Page Banner

United States Department of Agriculture

Agricultural Research Service

Research Project: DEVELOPMENT OF MODELS AND CONSERVATION PRACTICES FOR WATER QUALITY MANAGEMENT AND RESOURCE ASSESSMENTS

Location: Grassland, Soil and Water Research Laboratory

Title: Validation of a quantitative phosphorus loss assessment tool

Authors
item WHITE, MICHAEL
item Storm, Daniel -
item Smolen, Michael -
item Busteed, Philip -
item Zhang, Hailin -
item Fox, Garey -

Submitted to: Journal of Environmental Quality
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: May 17, 2012
Publication Date: November 16, 2011
Citation: White, M.J., Storm, D.E., Smolen, M.D., Busteed, P.R., Zhang, H., Fox, G.A. 2011. Validation of a quantitative phosphorus loss assessment tool. Journal of Environmental Quality. doi:10.2134/jeq2011.0434.

Interpretive Summary: Pasture Phosphorus Management Plus (PPM Plus) is a tool that allows nutrient management and conservation planners to evaluate phosphorus loss from agricultural fields. This tool is a modified version of the widely used Soil and Water Assessment Tool (SWAT) model with a vastly simplified interface. This tool was validated using 286 field years of data collected in the southern U.S. and did a good job of predicting sediment and phosphorus losses. PPM Plus is an easy to use conservation planning tool for P loss prediction.

Technical Abstract: Pasture Phosphorus Management Plus (PPM Plus) is a tool that allows nutrient management and conservation planners to evaluate phosphorus loss from agricultural fields. This tool is a modified version of the widely used Soil and Water Assessment Tool (SWAT) model with a vastly simplified interface. The development of PPM Plus has been fully described by White et al. (2007) and White et al. (2010). In this article we evaluate the accuracy of PPM Plus using 286 field-years of runoff, sediment, and phosphorus validation data from runoff studies at various locations in Oklahoma, Texas, Arkansas, and Georgia. Land uses include pasture, small grains, and row crops with rainfall ranging from 630 to 1390 mm/yr, with and without animal manure application. PPM Plus explained 68 percent of the variability in total phosphorus loss, 56 percent of runoff, and 73 percent of the variability of sediment yield. An empirical model developed from these data using Soil Test Phosphorus (STP), total applied phosphorus, slope, and precipitation only accounted for 15 percent of the variability in total phosphorus loss; which implies that a process-based model is required to account for the diversity present in these data. PPM Plus is an easy to use conservation planning tool for P loss prediction, which with modification, could be applicable at the regional and possibly national scales.

Last Modified: 9/29/2014
Footer Content Back to Top of Page