中文摘要：

以南京地区稻麦轮作体系为对象,研究了不同农业管理措施对CH4和N2O排放通量及年度动态变化的影响,用田间观测数据验证生物地球化学循环模型（DNDC）在该耕作制度下的适用性;利用DNDC模型模拟不同环境因子和管理措施对CH4和N2O综合温室效应（GWP）的影响.结果表明：除了对照和麦季对CH4排放的模拟偏差较大外,DNDC对其余各处理模拟的CH4和N2O累积排放量与田间观测结果基本吻合,相对偏差变幅7.1%～26.3%,可以直接应用DNDC模型模拟环境因子和主要管理措施对CH4和N2O累积排放量引起GWP的影响.模型灵敏度检验结果表明,年均温度、土壤容重、土壤有机碳、土壤质地、土壤pH等环境因子对GWP的影响显著;施用氮肥、秸秆还田量和烤田期长短等管理因子对GWP的影响明显.在估算我国稻麦轮作制度下温室气体的点或区域排放规律时,应考虑上述这些影响因子.

英文摘要：

Taking a rice-wheat rotation system in the suburb of Nanjing, Jiangsu Province of East China as test object, this paper studied the fluxes of CH4 and N2O and their annual dynamics under different farming managements in 2010-2011, and the field observation data were applied to vali- date the process-based model, denitrification-decomposition （DNDC） model, aimed to approach the applicability of the model to this rotation system, and to use this model to simulate the effects of different environmental factors and farming managements on the global warming potentials （GWPs） of CH4 and N2O. The results showed that except in the treatment control and during wheat growth season, the simulated cumulative emissions of CH4 and N2O from the rotation system in all treat- ments were basically in coincide with the observed data, the relative deviations being from 7.1% to 26.3%, and thus, the DNDC model could be applied to simulate the GWPs of cumulative emis- sions of CH4 and N2O as affected by various environmental factors or management practices. The sensitivity test showed that the GWPs of CH4 and N2O varied significantly with the changes of envi- ronmental factors such as the mean annual air temperature, soil bulk density, soil organic carbon, soil texture, and soil pH. Farming managements such as N fertilization, straw returning, and dura- tion of mid-season drainage also had significant effects on the GWPs of CH4 and N2O. Therefore,the above-mentioned environmental factors and farming managements should be taken into account to estimate the greenhouse gases emission from the rice-wheat cropping system on site-specific or re- gional scale.