Optimal Scheduling of Irrigation Machines. I: Model Development

Abstract

An irrigation scheduling model for a center‐pivot irrigation machine was developed to maximize returns in humid areas. A corn growth‐ and yieldsimulation model was incorporated to predict the end‐of‐season yield. The irrigation decision process for an irrigation machine was defined and formulated mathematically into a model that sequentially optimizes the irrigation schedule. The problem of optimal scheduling of an irrigation machine was divided into a singlefield problem and a multifield problem. Each problem was formulated as a decision‐tree problem and was solved using tree enumeration techniques. The model was coded into a computer program written in PASCAL that uses the corn simulation model (written in FORTRAN) as a subroutine. The model can aid in making the daily irrigation decision and the allocation of limited water resources when irrigating different fields under the same center‐pivot machine.