To definite the mechanism of the effects of exogenous organic carbon on soil organic carbon transport

we studied effect of exogenous organic carbon on concentrations and mineralization characteristics of soil organic carbon (SOC) and particular organic carbon (POC). We conducted a 5-year outdoor culture combined with the mineralization culture to analyze the translocation. There were 5 treatments: single chemical fertilizer

cow manure combined chemical fertilizer

chicken manure combined chemical fertilizer

corn stalks combined chemical fertilizer and poplar leaves combined chemical fertilizer. The results showed that: (1) SOC loss amount of the control in black soil mainly came from POC loss. The exogenous organic carbon was conducive to the accumulation of SOC and POC. Compared with the control

the average SOC and POC of animal manure treatments increased 16.6% and 27.8% respectively; plant residues treatments increased 27.0% and 46.4% respectively; (2) The dynamics of both SOC and POC mineralization preferably followed the first-order kinetics (R2 > 0.9). POC was more easily mineralized than SOC. The 60 days cumulative mineralization amounts of POC were 3 times higher than SOC; (3) The average POC mineralization rate of the treatments added animal manure or plant residues was 31.5% and 29.8% respectively. POC of animal manure treatment was easier to be mineralized. (4) The mineralization of black soil organic matter can be retarded by the addition of exogenous organic matter

especially the cow manure. The SOC mineralization rate of the cow manure treatment was 1.9%

3.4% lower than the control. The POC mineralization rate was 24.8%

17.4% lower than the control; (5) The ability of storage carbon of exogenous organic carbon in black soil followed the order of poplar leaves > corn stalks > cow manure > chicken manure.