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Publication #CIR 1304

UF/IFAS Nutrient Management Series: Computational Tools for Field Implementation of the Florida Phosphorus Index - Polk County Florida1

G.W. Hurt, R.S. Mylavarapu and S.P. Boetger2

The Phosphorus Index (P Index) is a site-specific, qualitative vulnerability assessment tool. This tool allows a conservation planner to determine the sites that are potentially most vulnerable to off-site movement of phosphorus. The P Index is used to determine whether application of manure/organic by-products should be based on either a nitrogen-based budget or a phosphorus-based budget. The P Index is NOT to be used in any area designated as phosphorus-limited by legislation (e.g. Everglades, Green Swamp, and Okeechobee Basin) to determine if a nitrogen-based nutrient budget can be used. These areas are to have phosphorus-based nutrient budgets regardless of the nutrient source or soil type. The P Index should, however, be used to implement conservation practices to reduce phosphorus movement in these areas.

The purpose of the P Index is to aid planners and others in the decision-making process involved in designing conservation plans related to land application of animal wastes. The P Index is not intended to be an evaluation tool to determine compliance of water quality standards by any regulatory agency. Any attempt to use the P Index as a regulatory tool would be grossly beyond the intent of the concept and philosophy of the P Index developers.

A copy of UF/IFAS Nutrient Management Series: Computational Tools for Field Implementation of the Florida Phosphorus Index - Polk County Florida can be downloaded into Adobe Acrobat Reader by clicking on this link or the PDF icon at the top right corner of the page. If you do not have Reader software, you can download it free by clicking here .



This is Circular 1304, one of a series of circulars from the Soil and Water Science Department, UF/IFAS Extension. Originally published in March 2002. Revised August 2013. Please visit the EDIS website at


G.W. Hurt, National Leader for Hydric Soils, USDA-NRCS, R.S. Mylavarapu, Nutrient Management Specialist and Director of UF/IFAS ARL/ESTL, Soil and Water Science Department, University of Florida, Gainesville, FL 32611 and S.P. Boetger, Agronomist, NRCS, Gainesville, FL, 32611.

The Institute of Food and Agricultural Sciences (IFAS) is an Equal Opportunity Institution authorized to provide research, educational information and other services only to individuals and institutions that function with non-discrimination with respect to race, creed, color, religion, age, disability, sex, sexual orientation, marital status, national origin, political opinions or affiliations. For more information on obtaining other UF/IFAS Extension publications, contact your county's UF/IFAS Extension office.

U.S. Department of Agriculture, UF/IFAS Extension Service, University of Florida, IFAS, Florida A & M University Cooperative Extension Program, and Boards of County Commissioners Cooperating. Nick T. Place, dean for UF/IFAS Extension.