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。
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.
出处
《农业环境科学学报》
CAS
CSCD
北大核心
2006年第5期1228-1233,共6页
Journal of Agro-Environment Science
基金
中国科学院知识创新工程重要方向项目(KZCX3-SW-426)
国家"973"项目课题(2002CB412503)
国家自然科学基金重点项目(40235057)