Crop Yield and Water Requirement Relationships for Major Irrigated Crops in Southern Alberta

Water supplies available for irrigation in southern Alberta are limited. A study was conducted in southern Alberta to develop crop yield and evapotranspiration (ETc) relationships for major irrigated crops based on current maximum potential crop yield data and improved methods for determination of crop evapotranspiration. Production functions for crop yield and the field water supply, which includes irrigation at 80% efficiency, effective precipitation, and stored soil moisture depletion, were subsequently determined. These empirical relationships may be used by water managers, economists, and producers to examine the economic implications of crop yield reductions from water stress due to limited water supplies, less than optimum (deficit) irrigation management, or variation in evaporative demand from year to year in different agro-climatic areas of southern Alberta. Potential yield estimates for different scenarios may be used with relevant economic information to determine optimum water use for irrigation.