模拟栽培条件的改变对稻田主要温室气体排放的影响

Simulation of greenhouse gas emissions as affected by cultivation practices in rice fields

利用IKONOS高分辨率(1 m)卫星遥感图,运用典型抽样和地形※土地利用※土地覆盖※综合信息提取的方法,选定了川中丘陵区代表区域,通过对研究区域农业生产情况、土样、水样和气象资料的调查和分析,利用DNDC模型模拟农户作物生产条件下稻田CO2、CH4和N2O排放情况,在此基础上,通过改变目前的研究区域冬水田(PF)(PF占研究区域面积的58.07%)生产条件中的某一影响因子,进一步研究这一因子的改变对CO2、CH4和N2O排放的影响及全球增温潜势(GWP)变化情况。结果表明:氮肥种类和数量、有机肥种类和动物粪尿投入数量、晒田和不晒田、耕地深度、年平均气温变化、降雨量变化、土壤pH值变化、土壤有机质含量变化、土壤质地变化均对稻田温室气体排放有较为显著的影响。冬水田(PF)、水稻-油菜田(RR)和水稻-小麦田(RW)全年排放CO2、CH4和N2O的综合GWP:RW>RR>PF。

Using the high resolution（1 m）IKONOS satellite and employing typical sampling and terrain→land use→land cover→comprehensive information extraction method,representative of the middle Jintang hilly area feature were selected .Detailed farmer investigations were carried out,including crop diversity,tillage,fertilizer,manure type,irri-gationsoil pH,meteorological data.Emissions of CO2,N2O and CH4 emissions of rice fields with farmers crop production conditions simulated using DNDC model .In-depth analysis of factors contributing to emissions of CO2,N2O,CH4,and global warming potential （GWP）was performed by changing a factor of production conditions of the winter water paddy rice field （winter paddy field area accounts for 58 .07%of the area of research）in the target area .The results show that nitrogen fertilizer,organic fertilizer number and variety types,animal dung urine into quantity,middle-stage drainage, depth of cultivated fields,average temperature,rainfall,soil pH,content of soil organic matter,soil texture have signifi-cant influence on greenhouse gas emissions in paddy field .GWP of CO2,CH4,and N2O emissions of one year from three kinds of paddy field-permanently flooded paddy fields （PF）,rapeseed-paddy rice fields （RR）and winter wheat-paddy rice fields （RW）were in the order of RW〉RR〉PF .