbe43ddCAS |

Edwards DR, Larson BT, Lim TT (2000b) Runoff nutrient and fecal coliform content from cattle manure application to fescue plots. Journal of the American Water Resources Association 36, 711–721.
Runoff nutrient and fecal coliform content from cattle manure application to fescue plots.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD3cXmtlSmt7c%3D&md5=05183de6b7b9c33bf4a8d894beb2ca1cCAS |

Esse PC, Buerkert A, Hiernaux P, Assa A (2001) Decomposition of and nutrient release from ruminant manure on acid sandy soils in the Sahelian zone of Niger, West Africa. Agriculture, Ecosystems & Environment 83, 55–63.
Decomposition of and nutrient release from ruminant manure on acid sandy soils in the Sahelian zone of Niger, West Africa.Crossref | GoogleScholarGoogle Scholar |

Floate MJS (1970a) Decomposition of organic materials from hill soils and pastures: III. The effect of temperature on the mineralization of carbon, nitrogen and phosphorus from plant materials and sheep faeces. Soil Biology & Biochemistry 2, 187–196.
Decomposition of organic materials from hill soils and pastures: III. The effect of temperature on the mineralization of carbon, nitrogen and phosphorus from plant materials and sheep faeces.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaE3cXltF2ks7c%3D&md5=fe8c52d4452247ba1e032497f43f402eCAS |

Floate MJS (1970b) Decomposition of organic materials from hill soils and pastures: IV. The effect of moisture content on the mineralization of carbon, nitrogen and phosphorus from plant materials and sheep faeces. Soil Biology & Biochemistry 2, 275–283.
Decomposition of organic materials from hill soils and pastures: IV. The effect of moisture content on the mineralization of carbon, nitrogen and phosphorus from plant materials and sheep faeces.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaE3MXpvV2rug%3D%3D&md5=e74515c8bdbbd17e4d7391366fef6203CAS |

Gallagher AV, Wollenhaupt NC (1997) Surface alfalfa residue removal by earthworms Lumbricus terrestris L. in a no-till agroecosystem. Soil Biology & Biochemistry 29, 477–479.
Surface alfalfa residue removal by earthworms Lumbricus terrestris L. in a no-till agroecosystem.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaK2sXktFCmtLk%3D&md5=0a580aeffa761add92d23f650c1df47bCAS |

Garcia AM, Veith TL, Kleinman PJA, Rotz CA, Saporito LS (2008) Assessing manure management strategies through small-plot research and whole-farm modeling. Journal of Soil and Water Conservation 63, 204–211.
Assessing manure management strategies through small-plot research and whole-farm modeling.Crossref | GoogleScholarGoogle Scholar |

Gittings T, Giller PS, Stakelum G (1994) Dung decomposition in contrasting temperate pastures in relation to dung beetle and earthworm activity. Pedobiologia 38, 455–474.

Haan MM, Russell JR, Powers WJ, Kovar JL, Benning JL (2006) Grazing management effects on sediment and phosphorus in surface runoff. Rangeland Ecology and Management 59, 607–615.
Grazing management effects on sediment and phosphorus in surface runoff.Crossref | GoogleScholarGoogle Scholar |

Harmel RD, Torbert HA, Haggard BE, Haney R, Dozier M (2004) Water quality impacts of converting to a poultry litter fertilization strategy. Journal of Environmental Quality 33, 2229–2242.
Water quality impacts of converting to a poultry litter fertilization strategy.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD2cXhtVegs7nP&md5=6f51c70035c2b1218b909ec03cc626cdCAS | 15537946PubMed |

Haynes RJ, Williams PH (1993) Nutrient cycling and soil fertility in the grazed pasture ecosystem. Advances in Agronomy 49, 119–199.
Nutrient cycling and soil fertility in the grazed pasture ecosystem.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaK3sXltlygs7Y%3D&md5=8b5b90b5c2607ef126fcc7cbe664668eCAS |

Herd RP, Stinner BR, Purrington FF (1993) Dung dispersal and grazing area following treatment of horses with a single-dose of ivermectin. Veterinary Parasitology 48, 229–240.
Dung dispersal and grazing area following treatment of horses with a single-dose of ivermectin.Crossref | GoogleScholarGoogle Scholar | 1:STN:280:DyaK3szkvVOhtA%3D%3D&md5=b85048b7fb74deb14855fb13541f1cc9CAS | 8346636PubMed |

Herrick JE, Lal R (1996) Dung decomposition and pedoturbation in a seasonally dry tropical pasture. Biology and Fertility of Soils 23, 177–181.
Dung decomposition and pedoturbation in a seasonally dry tropical pasture.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaK28XmvVWitrw%3D&md5=4dcac1a48d0e2bee5a5d9a582cee878cCAS |

Hirata M, Hasegawa N, Nomura M, Ito H, Nogami K, Sonoda T (2009) Deposition and decomposition of cattle dung in forest grazing in southern Kyushu, Japan. Ecological Research 24, 119–125.
Deposition and decomposition of cattle dung in forest grazing in southern Kyushu, Japan.Crossref | GoogleScholarGoogle Scholar |

Holter P (1979) Effect of dung-beetles (Aphodius spp.) and earthworms on the disappearance of cattle dung. Oikos 32, 393–402.
Effect of dung-beetles (Aphodius spp.) and earthworms on the disappearance of cattle dung.Crossref | GoogleScholarGoogle Scholar |

Holter P, Hendriksen NB (1988) Respiratory loss and bulk export of organic-matter from cattle dung pats—a field-study. Holarctic Ecology 11, 81–86.

James E, Kleinman P, Veith T, Stedman R, Sharpley A (2007) Phosphorus contributions from pastured dairy cattle to streams of the Cannonsville Watershed, New York. Journal of Soil and Water Conservation 62, 40–47.

Kaneda S, Yamashita N, Uchida T, Shimano S, Miyoshi N, Sasaki M, Enami Y (2006) Effects of ivermectin in dung pats on earthworm (Megascolecidae) populations and pat degradation in Japanese grassland. Applied Soil Ecology 31, 280–285.
Effects of ivermectin in dung pats on earthworm (Megascolecidae) populations and pat degradation in Japanese grassland.Crossref | GoogleScholarGoogle Scholar |

Kleinman PJA, Sharpley AN (2003) Effect of broadcast manure on runoff phosphorus concentrations over successive rainfall events. Journal of Environmental Quality 32, 1072–1081.
Effect of broadcast manure on runoff phosphorus concentrations over successive rainfall events.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD3sXktVGhs7o%3D&md5=180aa937429d7c7d65b8952e6a6be5d7CAS | 12809308PubMed |

Kleinman PJA, Wolf AM, Sharpley AN, Beegle DB, Saporito LS (2005) Survey of water-extractable phosphorus in livestock manures. Soil Science Society of America Journal 69, 701–708.
Survey of water-extractable phosphorus in livestock manures.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD2MXkt1CgsLk%3D&md5=8ced64d46bac5532587516bc2331efedCAS |

Kurz I, O’Reilly CD, Tunney H (2006) Impact of cattle on soil physical properties and nutrient concentrations in overland flow from pasture in Ireland. Agriculture, Ecosystems & Environment 113, 378–390.
Impact of cattle on soil physical properties and nutrient concentrations in overland flow from pasture in Ireland.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD28XhtlCmsLg%3D&md5=1828c06da201ca17fb676575933e6c24CAS |

Lee CM, Wall R (2006) Cow-dung colonization and decomposition following insect exclusion. Bulletin of Entomological Research 96, 315–322.
Cow-dung colonization and decomposition following insect exclusion.Crossref | GoogleScholarGoogle Scholar | 1:STN:280:DC%2BD28zlsV2mtw%3D%3D&md5=d1e6b71976986f12ff5dbf8fec6bb7eaCAS | 16768820PubMed |

Lovell RD, Jarvis SC (1996) Effect of cattle dung on soil microbial biomass C and N in a permanent pasture soil. Soil Biology & Biochemistry 28, 291–299.
Effect of cattle dung on soil microbial biomass C and N in a permanent pasture soil.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaK28XhsFaqtrs%3D&md5=0e0b3ea761a4ecc14ed77db56c313c5fCAS |

Lumaret JP, Kadiri N (1995) The influence of the first wave of colonizing insects on cattle dung dispersal. Pedobiologia 39, 506–517.

Madsen M, Nielsen BO, Holter P, Pedersen OC, Jespersen JB, Jensen KMV, Nansen P, Gronvold J (1990) Treating cattle with ivermectin—effects on the fauna and decomposition of dung pats. Journal of Applied Ecology 27, 1–15.
Treating cattle with ivermectin—effects on the fauna and decomposition of dung pats.Crossref | GoogleScholarGoogle Scholar |

Mapfumo E, Willms WD, Chanasyk DS (2002) Water quality of surface runoff from grazed fescue grassland watersheds in Alberta. Water Quality Research Journal of Canada 37, 543–562.

Moore PA, Daniel TC, Edwards DR (2000) Reducing phosphorus runoff and inhibiting ammonia loss from poultry manure with aluminum sulfate. Journal of Environmental Quality 29, 37–49.
Reducing phosphorus runoff and inhibiting ammonia loss from poultry manure with aluminum sulfate.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD3cXot1artg%3D%3D&md5=dd1537f3d2985f579e5a39a94ff75c6fCAS |

Murphy J, Riley JP (1962) A modified single solution method for determination of phosphate in natural waters. Analytica Chimica Acta 27, 31–36.
A modified single solution method for determination of phosphate in natural waters.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaF38XksVyntr8%3D&md5=e189243789e20e677e0bb4d0bf28f871CAS |

Nash JE, Sutcliffe JV (1970) River flow forecasting through conceptual models part I—a discussion of principles. Journal of Hydrology 10, 282–290.
River flow forecasting through conceptual models part I—a discussion of principles.Crossref | GoogleScholarGoogle Scholar |

Omaliko CPE (1981) Dung deposition, breakdown and grazing behavior of beef-cattle at 2 seasons in a tropical grassland ecosystem. Journal of Range Management 34, 360–362.
Dung deposition, breakdown and grazing behavior of beef-cattle at 2 seasons in a tropical grassland ecosystem.Crossref | GoogleScholarGoogle Scholar |

O’reagain PJ, Brodie J, Fraser G, Bushell JJ, Holloway CH, Faithful JW, Haynes D (2005) Nutrient loss and water quality under extensive grazing in the upper Burdekin river catchment, North Queensland. Marine Pollution Bulletin 51, 37–50.
Nutrient loss and water quality under extensive grazing in the upper Burdekin river catchment, North Queensland.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD2MXitF2guro%3D&md5=ae1020cb6769d21d95b21e47cf2fd935CAS | 15757706PubMed |

Rowarth JS, Gillingham AG, Tillman RW, Syers JK (1985) Release of phosphorus from sheep feces on grazed, hill country pastures. New Zealand Journal of Agricultural Research 28, 497–504.

Sauer TJ, Daniel TC, Moore PA, Coffey KP, Nichols DJ, West CP (1999) Poultry litter and grazing animal waste effects on runoff water quality. Journal of Environmental Quality 28, 860–865.
Poultry litter and grazing animal waste effects on runoff water quality.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaK1MXjt1yltLw%3D&md5=6e6bf2121946b2c91293104ab84a6a2cCAS |

Sharpley AN, Kleinman PJA, McDowell RW, Gitau M, Bryant RB (2002) Modeling phosphorus transport in agricultural watersheds: Processes and possibilities. Journal of Soil and Water Conservation 57, 425–439.

Sinton LW, Braithwaite RR, Hall CH, Mackenzie ML (2007) Survival of indicator and pathogenic bacteria in bovine feces on pasture. Applied and Environmental Microbiology 73, 7917–7925.
Survival of indicator and pathogenic bacteria in bovine feces on pasture.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD1cXotleh&md5=90f5dc5fa97c27e18fdcae7bff6e737fCAS | 17951435PubMed |

Soupir ML, Mostaghimi S, Yagow ER (2006) Nutrient transport from livestock manure applied to pastureland using phosphorus-based management strategies. Journal of Environmental Quality 35, 1269–1278.
Nutrient transport from livestock manure applied to pastureland using phosphorus-based management strategies.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD28Xns1CktL4%3D&md5=a8031af6f01b5cc4345f40db994aaf78CAS | 16825446PubMed |

Stroo HF, Bristow KL, Elliott LF, Papendick RI, Campbell GS (1989) Predicting rates of wheat residue decomposition. Soil Science Society of America Journal 53, 91–99.
Predicting rates of wheat residue decomposition.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaL1MXhslaht7g%3D&md5=9c9edd2fffd5a6f5725a37e686543d63CAS |

Svendsen TS, Gronvold J, Holter P, Sommer C (2003) Field effects of ivermectin and fenbendazole on earthworm populations and the disappearance of dung pats from bolus-treated cattle. Applied Soil Ecology 24, 207–218.
Field effects of ivermectin and fenbendazole on earthworm populations and the disappearance of dung pats from bolus-treated cattle.Crossref | GoogleScholarGoogle Scholar |

Tate KW, Atwill ER, McDougald NK, George MR (2003) Spatial and temporal patterns of cattle feces deposition on rangeland. Journal of Range Management 56, 432–438.
Spatial and temporal patterns of cattle feces deposition on rangeland.Crossref | GoogleScholarGoogle Scholar |

Tate KW, Atwill ER, McDougald NK, George MR, Witt D (2000) A method for estimating cattle fecal loading on rangeland watersheds. Journal of Range Management 53, 506–510.
A method for estimating cattle fecal loading on rangeland watersheds.Crossref | GoogleScholarGoogle Scholar |

Vadas PA, Gburek WJ, Sharpley AN, Kleinman PJA, Moore PA, Cabrera ML, Harmel RD (2007a) A model for phosphorus transformation and runoff loss for surface-applied manures. Journal of Environmental Quality 36, 324–332.
A model for phosphorus transformation and runoff loss for surface-applied manures.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD2sXnvFarug%3D%3D&md5=c3b324d2bd19733fe9d6511bd503485dCAS | 17215242PubMed |

Vadas PA, Harmel RD, Kleinman PJA (2007b) Transformations of soil and manure phosphorus after surface application of manure to field plots. Nutrient Cycling in Agroecosystems 77, 83–99.
Transformations of soil and manure phosphorus after surface application of manure to field plots.Crossref | GoogleScholarGoogle Scholar |

Vadas PA, Kleinman PJA, Sharpley AN, Turner BL (2005) Relating soil phosphorus to dissolved phosphorus in runoff: a single extraction coefficient for water quality modeling. Journal of Environmental Quality 34, 572–580.
Relating soil phosphorus to dissolved phosphorus in runoff: a single extraction coefficient for water quality modeling.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD2MXislOltLs%3D&md5=768dbc920c3ab709be5522504e75f3dbCAS | 15758110PubMed |

Wilkerson VA, Mertens DR, Casper DP (1997) Prediction of excretion of manure and nitrogen by Holstein dairy cattle. Journal of Dairy Science 80, 3193–3204.
Prediction of excretion of manure and nitrogen by Holstein dairy cattle.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaK1cXht1ynug%3D%3D&md5=c940527a00f3c601bbb4c37a93a68173CAS | 9436099PubMed |

Yamada D, Imura O, Shi K, Shibuya T (2007) Effect of tunneler dung beetles on cattle dung decomposition, soil nutrients and herbage growth. Grassland Science 53, 121–129.
Effect of tunneler dung beetles on cattle dung decomposition, soil nutrients and herbage growth.Crossref | GoogleScholarGoogle Scholar |