Conservation measures by farmers have reduced nitrogen and phosphorus runoff in Iowa and other states in the Upper Mississippi River Basin. Voluntary conservation practices have helped reduce nitrogen by as much as 34 percent and phosphorus by 10 percent, according to researchers at the U.S. Department of Agriculture and the U.S. Geological Survey, who used existing water quality data.
In an interview with the Des Moines Register, U.S. Agriculture Secretary Thomas Vilsack said the study provides evidence that investments by federal, state, local and nonprofit groups are improving water quality. He said more producers are using cover crops, not tilling their land and embracing precision agriculture to cut down on runoff of nitrogen, phosphorous and other pollutants from fertilizer and manure.
The Environmental Working Group, said the report is further proof that conservation practices the organization has backed for decades can have a meaningful impact on water quality. But the EWG argued that it would like to see more land owners using these conservation practices.