稻田CH_4排放和土壤、大气条件的关系

INFLUENCE OF SOIL AND ATMOSPHERIC CONDITIONS ON METHANE EMISSION FROM RICE PADDY FIELD

在杭州地区利用静态箱法对稻田CH_4排放进行连续观测,结果证明CH_4排放率有较大的日变化和季节变化,CH_4排放率的日变化较复杂,除了和温度变化一致的峰型外,还有夜间峰、双峰型、多峰等。CH_4排放率的季节波动较大,在分蘖期和长穗前期分别有一较大峰值,早稻和晚稻的变化规律略有不同。稻田CH_4排放规律可用稻田中有机物含量的变化和空气、土壤温度的变化等作一定性解释。 早稻和晚稻的CH_4排放总量有较大的差别,平均来看,早稻的排放量为0.46g·m^(-2)·d^(-1),晚稻为0.80g·m^(-2)·d^(-1)。稻田CH_4排放也有较大的年际变化,1988年全年CH_4排放量为0.23g·m^(-2)·d^(-1),1989年为0.95g·m^(-2)·d^(-1),施肥对CH_4排放有一定的影响,施有机肥的稻田CH_4排放量最高,施化肥的稻田次之,不施肥的稻田CH_4排放量最低。

Methane from rice field contributes an importment part to the atmospheric methane. In paddies methane is produces in anaerobic condition.After three year' s study of methane emission from rice paddies in Hangzhou China, we found the diurnal and seasonal variations of methane emission rate more complex than other scientists reported before. Seasonal variation was influenced by rice growing activities and weather conditions (e. g. pulm rain rain season in the lower reaches of Changjiang river).Fertilizer treatment did not show siginificant influence on methane emission which may be due to the rich content of organic matters in the soil.