Planning and Updating Farm Irrigation Schedules

The optimal utilization of water resources necessitates effective control over the use of water in various economic activities. One of the means useful in attaining this objective is a computer program which enables the planning of farm irrigation schedules, and can update such schedules when circumstances warrant it. The computer program is a simulation algorithm which schedules the application of water on the basis of soil moisture balances at given intervals of time. The irrigation requirements are then checked against the hydraulic characteristics of the farm water distribution system. Delays in replenishing the moisture deficiency within the root zone generate losses which are functions of the magnitude of the delay and of the vegetative status of the crop. The alternative schedule which minimizes these losses is selected. As the irrigation season progresses, data on crop status and soil moisture accumulate. On the basis of these data, the irrigation schedule can be updated.