Hydrological effect of land management and crop cover in the humid lowlands of Beles River sub-basin, Ethiopia

Abstract

ABSTRACT Land management and cropping practice effects on runoff were investigated through a field experiment on Nitisol in the Pawe area of Ethiopia. A randomized complete plot design with three replications by combining two tillage methods and four crop covers with continuous bare fallow plots as a control was laid out to isolate their effects. The result showed that land management and crop cover significantly affect runoff. Cultivation of crops without soil disturbance with full residue retention reduced runoff by 11%, 29%, 41%, and 92% under soybean, rotated maize, maize soybean intercropping, and maize, respectively. Similarly, the runoff coefficient was also reduced by 14%, 24%, 29%, and 50%, in a similar order as the runoff reduction. Zero tillage also improves in-situ water than conventional practice in all cropping patterns, i.e. soybean, rotated maize, maize, and maize soybean intercrop by 7%, 12.5%, 78%, and 106%, respectively. Thus, the conversion of conventional tillage to zero tillage reduces the runoff volume by 43%, runoff coefficient by 32%, and in-situ soil water by 51%. Generally, zero tillage with greater cover is an appropriate approach to reduce runoff by improving soil hydrological properties.