Agriculture Secretary Tom Vilsack this week released the results from a new USDA watershed assessment that shows farmers have significantly reduced the loss of sediment and nutrients from farm fields through voluntary conservation work.
The report, prepared by USDA's Natural Resources Conservation Service, demonstrates that better erosion control and nutrient monitoring reduced edge-of-field losses of sediment by 35%, nitrogen by 21% and phosphorous by 52%.
The study evaluated cropland in Louisiana, Arkansas, Kentucky, Mississippi, Missouri and Tennessee.
Vilsack said the findings not only illustrate the importance of providing scientific and technical expertise to growers, but it also supports increasing conservation practices in agriculture.
Runoff, nutrient management key message
USDA said a key takeaway from the study was the importance of the appropriate rate, form, timing and method of application for nitrogen and phosphorous.
As part of a larger project, the latest assessment has shown also that:
Conservation on cropland prevents an estimated 243 million tons of sediment, 2.1 billion pounds of nitrogen and 375 million pounds of phosphorus from leaving fields each year. USDA says these figures translate to a 55%, 34% and 46% reduction in sediment, nitrogen and phosphorus edge-of-field losses, respectively, compared to what would have been lost if no conservation practices were in place.
Similarly, conservation has resulted in an estimated 17% reduction in nitrogen and 22% reduction in phosphorus entering the Gulf of Mexico annually. An additional reduction of 15% of nitrogen and 12% of phosphorus can be achieved by implementing comprehensive conservation plans on all cropland in the basin in areas that have not adequately addressed nutrient loss.
The project extends USDA's Conservation Effects Assessment Project, or CEAP, which uses advanced modeling techniques to assess the effects of conservation practices.
By comparing losses of sediment and nutrients from cultivated cropland to losses that would be expected if conservation practices weren't used, CEAP reports give science-based insight into the techniques that most benefit water quality, soil health and other resource concerns.
"These assessments are part of the scientific backbone that helps us work with farmers to get the right conservation techniques on the right acres," said NRCS Chief Jason Weller. "A focus on the most effective conservation techniques means that we're helping to deliver the best results for farmers and our natural resources."
The NRCS' scientific-based modeling also pointed out that higher rainfall and more intense storms lead to higher edge-of-field losses of sediment and nutrients in the lower Mississippi River basin than the other four basins in the Mississippi River watershed.
Click here to read the full report.