Climate and choice of irrigation technology: implications for climate adaptation

Abstract

Because studies of irrigation technology adoption often concentrate on small geographic areas with the same climate, few have estimated effects of climate on irrigation technology choice. This study examines the choice of sprinkler versus gravity-flow irrigation across 17 western states. Analysis considers long-term seasonal temperatures and growing season length. An erosion index captures effects of rainfall, field slope, and soil water-holding capacity. Sprinkler adoption increases with reliance on groundwater, pumping costs, farm wage growth, and erosion. Sprinkler adoption was significantly lower for smaller farms. In colder climates, climate warming may lengthen the growing season, but increase susceptibility to frost during the expanded growth period, which may encourage sprinkler adoption. In warmer areas, there is less scope to adapt to warming by switching from gravity to sprinkler technology. Sprinkler adoption declines monotonically in Spring/Summer temperature and growing-season-adjusted Fall/Winter temperature. A drier climate would reduce sprinkler adoption, while climates with more rainfall and more intense rain events would see greater adoption.

Keywords:

• irrigation
• climate change
• technology adoption
• farm size
• sprinkler
• erosion

Acknowledgments

We thank two anonymous reviewers for comments that greatly improved the manuscript. This work was supported by the National Oceanic and Atmospheric Administration's Climate Program Office through Grant NA07OAR4310382 with the Climate Assessment for the Southwest program at The University of Arizona.

Notes

1. One reviewer noted that irrigation technology and crop choice can be joint decisions as modeled by Green et al. (1996), Moreno and Sunding (2005), and Schoengold et al. (2006). Thus, explanatory variables may affect results via their unobserved effects on crop choice. The ERS Special Tabulation, however, does not report irrigation technology choice by crop choice. We consider the scope for using aggregate FRIS data from multiple survey years for analysis of joint crop-technology choices in the concluding section of this article.