CH4 transport mechanisms via rice plants: a new approach using isotopic fractionation of 13C-CH4

2014 Fiscal Year Final Research Report

• Project/Area Number: 25660200
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Agricultural environmental engineering/Agricultural information engineering
• Research Institution: National Institute for Agro-Environmental Sciences
• Principal Investigator: TOKIDA Takeshi 独立行政法人農業環境技術研究所, その他部局等, 研究員 (20585856)
• Project Period (FY): 2013-04-01 – 2015-03-31
• Keywords: メタン / 水田 / イネ / 炭素安定同位体比 / ガス輸送 / 移流 / 拡散

Outline of Final Research Achievements

Rice paddies represent one of the largest anthropogenic sources of atmospheric CH4. Methane is produced by methanogens in anoxic soil and released into the atmosphere mainly via aerenchyma tissue of rice plants; however physical mechanisms of the emissions remain unclear. In this study CH4 emission was measured at a farmer's rice paddy, showing a large (>2-3 folds) diurnal variation in CH4 emissions after the middle of the growth season. The larger emissions during the daylight hours accompanied relatively heavier CH4 (enriched in 13C) while smaller emissions during the nighttime were characterized with lighter (less 13C) CH4. These results suggest occurrence of and shift in different transport mechanisms of CH4 through rice plants.

Free Research Field

生物地球科学