Distribution characteristics of surface soil organic carbon in different land types in the loess hilly region

Management of land and soil resources is important in the loess hilly region to explore the change characteristics of soil organic carbon in different land types. Four major land use types, including jujube orchard, 7-yr-old grassland, Cropland, and 30-yr-old grassland, were selected to study the distribution characteristics of soil organic carbon content from 0-100 cm in the small watershed of Yuanzegou watershed in the loess hilly region. The results showed that the soil organic carbon content of different land use types decreased with soil layer increasing. The contents of soil organic carbon at different depths were as follows: 7-yr-old grassland < Cropland < jujube orchard < 30-yr-old grassland, and there were significant differences among different land use types in 0-20 cm soil layer (P<0.05).