PERFORMANCE OF SUBSURFACE DRIP IRRIGATION UNDER DIFFERENT CONDITIONS

Subsurface drip irrigation systems can be an efficient water saving method of irrigation for many regions. Maximizing the efficiency of this system requires guidelines and criteria for system design. In this study, the Windows-based computer software package HYDRUS 2D/3D, which numerically simulates water, heat, and/or solute movement in two dimensional, variably saturated porous media, was used to evaluate the soil wetting patterns, irrigation efficiency, and relative transpiration for different installation depths 5, 15, 25, and 35 cm, and different root distribution shapes triangular and trapezoidal. Irrigation depth equal to evapotranspiration is applied daily for a period of 45 minutes. The simulations were done at plant maturity and extended for about 40 days. The evaporation, deep percolation, relative transpiration, and irrigation efficiency are calculated. The results showed that the irrigation efficiency and relative transpiration significantly depend on the installation depth and the root distribution shape.