More than 40 percent of the freshwater bodies in the United States are not currently meeting water quality standards.

In north-central Missouri, the Goodwater Creek watershed occasionally has high levels of the agricultural herbicide atrazine. This is mainly due to the high-runoff potential of soils within the watershed, and to atrazine's tendency to remain near the soil surface, where it can be easily washed away.

After much study, Agricultural Research Service scientists at the Cropping Systems and Water Quality Research Unit in Columbia, Mo., have shown that pesticide contamination can be reduced if growers in the region adopt runoff control practices and use pesticides that can be incorporated into the soil or applied at low rates.

Headed by John Sadler, the Columbia unit has generated more than 30 years' worth of historical watershed data that's now being used to determine the impact of conservation practices on water, soil and air quality and wildlife habitat. Such data are critical to the outcome of the USDA's Conservation Effects Assessment Project.

Funded by ARS, USDA's Natural Resources Conservation Service, and other federal and state agencies, CEAP was instituted in 2003 to provide the Office of Management and Budget, lawmakers, farming and conservation communities, and others with measured evidence of the environmental effects and economic benefits derived from decades of conservation efforts.

This information is critical to scientifically documenting the local and national benefits of conservation practices for improving the quality of U.S. freshwater resources.

Sadler is helping set up an ARS Web-based data system called STEWARDS (Sustaining the Earth's Watersheds -- Agricultural Research Data System). It should be helpful to agricultural producers in determining which conservation practices are the most economical for achieving desired environmental benefits.

This week, Sadler will be discussing updates on CEAP and STEWARDS at a workshop organized by the Soil and Water Conservation Society, "Managing Agricultural Landscapes for Environmental Quality: Strengthening the Science Base," in Kansas City, Mo.

SOURCE: News release from the ARS, USDA's chief scientific research agency.