A rotating-boom rainfall simulator, operating at a constant rainfall intensity of 64 mm h-1 for sufficient time to runoff reaches steady-rate, was used to investigate water erosion and other related parameters in three tillage systems. The experiments were carried out immediately following corn and wheat harvesting, in a sandy loam Red-Yellow Podzolic soil (Paleudult) with a 0.066 m m-1 average slope, in Eldorado do Sul, State of Rio Grande do Sul, Brazil, from 1992 to 1994. No-tillage, chiselling and disk-plowing followed by disking, were studied in the presence and absence of fresh crop residues. Results showed that no-tillage and disk plowing followed by disking, combined with residues maintained on the surface, reduced soil losses more efficiently than when the residues were removed. No-tillage, with residues maintained, was the most efficient system to control erosion, while disk plowing followed by disking, without residues, was the least efficient. Water losses followed the same tendency of soil losses, although being less affected by the treatments.
soil; water erosion; conservation tillage; rainfall simulator; residue management