Production Efficiency and Irrigation of 110 Paddy Fields in Kanto Region

Irrigation is increasingly important for rice productivity to maintain soil temperature and fertility with the presence of global warming. Meanwhile, rice production in Japan is in urgent need to reduce the costs through improving the efficiency and market competitiveness. This chapter aimed to measure effect of water depth and water temperature on rice yield of individual paddy fields and improve the practice of irrigation management for them. In first stage, we measured the production efficiency of rice yield through the adoption of DEA. The results indicated that enlarged scale of the paddy fields increases the efficiency, and rice quality can be improved more than quantity.