Simulation of Surface lrrigation Strategies with Limited Water Supplies

Abstract

The distribution of irrigation water across a field can dramatically affect management of furrow irrigation systems as water supplies become limiting. To asses management strategies for deficit irrigation with a furrow system we used a set of simulation models to determine the average corn yield for the field. We combined an infiltration model, a surface irrigation model and a crop model (CERES-MAIZE) to predict the yield along and across the field. A two dimensional Green and Ampt infiltration model was developed to simulate infiltration changes due to soil water content and cracking. A case study for western Nebraska for a Cozad silt loam soil with and without cracks was used to illustrate development of production functions resulting from management strategies for a limited irrigation water supply. It was concluded that the infiltration model was necessary to simulate deficit irrigation and that the system of models can be used to develop farm management recommendations.