The Nutrient Use Geographic Information System (NuGIS)

The Nutrient Use Geographic Information System (NuGIS) is a project sponsored by the International Plant Nutrition Institute (IPNI). 
The NuGIS project seeks to create a tool to help better understand and visualize how efficiently fertilizer nutrients are used across the contemporaneous United States.
IPNI is interested in knowing where nutrient application is not in balance with nutrient use by agricultural crops, and how that balance has changed over the past 20 years. 
IPNI worked with PAQ to develop a model that considered nutrient input to the land from fertilizers, manure application, an Nitrogen fixation by leguminous crops and nutrient removal when crops are harvested and estimated a ratio of nutrient input to nutrient removal. IPNI and PAQ then sought out data sources for each input to the model.
Many agricultural data sources were not available for each year or were not complete at the spatial resolution needed. To accomodate these data shortfalls, PAQ and IPNI developed several more models that could predict agronomic data for an area based on data from other years and other agronomic data that was available for that area.
PAQ and IPNI continue to develop estimation models for Fertilizer Use, Manure from Livestock,  Crop Production, and Nutrient removal by harvested crops. These models allow the NuGIS project to provide County and Watershed scale estimations of agricultural nutrient use efficiency for every 5 years, from 1987 through 2007, for all of the contemporaneous United States.