Evaluation of Moisture Front Redistribution in Surface and Subsurface Drip Irrigation Systems

One of the strategies for improving the management of drip irrigation systems is considering the soil water redistribution in different directions (horizontal، downward، radial and upward) which can be of considerable importance. In this research، the wetting front and water redistribution in light-، medium- and heavy-textured homogeneous soils were evaluated in drip irrigation systems. Irrigation time was set to 6 hours and measurements continued until 68 hours after irrigation. Experiments were carried out in a plexiglass container with transparent walls. Emitters were installed at 15، 30 and 45 cm depths and discharge rates of 2. 4 and 4 L/hr were applied. Observations of water front in surface drip irrigation showed that the water redistributed more in horizontal and vertical directions for lesser emitter discharges than the highest ones، but the contrary was observed for subsurface drip irrigation. For the same emitter discharge، the largest depth showed less water redistributed in the horizontal direction but the contrary was observed for shallow depths. This could be explained considering the dry soil area above the emitters that is larger in the deepest location.