Possible options for mitigating methane emission from rice cultivation

Studies focused on mitigating CH4 emission from rice paddy fields are summarized and the possibilities and limits that the options might be applied to world's rice cultivation are discussed. The mitigation options are water management, soil amendments, organic matter management, different tillage, rotation, and cultivar selection. Altering water management, in particular promoting midseason aeration by short-term drainage, is one of the most promising strategies, although these practices may be limited to the rice paddy fields where the irrigation system is well prepared. Improving organic matter management by promoting aerobic degradation through composting or incorporating into soil during off-season drained period is another most promising candidate. There are several formidable obstacles to adopt the mitigation options into local rice farming, including limited applicability to different types of rice fields, increasing cost and labor, negative effects on rice yield and soil fertility, and time requirement for practical application. Further studies to verify the mitigation options should focus on the feasibility for local farmers.