Distribution characteristics of soil organic carbon and nitrogen in farmland and adjacent natural grassland in Tibet

Land-use significantly affects soil organic carbon (SOC) and nitrogen cycling, eventually leading to global climate change. Hence, research on SOC and nitrogen distribution under different land-use patterns in Tibet is an important basis to assess the soil carbon and nitrogen potential in the land ecosystem of this area. This study aims to explain the effects of two land-use patterns, namely, farmland and grassland, on SOC and nitrogen contents in the cold regions of Tibet. This study also seeks to provide a scientific basis for the agricultural and grass production system. To achieve these goals, the changing features of total nitrogen (TN), mineralized nitrogen, and SOC were analyzed in different soil depths in farmland and adjacent natural grassland. Results showed that the contents of SOC, TN and mineralized nitrogen in the grassland and farmland decreased with increasing soil depth mainly in the surface with depth of 0-20 cm.