The investigating of the effects of soil's texture and discharge of irrigation water on the water infiltration pattern from a point source

Drip irrigation is a good way to reduce wasting water and to use the water and soilnutrients in a better way. Being aware of the soil moisture distribution pattern underemitter is necessary to design and manage drip irrigation system. Shape (diameter anddepth of the wet soil) and the distribution pattern of the wetting front under emitter willbe affected by soil properties (structure, texture, and hydraulic conductivity), strength,and also duration of water application.In this research, by making a physical model, the effects of three textures of sandy clay,sandy clay loam, and loamy sandy, four applied discharges of 1.5, 3, 6, and 9 lit/h, andfive irrigation water volumes of 10, 20, 40, and 60 lit. on the distribution pattern of thewetting front under emitter have been investigated. The results of the research haveshown that the raise in the emitter discharge has increased the wet surface of the wetting front; however, the increase pattern has been differently based on the soil texture. This means that, while the wet surface of the sandy clay has shown greater increase and has been more superficial than two other kinds of soil texture, the wetting front in the loamy sandy has got deeper (deeper and more narrow). So the discharge raise has increased the wet surface of the wetting front; however, for the lower discharges, with the same volume of the irrigation water, the wetting fronts were deeper than those of the higher discharges. The distribution pattern of the wetting fronts in sandy clay, sandy clay loam, and loamy sandy were half-elliptical, sagittal, and fine drawn wetting front, respectively for all applied discharges.The results of the research have also shown that the discharge increase will reduce thechanges of the wet surface. For the discharges of 6 lit/h and more no considerableincrease in the wet surface has been seen. So it is recommended that do not to useemitters with the discharges of more than 6 lit/h.