Effects of free-air CO2 enrichment (FACE) on soil microbial biomass under rice-wheat rotation Soil biochemical characters of Pinus koraiensis and Pinus sylvestriformis plantations under different elevated CO2 concentration BIOLOGICAL PROPERTIES AND ENZYMATIC ACTIVITY OF ARABLE SOILS AFFECTED BY LONG-TERM DIFFERENT FERTILIZATION SYSTEMS Soil heterotrophic respiration and its temperature sensitivity in different-aged orange plantations in Three Gorges Reservoir area of China Vertical distribution characteristics of N2O emission in tea garden and its adjacent woodland. The dynamics of soil microbial biomass nitrogenand its biological availability Distribution and fate of nitrogen fertilizer in various soil nitrogen pool at wheat seedling stage