鄱阳湖生态区长期施肥对稻田土壤碳汇效应与固碳潜力的影响

在施肥条件下确定平衡状态时，土壤有机碳含量水平对于正确评价土壤的固碳潜力和制定合理的有机物质分配措施具有重要意义。分析了前人研究的江西省有机碳储量数据并采用Jenny模型对长期不同施肥下有机碳动态数据进行模拟。结果表明，鄱阳湖生态区有机碳储量占全省的46%，以鹰潭地区最高，九江地区最低。施肥明显增强了土壤的碳汇作用，单施有机肥或有机无机肥配施（70F+30M、50F+50M、30F+70M、NPKM、NPK+S、NPK+P和NPK+C）处理的土壤有机碳含量明显高于施化肥处理，以南昌县的30F+70M、进贤县的NPKM和余江县的NPK+P处理最高，其平衡时有机碳含量和固碳潜力分别较施化肥处理提高了3061%和6115%、3017%和5496%、3826%和7479%。因此，提高鄱阳湖生态区农田有机碳密度和固碳潜力最有效方法是有机无机肥配施，其配施方式以猪粪配施化肥相对最好，配施比例以70%有机肥配施30%化肥为宜

EFFECTS OF LONG-TERM FERTILIZATION ON STORAGES AND CAPACITIES OF SOC IN THE PADDY TOPSOIL IN POYANG LAKE ECOLOGICAL AREA

It is important to determine the equilibrium of soil organic carbon content for the correct evaluation of the carbon sequestration potential and the reasonable distribution of organic matter under the fertilization condition.This article tried to analyze previous studies of organic carbon storage in Jiangxi Province,and used Jenny model to simulate dynamics of soil organic carbon under long-term fertilization condition.Results show that the soil organic carbon reserves in Poyang Lake ecological area account for 46% of the whole province,and the highest is in the Yingtan area,the lowest is in the Jiujiang area.Fertilization increased the contents of soil carbon significantly.The soil organic carbon contents of single application of organic or combined application of organic manure and chemical fertilizers(70F+30M,50F+50M,30F+70M,NPKM,NPK+straw,NPK+pig manure and NPK+ clover)treatments are higher than that of the application of chemical fertilizer treatment,in which 30F+70M of Nanchang County,OM of Jinxian County and NPK + pig manure of Yujiang County treatments were the highest.Compared with application of chemical fertilizers treatments,its organic carbon content at steady state and C sequestration potential of paddy soils were increased by 30.61% and 61.15%,30.17% and 54.96%,38.26% and 74.79%,respectively.Therefore,the combined application of organic manure and chemical fertilizers are the most effective application methods to improve soil organic carbon density and sequestration potential of paddy soils in Poyang Lake ecological area.Combined application of pig manure and chemical fertilizer is the best,and the ratio of 70% organic manure combined with 30% chemical fertilizers is the most suitable fertilization.