The role of dissolved CH4 in soil solution in the CH4 emission from water-saving irrigated rice fields
To examine how the dissolved CH4 in soil solution would affect the CH4 emission from rice field, fluxes of CH4 emission were measured by using a manually closed static chamber-gas chromatography method, and the dissolved CH4 in soil solution was obtained through shaking soil solutions, which were extracted from different paddy soil layers by a soil solution sampler with suction and pressure. The results show that the CH4 fluxes from rice fields and the concentration of dissolved CH4 in soil solution are both reduced significantly under the water-saving irrigation as compared to the traditional flooded irrigation. Under the water-saving irrigation, naturally receding water-layer during the early stage leads to an earlier peak of CH4 flux, but dramatically reduces the concentration of dissolved CH4 in soil solution. The maximum concentration is shifted to about 20-cm depth soil layers, and the relationship between CH4 emissions and dissolved CH4 in soil solution can be estimated using an exponential function of dissolved CH4 in soil solution at the depth of about 20 cm (R2=0.89, p <0.001). It is believed that the dissolved CH4 in soil solution plays a more dominant role in CH4 emission under the water-saving irrigation than that under continuously flooded irrigation.
Water-saving irrigation Dissolved CH4 CH4 emissions Rice fields
Daoxi LI
North China University of Water Resources and Electric Power, 36 nanhuan Road, Zhengzhou 450011, China
国际会议
大连
英文
977-982
2011-10-19（万方平台首次上网日期，不代表论文的发表时间）