Evaluation of wetting pattern in deep subsurface irrigation method using PVC pipes in desert areas

Due to the lack of water in the deserts of Iran and the high rate of evaporation, the establishment of vegetation and their irrigation are associated with many problems. Therefore, in the management programs for the sustainable development of dry and desert areas, it is very necessary to use less water. Among these methods, deep subsurface irrigation using PVC pipes can be mentioned. In this study, a hole with a depth and diameter of 50 cm was dug, and then two pipes were mutually placed at a distance of 20 cm from each other on both sides of the pit. After placing the pipes, the pit was filled with soil. The wetting pattern in eight treatments has been examined in terms of the location of the water exit holes, the diameter of the pipe, the number of holes in the upper and lower half of the pipe, as well as the diameter of the holes. The results demonstrated that pipes with a diameter of 12.5 cm and a height of 55 cm, with five double rows of 6 mm holes in the upper half of the pipe at a distance of 3 cm from each other and two holes in the lower half of the tube at a distance of 10 cm from each other, The best depth of wetting pattern is created. The depth of the wetting pattern created in the soil around the plant root as a representative of water use efficiency is very important in the management and correct use of water resources as well as encouraging the plant to take deep roots. .