WASHINGTON, Feb. 10 – A U.S. Department of Agriculture study shows that conservation practices applied to cultivated cropland in the Ohio-Tennessee River Basin are reducing losses of sediment, nitrogen and phosphorus from farm fields and decreasing the movement of these materials into the Mississippi River and other waterways. The study focused on the Ohio-Tennessee River Basin Conservation Effects Assessment Project (CEAP).
“Farmers are showing that putting practices where they are needed most benefits natural resources, the agriculture industry, the public and the economy,” said Agriculture Secretary Tom Vilsack. “This study also gives us new input as we continue working with farmers throughout the basin to make even greater progress in the years ahead.”
This latest CEAP study examines nearly 204,000 square miles in the river basin, including parts of Alabama, Georgia, Illinois, Indiana, Kentucky, Maryland, Mississippi, New York, North Carolina, Ohio, Pennsylvania, Tennessee, Virginia and West Virginia.
Prepared by NRCS, the Ohio-Tennessee River Basin report estimates conservation practices have reduced edge-of-field losses of:
• Waterborne sediment by 52 percent;
• Nitrogen in surface runoff by 35 percent;
• Nitrogen in subsurface flows by 11 percent; and
• Phosphorus (sediment attached and soluble) by 33 percent.
Additional model simulations show that from 2003 to 2006 conservation practices in the basin reduced loads of waterborne sediment, nitrogen and phosphorus entering the Mississippi River by 16, 15 and 21 percent, respectively.
NRCS and its partners determined these losses and loadings by computer model simulations based on scientific data that compare farming and conservation practices from 2003 to 2006 to conditions that would be expected if no conservation practices were in place. USDA’s National Agricultural Statistics Service provided data for the simulations.
This study also shows that nearly 6 million acres—nearly 24 percent of cultivated cropland in the basin—now have a high level of need for conservation treatments to reduce losses of sediment and nutrients. Modeling simulations show that the most cost-effective way to address these losses is through planning and implementation of appropriate suites of erosion-control and nutrient management practices.
Excessive loss of phosphorus from farm fields is the most critical agricultural conservation concern in the basin, according to USDA. This finding contrasts with findings from the previous studies in other river basins in this series that found that nitrogen loss through leaching was the most critical agricultural conservation concern.
The full report on the Ohio-Tennessee River Basin Conservation Effects Assessment Project study is available here http://go.usa.gov/QWw.
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