The importance of agricultural management on soil organic carbon (SOC) is well known.However,its effects on soil inorganic carbon (SIC),another potentially important carbon(C) sink,have been poorly studied,especially in semihumid soils.Current study focused on the effects of 40 years old land use change from natural vegetation to intensive agriculture and a subsequent 20-year long term fertilizer experiment involving four treatments,i.e.,organic fertilizer at high and low rate (OFH and OFL),mineral fertilizer (MF) and control(CK).