Andrew N. Sharpley

Andrew N. Sharpley

Professor of Soils and Water Quality

Director Experiment Station

(CSES)-Crop, Soil and Environmental Sciences

Phone: 479-575-5721

Fax: (479) 575-7465

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Andrew Sharpley was born in Manchester, England, helped on his uncle’s dairy farm and worked as a National Park Ranger during the summers, where he gained an appreciation for agriculture and the environment.

Recent Accomplishments:

  • Quantified the impact of agricultural P and N management practices on surface and ground water quality.
    Dr. Sharpley showed effective fertilizer/animal manure and tillage use strategies can be devised to minimize pollution problems and still achieve agricultural production goals.  He was an early advocate and first to systematically design research to compare the potential environmental benefits of conservation measures with surface or groundwater quality tradeoffs.
  • Developed a simple, routine, and interference-free method to estimate the amount of algal-available P transported in agricultural runoff. 
    The innovative method uses iron-oxide impregnated filter paper that reacts with P in a runoff sample, which is easily removed for analysis.  Because of his cooperative research and technology transfer, the method is used worldwide to identify, assess, and select agricultural management practices that may reduce surface water eutrophication potential.
  • Formulated and refined equations to predict the transport of dissolved and sediment-bound P and N in runoff using laboratory and field studies. Transport in solution was described by the innovative application of a kinetic equation, with parameters being dynamic functions of watershed management and soil properties.
  • Developed an indexing system to identify soils, landscapes, and management systems vulnerable to P loss in runoff. Dr. Sharpley led a USDA team that developed the P index, which combines the relative contribution of site characteristics controlling P loss to identify sensitive areas and target management alternatives and remedial measures to reduce the risk of P loss from farms.
  • Established the basic principles used in the development of environmental P testing programs for soil and manure in the U.S. and overseas. Dr. Sharpley’s research on the depth of surface soil - runoff interaction and alternative soil and manure P extractions, provides the conceptual and methodological basis for defining P transfers from land to runoff water.
  • Coordinates the National Phosphorus Research Project.  This project is a consortium of ARS, Universities, EPA, and NRCS personnel at over 25 locations that will determine threshold soil P levels and define critical sources within watersheds to protect water quality by reducing surface runoff and subsurface flow P export to surface waters.

Research Emphasis

  • His research investigates the cycling of phosphorus in soil-plant-water systems in relation to agricultural production systems and water quality and includes the management of animal manures, fertilizers, and crop residues.
  • He evaluates the role of stream and river sediments in modifying the amounts and forms of phosphorus transported to lakes and reservoirs in Arkansas.
  • Most recently he developed decision making tools for agricultural field staff to identify sensitive areas of the landscape and to target management alternatives and remedial measures that have reduced the risk of nutrient loss from farms.  These tools are now widely accepted by US EPA, NRCS, and the Comprehensive Nutrient Management Planning Strategy. 
  • He works closely with producers, farmers, and action agencies, stressing the dissemination and application of his research findings.  With others in the Univ. of Arkansas’s Division of Agriculture, Farm Bureau, Arkansas Natural Resources Commission, and various commodity and producer groups, is developing an on-farm demonstration, verification, and research program to show the benefits of Best Management Practices that protect water quality and promotes sustainability.
  • He served on National Academy of Science’s Committee on “Causes and Management of Coastal Eutrophication (2000);” USDA-CSREES-EPA “National Livestock Curriculum Project (2004);” and EPA’s Scientific Advisory Board “Hypoxia Advisory Panel (2007).” 


  • 1973, University of North Wales, Wales, Soil Science and Biochemistry, B.Sc.
  • 1977, Massey University, Palmerston North, New Zealand, Soil Science, Ph.D.


  • Sharpley, A. N. 2007.  Modeling phosphorus movement from agriculture to surface waters. p. 3-19.  In D. Radcliffe and M. Cabrera (eds.), Modeling phosphorus in the environment: State of the art. CRC Press, Boca Raton, FL.
  • Sharpley, A. N., Herron, S., and Daniel, T.C.  2007. Overcoming the challenges of phosphorus-based nutrient management in poultry farming.  J. Soil Water Conserv. 62(6):375-389.
  • Sharpley, A. N., Kleinman, P. J. A., Jordan, P., Bergstrom, L.. 2007.   Demonstrating phosphorus mitigation strategies can work at field and catchment scales.  p. 29-31.  In G. Hechrath, G. H. Rubaek, and B. Kronvang (eds), Diffuse Phosphorus Loss:  Risk assessment, Mitigation Options and Ecological Effects in River Basins.  DJF Plant Science Volume 130.  
  • Sharpley, A. N., Krogstad, T., Kleinman, P. J. A., Haggard, B. E., Shigaki, F., and Saporito, L. 2007. Managing natural processes in drainage ditches for non-point source phosphorus control.  J. Soil Water Conserv. 62:197-206.
  • Daniel, M., Haggard, B. E., and Sharpley, A. N.  2007. Arkansas watersheds.  Cooperative Extension Service, Division of Agriculture, University of Arkansas.  Fact Sheet FSA 9521. 8 pages.
  • Haggard, B. E., and Sharpley, A. N.  2007. Phosphorus transport in stream: Processes and modeling considerations. p. 105-130.  In D. Radcliffe and M. Cabrera (eds.), Modeling phosphorus in the environment: State of the art. CRC Press, Boca Raton, FL.
  • James, E., Kleinman, P. J. A., Veith, T. L., Stedman, R. and Sharpley, A. N.  2007. Phosphorus contributions from pastured dairy cattle to streams of the Cannonsville Watershed.  J. Soil Water Conserv.  62:40-47. 
  • Kleinman, P. J. A., Allen, A., Needelman, B., Sharpley, A. N., Vadas, P. A., Saporito, L., Folmar, G., and Bryant, R. B.  2007. Dynamics of phosphorus transfers from heavily manured coastal plain soils to drainage ditches. J. Soil Water Conserv. 62:225-235.
  • Kleinman, P.J.A., Sullivan, D., Wolf, A., Brandt, R., Dou, Z., Elliot, H., Kovar, J., Leytem, A., Maguire, R., Moore, P., Saporito, L., Sharpley, A.N., Shober, A., Sims, T., Toth, J., Toor, G., Zhang, H., Zhang, T.  2007.  Selection of a water-extractable phosphorus test for manures and biosolids as an indicator of runoff loss potential.  J. Environ. Qual. 36:1357-1367.
  • Shigaki, F., Sharpley, A. N., and Prochnow, L. I.  2007.  Rainfall intensity and phosphorus source effects on phosphorus transport in surface runoff from soil trays. Sci. Total Environ. 373:334-343.
  • Srinavasan, M. S., Kleinman, P. J. A., Sharpley, A. N., Boub. T. A., and Gburek, W. J.  2007.  Hydrology of small field plots used to study phosphorus runoff under simulated rainfall.  J. Environ. Qual.  36:1833-1842. 
  • Vadas, P. A., Gburek, W. J., Sharpley, A. N., Kleinman, P. J. A., Moore, Jr., P.A., Cabrera, M. L., and Harmel, R.D.  2007.  A model for phosphorus transformation and runoff loss for surface-applied manures. J. Environ. Qual. 36:324-332.
  • Weld, J. L., and Sharpley, A. N.  2007.  Phosphorus indices. p. 301-332.  In D. Radcliffe and M. Cabrera (eds.), Modeling phosphorus in the environment: State of the art. CRC Press, Boca Raton, FL.


  • Sharpley, A.N.  2008.  Bioavailable phosphorus in soil.  p. 37-42.  In G.M. Pierzynski and J.L. Kovar (eds.), Methods for Phosphorus Analysis for Soils, Sediments, Residuals, and Waters.  Southern Cooperative Series Bulletin. 
  • Sharpley, A. N., and West C.  2008.  Pressures on beef grazing in mixed production farming.  p.187-208.  In R. W. McDowell (ed.), Environmental Impacts of Pasture-based Faming.  CABI Publishing, Wallingford, Oxfordshire, United Kingdom. 
  • Sharpley, A. N., Kleinman, P. J. A., Heathwaite, A. L., Gburek, W. L., Folmar, G. L., and Schmidt, J. P.  2008.  Phosphorus loss from an agricultural watershed as a function of storm size.  J. Environ. Qual. 37:362-368.
  • Sharpley, A. N., Kleinman, P. J. A., Heathwaite, A. L., Gburek, W. L., Weld, J. L. and Folmar, G. L. 2008.  Integrating contributing areas and indexing phosphorus loss from agricultural watersheds.  J. Environ. Qual. 37:1488-1496. 
  • Hypoxia Advisory Panel Member, Scientific Advisory Board, U.S. Environmental Protection Agency.$File/EPA-SAB-08-003complete.unsigned.pdf .  Hypoxia in the Northern Gulf of Mexico: An update by the Scientific Advisory.  2008.
  • McDowell, R. W., Sharpley, A. N., and Bourke, W.  2008.  Treatment of drainage water with industrial by-products to prevent phosphorus loss from tile-drained land.  J. Environ. Qual. 37:1575-1582. 
  • Pennington, J., Daniels, M., and Sharpley, A. N.  2008.  Using the watershed approach to maintain and enhance water quality.  Cooperative Extension Service, Division of Agriculture, University of Arkansas.  Fact Sheet FSA. 9526.  8 pages. 
  • Pennington, J., Daniels, M., and Sharpley, A. N.  2008.  Best management practices for livestock farms.  Cooperative Extension Service, Division of Agriculture, University of Arkansas.  Fact Sheet FSA 9527.  8 pages. 
  • Robertson, G. P., Dale, V. H., Doering, C. D., Hamburg, S. P., Melillo, J. M., Wander, M. M., Parton, W. J., Adler, P. R., Barney, J., Cruse, R. M., Duke, C. S., Fearnside, P. M., Follett, R. F., Gibbs, H. K.,  Goldemberg, J., Mladenoff, D. J., Ojima, D., Palmer, M. W., Sharpley, A. N., Wallace, L. W., Weathers, K. C., Wiens, J. A., and Wilhelm, W. W.  2008.  Sustainable biofuels redux.  Science 322:49-50. 
  • Shigaki, F., Kleinman, P. J. A., Schmidt, J. P., Sharpley, A. N., and Allen, A. L.  2008.  Impact of dredging on phosphorus transport in agricultural drainage ditches of the Atlantic Coastal Plain.  J. Am. Water Resour. Assoc. 44(6):1500-1511. 
  • Simpson, T. W., Sharpley, A. N., Howarth, R. W., Paerl, H.W., and Mankin, K. R.  2008.  The new gold rush:  Fueling ethanol production while protecting water quality.  J. Environ. Qual. 37:318-324. 
  • Veith, T. L., Sharpley, A. N., Arnold J. G.  2008.  Modeling a small, northeastern watershed with detailed, field-level data.  Trans. Am. Soc. Agric. Bio. Eng. 51(2):471-483. 


  • Sharpley, A.N., Herron, S., West, C., Daniel, T. Outcomes of phosphorus-based nutrient management in the Eucha-Spavinaw watershed, Proceedings of a conference, Farming with Grass: Sustainable Mixed Agricultural Landscapes in Grassland Environments, Oklahoma Soil and Water Conservation Society. (in press).  (PDF )

Professional Backround

  • 2006 – present, Professor, Department of Crop, Soil and Environmental Sciences, University of Arkansas, Fayetteville, AR
  • 1995 – 2006, Soil Scientist, USDA-ARS, University Park, PA, and Adj. Prof., Penn State Univ.
  • 1985 – 1995, Soil Scientist, USDA-ARS, Durant, OK

Professional Involvement/Memberships:

  • Soil Science Society of America
  • American Society of Agronomy
  • International Soil Science Society
  • Soil Water Conservation Society
  • SERA IEG-17
  • Gamma Sigma Delta 

Honors and Awards

  • Fellow, American Society of Agronomy, 1990.
  • Fellow, Soil Science Society of America, 1991.
  • Recipient of the 1994 American Society of Agronomy Environmental Quality Research Award.  November 1994.
  • USDA-ARS, Northeast Atlantic Area Research Scientist of the Year Award, 1998.
  • Soil Science Applied Research Award, Soil Science Society of America, 1998.
  • Northeastern Branch of American Society of America’s Research Award, 2001.
  • USDA Secretary’s Honor Award, 2001.
  • Gamma Sigma Delta Research Award, in recognition of outstanding research productivity and impact to Pennsylvania State University.  2003. 
  • USDA Secretary’s Plow Honor Award for Group Achievements in “Maintaining and Enhancing the Nation’s Natural Resources and Environment.”  2003.
  • Soil Science Research Award, Soil Science Society of America, 2003.
  • ARS Technology Transfer Award for “For development and implementation of a Phosphorus Indexing procedure to target remedial measures for nutrient management strategies that maintain productivity and protect water quality,”  2004.
  • System-wide Integration Award from the Association of Extension Administrators and Association of Agricultural Research Directors of 1890 land-grant institutions in recognition of the collaborative efforts of a multi-disciplinary, multi-institutional team of researchers, extension educators and others to improve water quality in the Chesapeake Bay, 2005.
  • Recipient of the Soil and Water Conservation Society’s 2007 Research Award for Impact and Quality of a Paper published between 2000 and 2006.  The paper is “Development of phosphorus indices for nutrient management planning strategies in the United States,” 2007.
  • Inducted into the USDA-ARS Hall of Fame.  “For pioneering nutrient research leading to the development of agricultural management practices and strategies that are used nationally and internationally to protect water quality,” 2008.