About Us | Help Videos | Contact Us | Subscriptions

Journal of Environmental Quality Abstract - Ecological Risk Assessment

Predicted Impact and Evaluation of North Carolina's Phosphorus Indexing Tool


This article in JEQ

  1. Vol. 34 No. 5, p. 1801-1810
    Received: Jan 19, 2005

    * Corresponding author(s): amjohns2@unity.ncsu.edu
Request Permissions

  1. Amy M. Johnson *a,
  2. Deanna L. Osmonda and
  3. Steven C. Hodgesb
  1. a Soil Science Department, North Carolina State University, Campus Box 7619, Raleigh, NC 27695-7619
    b Crop and Soil Environmental Science Department, Virginia Polytechnic Institute and State University, 330 Smyth Hall, Blacksburg, VA 24061


Increased concern about potential losses of phosphorus (P) from agricultural fields receiving animal waste has resulted in the implementation of new state and federal regulations related to nutrient management. In response to strengthened nutrient management standards that require consideration of P, North Carolina has developed a site-specific P indexing system called the Phosphorus Loss Assessment Tool (PLAT) to predict relative amounts of potential P loss from agricultural fields. The purpose of this study was to apply the PLAT index on farms throughout North Carolina in an attempt to predict the percentage and types of farms that will be forced to change management practices due to implementation of new regulations. Sites from all 100 counties were sampled, with the number of samples taken from each county depending on the proportion of the state's agricultural land that occurs in that county. Results showed that approximately 8% of producers in the state will be required to apply animal waste or inorganic fertilizer on a P rather than nitrogen basis, with the percentage increasing for farmers who apply animal waste (approximately 27%). The PLAT index predicted the greatest amounts of P loss from sites in the Coastal Plain region of North Carolina and from sites receiving poultry waste. Loss of dissolved P through surface runoff tended to be greater than other loss pathways and presents an area of concern as no best management practices (BMPs) currently exist for the reduction of in-field dissolved P. The PLAT index predicted the areas in the state that are known to be disproportionately vulnerable to P loss due to histories of high P applications, high densities of animal units, or soil type and landscapes that are most susceptible to P loss.

  Please view the pdf by using the Full Text (PDF) link under 'View' to the left.

Copyright © 2005. American Society of Agronomy, Crop Science Society of America, Soil Science SocietyASA, CSSA, SSSA