Soil Erodibility

The most important index of erodibility, according to Wischmeier et al. (1969) is particle size distribution. He has found that soils that are high in silt, low in clay, and low in organic matter are the most erodible. Usually a soil type becomes less erodible with decrease in silt fraction, regardless of whether the corresponding increase is in the sand fraction or the clay fraction. However, percentages of silt, clay and sand must be considered in relation to existing levels of other physical and chemical properties.