The study by the International Water Management Institute (IMWI) and the International Center for Tropical Agriculture (CIAT) was carried out in Jawe-gumbura watershed in southern Ethiopia. It assessed the effect of soil bunds on run-off, soil loss and yield of wheat, and assessed soil moisture dynamics under conserved and non-conserved plots.
Three treatments including five-year-old soil bunds with Desho grass, one-year-old soil bunds with Desho grass and control (without soil bunds) were compared at three farmers’ fields in the 2015 rainy season.
Results showed that in the control and 5-year-old soil bund plots, 4.4 mm and 3.2 mm run-off were generated, respectively. The result of 2 days rainfall shows that 30% and 22% of the rainfall was converted into run-off in control and 5-year-old soil bund, respectively. The corresponding sediment concentration of run-off from control plots and 5-year old soil bunds plots were 11 gm-2 and 6.4 g m-2. However, run-off and soil losses were generated only from two rainfall days out of 29 rainfall days. Soil moisture measurement over the growing period shows that there is spatial variability of soil moisture with reference to soil bunds. The average available soil water (%) were 29.3, 29.8 and 30.2 for the control, 1-year-old soil bunds and 5-year-old soil bunds, respectively.
According to the report, more long-term erosion studies are needed to support farmers’ trade-offs and opportunities in soil conservation to better understand the benefits of sustainable intensification.
Download the full report.