Rules and Differences of Soil Organic Carbon Mineralization between Paddy Field and Upland Soils

Paddy field and upland soils are the main use patterns of farmland which are specially important to the mechanism of organic carbon stability and the rules of soil organic carbon mineralization.By lab incubation experiment,the dynamic mineralization of SOC in paddy field and upland soils were observed,and the difference of SOC mineralization between paddy field and upland soils were also compared.The results showed that the SOC mineralization in both paddy field and upland soils decreased quickly in the beginning of the incubation,and keep relatively constant at the later incubation time and fitted to logarithmic equation.In the whole incubation time,the SOC mineralization rate in paddy field was from 0.48% to 48.40% higher than that in upland soils,and the average was 24.09%.The cumulative mineralization in paddy field was from 4.20% to 48.40% higher than that of upland soils.But the difference in soil organic carbon mineralization was mainly in the beginning of the incubation period,and the gaps narrowed along with the incubation time.Soil organic carbon mineralization was mainly influenced by the content of soil organic carbon,microbial biomass carbon and dissolved organic carbon,and the correlation coefficients were 0.948,0.745,0.763 respectively.