Extension and enhancement of national agricultural pesticide risk analysis (NAPRA) WWW decision support system to include nutrients

The nutrient component of the groundwater loading effects of agricultural management systems (GLEAMS) model was incorporated into the original national agricultural pesticide risk analysis (NAPRA) WWW system to create a nutrient loss decision support system to evaluate the effects of agricultural management systems on surface and subsurface nutrient water quality. The NAPRA WWW system (http://pasture.ecn.purdue.edu/napra) was extended to the entire US by adding soil data and weather generator models with supporting input data for the continental US. Thus, the NAPRA WWW system can be run for any location in the US. The nutrient enabled NAPRA WWW system can be accessed from any location with a web browser, and it provides an easy to use interface for model users by simplifying model input preparations. The NAPRA WWW system can be used to identify appropriate nutrient application rates to meet water quality specifications such as total maximum daily loads, and to identify critical watersheds or areas from nutrient management perspectives.