Land use change

Surface soil samples (0-10 cm) were taken from three diffenrent land use types; grassland, cropland, and bare fallow. In each of the four field replicates, five-point sampling method was used to collected a composite soil sample. Soil sample was air-dried for 1 week, passing through a 2 mm sieve. A portion of the soil samples was used for initial physicochemical analysis, while the remaining portion was stored for incubation experiments.本研究从3种不同土地利用类型（草地、农田、裸休耕地）采集0~10 cm表层土壤样品。在4个田间重复样地中，均采用五点采样法采集混合土壤样品。将土壤样品自然风干1周后过2 mm孔径筛。取部分土壤样品用于初始理化性质分析，剩余样品留存用于培养试验。