Assessment and Prevention Strategies of Soil Surface Crusting Caused by Rainfall Events: Case Study of Sebeya Catchment Agricultural Land in Rwanda

Abstract

The history of soil erosion is an integral part of the agriculture. All over the world, wherever human being started the agricultural operations, there exists the problem of soil erosion in some extent. Soil erosion leads to the reduction of water infiltration rate and enhances runoff and soil degradation. This study focuses on Sebeya catchment located in the Western part of Rwanda. The main objective of this study was to assess various preventive measures against soil surface crusting and development of runoff coefficients in order to minimize the soil loss in Sebeya catchment agricultural fields. The proposed methodology was much concerned with the efficiency analysis of soil conservation practice of mulching in maize cover crops. The names of the three experimental field plots sited are Maize-Fertilizer-Mulching (MFM), Maize-Fertilizer (MF) and Bare Soil (BS) which were set in Rugerero Sector of Rubavu District. Each of these 3 plots was constructed with its runoff collecting tank and they were under similar conditions except land cover. Samples of soil from field plots and water from runoff collecting tanks were tested for soil classification and soil loss estimation from each plot respectively. The analysis of results showed that soil of the experimental plots is a gravelly sand with (sand:56.27%; clay and silt: 3.24% and gravel: 40.49%). Also, the results showed that the plot coded as MFM, has high moisture content with low runoff and soil loss compared to 2 other plots. This research revealed that soil conservation practices such as surface mulching and vegetative cover reduce runoff, soil loss and are well recommended for preventing and controlling soil surface crusting. Keywords: Soil erosion, mulching, soil crusting, field experiments, Rwanda