The U.S. Department of Agriculture (USDA) recently released a summary of findings from an evaluation of the effects of conservation practices on cultivated croplands in the Lower Mississippi River basin. The study was conducted through the Conservation Effects Assessment Project (CEAP).

The researchers concluded that while voluntary, incentives-based conservation practices do, in fact, reduce sediment, nutrient and pesticide losses from farm fields, opportunities exist to further reduce these losses. Sediment loss was estimated at approximately 30 percent of the potential reduction. Loss of nitrogen was estimated to be 7 percent and loss of phosphorous was estimated to be 51 percent of the potential reduction. The study's authors further concluded that these rates could be improved significantly by targeting conservation practices in critical areas.

"Use of additional erosion- and nutrient-control practices on acres that have a high need for additional treatment?acres most prone to runoff or leaching and with low levels of conservation practice use?can reduce most edge-of-field losses by about twice as much or more compared to treatment of acres with a moderate level of need," according to the report.

It was determined that farmers met the criteria for good nitrogen management on only about 14 percent of the cropped acres and good phosphorus management on 17 percent of the land in the study area.

This study was the seventh in a series of research efforts conducted through CEAP to assess the effects of conservation practices on cultivated croplands. Reports for other regions include the Upper Mississippi River Basin, the Chesapeake Bay Region, the Great Lakes Region, the Ohio-Tennessee River Basin, the Missouri River Basin and the Arkansas-White-Red River Basin.

The report's summary states: "Sediment losses, nitrogen losses through surface and subsurface pathways, and phosphorus losses are higher in the Lower Mississippi than in any of the other regions in the Mississippi River drainage. Reductions in sediment and nitrogen losses due to conservation practice use are lower in the Lower Mississippi than in the other regions. Only in the Ohio-Tennessee River Basin are phosphorus loss reductions less than in the Lower Mississippi. As a result, the percentage of high- and moderate-treatment-need cropland in the Lower Mississippi River Basin is much higher than in the other four regions."

To view or download a PDF version of these reports, visit the NRCS website. (pmr)