Research on soil erodibility under different land-use conditions in hilly area of purple soil

The Erosion-productivity impact calculator (EPIC) model was used to estimate soil erodibility (K) in a small watershed where the main soil type is purple soil. Purple soil is a typical sandy loam soil in the Three Gorges reservoir area and most distributes in southwest China. The objectives of this paper were to explain the relationship between erodibility (K) and land-uses. Spatial variability characteristics of soil erodibility (K) under different land-uses (woodland - Pinus massoniana Lamb and Robinia pseudoacacia L, economic fruit forest - Citrus reticulata Banco, cropland - Zea mays L and Lpomoea batatas, wastegrassland) were studied. Results indicated that: (1) Soil texture and human activities were the main factors that influenced the soil erodibility (K), erodibility (K) increased with the content of sand while decreased with the content of silt, clay and organic matter. (2) The order of soil erodibility (K) from large to small under six land-uses in the watershed was: waste-grassland > economic fruit forest (Citrus reticulata Banco)> woodland (Pinus massoniana Lamb)> woodland (Robinia pseudoacacia L) > cropland (Lpomoea batatas) > cropland (Zea mays L). (3) Soil erodibility (K) of the whole purple soil watershed area showed a positive trend with elevation of the watershed from east to west. Erodibility (K) of woodland (Robinia pseudoacacia L) exhibited Kupstream midstream downstream, however, the erodibility (K) under other land-use showed the opposite trend, manifesting in Kupstream > Kmidstream > Kdownstream. © Sila Science.