Soil water infiltration rate may be the soil property which best reflects the general soil physical conditions, especially the structural quality. A field study was conducted at the Embrapa Trigo, Passo Fundo, Brasil in an Oxisol under long-term soil tillage systems, to evaluate the influence of these systems on soil water infiltration rate as a function of the soil cover and soil physical conditions caused by the different tillage systems. During a corn cropping period, a simulated rainfall with intensity of 120 mm h-1 and 90 minutes duration was applied in three replications and three different runs: (1) 45 days after corn sowing; (2) immediately after corn harvest; and (3) immediately after oat sowing. The simulated rainfall was applied on small plots of 0.81 m² area inside larger plots where conventional tillage, minimum tillage and no-tillage were applied. In all runs, minimum tillage showed the highest soil water infiltration rates, while the no-tillage system yielded the highest amount of crop residues on the soil surface.
infiltration rate; simulated rainfall; No-tillage; soil cover; corn residues