Water Quality research at CSWQRU concentrates on the claypan soils which cover over 10 million acres in northeast Missouri and surrounding states.
Herbicide contamination of surface runoff is the principal water quality problem on claypan soil watersheds. Atrazine and alachlor concentrations in surface runoff from cropped fields are from 10 to 100 times higher than current drinking water standards in the 45 to 60 days following chemical application in the spring.
Lowering herbicide application rates in alternative farming systems reduces concentrations in surface runoff, but not enough to meet drinking water standards.
Nitrate-N contamination of the aquifer is widespread throughout the claypan soil region. Approximately 25% of wells exceed the 10 ppm nitrate-N drinking water standard. In some cases, elevated ground water nitrates are associated with poor nitrogen management on cropped fields.