The 2008 spring rains in Illinois, Missouri, and Indiana delayed planting, drowned corn and soybean plants and resulted in significant re-planting. From May 30, 2008 to June 12, 2008, the previously saturated soils could not retain any more rainfall and the wetlands, potholes and depressions in the upland landscape filled with water and then began to runoff through waterways and into small streams. As much as 30% of the upland soils in south central Illinois, northern Missouri, and southern Indiana were affected by ponding. Approximately 1/3 of that ponded acreage was not re-planted in 2008. As overland flow started to occur so did sheet, rill and gully erosion. Where significant topsoil loss occurs, it can eventually result in the erosion phase change of the soil. Any soil erosion phase change from slightly to moderately or severely eroded can reduce the crop yield potential from 5 to 15 bu/ac depending on whether the soils have favorable or unfavorable subsoils for rooting. One year’s erosion events do not change the erosion phase of the soil unless gullying occurs. However, the 2008 soil loss, when added to the soil loss from erosion in previous years, could eventually result in a soil erosion phase change.
Soil Science Extension
University of Wisconsin Madison