Influence of Long-Term Tillage and Crop Rotation on Water Erosion
1984
Van Doren, D. M. | Moldenhauer, W. C. | Triplett, G. B.
Soybeans (Glycine max. L.) apparently predispose a field to greater erosion by water than does corn (Zea mays L.) at equal residue cover. Most of the available data have been obtained from locations with 5 years or less history of a specific management. This study measured soil loss during simulated rainfall from plots having an 18-yr history of management to ascertain deviations, if any, from current expectations. The soil was a fine-loamy, mixed mesic, Typic Fragiudalfs having an average slope of 3%. Tillage variables included no-tillage, spring plow 20 cm deep, and spring plow 20 cm deep followed by 10 cm deep disking or equivalent. Rotations were continuous corn or corn-soybeans. Kinetic energy of applied water was about 70% of natural rainfall at 63 mm/h rate. Runoff and soil loss were measured at 60-s intervals during the 30- to 60-min runs. Soil loss per unit of rainfall following either crop in the corn-soybeans rotation was 45% greater than from continuous corn, after accounting for differences in residue cover by use of the Universal Soil Loss Equation (USLE). Soil loss per unit of rainfall for land not tilled for 1 or over 20 years was 90% less than expected according to the current version of the USLE.
显示更多 [+] 显示较少 [-]