Changes of carbon input influence soil respiration in a Pinus tabulaeformis plantation Effects of land use pattern on soil microbial biomass carbon in Xishuangbanna. Spatio-temporal variations in carbon efficiency of crops in Poyang Lake Eco-Economic Region Response of soil organic carbon and its particle-size fractions to different long-term fertilizations in red soil of China Evolution of soil organic carbon and crop yield under long-term fertilization in grey desert soils Effects of reduced nitrogen application and sugarcane-soybean intercropping on carbon balance in sugarcane fields Balance characteristics of soil organic carbon under different long-term fertilization models in the upland fluvo-aquic soil of North China