摘要
通过对中国五大水稻产区稻田甲烷排放的多年观测实验，描述了稻田甲烷排放的时空变化规律及特征并分析研究了其形成机理。稻田甲烷排放的日变化有四种类型，甲烷的传输效率是日变化形成的主要因素。稻田甲烷土壤中排放率的季节变化型式在不同的地区是不同的，这取决于气温变化、水稻品种、施肥及水管理等不同因素。甲烷产生主要发生在稻田土壤耕作还原层（２～２０ｃｍ），氧化主要发生在水土交界面的氧化层和根部氧化膜，并受多种因子的影响。土壤中的甲烷通过三个路径向大气排放，不同时期三个路径在甲烷传输中的相对重要性不同。施用化肥和沼渣肥可以降低土壤中甲烷的产生和排放，而有机肥会增加土壤中甲烷的产生和排放。中国的稻田每年向大气中排放９６７～１２６６百万吨甲烷，全球稻田甲烷的总排放量约为３５～５６Ｔｇ／ａ。
CH 4 emission rates from Chinese rice fields have been measured in all the five major rice culture regions in China Four types of diurnal variations of CH 4 emission rates have been found Seasonal variation patterns of CH 4 emission differ slightly in different field locations, where climate system, cropping system and other factors are different CH 4 production mainly occurs in the reduced soil layer (2～20 cm) CH 4 is oxidized mainly in the thin surface layer of paddy soil, and the rhizosphere of rice plants Production and oxidation rates are effected by many factors CH 4 transport through rice plant, gas bubble and diffusion in flooded water Relative importance of each route is different in different stages during rice growing The effects of various mineral fertilizers on CH 4 emission were rather contradictory, while the amount and the type of organic manure will enhance CH 4 emission from rice fields, which has been also indicated by CH 4 production rates Application of fermented sludges from biogas generators and farmyard-stored manure instead of fresh organic manure seem to be promising China's rice fields contribute about 9 67～12 66 Tg/a to the atmosphere The total methane emission from global rice fields can be estimated as 35～56 Tg/a
出处
《大气科学》
CSCD
北大核心
1998年第4期600-612,共13页
Chinese Journal of Atmospheric Sciences
关键词
土壤
甲烷排放
日变化
季节变化
输送机理
稻田
methane emission diurnal variation seasonal variation oxidation and transportation influence factors
