The sediment particle size distribution depends on soil type and texture. This study had the objective to evaluate the sediment yield by interrill soil erosion in three Oxisols of Rio Grande do Sul state, Brazil: Rhodic Hapludox (LVaf and LVdf) and a Typic Hapludox (LVd), of different textural classes, by simulated rainfall events in laboratory. Experimental plot with test area of 0.36 m² and 0.09 m m-1 slope was used. Simulated rainfall with mean intensity of 88 mm h-1 and duration of 90 min was applied in three replications on three oxisols. Sediment particles leaving the experimental plots were collected in a set of sieves. The distribution of sediment diameter varied as the soil texture. The sediment yielded by interrill soil erosion had individual particles and aggregates smaller than those in the original soil. Most of the sediment yielded by interrill soil erosion at LVdf soil was in the class diameter from 9.51 to 4.76 mm whereas in LVaf was from 4.76 to 2.00 mm and in LVd was from 1.00 to 0.25 mm. The original LVdf and LVaf soils present higher clay, organic carbon and iron oxides contents and greater aggregate water stability than the LVd soil, and this probably explains the differences among size classes of sediment yielded by interrill soil erosion.
particle size distribution; aggregates; particles diameter; simulated rainfall
