Irrigation Production Functions Reflecting Weather Conditions

Burton C. English
September 1984  [84-WP 8]

National water production functions reflecting regional weather conditions for corn, cotton, sugar beets, and wheat are derived. A least squares regression technique is used with the actual yield as the dependent variable. The independent variable is a composite of four components. These components include the potential yield, the amount of irrigated water used by the crop, the effective rainfall, and the potential evapotranspiration. These functions are transformed into regional production functions. The impact of a decrease in the amount of irrigated water consumed is examined through these regional functions. Finally, a demand curve for water used in irrigation is derived. It is found that the demand for water is more elastic at low corn prices. However, as corn prices increase, the demand for water becomes more inelastic.