การจัดการน้ำในนาข้าวเพื่อลดผลกระทบสิ่งแวดล้อมเกี่ยวกับน้ำและบรรยากาศ

Abstract

This research focuses on water management in paddy fields by applying the shallow water depth (10 to 5 cm.), the combination of wetting and drying (5 to -5 cm.) and the traditional irrigation (30 to 20cm.). Observation samples were regularly collected from paddy fields during the dry and rainy seasons of 2006 in the Maeklong river basin, Thailand. The results showed that higher and longer flooding period of paddy fields increased methane emission and water quality impacts. The traditional irrigation induced the most impacts, while the shallow water depth and the combination of shallow water depth with drying period showed decreasing impacts, respectively. Moreover the combination of wet and dry periods gave the lowest methane emission in paddy field, nitrate and phosphate concentration in drainage canal. In comparison with traditional irrigation, the other two methods indicated that methane emission, nitrate and phosphate concentration were reduced by 20.2–81.6%, 51-61% and 97-98%, respectively. In addition, water supply decreased 31.64–52.57% without any significant rice yield reductions. To summarize, the proper water management is an effective way to reduce water use, enhance sustainable environmental of atmosphere and water resources, including improvement quality of life under better condition of ecosystem.