Efficient irrigation and water conservation: Evidence from South India
通过印度安得拉邦的随机对照试验，评估滴灌技术对小农户的生产力和节水效果，发现滴灌虽提高利润但未减少地下水抽取。
Widespread adoption of efficient irrigation technologies, including drip irrigation , has been proposed to limit groundwater over-exploitation, especially in water-stressed South Asia. This paper evaluates the potential productivity and water-saving benefits of smallholder drip irrigation by conducting a randomized control trial in Andhra Pradesh, India. A group of well-owners was offered a subsidy to adopt drip irrigation , while a comparable group acted as controls. After three years, the drip group shifted more into horticultural crops , enjoyed higher farm profit, and transferred (primarily through cash sales) more of its groundwater to adjacent plots. There is no difference in groundwater pumping, which is constrained by electricity rationing in this setting. The evidence thus suggests that drip adoption in South India, while increasing irrigation efficiency , will not save groundwater.