Effect of Long-term Fertilization on Soil Organic Carbon and Soil Inorganic Carbon in Oasis Cropland

In this study,the Fukang Station for Desert Ecological Research,Chinese Academy Sciences,was regarded as a platform to lucubrate the dynamic change of soil carbon content,soil carbon sequestration potential and long-term oasis agricultural nutrient cycling,including the distribution of soil inorganic carbon content(SIC) and organic carbon content(SOC) along soil profile and at different fertilization time under the different soil fertilization treatments,such as the treatment without fertilization(CK),single fertilizer application(NPK),and fertilization treatment with straw(S) in arid area.The results showed that the fertilizer application,soil depth and fertilization time affected significantly the SOC content and SIC content in soil(P0.01).Compared with CK,the SOC content and SIC content under NPK,M and S were significantly increased(P0.05),and the SIC content under the organic/inorganic fertilizing combination(M) was significantly higher than that under chemical fertilizer application.The average SIC content was increased from 9.12 g/kg in soil layer of 0-20 cm in depth to 9.17 g/kg in soil layer of 20-40 cm and to 9.94 g/kg in soil layer of 40-60 cm respectively,but the SOC content was contrary.These revealed that the rational fertilization could increase the organic carbon content in topsoil,and the carbon sequestration in soil could be increased under organic/inorganic fertilizing combination(M).