Introduction

Several critical contemporary agricultural issues have the potential to impact nutrient balances for U.S. cropland. Production of bioenergy can alter nutrient removal due to changes in crop species and plant parts harvested, and can alter nutrient additions due to production of bioash and changes in manure composition induced by feeding distillers grain. Climate change may cause changes in crop yields, cropping patterns, and soil processes. Accelerated genetic changes have been promised that could alter crop yields and nutrient use efficiency. Recent volatility in fertilizer costs and crop prices have altered farm fertilizer use decisions. And, government policy can cause shifts in all of the above. Considering the potential future impact of these issues, it is critical to understand the current status of nutrient balances, temporal trends of those balances, and relevant inferences about nutrient use efficiency.

The Nutrient Use Geographic Information System (NuGIS) integrates multiple tabular and spatial datasets to create county-level estimates of nutrients applied to the soil in fertilizer and livestock manure, and nutrients removed by harvested agricultural crops. Nutrient balances and removal efficiencies are estimated for five years, coinciding with the USDA Census of Agriculture, from 1987 - 2007. Geospatial techniques are used to estimate balances and efficiencies for 8-digit hydrologic units using the county-level data. The results of this project are shown here with interactive thematic maps.
 
The NuGIS project is sponsored and directed by the International Plant Nutrition Institute (IPNI). The two primary objectives of this project are to assess nutrient use efficiency and balance in crop production and identify weaknesses in the balance estimation processes and the datasets used for these estimations.
 
The NuGIS Project is a cooperative effort among many people. The concept was first presented by the Potash & Phosphate Institute (PPI) in 2005, at one of the first meetings of the TFI-PPI Nutrient Use Task Force. The conceptual framework, interpretation, and reviewing were a joint effort of the IPNI staff: C.S. Snyder, T.W. Bruulsema, T.S. Murrell, H.R. Reetz, S.B. Phillips, R.L. Mikkelsen, W.M. Stewart, and T.L. Jensen. Quentin Rund and Ryan Williams of PAQ Interactive converted concepts and tactical approaches into numeric estimates and graphical representations. Final editing and production support were coordinated by D.L. Armstrong, G.D. Sulewski and K.P. Griffin of IPNI's editorial group.
 
The project is coordinated by P.E. Fixen of IPNI. NuGIS is a work in progress and we welcome your comments at nugis@ipni.net
 
Data taken from NuGIS should be cited as: IPNI. 2012. A Nutrient Use Information System (NuGIS) for the U.S. Norcross, GA. January 12, 2012. Available on line >www.ipni.net/nugis<.