This package uses two primary data sources:
NuGIS Agricultural Data
The Nutrient Use Geographic Information System (NuGIS) presents cropland nutrient balances for the conterminous United States from 1987-2016.
Source: The Fertilizer Institute (TFI) and Plant Nutrition Canada (PNC)
Website: https://nugis.tfi.org/tabular_data
Contact: nugis@tfi.org
Components:
County-level crop and livestock data from USDA Census of Agriculture
Fertilizer use data from AAPFCO
Geospatial nutrient balance estimates
Available for counties, HUC8, and HUC2 watersheds
Data Processing: The manureshed package uses cleaned versions of NuGIS data with resolved metadata issues and enhanced spatial integration, as detailed in the manureshed methodology paper (Akanbi et al., 2026).
EPA WWTP Data
Source: U.S. Environmental Protection Agency
System: Discharge Monitoring Report (DMR) Loading Tool via ECHO
Website: https://echo.epa.gov/trends/loading-tool/water-pollution-search
Data Years: 2007-2016 (nitrogen and phosphorus loads)
License: Public domain (U.S. Government work)
Data Attribution
When using this package, please cite both the package, methodology paper, and the underlying
data sources. Use citation_info() to display full citation information.