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利用农业生态系统生物地球化学模型(DNDC)方法,在GIS区域数据库支持下运行模型,研究了东北三省地区土壤有机碳储量状况,及其在现行农田管理措施下的变化特征。结果表明,以1998年为例,东北三省耕地土壤有机碳(SOC)储量(0-30cm土层)约为124 348万t,黑龙江、吉林和辽宁省分别占58.4％、25.5％和16.1％;在目前的农作制度下土壤有机碳库处于严重的负平衡,每年净丢失有机碳3122万t,黑龙江、吉林和辽宁省分别占59.3％、25.9％和14.8％;单位面积耕地SOC年减少量高达2.05 t·ha-1,黑龙江、吉林耕地SOC丢失最严重。增加秸秆还田比例,提倡免耕和人畜粪便还田,增施有机肥都有助于土壤有机碳的积累和有效地保持土壤有机碳平衡。
Using the model of biogeochemical bioenergetics (DNDC) in agroecosystem and the operation model supported by the GIS regional database, the status of soil organic carbon storage in the three provinces of Northeast China and its changing characteristics under the current farmland management measures were studied. The results showed that the soil organic carbon (SOC) reserves (0-30cm soil layer) in the three northeastern provinces were about 124.38 million tons in 1998, and 58.4%, 25.5% and 16.1% respectively in Heilongjiang, Jilin and Liaoning Provinces. Under the current cropping system, the soil organic carbon pool is in a serious negative balance with a net loss of 31.22 million tons of organic carbon each year, accounting for 59.3%, 25.9% and 14.8% of the total in Heilongjiang, Jilin and Liaoning Provinces respectively; SOC declines per unit area of cultivated land As high as 2.05 t · ha-1, the SOC loss of arable land in Heilongjiang and Jilin was the most serious. Increasing the proportion of straw returning, advocating no-till and manure and livestock manure returning to the field. Adding organic manure all contributed to the accumulation of soil organic carbon and effectively maintained the balance of soil organic carbon.