施氮对稻麦轮作系统综合增温潜势的影响

采用典型区域田间试验结合生物地球化学模型（DNDC模型），以上海市崇明岛为例对稻麦轮作系统作物产量和温室气体排放进行了模拟研究。结果表明：DNDC模型能较好地模拟田间实测到的稻麦轮作系统温室气体排放通量。在常规用量的80%~150%之间增施氮肥对作物产量无显著增加，但稻麦轮作系统综合温室效应呈递增趋势。东滩农业园区稻麦轮作系统最优施氮量为常规用量的6298%，此时单位产量增温潜势（Global Warming Potential,GWP）最小，作物产量为12 8775 kg/(hm2〖DK〗·a)，综合温室效应较常规施氮降低3670%。长江下游地区稻麦两熟制农业生态系统能够通过合理控制农田氮肥用量减少温室气体排放净通量，降低作物单位产量GWP

EFFECTS OF NITROGEN APPLICATION ON GLOBAL WARMING POTENTIALS IN RICE-WHEAT ROTATION SYSTEM

This paper studied the effects of different nitrogen levels on crop yield and global warming potential through Denitrification-Decomposition Model(DNDC) model and a farm automatic sampling system.The results showed that DNDC model was well applied to simulate the greenhouse gas emissions.There was no significant increase of crop yield with the increase of N fertilizer between the normal usages of 80 percent to 150 percent.There was an optimization unit crop yield Global Warming Potential(GWP),when the nitrogen application rate was reduced to 62.98 percent of the normal usages,with crop yield 12 877.5 kg/(hm2·a) and 36.70 percent reduction of GWP.This study showed that reducing the amount of nitrogen reasonably can bring down the greenhouse gas emissions of wheat rotation system at the Lower Reaches of the Yangtze River,and reduce the global warming potentials per kilogram crop yield.