Simulation of Carbon Sequestration Potential of Paddy Soils in Hunan Province, China
湖南省稻田表层土壤固碳潜力模拟研究

Organic carbon sequestration of paddy soils plays an important role in mitigating the global warming.China is the largest country of rice production in the world,and for UNFCCC,carbon sequestration status,potential and corresponding measures to enhance the carbon stocks of rice cultivation system should be investigated independently and urgently.With SCNC model we developed independently,this paper simulated the potential of carbon sequestration in paddy soils in Hunan province,and the aim is to illustrate the carbon sequestration potential of paddy soils and find the countermeasures to improve the current conditions.The simulated results showed that saturated carbon storage of paddy soils ranged from 39.75-64.90t/ha under conventional fertiliza-tion,and half of the modeling plots have been saturated,while for the remaining plots,the carbon sequestration potential ranged from 3.38-4.19t/ha.The saturated carbon storage under 50% of straw incorporation was lower than the conventional fertilization,but the storage of 50% straw incorporation combined with green manure plantation treatment was higher than the conventional fertilization(increased by 10.54t/ha averagely).The saturated carbon storage with 100% straw incorporation ranged from 55.57-94.25t/ha,compared with current carbon storage,the potential in-crement was 4.15-33.46t/ha.The saturated carbon storage of 100% straw combined with green manure incorporation was 65.77% higher than that of current carbon storage.The simulation results also showed that the saturated carbon storage would hit 12t/ha under the condition of incorporating 1t/ha fresh organic material annually into paddy field of Hunan Province.Therefore,increasing the amount of organic material and planting green manure are effective measures to enhance carbon storage of paddy field.