The goal of this program was to quantify the effect of existing and new farming practices on water quality in the Corn Belt. Approach Walnut Creek watershed was selected because of the intensity of crop production, location on the Des Moines Lobe landform region, and intensity of subsurface drainage in the watershed. The watershed is nearly 5400 ha of undulating land surface with no surface water channels in the upper two-thirds of the watershed and a stream channel that connects with the Skunk River at the outlet. These data are collected throughout the year and extensive use is made of Geographic Information Systems as shown in the two watershed maps with soils and crop distribution of corn and soybean within the watershed. Findings and Application of Results Through the farmer surveys we have been able to quantify the load of herbicide and fertilizer applied throughout the watershed.
Efforts are underway to change nitrogen management practices within one subbasin.
Walnut Creek watershed has become an integral part of the MSEA program and represents the combined efforts of a number of individuals.