Date of this Version
Transactions of the ASAE, vol. 28, No. 4, pp. 1124-1129, 1985.
Rainfall simulation techniques were used to compare soil losses from various tillage systems used on plots where corn and soybeans had been grown the previous season. The two year study was conducted on a silty clay loam soil with a 5% slope and on a silt loam soil with a 10% slope. Five tillage treatments, ranging from a moldboard plow system to no-till, were evaluated for each residue at each site. Tillage and planting operations were conducted up-and-down hill on replicated plots. Total soil loss following 63.5 mm of rainfall applied during a 60 min period averaged more than 40% greater from the soybean residue plots than from the corn residue plots for equivalent tillage treatments on the 5% slope. For the 10% slope, the soil loss ranged from 50% to about 12 times greater for the soybean residue. Equivalent tillage treatments in soybean residue had about 40% less surface cover relative to corn residue, which contributed to the difference in soil erosion. Relationships between residue cover and soil loss showed that a 20% cover of either soybean or corn residue generally reduced soil loss by at least 50% of that which occurred from cleanly-tilled soils. Several tillage systems left more than a 20% cover in corn residue. Only no-till consistently left more than a 20% residue cover following soybeans.