Improving the soil wetting pattern in drip irrigation systems with emphasis on pulsed management

The depth and width of the soil wetting pattern determine the spacing between irrigation laterals and the irrigation drippers that influence their numbers and the overall cost of the irrigation system. Therefore, researchers look for solutions to adapt the soil wetting pattern to the pattern of crop root growth as much as possible such as adjusting the irrigation depth and irrigation intervals, utilizing physical, capillary, and hydraulic barriers, as well as pulsed management. Pulsed drip irrigation can replace the usual method of continuous irrigation due to its ability to improve the distribution of soil moisture and consequently crop yield. It also, prevents the accumulation of water in a specific point of the soil and decrease evaporation by improving moisture distribution in the soils with heavy texture and in the soils with a light texture, can lead to a reduction of deep percolation bellow the crop root zone. The results of studies have shown that pulsed drip irrigation can have a positive effect on reducing the clogging of irrigation drippers by providing the possibility of using a dripper with a high flow rate. Therefore, the general results of the research show that the use of pulsed drip irrigation can improve crop yield and water productivity. The purpose of this study is to review the experiences of using different management methods to improve the soil wetting pattern in drip irrigation systems and also provide experimental equations for simulating the soil wetting pattern under drip irrigation systems with emphasis on pulsed management.