Residue cover effects on soil erosion and the infiltration in black soil under simulated rainfall experiments

Abstract

Residue cover is widely used in the Northeastern China Black Soil Region for soil erosion control due to the large annual production of crop residues. Quantitative evaluations of the residue cover effects on preventing soil loss and on the cumulative infiltration amount are thus desirable. Herein, rainfall simulation experiments were conducted using simulators and soil flumes to study the effects of residue cover on soil erosion and infiltration under various rainfall events. Laboratory experiments were designed utilizing five levels of residue cover (bare, 15%, 35%, 55% and 75%), four rainfall intensities (30mm/h, 60mm/h, 90mm/h and 120mm/h), two soil moistures (dry and wet run) and a fixed slope of 7%.The results indicated that residue cover strongly affects runoff, soil loss and infiltration. Equations for predicting the soil loss ratio and infiltration ratio (the ratio of residue cover soil to bare soil) are herein proposed based on nonlinear curve regression. An empirical approach presented as the infiltration ratios multiplied Philip’s equation derived from bare soil was established for estimating the cumulative infiltration amounts under various residue covers. The equation was demonstrated to be suitable for infiltration prediction for black soil by the root mean square error value and 1:1 line method. In addition, the relationship between the residue cover and biomass of corn residues was provided in order to enable accurate measurement of the residue coverage. These derived equations could be used for soil erosion and infiltration prediction under no-till and residue cover management conditions in the black soil region.