IRRIGATIONDECISIONS FORMAJORWEST COASTCROPS:WATER SCARCITY AND CLIMATICDETERMINANTS

Department of Agriculture to assess the impact of water scarcity and climate on irrigation decisions for producers of specialty crops, wheat, and forage crops. We estimate an irrigation management model for major crops in the West Coast (California, Oregon, and Washington), which includes a farm-level equation of irrigated share and crop-specific equations of technology adoption and water application rate (orchard/vineyard, vegetable, wheat, alfalfa, hay, and pas-ture). We find that economic and physical water scarcity, climate, and extreme weather, such as frost, extreme heat, and drought, significantly impact producers ’ irrigation decisions. Producers use sprinkler technologies or additional water applications to mitigate risk of crop damage from extreme weather. Water application rates are least responsive to surface water cost or groundwa-ter well depth for producers of orchard/vineyard. Water supply institutions influence producers’ irrigation decisions. Producers who receive water from federal agencies use higher water appli-cation rates and are less likely to adopt water-saving irrigation technologies for some crops. Institutional arrangements, including access to distinct water sources (surface or ground) and whether surface water cost is fee based, also affect the responsiveness of water application rates to changes in surface water cost. The analysis provides valuable information about how producers in irrigated agricultural production systems would respond and adapt to water pricing policies and climate change