不同水份管理對水稻生產及甲烷減排之研究

水稻(Oryza sativa L.)為世界重要糧食作物之一，全球暖化及水資源分布不均的現今，水稻連續湛水的水份管理必須做出改變。本論文試驗以傳統的連續湛水(continuous flooding, CF)與乾溼交替灌溉法(alternate wetting and drying, AWD)及穿孔管灌溉技術(perforated pipe irrigation, PPI)，三種栽培方法，進行不同的水份管理對水稻生長、產量、米質、水分利用效率及甲烷排放的研究。結果顯示，PPI灌溉在穀粒充實期時葉片有提早老化的現象，且稔實率單株產量均顯著最低，但具有高水分利用效率及低甲烷排放的特性。AWD灌溉沒有出現與PPI水份管理對水稻造成葉片提早黃化之問題發生，且亦有不錯的水分利用效率及低甲烷排放量。綜合試驗結果，節水水份管理雖然對水稻減少7.8%~17.8%的產量，但能提高水分利用效率9.1%~24.2%及降低甲烷排放量42.6%~65.0%，在減碳具備價值性的現今，節水栽培具備可行性及必然性。

關鍵字

水稻；乾濕交替灌溉法；通氣灌溉；甲烷；水分利用效率

並列摘要

Rice (Oryza sativa L.) is one of the most important food crops in the world. Nowadays, global warming and uneven distribution of water resources, the water supply mode of traditional rice irrigation must be changed. In the experiment, study of different water supply mode of the continuous flooding (CF), impact of water-saving cultivation modes, alternate wetting and drying (AWD) and sprinkler irrigation (PPI) to explore in rice growth, yield, quality, water use efficiency and methane emissions. The results show that PPI is a water-saving cultivation that has high water use efficiency and low methane emissions. However, there is some drawbacks on PPI, such as yield declining and weeds increasing. In the experience, we found the total days of each rice growth period between AWD and CF make no difference and AWD doesn't have early yellowing of rice leaves same as the PPI. In addition to, the water use efficiency of AWD between the CF and the PPI, AWD can attain to stable yields and low methane emissions as well. In summary, although water-saving irrigation methods can reduce rice yield by 7.8%~17.8%, they can increase water use efficiency by 9.1%~24.2% and reduce methane emissions by 42.6%~65.0%, which is feasible in now “climate change”.