Effect of soil structure breakdown on splash erosion in different soil textures

This study was carried out to investigate the role of soil structure in splash erosion in semi-arid soils. Splash erosion was measured in four soil textures (silty clay loam, sandy clay loam, silt loam and sandy loam) with two soil structure conditions (with natural structure and under aggregate breakdown) using a simulated rainfall with 50 mmh-1 in intensity for 30 min in splash caps with 10-cm height and 8-cm diameter. Soil physical properties consisted of mean aggregate size, aggregate stability, bulk density and saturated hydraulic conductivity (Ks) were determine in the two soil structure conditions. Results indicated that sandy loam is the most susceptible soil structure to splash erosion, so it appeared about 52 percentages more splash erosion in the breakdown structure condition. Bulk density, aggregate stability and Ks were significantly deteriorated by aggregate breakdown in the soils. A significant relationship was found between the splash erosion variation and variation of Ks in the two soil structure conditions (R2=0.90, P<0.05). Splash erosion was largely increased in the soils with decreasing the Ks by aggregate breakdown. This study revealed that in the soils affected by aggregate breakdown, splash erosion is strongly increases due to decline in the soil’s saturated hydraulic conductivity.