Saline Soils and Alkali Soils of the Fergana Valley and Ways to Improve Them

Abstract

Today, about 66% of irrigated lands of Uzbekistan are saline, and almost all areas of Khorezm, Bukhara, Syrdarya, Navoi, Jizzakh, Fergana and the Republic of Karakalpakstan are considered such lands. As a result of salinization, the country loses 18-25% of its annual crop yield. The location of geochemical compounds in carbonate-gypsum saline soils of the Fergana Valley in space and time, as well as in the profile of soil grounds and their formation conditions differ from such alternative and similar regions of the Republic (Mirzachul, Jizzakh desert, Zarafshan and Vakhsh valleys). According to the origin, morphological structure, halochemical composition, water and physical properties and specificity of meliorative properties of gypsum, nutrient soils common in the territory of the Fergana Valley, it is separated into an individual province of carbonate-gypsum geochemical soils. The historical integrity and continuity of salt formation processes in the valley area have been identified. The accumulation of salts and geochemical compounds is considered as the result of a complex of ancient and modern complicated processes that have been formed over many centuries of geological periods.