Japan Geoscience Union Meeting 2014

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Oral

Symbol A (Atmospheric, Ocean, and Environmental Sciences) » A-HW Hydrology & Water Environment

[A-HW29_2PM1] JapanFlux: Role of terrestrial ecosystems in water/material cycles

Fri. May 2, 2014 2:15 PM - 4:00 PM 314 (3F)

Convener:*Takashi Hirano(Research Faculty of Agriculture, Hokkaido University), Katsumi Yamanoi(Forestry and Forest Products Research Institute), Kazuhito Ichii(Faculty of Symbiotic Systems Science, Fukushima University), Nobuko Saigusa(National Institute for Environmental Studies), Chair:Kazuhito Ichii(Japan Agency for Marine-Earth Science and Technology)

3:15 PM - 3:30 PM

[AHW29-05] The variations of ORP in the paddy soil and effects on the methane emission from a periodically irrigated paddy field.

Kenta YAGI1, Naoki WAKIKUROMARU1, *Toru IWATA1 (1.Graduate school of Environmental and Life Sciense, Okayama University)

Keywords:Rice Paddy, Methane, soil, Oxidation-Reduction Potential

Oxidation-Reduction Potential (ORP) in the paddy soil was measured during rice cultivaled season at a periadically irrigated paddy field, and some effects on the methane flux from the paddy soil was investigated. ORP showed rapid decrease when irrigation water was introduced in the paddy field, and lower ORP was shown under the longer flooded condition. From the seasonal-term point of view, lower ORP was shown in later rice season. ORP was suitably modeled as a function of irrigation time. During an irrigation period for four days, higher methane emissions were shown under lower OPR conditions. From the seasonal-term point of view, however, no significant relationship between ORP and methane fluxes. It is suggested that seasonal change of methane flux is affected by seasonal changes of soil temperature and the growth level of rice plants.