华北平原典型农业区土壤甲烷通量研究

Methane Fluxes of Typical Agricultural Soil in the North China Plain.

利用静态箱法原位测定了华北农田不同施肥处理夏玉米和冬小麦生长季土壤甲烷的通量。结果表明 ,施肥农田夏玉米和冬小麦生长季甲烷通量分别为 -79.8和 -2 1.6μg·(m2 ·h) - 1 ,年平均通量为 -4 3 .1μg·(m2 ·h) - 1 。未施肥农田夏玉米和冬小麦生长季甲烷通量分别为 -110 .0和 -88.2 μg·(m2 ·h) - 1 ,年平均通量为 -95 .2 μg·(m2 ·h) - 1 。在不同生长季 ,各处理农田土壤甲烷通量均为负值 ,即土壤为大气甲烷的吸收“汇” ,在各个生长季施肥农田对甲烷的吸收量均低于未施肥农田 ,各处理冬小麦生长季土壤对CH4 的吸收量均低于同一处理的夏玉米生长季的吸收量 ;各处理甲烷通量具有较明显的季节变化 ,5月上旬至 9月中旬 ,土壤的甲烷吸收能力较强 ,其他时间吸收量较低 ;施肥土壤约比未施肥土壤对甲烷的氧化吸收能力降低 2 7%～ 76% ;

Using the static chamber technique,in situ fluxes of methane from the soil of farmland in the North China Plain under different fertilization treatments and different crops(summer maize and winter wheat) were measured.Results showed that of the fertilized soil,with crops of summer maize and winter wheat,the mean methane flux was -79.8 and -21.6 μg·(m 2·h) -1 respectively,and -43.1 μg·(m 2·h) -1 for the year.And of the non fertilized soil with crops of summer maize and winter wheat,it was -110.0 and -88.2 μg·(m 2·h) -1 respectively,and -95.2 μg·(m 2·h) -1 for the year.All are negative values,which means that the soil is still a sink for methane.Non fertilized soil absorbed more methane than the other,and the soil under summer maize did more than the soil under winter wheat in the same treatment.Methane fluxes showed obvious variation with the season.During the period of May to mid September,the soil absorbed more methane than in the rest of the year.Fertilization could reduce consumption of methane significantly (about 27% to 76%).In the experiment area,higher precipitation stimulated consumption of methane in a certain period.