INTEGRATED MANAGEMENT OF LAND AND WATER RESOURCES FOR ENVIRONMENTAL AND ECONOMIC SUSTAINABILITY IN THE NORTHEAST U.S.
Location: Pasture Systems & Watershed Management Research
Title: Managing agricultural phosphorus for water quality protection: principles for progress
Submitted to: Plant and Soil
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: May 30, 2011
Publication Date: December 1, 2011
Citation: Kleinman, P.J.A., Sharpley, A.N., Mcdowell, R.W., Flaten, D., Buda, A.R., Tao, L., Bergstrom, L., Zhu, Q. 2011. Managing agricultural phosphorus for water quality protection: principles for progress. Plant and Soil. 349:169-182.
Interpretive Summary: Managing phosphorus in agriculture is not only a production concern, but also a water quality concern, as phosphorus lost from agriculture contributes to eutrophication. Considerable experience now exists in managing phosphorus to protect water quality. We review the major management concerns, identifying principals for prudent phosphorus management.
The eutrophication of aquatic systems due to diffuse pollution of agricultural phosphorus (P) is a local, even regional, water quality problem that can be found world-wide. Sustainable management of P requires prudent tempering of agronomic practices, recognizing that additional steps are often required to reduce the downstream impacts of most production systems. Strategies to mitigate diffuse losses of P must consider chronic (edaphic) and acute, temporary (fertilizer, manure, vegetation) sources. Even then, hydrology can readily convert modest sources into significant loads, including via subsurface pathways. Systemic drivers, particularly P surpluses that result in long-term over-application of P to soils, are the most recalcitrant causes of diffuse P loss. Even in systems where P is in balance, diffuse pollution can be exacerbated by management systems that promote accumulation of P within the effective layer of interaction between soils and runoff water. Indeed, conventional conservation practices aimed at controlling soil erosion must be evaluated in light of their ability to exacerbate dissolved P pollution. Understanding the opportunities and limitations of P management strategies is essential to ensure that water quality expectations are realistic and that our beneficial management practices are both efficient and effective.