Predicting Wetting Patterns in Soil from a Single Subsurface Drip Irrigation System

Abstract

Soil wetted pattern from a subsurface drip plays great importance in the design of subsurface drip irrigation (SDI) system for delivering the required water directly to the roots of the plant. An equation to estimate the dimensions of the wetted area in soil are taking into account water uptake by roots is simulated numerically using HYDRUS (2D/3D) software. In this paper, three soil textures namely loamy sand, sandy loam, and loam soil were used with three different types of crops tomato, pepper, and cucumber, respectively, and different values of drip discharge, drip depth, and initial soil moisture content were proposed. The soil wetting patterns were obtained at every thirty minutes for a total time of irrigation equal to three hours. Equations for wetted width and depth were predicted and evaluated by utilizing the statistical parameters (model efficiency (EF), and root mean square error (RMSE)). The model efficiency was more than 95%, and RMSE did not exceed 0.64 cm for three soils. This shows that evolved formula can be utilized to describe the soil wetting pattern from SDI system with good accuracy.