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New York Phosphorus Runoff Index

p index

Photo by L.D. Geohring, 2002

Cornell University faculty and staff, Cornell Cooperative Extension field staff, agencies including NRCS and Soil & Water Conservation Districts, private sector crop consultants and producers have jointly developed a second draft of the New York Phosphorus Runoff Index.

This draft version includes transport (soil drainage class, flooding frequency, distance to the stream and stream type, presence or absence of concentrated flows) and source factors (soil test P, fertilizer and manure P application rate, timing and method). Click on the link below to access tools and information about the New York Phosphorus Runoff Index.

Natural Resources Conservation Service Practice Standard Code 590 mandates that field-specific assessment of the potential for P transport must be completed prior to the actual manure and fertilizer application. Code 590 states that "when manure or other organic by-products are used, the planned rates of P application shall be consistent with any one of the following options: 1) phosphorus index (P Index) rating; 2) soil phosphorus threshold values; 3) soil tests". The use of a P Index is environmentally and economically the most sensible option as it will eventually allow soils with low P runoff risk to act as P sinks while soils that contribute to P release to the surface and ground waters are gradually brought to levels just below P breakthrough.

Several states are presently developing a P Index. In New York State, Cornell University faculty and staff, Cornell Cooperative Extension field staff, agencies including NRCS and Soil & Water Conservation Districts, private sector crop consultants and producers have developed the current New York P Index. The New York P Index includes transport (soil drainage class, flooding frequency, distance to the stream and stream type, concentrated flows) and source factors (soil test P, fertilizer and manure P application rate, timing and method).

The current New York P Index Work Group consists of Shawn Bossard (CCE), Dale Dewing (CCE), Greg Albrecht (CSS), Tibor Horvath and Bill Elder (NRCS), Tammo Steenhuis and Larry Geohring (BEE), Jeff Ten Eyck (DAM), Karl Czymmek (ProDairy) and Quirine Ketterings (CSS). The P Index is incorporated into Cornell Cropware, Cornell University's nutrient management software program.

Training sessions on the use of the P Index and Cropware are currently being conducted. For further information contact Karl Czymmek kjc12@cornell.edu. See the links below for more tools and information about the New York Phosphorus Index.

P Index Files
P Index Users Manual
Czymmek, K.J., Q.M. Ketterings, L.D. Geohring, and G.L. Albrecht (2003). The New York Phosphorus Index. User's guide and documentation. CSS Extension Bulletin E03-13. 64 pp.
Basic P Index Structure
P Index Article from "What's Cropping Up"
Czymmek, K.J., Q.M. Ketterings and L. Geohring (2001). Phosphorus and Agriculture VIII: The New Phosphorus Index for New York State. "What's Cropping Up?" 11(4): 1-3.