DNDC模拟中国20年农田管理土壤碳变化

Analysis of the Change of Soil Carbon under Cropland Management in China between 1981 and 2000 by DNDC

利用生物地球化学模型（DNDC模型）对中国大陆的东南沿海、东北、黄淮海、长江上中游、西北和西南6大区进行区域模拟,分析了1981~2000年20 a间单施化肥、单施有机肥、化肥有机肥配施、秸秆还田和免耕等5种农田管理措施下农田土壤有机碳的动态变化。模拟结果表明：配施和施有机肥的固碳效果最明显,20 a平均固碳量均为1.78 t hm-2 a-1。其次是免耕,为0.71 t hm-2 a-1。秸秆还田略低,为0.47 t hm-2 a-1。施化肥的固碳效果最差,仅固定0.09 t hm-2 a-1。

On the scale of Chinese Mainland,DNDC model was used to simulate in the six regions,Southeastern littoral region,Northeast region,The Yellow-Huaihe-Haihe Rivers region,Upper and middle reaches of Yangtze River region,Northwest region,Southwest region.The dynamic changes of soil organic carbon were analyzed under five cropland regimes,such as chemical fertilizer utilization,organic fertilizer utilization,chemical and organic fertilizer utilization,straw returning and no-tillage,between 1981 and 2000.The results showed that the effect of carbon stocking was significant,the average of 1.78tC hm-2 a-1.Next was no-tillage,0.71tC hm-2 a-1.The increasing of carbon under straw returning was 0.47tC hm-2 a-1.The last one was chemical fertilizer utilization,which only made carbon increase by 0.09tC hm-2 a-1.