@inproceedings{oai:soar-ir.repo.nii.ac.jp:00010508,
 author = {Yang,  Z and Hayakawa,  T and Inoue,  N},
 book = {信州大学農学部紀要},
 issue = {1-2},
 month = {Mar},
 note = {Proceedings of Shinshu University International Symposium 2007 “Sustainable Agriculture and Environment:Asian Network”, Paddy fields is significant source of methane （CH4）, a major greenhouse gas. Therefore, agro-technological developments to inhibit CH4 emission from paddy fields are required. However, little information is available on CH4 emission from paddy fields in tropical Asia. We measured CH4 gas emission to observe its diel change in a permanently flooded paddy field in which a high-yielding hybrid rice variety was established and no organic fertilizer was applied. The field study was conducted on Hainan island （latitude:19°31'N, altitude:168m） from September 21 to 26, 2006. The rice developmental stage was booting, and the leaf area index was 5.0. The CH4 flux was calculated by the eddy correlation method. The CH4 concentration was measured using a laser gas detector. The vertical wind speed was measured using an ultrasonic anemometer and atmospheric density. The CH4 flux peaks were observed at predawn, which decreased rapidly after sunrise with an increase in temperature. This diel oscillation pattern of methane flux was similar to that observed in August 2006 in a highland area of central Japan. The CH4 flux seemed to be suppressed by the photosynthesis of the rice canopy. The oxygen flux from plant top to rhizosphere increased due to photosynthesis during the daytime and inhibited methanogen activity under the ground., Article, 信州大学農学部紀要. 44(1-2): 47-51 (2008)},
 pages = {47--51},
 publisher = {信州大学農学部},
 title = {Methane Emission Peak observed at Predawn in Tropical Paddy Field:A Case Study of Hainan Island, China},
 volume = {44},
 year = {2008}
}