抄録
With the economic growth of Thailand, change from monoculture of rice to diversified farming is about to occur in the Chao Phraya delta. Diversified farming offers high profit, but requires high initial investment for upgrading of farming conditions. Its expansion is still limited to scattered areas of the delta. The present study discusses effective land and water resources management in crop diversification in the delta based on an analysis of the impacts of urbanization, the land reform program, and irrigation and drainage conditions on the expansion of citrus cultivation in the North Rangsit Irrigation Project. Reliable irrigation and drainage conditions, stable land use and water availability, and direct access to irrigation and drainage canals and farm roads are identified as prerequisites for substantial expansion of citrus cultivation in the selected area. Therefore, instead of flexible and extensive land and water resources management for monoculture of rice, long-term planning of land and water resources utilization, and farm-level infrastructure development are recommended to encourage farmers to diversify their farming.