Soil Science and Plant Nutrition | 2019
Abstracts of Nippon Dojo-Hiryogaku Zasshi
Abstract
Abstracts of Nippon Dojo-Hiryogaku Zasshi (Japanese Journal of Soil Science and Plant Nutrition) Vol. 90(2019) No. 3 Vol. 90 (2019) No. 3 Original paper Interannual variability ofmethane emission frompaddyfields incorporated with rice straw and mitigation by prolonging midseason drainage in a cold region of Japan1. Effect of temperature and soil redox potential (Eh) on interannual variability of methane emission over 17 years at the same location in 21 cases Hiroyuki Shiono, Hiroshi Saito, Youichi Konno and Katsumi Kumagai Yamagata Integrated Agricultural Research Center Present address: Yamagata Prefectural College of Agriculture and Forestry Present address: Rice Breeding and Crop Science Experiment Station of Yamagata Integrated Agricultural Research Center Present address: Yamagata Murayama Area General Branch Administration Office Present address: Katakura & Co-op Agri Corporation Miyagi Branch Office To clarify the cause of annual changes in methane (CH4) emission from paddy fields incorporated with rice straw in a cold region of Japan, we measured methane flux from 1992 to 2013 (excluding 1997–2002). Annual methane emission was correlated with the cumulative average day temperature. Methane flux could not be clearly correlated with the soil redox potential (Eh) were not correlated when Eh was under −100mV, which was the reducing condition. However, methane flux in June could be correlated with the average temperature in the same month. Methane flux decreased in June when Eh was over −100mV, which was not the reducing condition. In contrast, methane flux in June correlated with methane flux in July, and methane flux in July decreased when Eh was over −100mV in the same month. The results suggest that the duration of midseason drainage influences soil Eh in July and thatmethane emissionmay be reduced by prolonging the midseason drainage from paddy fields in cold regions of Japan.