|| 要旨トップ | 目次 |||日本生態学会第64回全国大会 (2017年3月、東京) 講演要旨
一般講演（ポスター発表） P1-J-302 （Poster presentation）
Paddy field is a major source of methane (CH4) emission. Farming practices like fertilization and tillage are important for proper growth of rice plants. Feeding activities of aquatic earthworms in paddy soil add oxygen in upper soil layers by introducing oxygen rich water. Therefore, field and pot experiments were conducted to identify effects of agro-chemicals and tillage on CH4 emission and earthworm density and role of aquatic earthworms on reduction of CH4 emission. During field experiments, soil samples were collected under fertilizer (organic and chemical) and tillage (conventional and no-tillage) treatments to measure earthworm density and gas samples were collected to measure CH4 flux. In pot experiments, urea, ammonium sulfate and aquatic earthworms (Branchiura sowerbyi) were imposed in soil in combination. In the field experiment, organic fertilizers enhanced earthworm density and no-tillage farming practice reduced CH4 emission. In the pot experiment, ammonium sulfate directly reduced CH4 emission and the aquatic earthworms were found to have significant effect on suppression of CH4 emission from paddy soil. While the application of urea increased CH4 emission, earthworm reduced CH4 flux under urea fertilization condition. Results of these studies revealed that aquatic earthworms may play important role to reduce CH4 emission from paddy field.