摘要：Policies that encourage the use of more efficiency irrigation technology are often viewed as effective, politically feasible methods to reduce the consumptive use of water for agricultural production. Despite their widespread use, these policies have not been subject to empirical evaluation. In this article, we evaluate the effect on groundwater extraction of a widespread conversion from traditional center pivot irrigation systems to higher efficiency dropped-nozzle center pivot systems that has occurred in western Kansas. State and national cost-share programs subsidized the conversion. We find that the programs have not had the intended effect; the shift to more efficient irrigation technology has not decreased the amount of water applied to a given crop, and has actually increased groundwater extraction through changing cropping patterns.
