Evaluating the Success of Phosphorus Management from Field to Watershed
- Andrew N. Sharpley *a,
- Peter J.A. Kleinmanb,
- Philip Jordanc,
- Lars Bergströmd and
- Arthur L. Allene
- a Dep. of Crop, Soil and Environmental Sciences, Division of Agriculture, Univ. of Arkansas, Fayetteville, AR 72701
b USDA-ARS, Pasture Systems and Watershed Management Research Unit, Bldg. 3702, Curtin Rd., University Park, PA 16802
c Environmental Science, University of Ulster, Coleraine, N. Ireland (seconded to Teagasc, Wexford, Ireland)
d Swedish Univ. of Agricultural Sciences, Uppsala, Sweden
e Univ. of Maryland Eastern Shore, Princess Anne, MD 21853
Studies have demonstrated some P loss reduction following implementation of remedial strategies at field scales. However, there has been little coordinated evaluation of best management practices (BMPs) on a watershed scale to show where, when, and which work most effectively. Thus, it is still difficult to answer with a degree of certainty, critical questions such as, how long before we see a response and where would we expect to observe the greatest or least response? In cases where field and watershed scales are monitored, it is not uncommon for trends in P loss to be disconnected. We review case studies demonstrating that potential causes of the disconnect varies, from competing sources of P at watershed scales that are not reflected in field monitoring to an abundance of sinks at watershed scales that buffer field sources. To be successful, P-based mitigation strategies need to occur iteratively, involve stakeholder driven programs, and address the inherent complexity of all P sources within watersheds.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
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