Biological Systems Engineering


Date of this Version



Published in JOURNAL OF IRRIGATION AND DRAINAGE ENGINEERING 115:1 (January/February 1989), pp. 58-77. Copyright © 1989 ASCE. Used by permission.


A method is developed to determine optimal irrigation strategies for a single season using crop production functions which incorporate physically based coefficients. The relationship of yield to evapotranspiration is used to develop the yield-irrigation function. The physical parameters used in the production function can be determined from field measurements or various types of computer simulation. Using this approach, the optimal irrigated area and depth of water to apply can be related to prices, costs, and physical parameters. This produces a more general solution than commonly used production functions that depend on limited experimental results. The optimal irrigation depth and irrigated area can be determined for either land or water limiting conditions. The analysis also allows consideration of different irrigated and dryland crops. Three examples are analyzed to illustrate the use of the technique and to develop some general guidelines.