Green‐Ampt—Model to Predict Surge Irrigation Phenomena

Abstract

A significant advantage attributed to surge flow irrigation is that for the same volume of water applied the stream will advance farther along the furrow than with continuous flow. Where this advance phenomenon exists, the reduction in runoff and deep percolation will improve uniformity and application efficiency. The mechanism for improvement in advance time has generally been ascribed to surface sealing and surface layer consolidation. However, these phenomena do not satisfactorily explain improved advance times in sandy soils. The Green‐Ampt model combined with a simple redistribution model is used to illustrate the effects of reduced wetting front suction due to intermittent wetting on the instantaneous infiltration rate on two soils. The effect of various surge cycle times on the volume infiltrated versus time is also predicted by the model. This approach to modeling infiltration under surge irrigation shows considerable potential for determining the effect of surge irrigation on a range of soil textures, and as a design tool for optimizing surge cycle times.