Review of Reclamation of salinity affected soils by leaching and their effect on soil properties and plant growth
The irrigated soils in dry and semi-arid areas suffer from the problem of salt accumulation because of not using sufficient leaching water to remove the salts added with the irrigation water. Soil salinity contributes to a decrease in the growth and productivity of plants grown in those conditions, as well as affecting the physical, chemical and hydraulic properties of the soil. The reclamation process is a radical solution to the problem of salinization, and one of the most important basic ingredients for the success of the process of reclamation of saline soils is to determine the optimal amount of leaching water or what is called ( leaching Norm). Hence, the leaching process and the net movement of the leaching water are required to remove the salts to prevent them from concentrating in the root zone to the appropriate level for the plants' tolerance to ensure that it does not affect their growth and productivity. The concept of leaching a soil from salts and improving its physical and chemical properties depends on several factors, including the method of leaching, salinity, the amount of water added during the leaching process and the time period for leaching, as well as the properties of the soil and other factors. The salts present in the surface layer and their transfer with the movement of water to the depths and from there to the places of puncture, they also indicated that the increase in the leaching periods with low salinity of leaching water in the intermittent leaching method showed greater efficiency in using less quantities of water, in addition to that the increase in the leaching periods may increase From the speed of leaching salts from the soil, they also indicated that increasing the amount of water and leaching periods may contribute to reducing the salinity of the studied soil, especially in unsaturated soil conditions.