Principal Investigator: Gyles Randall
Co-Investigator(s): Jeffrey Vetsch
Organization(s): University of Minnesota Southern Research and Outreach Center
Sponsor: Clean Water Legacy Act
Award Amount: $30,000
Start Date: 7/1/2008 | End Date: 12/31/2010
Project Manager(s): Ron Struss (Ron.Struss@state.mn.us)
Evaluation of Reduced Application Rates of Acetochlor to Reduce Concentration in Tile Drainage Water (PDF: 146 KB/ 22 pages)
Two Minnesota water bodies, the Le Sueur River and Little Beauford Ditch, are included in Minnesota Pollution Control Agency's 2008 303(d) list of impaired waters due to concentrations of the corn herbicide acetochlor. This is the first time that a water body in Minnesota has been listed because of the detection of an herbicide. Acetochlor losses can occur by both surface runoff and leaching through the soil profile. This project will characterize leaching losses of acetochlor to drainage tile lines.
Leaching, the loss of water-soluble products through the soil profile, has been proposed as a mechanism transporting acetochlor in poorly drained soils. This study was initiated in the spring of 2008 and continued in 2009 and 2010 at the University of Minnesota Southern Research and Outreach Center at Waseca to determine if reduced application rates would result in reduced concentration and losses of acetochlor (and associated breakdown products) in tile drainage water from a corn-corn-soybean rotation.
Nine small plots located on a Canisteo-Webster clay loam soil complex were used to conduct the acetochlor study. These nine plots are part of a 36-plot tile drainage facility located at the University of Minnesota's experimental research station in Waseca. These soils are representative of the area and benefit from tile drainage to maximize productivity.
For more details about the experimental design, please refer to the Final Report.
2008 and 2009 were relatively dry years; it was difficult to measure tile drainage losses because there was little to no water being drained.
2010 was considered a banner year to determine acetochlor losses in tile drainage, especially since flow was abundant both prior to and after acetochlor application.
For result from the 2008 and 2009 growing seasons and a discussion of acetochlor breakdown products, please refer to the following progress reports: Progress Report 1 (7/1/08-7/31/08), Progress Report 3 (1/1/09 - 6/30/09), Progress Report 4 (7/1/09 - 12/31/09) and Progress Report 5 (1/1/10 - 6/30/10).
Fertilizer Field Unit Supervisor
Ron.Struss@state.mn.us ~ 651-201-6269