Management Model for Control of On‐Farm Irrigation

Abstract

A physically based model for the management and forecasting of irrigation water requirements at an on‐farm level is developed. The model includes mechanisms for simulating root and soil‐water movement, root growth, and crop yield. Model inputs and soil and crop parameters are easily attainable so that the model is usable in field situations. The management model is verified by calibrating it to a crop of cotton grown on an experimental plot at the University of California at Davis, then comparing the results of the model simulations to the field measured data for two alternate water treatments that were used to irrigate the experimental cotton crop. These verifications indicate that the soil‐water content distributions are simulated with a high degree of accuracy, and root‐density distributions are better simulated under moist soil conditions. Further analysis indicates that maintaining moist soil conditions during the bloom stage of cotton growth is critical for consistently high cotton crop yields.