The effect of water management based on soil redox potential on methane emission from two kinds of paddy soils in Japan

The CH4 emissions of MD, IM, and EH were 64, 26, and 17% of CF, respectively. However, the order of brown rice yield was as follows: IM > MD > CF > EH. With the drainage for Eh control, soil Eh increased to higher than 400 mV several times, and this condition was maintained for up to one day. This excessive drying of the soil affected rice growth and yield of EH. To apply Eh control to field conditions, the upper limit of soil Eh must be controlled to avoid the excessive drying. Moreover, water demand of rice plants is necessary to be considered.