USDA Issues Assessment of Conservation Practices in Upper Mississippi River
June 18th, 2010
On Wednesday, June 16, USDA announced the release of the report Assessment of the Effects of Conservation Practices on Cultivated Cropland in the Upper Mississippi River Basin. The report is a comprehensive look at the effects of NRCS conservation practices on about 190,000 square miles, including the large portions of Illinois, Iowa, Minnesota, Missouri, Wisconsin and small portions of Indiana, Michigan and South Dakota that are within the Basin.
Nearly one-half the acres in the Basin are planted to corn or soybeans, so the Report focuses on the effects of nutrients and sediment from agricultural land on water quality in the Basin. Key findings of the Report include:
• Suites of practices work better than single practices;
• Targeting critical acres improves effectiveness significantly; practices have the greatest effect on the most vulnerable acres, such as highly erodible land and soils prone to leaching;
• Uses of soil erosion control practices are widespread in the basin. Most acres receive some sort of conservation treatment, resulting in a 69 percent reduction in sediment loss. However, about 15 percent of the cultivated cropland acres still have excessive sediment losses and require additional treatment; and
• The most critical conservation concern in the region is the loss of nitrogen from farm fields through leaching, including nitrogen loss through tile drainage systems.
The Report emphasizes that conservation practices have resulted in reducing nitrogen losses from the surface by almost 46 percent but have reduced losses from leaching, including tile drainage, by only 5 percent. Moreover, measures to control soil erosion may result in increased loss of nitrogen below the surface, unless nutrient management practices are also implemented.
The Upper Mississippi River Basin report is the first of twelve regional reports on conservation practices on cropland that will be issued as part of the Conservation Effects Assessment Project (CEAP). The Project is intended to assess the effects of conservation practices on the nation’s cropland, grazing lands, wetlands, wildlife and watersheds. It is a multi-agency, multi-resource effort led by the USDA’s Natural Resources Conservation Service. Additional information, including a powerpoint presentation on the Upper Mississippi River Basin report, is posted on the NRCS website for CEAP.