Phosphorus management in grazingland ecosystems represents a major challenge of agronomic and environmental importance. Because of the extensive acreage occupied by grazinglands, decisions concerning pasture fertilization and nutrient management in forage-based livestock systems are crucial to both farmers and regulatory agencies. The purpose of this paper is to provide an overview of the literature relevant to pasture P fertilization and the potential impacts on water quality. There continue to be uncertainties regarding interrelationships between pasture management and water quality issues. Despite the extensive body of literature on nutrient transport from grazinglands, limited information is available on the relationships between land use, transport potential, water management, and climatic conditions affecting nutrient losses at a watershed scale. As agriculture continues to modernize and intensify, public concerns about the impacts of plant nutrients on environmental quality will likely increase. Managing water quality protection and profitable agriculture will be a major challenge for the next generations. 1. Introduction A total of 17 elements are considered essential for the growth of higher plants [1]. These include carbon (C), hydrogen (H), oxygen (O), nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), sulfur (S), boron (B), manganese (Mn), copper (Cu), zinc (Zn), molybdenum (Mo), iron (Fe), chlorine (Cl), and nickel (Ni). Carbon, N, and O are obtained from the air and soil water, while the other 14 are supplied by the soil. Nitrogen, P, and, K are considered “primary nutrients” because they are taken up by plant in the largest amounts. Calcium, Mg, and S are considered “secondary nutrients” and are taken up in the next largest amounts. Iron, Mn, Zn, Cu, B, Mo, Cl, and Ni are required by the plants in very small amounts and are known as “micronutrients”. Regardless of the class to which they belong, all essential nutrients are equally important for plant growth. Soil fertility is a key component in sustainable forage production systems. Because most of the essential plant nutrients are supplied by the soil, as soils become nutrient deficient, forage yield and quality can be significantly affected. Most soils in the world are deficient in more than a single essential plant nutrient, so fertilization is generally necessary to improve and maintain forage production. Nitrogen is often a limiting nutrient in grassland systems and is typically applied to pastures as commercial fertilizer, animal manure, or organic
References
[1]
D. G. Blevins and D. J. Barker, “Nutrients and water in forage crops,” in Forages: The Science of Grassland Agriculture, R. F. Barnes, et al., Ed., pp. 67–80, Blackwell, Ames, Iowa, USA, 2007.
[2]
M. B. Adjei and J. E. Rechcigl, “Bahiagrass production and nutritive value as affected by domestic wastewater residuals,” Agronomy Journal, vol. 94, no. 6, pp. 1400–1410, 2002.
[3]
G. C. Sigua, M. J. Williams, S. W. Coleman, and R. Starks, “Nitrogen and phosphorus status of soils and trophic state of lakes associated with forage-based beef cattle operations in Florida,” Journal of Environmental Quality, vol. 35, no. 1, pp. 240–252, 2006.
[4]
J. C. Capece, K. L. Campbell, P. J. Bohlen, D. A. Graetz, and K. M. Portier, “Soil phosphorus, cattle stocking rates, and water quality in subtropical pastures in Florida, USA,” Rangeland Ecology and Management, vol. 60, no. 1, pp. 19–30, 2007.
[5]
J. E. Rechcigl, G. G. Payne, A. B. Bottcher, and P. S. Porter, “Reduced P application on bahiagrass and water quality,” Agronomy Journal, vol. 84, pp. 463–468, 1992.
[6]
G. C. Sigua, R. K. Hubbard, and S. W. Coleman, “Quantifying phosphorus levels in soils, plants, surface water, and shallow groundwater associated with bahiagrass-based pastures,” Environmental Science and Pollution Research, vol. 17, pp. 210–219, 2010.
[7]
J. E. Rechcigl, P. Mislevy, and H. Ibrikci, “Response of established bahiagrass to broadcast lime and phosphorus,” Journal of Production Agriculture, vol. 8, no. 2, pp. 249–253, 1995.
[8]
F. Adams, “Crop response to lime in the southern United States,” in Soil Acidity and Liming, Mong, F. Adams, Ed., vol. 12, American Society of Agronomy, Madison, Wis, USA, 1984.
[9]
R. Mylavarapu, D. Wright, G. Kidder, and C. G. Chambliss, “UF/IFAS Standardized fertilization recommendations for agronomic crops,” Cooperative Extension Service, IFAS, University of Florida. SL129, 2007, http://edis.ifas.ufl.edu/SS163.
[10]
M. L. Silveira, J. M. Vendramini, L. E. Sollenberger, C. L. Mackowiak, and Y. C. Newman, “Tissue analysis as a nutrient management tool for bahiagrass pasture,” Cooperative Extension Service, IFAS, University of Florida. SS475, 2007, http://edis.ifas.ufl.edu/SS475.
[11]
C. L. Mondart Jr., H. E. Harris, R. H. Brupbacher Jr., and J. E. Sedberry, “Influence of annual applications of phosphorus on the yield and chemical composition of common bermudagrass and on the chemical composition of a Bowie soil,” Louisiana Agricultural Experiment Station Bulletin, no. 684, 1974.
[12]
K.A. Kelling and J. E. Matocha, “Plant analysis as an aid in fertilizing forage crops,” in Soil Testing and Plant Analysis, R. L. Westerman, Ed., pp. 603–643, Soil Science of Americ, Madison, Wis, USA, 1990.
[13]
P. R. Peterson and J. R. Gerrish, “Grazing systems and spatial distribution of nutrients in pastures: livestock management considerations,” in Nutrient Cycling in Forage Systems, R. E. Joost and C. A. Roberts, Eds., pp. 203–212, Potash and Phosphate Institute and Foundation for Agron Research, Columbia, MO, USA; PPI, Norcross, Ga, USA, 1996.
[14]
F. M. Rouquette, J. E. Matocha, and R. L. Duble, “Recycling and recovery of nitrogen, phosphorus, and potassium by Coastal bermudagrass: II. Under grazing conditions with two stocking rates,” Journal of Environmental Quality, vol. 2, pp. 129–132, 1973.
[15]
A. S. Dahlin, U. Emanuelsson, and J. H. McAdam, “Nutrient management in low input grazing-based systems of meat production,” Soil Use and Management, vol. 21, pp. 122–131, 2005.
[16]
J. C. B. Dubeux Jr., L. E. Sollenberger, B. W. Mathews, J. M. Scholberg, and H. Q. Santos, “Nutrient cycling in warm-climate grasslands,” Crop Science, vol. 47, no. 3, pp. 915–928, 2007.
[17]
D. R. Edwards, “Recycling livestock manure on pastures,” in Nutrient Cycling in Forage Systems, R. E. Joost and C. A. Roberts, Eds., pp. 45–63, Potash and Phosphate Institute and Foundation for Agron Research, Columbia, MO, USA, 1996, PPI, Norcross, Ga, USA, 1996.
[18]
K. F. Knowlton and R. Kohn, “Feeding management to reduce phosphorus losses from dairy farms,” in Proceedings of the Mid-Atlantic Dairy Management Conference, pp. 94–108, Pennsylvania State University Park, Camp Hill, Pa, USA, February 1999.
[19]
B. Eghball, “Leaching of phosphorus fractions following manure or compost application,” Communications in Soil Science and Plant Analysis, vol. 34, no. 19-20, pp. 2803–2815, 2003.
[20]
A. N. Sharpley, S. C. Chapra, R. Wedepohl, J. T. Sims, T. C. Daniel, and K. R. Reddy, “Managing agricultural phosphorus for protection of surface waters: issues and options,” Journal of Environmental Quality, vol. 23, no. 3, pp. 437–451, 1994.
[21]
S. R. Carpenter, N. F. Caraco, D. L. Correll, R. W. Howarth, A. N. Sharpley, and V. H. Smith, “Nonpoint pollution of surface waters with phosphorus and nitrogen,” Ecological Applications, vol. 8, no. 3, pp. 559–568, 1998.
[22]
B. Eghball, B. J. Wienhold, B. L. Woodbury, and R. A. Eigenberg, “Plant availability of phosphorus in swine slurry and cattle feedlot manure,” Agronomy Journal, vol. 97, no. 2, pp. 542–548, 2005.
[23]
B. W. Mathews, L. E. Sollenberger, P. Nkedi-Kizza, L. A. Gaston, and H. D. Hornsby, “Soil sampling procedures for monitoring potassium distribution in grazed pastures,” Agronomy Journal, vol. 86, no. 1, pp. 121–126, 1994.
[24]
B. W. Mathews, L. E. Sollenberger, and J. P. Tritschler II, “Grazing systems and spatial distribution of nutrients in pastures: soil considerations,” in Nutrient Cycling in Forage Systems, R. E. Joost and C. A. Roberts, Eds., pp. 213–229, Potash and Phosphate Institute and Foundation for Agron Research, Columbia, MO, USA; PPI, Norcross, Ga, USA, 1996.
[25]
C. J. Johnson, P. A. Bonrud, T. L. Dosch, et al., “Fatal outcome of methemoglobinemia in an infant,” Journal of the American Medical Association, vol. 257, no. 20, pp. 2796–2797, 1987.
[26]
A. N. Sharpley and A. D. Halvorson, Soil Process and Water Quality, Lewis Publishers, Boca Raton, Fla, USA, 1994.
[27]
J. E. Rechcigl and A. B. Boucher, “Fate of phosphorus on bahiagrass (Paspalum notatum) pastures,” Ecological Engineering, vol. 5, no. 2-3, pp. 247–259, 1995.
[28]
M. L. Silveira, A. K. Obour, J. M. Vendramini, and L. E. Sollenberger, “Using tissue analysis as a tool to predict bahiagrass phosphorus fertilization requirement,” Journal of Plant Nutrition. In press.
[29]
A. K. Obour, M. L. Silveira, J. M. B. Vendramini, L. E. Sollenberger, G. A. O'Connor, and J. W. Jawitz, “Agronomic and environmental impacts of phosphorus fertilization of low input bahiagrass systems in Florida,” Agronomy Journal. In press.
[30]
D. R. Keeney and M. A. Sanderson, “Forages and the environment,” in Forages: The Science of Grassland Agriculture, R. F. Barnes, et al., Ed., pp. 167–176, Blackwell, Ames, Iowa, USA, 2007.
[31]
R. J. Haynes and P. H. Williams, “Nutrient cycling and soil fertility in grazed pasture ecosystem,” Advances in Agronomy, vol. 49, pp. 119–199, 1993.
[32]
P. H. Williams and R. J. Haynes, “Influence of improved pastures and grazing animals on nutrient cycling within New Zealand soils,” New Zealand Journal of Ecology, vol. 14, pp. 49–57, 1990.
[33]
A. N. Sharpley, P. J. A. Kleinman, R. W. McDowell, M. Gitau, and R. B. Bryant, “Modeling phosphorus transport in agricultural watersheds: processes and possibilities,” Journal of Soil and Water Conservation, vol. 57, no. 6, pp. 425–439, 2002.
[34]
J. M. Novak, D. W. Watts, P. G. Hunt, and K. C. Stone, “Phosphorus movement through a Costal Plain soil after a decade of intensive swine manure application,” Journal of Environmental Quality, vol. 29, pp. 1310–1315, 2000.
[35]
M. L. Silveira, M. K. Miyittah, and G. A. O'Connor, “Phosphorus release from a manure-impacted spodosol: effects of a water treatment residual,” Journal of Environmental Quality, vol. 35, no. 2, pp. 529–541, 2006.
[36]
P. J. A. Withers and E. I. Lord, “Agricultural nutrient inputs to rivers and groundwaters in the UK: policy, environmental management and research needs,” Science of the Total Environment, vol. 282-283, pp. 9–24, 2002.
[37]
G. M. Pierzynski, J. T. Sims, and G. F. Vance, Soils and Environmental Quality, CRC Press, Boca Raton, Fla, USA, 2005.
[38]
J. K. Syers, R. F. Harris, and D. E. Armstrong, “Phosphate chemistry in lake sediments,” Journal of Environmental Quality, vol. 2, pp. 1–13, 1973.
[39]
USEPA, “Environmental indicators of water quality in the United States,” EPA 841-R-96-002, U.S. Government Printing Office, Washington, DC, USA, 1996.
[40]
S. Agyin-Birikorang, G. A. O'Connor, L. W. Jacobs, K. C. Makris, and S. R. Brinton, “Long-term phosphorus immobilization by a drinking water treatment residual,” Journal of Environmental Quality, vol. 36, no. 1, pp. 316–323, 2007.
[41]
M. G. Hutchins, S. G. Anthony, R. A. Hodgkinson, and P. J. A. Withers, “Modularised process-based modelling of phosphorus loss at farm and catchment scale,” Hydrology and Earth System Sciences, vol. 6, no. 6, pp. 1017–1030, 2002.
[42]
P. S. Davison, P. J. A. Withers, E. I. Lord, M. J. Betson, and J. Str？mqvist, “PSYCHIC—a process-based model of phosphorus and sediment mobilisation and delivery within agricultural catchments. Part 1: model description and parameterisation,” Journal of Hydrology, vol. 350, no. 3-4, pp. 290–302, 2008.
[43]
D. E. Radcliffe, J. Freer, and O. Schoumans, “Diffuse phosphorus models in the United States and Europe: their usages, scales, and uncertainties,” Journal of Environmental Quality, vol. 38, no. 5, pp. 1956–1967, 2009.
[44]
L. M. Pease, P. Oduor, and G. Padmanabhan, “Estimating sediment, nitrogen, and phosphorous loads from the Pipestem Creek watershed, North Dakota, using AnnAGNPS,” Computers and Geosciences, vol. 36, no. 3, pp. 282–291, 2010.
[45]
B. Eghball and J. E. Gilley, “Phosphorus and nitrogen in runoff following beef cattle manure or compost application,” Journal of Environmental Quality, vol. 28, no. 4, pp. 1201–1210, 1999.
[46]
D. R. Edwards and T. C. Daniel, “Drying interval effects on runoff from fescue plots receiving swine manure,” Transactions of the American Society of Agricultural Engineers, vol. 36, no. 6, pp. 1673–1678, 1993.
[47]
D. R. Edwards, T. C. Daniel, P. A. Moore Jr., and A. N. Sharpley, “Solids transport and erodibility of poultry litter surface-applied to fescue,” Transactions of the American Society of Agricultural Engineers, vol. 37, no. 3, pp. 771–776, 1994.
[48]
I. C. Daverede, A. N. Kravchenko, R. G. Hoeft, E. D. Nafziger, D. G. Bullock, J. J. Warren, and L. C. Gonzini, “Phosphorus runoff from incorporated and surface-applied liquid swine manure and phosphorus fertilizer,” Journal of Environmental Quality, vol. 33, no. 4, pp. 1535–1544, 2004.
[49]
A. N. Sharpley, T. Daniel, R. Qright, et al., “National research project to identify sources of agricultural phosphorus loss,” Better Crops, vol. 83, pp. 12–14, 1999.
[50]
A. N. Sharpley, P. J. A. Kleinman, R. J. Wright, et al., “The National Phosphorus Project: addressing the interface of agriculture and environmental phosphorus management in the USA. Section 2.3. Indicators for environmental performance,” in Agricultural Effects on Ground and Surface Water: Research at the Edge of Science and Society, F. Steenvoorden and J. Willems, Eds., vol. 273, pp. 95–100, International Association of Scientific Hydrology Press, Wallingford, UK, 2002.
[51]
D. D. Tarkalson and R. L. Mikkelsen, “Runoff phosphorus losses as related to phosphorus source, application method, and application rate on a Piedmont soil,” Journal of Environmental Quality, vol. 33, no. 4, pp. 1424–1430, 2004.
[52]
P. J. A. Kleinman, A. N. Sharpley, T. L. Veith, R. O. Maguire, and P. A. Vadas, “Evaluation of phosphorus transport in surface runoff from packed soil boxes,” Journal of Environmental Quality, vol. 33, no. 4, pp. 1413–1423, 2004.
[53]
National Phosphorus Research Project, “National research project for simulated rainfall-surface runoff studies,” North Carolina State University, Raleigh, NC, USA 2001, http://www.sera17.ext.vt.edu/Documents/National_P_protocol.pdf.
[54]
A. N. Sharpley, J. L. Weld, D. B. Beegle, P. J. A. Kleinman, W. J. Gburek, P. A. Moore Jr., and G. Mullins, “Development of phosphorus indices for nutrient management planning strategies in the United States,” Journal of Soil and Water Conservation, vol. 58, no. 3, pp. 137–152, 2003.
[55]
W. G. Harris, R. D. Rhue, G. Kidder, R. B. Brown, and R. Littell, “Phosphorus retention as related to morphology of sandy coastal plain soil materials,” Soil Science Society of America Journal, vol. 60, no. 5, pp. 1513–1521, 1996.
[56]
C. S. Snyder, T. W. Bruulsema, A. N. Sharpley, and D. B. Beegle, “Site-specific use of the environmental Phosphorus-Index concept,” in Site Specific Management Guidelines, SSMG-1, Potash and Phosphate Instituteitute, Norcross, Ga, USA, 1999.
[57]
H. E. Andersen and B. Kronvang, “Modifying and evaluating a P index for Denmark,” Water, Air, and Soil Pollution, vol. 174, no. 1–4, pp. 341–353, 2006.
[58]
U. Buczko and R. O. Kuchenbuch, “Phosphorus indices as risk-assessment tools in the U.S.A. and Europe—a review,” Journal of Plant Nutrition and Soil Science, vol. 170, no. 4, pp. 445–460, 2007.
[59]
G. Heckrath, M. Bechmann, P. Ekholm, B. Ulén, F. Djodjic, and H. E. Andersen, “Review of indexing tools for identifying high risk areas of phosphorus loss in Nordic catchments,” Journal of Hydrology, vol. 349, no. 1-2, pp. 68–87, 2008.
[60]
S. E. A. T. M. van der Zee and W. H. van Riemsdijk, “Model for long-term phosphate reaction kinetics in soil,” Journal of Environmental Quality, vol. 17, no. 1, pp. 35–41, 1988.
[61]
P. S. Hooda, A. R. Rendell, and A. C. Edwards, “Relating soil phosphorus indices to potential phosphorus release to water,” Journal of Environmental Quality, vol. 29, no. 4, pp. 1166–1171, 2000.
[62]
V. D. Nair and W. G. Harris, “A capacity factor as an alternative to soil test phosphorus in phosphorus risk assessment,” New Zealand Journal of Agricultural Research, vol. 47, no. 4, pp. 491–497, 2004.
[63]
V. D. Nair, K. M. Portier, D. A. Graetz, and M. L. Walker, “An environmental threshold for degree of phosphorus saturation in sandy soils,” Journal of Environmental Quality, vol. 33, no. 1, pp. 107–113, 2004.
[64]
M. Chrysostome, V. D. Nair, W. G. Harris, and R. D. Rhue, “Laboratory validation of soil phosphorus storage capacity predictions for use in risk assessment,” Soil Science Society of America Journal, vol. 71, no. 5, pp. 1564–1569, 2007.
[65]
V. D. Nair, S. G. Haile, G.-A. Michel, and P. K. R. Nair, “Environmental quality improvement of agricultural lands through silvopasture in Southeastern United States,” Scientia Agricola, vol. 64, no. 5, pp. 513–519, 2007.
