A Nutrient Use Geographic Information System (NuGIS) for the U.S. (Final Version)
NuGIS creates county-level estimates of N, P and K applied to the soil in fertilizer and livestock manure, and removed by harvested agricultural crops. Geospatial techniques are used to estimate balances for 8-digit hydrologic units using the county-level data. The current version makes estimates for five years, coinciding with the USDA Census of Agriculture, from 1987 - 2007. A version that can be updated annually for non-Census years is under development. Results are viewable through an interactive color map or exportable as tabular data (see below).
A pdf file of a short article providing a summary of the methods used in NuGIS is attached below. In-depth methods are provided on the website to offer complete transparency into how the balance estimates are made and displayed. Interpretation of the results, other than a few summary bullets, is not done here. Future focused publications will emphasize interpretation.
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