A new study shows that conservation practices have made great strides in reducing pollutant losses from cultivated cropland in the Missouri River Basin. The study, called the "Assessment of the Effects of Conservation Practices on Cultivated Cropland in the Missouri River Basin" showed that conservation practices, such as building terraces and reducing tillage, reduce the runoff of sediment by 76%, nitrogen by 54% and phosphorus by 60%.
The report is part of USDA's tradition to assess the effects of conservation practices and how they can be improved. It is part of a series completed for USDA's Conservation Effects Assessment Project and it covers Nebraska, Colorado, Iowa, Kansas, Minnesota, Missouri, Montana, North Dakota, South Dakota and Wyoming.
"This study shows the hard work of conservation-minded farmers and ranchers is having positive benefits for waterways downstream," says Dave White, chief of USDA's Natural Resources Conservation Service.
"We are seeing cleaner water in the Missouri River, which means that we are sending cleaner water to the Mississippi River and the Gulf of Mexico. Conservation efforts like the ones we have seen in this basin are testament to the importance of conservation on the landscape level."
"These reports compose part of the scientific backbone that we use to improve and update our conservation efforts," White says. "We use the assessments to strengthen our service to our nation's landowners and natural resources."
Although conservation practices installed by producers have reduced the runoff of sediment and nutrients in the Missouri River Basin, wind erosion remains the top conservation concern in the region.
The report found that 18% of cultivated cropland in the region has a moderate or high need for additional conservation practices to further reduce sediment and nutrient losses from the basin. Although this percentage is lower than in other regions studied by USDA, it represents more than 15 million acres in the vast Missouri River Basin. Soil and nutrient losses through wind erosion, particularly in the western part of the basin which is drier, are the most critical conservation concern in the region.
If additional conservation practices were implemented, NRCS technical experts estimate that the conservation practices would reduce runoff of sediment by an additional 28%, nitrogen by an additional 13% and phosphorus by an additional 12 percent. Comprehensive conservation planning that includes both erosion control and nutrient management practices is needed to simultaneously reduce sediment and nutrient losses through wind, runoff and leaching.
Download a fact sheet, a summary or the full report for the Missouri River Basin.
This CEAP-Cropland report uses computer simulations to compare losses of sediment and nutrients from cultivated cropland to losses that would be expected if no conservation practices were in place.
Additional simulations suggest potential for further reductions in sediment and nutrient losses through use of additional conservation practices in areas of greatest conservation need. Estimates in the study were based on an extensive survey of farming and conservation practice use at selected National Resources Inventory sample points throughout the region from 2003 to 2006. The farmer survey data and information from other sources were statistically expanded to represent the entire region. The
study included conservation practices installed with USDA or state assistance as well as those installed through landowner initiative and expense.