|Mudgal, Ashish -|
|Anderson, Stephen -|
Submitted to: International Soil and Water Conservation Conference
Publication Type: Abstract Only
Publication Acceptance Date: March 10, 2011
Publication Date: N/A
Technical Abstract: Over the past century, agriculture had detrimental impacts on soil and water quality revealed by increased surface runoff and non-point source pollution. In this study, we estimated the impact of long-term agriculture on surface runoff, sediment yield, atrazine load, and crop yields. Soil samples were collected from two fields with claypan soils, one that has been under cultivation for more than 100 years (Field 1) and a native prairie (Tucker Prairie; TP). Current soil profiles throughout Field 1 were derived from topography, soil survey, and depth to claypan. An enhanced profile was defined for pre-agricultural conditions using remote sensing, historical pictures, elevation, and slope in Field 1 along with TP soil properties. Several scenarios were established to simulate the effects of current and alternative management, with the current and enhanced soil profiles, and different weather sequences. A calibrated and validated APEX (Agricultural Policy Environmental eXtender) model for Field 1 was used to compare selected outputs over thirty years. The current management would have produced significantly smaller average annual atrazine load (82%) if it had been implemented on pre-agricultural soils, as well as higher corn (39%) and soybean (75%) yields. Atrazine load and crop yields were more sensitive to the soil properties, whereas runoff and sediment yield were more dependent on land cover. Conservation efforts toward restoration of soil properties would be beneficial to reduce non-point source pollutants and enhance crop yields. Producers, conservation interests, and agencies will benefit from the research.