Submitted to: Journal of Environmental Quality
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/20/2009
Publication Date: 8/24/2009
Publication URL: http://jeq.scijournals.org/cgi/content/full/38/5/1981
Citation: Sharpley, A.N., Kleinman, P.J.A., Jordan, P., Bergstrom, L., Allen, A. L. 2009. Evaluating the Success of Phosphorus Management from Field to Watershed. Journal of Environmental Quality. 38(5):1981-1988. Interpretive Summary: Phosphorus-based nutrient management has now been widely adopted in the US, largely due to water quality concerns over phosphorus loss from agricultural fields. Documenting the success of phosphorus-based management has been elusive, particularly at watershed scales where water quality concerns are borne. This study reviews a variety of case studies to provide insight into areas where phosphorus - based management practices have been successful and where they have not.
Technical Abstract: Studies have demonstrated some phosphorus (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.