Effects of Amendment C/N Ratio on Soil Organic Carbon Mineralization of Meadow Marshes in Sanjiang Plain

An incubation expericment with typical Deyeuxia angustifolia meadow soil and artificial forest soil in the Sanjiang plain was conducted under different soil C/N(Ⅰ: 9-10,Ⅱ:11-12,Ⅲ: 13-16,Ⅳ: 16-22) to examine the responses of soil organic carbon(SOC) mineralization to C/N changes.The result showed that during the period of 36d incubation,the SOC accumulative losses of two kinds of soils under high C/N treatment were about 2.78 and 2.68 times as much as that under low C/N,respectively.SOC mineralization rates for both the two kinds of soils were higher in the first 4 days of incubation,and became stable as the time prolonged.The dynamics of SOC mineralization of two kinds of soil preferably followed the first-order kinetics,and the C0 and C0/SOC values increased exponentially with the increasing of C/N.The regression analysis also found that there were significant linear or conic relationships between the accumulative loss and mineralization rate of SOC and C/N,which explained that C/N was the key factor in affecting the sequestration of SOC in wetland.