The purpose of the study is to reveal the mechanisms of interaction of some acid ameliorants in the process of chemical reclamation of Sodic Solonetzes-Solonchaks (SSS). The experiments have been carried out within 2018-2020 under laboratory conditions using soil column techniques.13 soil samples have been collected from Ararat valley, Republic of Armenia. These soils have a high alkaline reaction (pH 9.5-10.5), a sodium exchangeable percentage (ESP 44.5-74.0%) and electrical conductivity (EC 12.4-42.2 dS cm-1).It has been shown, that in thecase of iron sulphate application the products of its hydrolysis promote soil dealkalization and improvement of soil physical properties due to creation of iron-clay complexes accumulated in the soil primarily in crystalline form (66-67 %). It has been revealed, that the penetration depth of 1% of sulphuric acid and iron sulphate solutions during the chemical reclamation is 8-12 cm, and the accumulation of gypsum in topsoil (0-12 cm) is observed. Due to thehigher solubility of magnesium sulphate in the process of acidification, soil dealkalization and the increase of filtration rate of soil solutions (10-12 cm day -1 ) are watched. During the soil leaching process, the newly-formed gypsum plays a major role in further dealkalization process of soils and regulation of exchangeable Ca and Mg relation in optimal range. It is shown, that in the process of acidification, the pressure of the formed carbon dioxide gas (CDG) in the soil may reach up to 2.2 atm, in which the solubility of calcium and magnesium carbonate are increased, and the share of CDG in soil dealkalization process is in average 50%. The results obtained allow for the opportunity to recommend improvements of SSS chemical reclamation technology.

The dynamics of water intake for different purposes from the Ararat artesian basin has been studied in connection with the overuse of water by fish farms in Ararat Valley. It has been shown that as a result of those negative processes the surface area of groundwater with positive pressure has decreased by 3 times, 31 communities are partially or completely deprived of water obtained from fountain boreholes for various purposes. As a consequence of the decline in groundwater level irrigation norms of agricultural crops have increased by 25% or about 14 million m3, the physical properties of soils have deteriorated on the area of 7 thousand hectares. It has been proposed to reuse discharge waters from fish-farms for irrigation. Through technical and economic calculations, it has been shown that in case of solar station-pump station-irrigation pipeline construction the cost price of irrigation water per 1 m3 is 8-10 times cheaper than in case of reservoir construction and irrigation water supply systems.

The aim of the study is to provide integrated solution of environmental problems by help of conservation emissions of sulphurous gases in form of sulphur or treated cement dust and their application for improvement of Alkaline Soils. New ameliorants for improvements of Alkaline soils under laboratory conditions were obtained: electro-treated mixture of sulphurous and sulphuric acids, treated cement dust containing sulphite and sulphate salts of Ca. Two electrochemical methods for production of sulphuric acid and mixture of sulphuric and hydrochloric acids from sulphurous acid were developed and the electric energy requirement for their production is calculated. The process of retention of sulphurous gases, by water solution of cement dust is studied. It is shown, that for conservation of 1 t of sulphurous gases 2 t of cement dust is required. The influence of newly-received ameliorants on physical and chemical properties of Alkaline soils during their chemical reclamation and leaching processes was studied. The most ameliorative effect, obtained in the variant, where electrochemical treated solution of the mixture of sulphurous and sulphuric acids were used.

In the perennial plantations it is possible to apply spray irrigation method instead of drip irrigation, in case of which the drippers are replaced with the holes made on the pipes, wherefrom the water is supplied through the spraying jet. Upon the hydraulic calculations water flow pressure in water supply pipes, supplied water yields and diameter of the opened holes have been estimated by means of which the balanced water supply is ensured. Introduction of the recommended spray method will enable to significantly reduce the operational costs of irrigation systems.

The chemical composition of waters of the Arzni-Shamiram and Lower Hrazdan canals fed by the Hrazdan River, as well as Hrazdan River water in that area, was studied, and their suitability for irrigation was assessed. Water samples were collected from 7 sampling points and the total amount of salts, electrical conductivity (EC), pH, bicarbonates as well as some toxic microelements (Al, As, Be, Cd, Co, Cr, Cu, Fe, Li, Mn, Mo, Zn, Ni, Pb, Se, V) were determined. It has been shown that waters of the Arzni-Shamiram canal are suitable for irrigation. The water pollution processes in the Lower Hrazdan Canal is observed. Despite the fact that the concentrations of some heavy metals and hydrocarbonates don't exceed the MPC for irrigation, depending on amount and composition of wastewater discharging this system, there is a high probability that their concentrations in the canal exceeds the permissible limit in the near future.