亚热带红壤性稻田的甲烷排放

Methane Emission from Paddy Fields Derived from Red Soil in Snbtropics

亚热带红壤性稻田的甲烷排放量为５５．２３９／ｍ２·ａ．不同年度间有差异；在年度内（水稻生长季节）亦有差异．以８月排放最多，其余月份依其排放量的顺序是７月，６月，５月，９月，１０月．甲烷排放率的日变化有规律性，１６时前后出现最大值，６时左右出现最小值，呈单峰型，日变化幅度与天气有关，季节变化比较复杂，无规律性，在不同年度、不同稻季（早、晚季），其变化也不一致．稻田甲烷排放与水稻生产和生长密切相关，水稻的种植和生长是稻田甲烷排放的基础和根源．

Annual methane emission from paddy fields derived from red soil in subtropics is about 55. 23g/m2 and there are annual variation and seasonal variation. In the rice growing seasons, maximum emission appears in August, and then July, June, May, September, and October in the order. Diurnal variation of methane emission rate shows obvious regularity,which is similar to but appears a little delay than that of air temperature. Seasonal variation of methane emission rate is more complicated and differs annually and seasonally. Planting and growth of rice are important factors influencing methane emission from paddy fields.