Table of Contents
International Scholarly Research Notices
Volume 2015, Article ID 623901, 8 pages
http://dx.doi.org/10.1155/2015/623901
Research Article

Contribution of Ebullition to Methane and Carbon Dioxide Emission from Water between Plant Rows in a Tropical Rice Paddy Field

1Graduate School of Agriculture, Meiji University, Kawasaki, Kanagawa 214-8571, Japan
2School of Agriculture, Meiji University, Kawasaki, Kanagawa 214-8571, Japan
3Formerly Graduate School of Agriculture, Meiji University, Kawasaki, Kanagawa 214-8571, Japan
4Department of Agronomy, Kasetsart University, Kamphaeng Saen, Nakhon Pathom 73140, Thailand
5Rice Gene Discovery Unit, National Center for Genetic Engineering and Biotechnology (BIOTEC), National Science and Technology Development Agency, Kasetsart University, Kamphaeng Saen, Nakhon Pathom 73140, Thailand

Received 12 October 2015; Revised 9 December 2015; Accepted 9 December 2015

Academic Editor: Weixin Ding

Copyright © 2015 Shujiro Komiya et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Although bubble ebullition through water in rice paddy fields dominates direct methane (CH4) emissions from paddy soil to the atmosphere in tropical regions, the temporal changes and regulating factors of this ebullition are poorly understood. Bubbles in a submerged paddy soil also contain high concentrations of carbon dioxide (CO2), implying that CO2 ebullition may occur in addition to CH4 ebullition. We investigated the dynamics of CH4 and CO2 ebullition in tropical rice paddy fields using an automated closed chamber installed between rice plants. Abrupt increases in CH4 concentrations occurred by bubble ebullition. The CO2 concentration in the chamber air suddenly increased at the same time, which indicated that CO2 ebullition was also occurring. The CH4 and CO2 emissions by bubble ebullition were correlated with falling atmospheric pressure and increasing soil surface temperature. The relative contribution of CH4 and CO2 ebullitions to the daily total emissions was 95–97% and 13–35%, respectively.