| ca.gov | Smoke Management Program |
| eea.eu.int | European Environment Agency - Agriculture Themes |
| umd.edu | University Of Maryland Agricultural Nutrient Management Program |
| iatp.org | Institute for Agriculture and Trade Policy |
| tamus.edu | Blackland Research Center - Water Sciences Laboratory |
| tamu.edu | Grazing Management - An Ecological Perspective |
| usda.gov | Phosphorus Index |
| aftresearch.org | Center for Agriculture in the Environment |
| uni-hohenheim.de | Strategies to Reduce the Emission of Greenhouse Gases and Environmental Toxic Ag |
| montana.edu | The Soil Management Collaborative Research Support Program (SM-CRSP) |
United States , Virginia , Herndon