Erodibility Evaluation and the Effect of Land Management Practices on Soil Erosion from Steep Slopes in Leyte, the Philippines

Abstract

The paper reports selected results from an extensive experiment in which runoff and soil loss were measured from a range of treatments applied to runoff plots at the Visayas State College of Agriculture (VISCA) in the Philippines. Treatments included bare soil, common agricultural practice, and a range of soil-conserving practices, including intercrops and hedgerows of Leucaena leucocephala. The presence of a maize crop reduced soil loss but not runoff relative to the bare plot. Addition of hedgerows approximately halved runoff from the steep experimental plots, thereby reducing soil loss, though sediment concentration was similar to the cropped treatment. The addition of an intercrop of peanut further reduced both runoff and sediment concentration in the runoff, thus leading to a substantial reduction in soil loss. The erodibility of a nearby different soil at low slope (10%) was found to be high, but its erodibility appeared to be increased following cultivation.