【摘要】 应用自主建立的土壤碳循环模型(SCNC)模拟了中亚热带地区6个稻田长期定位试验土壤有机碳15年间的变化。结果表明,SCNC模型较为准确地模拟了各处理土壤有机碳的变化趋势,在所有模拟值与实测值的比较中,相对误差的绝对值<5%的比率占43.89%,<10%的则占71.11%。监测点土壤有机碳实测值和模拟值的相关性均达到了极显著水平,二者相关曲线的斜率均在0.95￣1.05之间。说明SCNC模型适合于我国亚热带稻田土壤有机碳的模拟,但模拟结果也表明,模型在一定程度上(<20%)低估了不施肥处理的有机碳积累量,需要进一步改进。更多还原

【Abstract】 Paddy field is the main production system in the subtropical region of China.Due to waterlogged condition,the turnover of soil organic C(SOC) is different with dry upland.Based on the Soil Organic Carbon and Nitrogen Cycling Model(SCNC) built by us,we developed a simulation model for paddy soils.Here we simulated the changes of SOC in 6 long-term field experiments with 4 types of fertilization.Without any fertilizer incorporated,SOC showed no declining trend during the experimental period.Chemical fertilizer application enhanced the accumulation of soil organic C in half of the experiments.Soil organic C under middle-level manure(M-M) and high-level manure(H-M) treatments increased significantly,and the effect of H-M was obviously higher than that of L-M.The changes of soil organic C were simulated by SCNC paddy sub-model accurately.According to the statistics of relative errors between simulated and observed values,about 43.89% of relative errors were less than 5%,71.11% less than 10%.The correlation between simulated and observed values was significant(p<0.01).The slopes of 6 sites were all between 0.95 ~ 1.05.All these proved that SCNC model was suitable for the simulation of soil organic C changes in subtropical paddy soils.But the simulating results also showed that the model underestimated the accumulation of soil organic C in NIL treatment,and needed to be improved.更多还原