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ARS Home » Northeast Area » University Park, Pennsylvania » Pasture Systems & Watershed Management Research » Research » Publications at this Location » Publication #147538
Title: SCALING UP: USING THE P INDEX TO ASSESS RISKS TO REGIONAL WATER QUALITY

Author
item Bryant, Ray
item KOGELMANN, WILHELM - PENN STATE UNIV.
item LIN, HENRY - PENN STATE UNIV.
item WOLF, ANN - PENN STATE UNIV.
item BEEGLE, DOUG - PENN STATE UNIV.

Submitted to: Sustainable Land Application Conference
Publication Type: Abstract Only
Publication Acceptance Date: 1/5/2004
Publication Date: 1/8/2004
Citation: Bryant, R.B., Kogelmann, W., Lin, H., Wolf, A., Beegle, D. 2004. Scaling up: Using the P index to assess risks to regional water quality [Abstract]. Sustainable Land Application Conference. p. 89.

Interpretive Summary:

Technical Abstract: The Phosphorus Index contains the best available scientific knowledge and understanding of soil P interactions and landscape processes that affect the potential risks of P loss to surface waters. Using soil test databases and geographic information, elements of the P Index were combined to provide regional assessments of the relative risks to water quality posed by agricultural non-point sources across the state of Pennsylvania. P source potential was represented by soil test data obtained from the Penn State University Agricultural Analytical Services Laboratory. Results from nearly 100,000 individual agronomic samples analyzed from 1996 to 2001 were georeferenced using the zip code recorded for the grower for whom the sample was submitted. Land cover, streams, soil and topographic data were used to assess P transport potential. The combined results, summarized by counties and watersheds, identify the southeast, south central and northeast areas of Pennsylvania as being those areas where potential P loading to surface waters is greatest. These areas generally correspond to areas of high animal population densities in the state. Although stream water quality may also be affected by urban sources and other land uses, this regional assessment identifies priority areas for targeting agricultural programs and technical assistance to farmers aimed at reducing agricultural impacts on water quality.