The aim of the research was to reveal the orientation of soil processes during continuous irrigation of various types of soil. The objects of the research are soils on key irrigated plots and plots without irrigation in various agroclimatic zones of the European part of Russia: gray forest, typical black chernozems, chernozems ordinary of the Central Black Earth region, chernozems ordinary in the south of Russia and southern chernozems in complex with solonetzes, dark chestnut and brown semi-desert soils. Studies have revealed that each type of soil has its own peculiarities in soil-forming processes orientation with continuous long-term irrigation at rates that correspond to the biological needs of crops, which are largely determined by the drainage conditions of territories, soil-forming material, genetic features of soils, mineralization and quality of irrigation water. It has been found that for the types of soils studied, prolonged irrigation with water of any composition is characterized by processes of overcompaction and leaching. Most of unfavorable soil processes (about 60 %) are manifested in the absence of drainage of the territory (ordinary chernozem, irrigated with fresh water), especially when using sulphate-sodium composition for irrigation of low mineralized waters (chernozems of the Central Black Earth region, chernozems of the south of Russia, the southern chernozems, located together with solonetz). In these soils, long-term irrigation results in such negative processes as waterlogging, resalting, solonization, alkalization, dehumification, exhaustion.
Key words: soil types, prolonged irrigation, negative soil process, groundwater level, mineralization of irrigation water.
