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ARS Home » Northeast Area » University Park, Pennsylvania » Pasture Systems & Watershed Management Research » Research » Publications at this Location » Publication #124133
Title: PHOSPHORUS, AGRICULTURE, AND WATER QUALITY: A NORTHEAST PERSPECTIVE

Author
item JOKELA, WILLIAM - UNIVERSITY OF VERMONT
item CLAUSEN, JOHN - UNIV. OF CONNECTICUT
item MEALS, DONALD - NEW ENGLAND WATER COMM.
item Sharpley, Andrew

Submitted to: American Society of Agronomy Branch Meeting
Publication Type: Proceedings
Publication Acceptance Date: 5/20/2001
Publication Date: 6/24/2001
Citation: Jokela, W.E., Clausen, J.C., Meals, D.W., Sharpley, A.N. 2001. Phosphorus, agriculture, and water quality: a northeast perspective [Abstract]. Northeast Branch of American Society of Agronomy Abstracts. 24-27.

Interpretive Summary:

Technical Abstract: Inputs of phosphorus (P) are essential for profitable crop and livestock agriculture. However, its export in watershed runoff can accelerate the eutrophication of receiving fresh waters. Eutrophication has been blamed for the decline in water quality in freshwater lakes and estuaries in the Northeast over the past decades. The issue has received increased public attention recently as a result of human health problems, such as the impaired drinking water supply for New York City and outbreaks of the dinoflagellate Pfiesteria in waters off the east coast. Increased P loading to surface waters has come from a range of point sources and both urban and agricultural nonpoint sources. Recent estimates for Lake Champlain, for example, indicate that 30% of the P comes from point sources, primarily sewage treatment plants, and 70% from nonpoint sources in the Vermont-New York watershed. Agriculture contributes about two- thirds of the nonpoint P. Estimates for the Chesapeake Bay watershed are slightly higher, with over 80% of the nonpoint source and about half of the total P loading contributed by agriculture. The Chesapeake Bay is especially sensitive to nutrient inputs from the watershed because the land area to water volume ratio is much higher than other riverine estuaries in the world. Implementation of best management practices (BMPs) that reduce erosion and runoff or limit loss of P from a field can lead to improved water quality in some situations; but in the long term such improvements will be limited unless whole-farm P budgets are brought into closer balance.