Soils of floodplains in arid regions of Inner Asia (the Zavkhan River, Mongolia)

The environmental conditions of soil formation and the diversity and classification position of soils developing on the Zavkhan River floodplain are considered, and the morphogenetic and agrochemical properties of these soils are characterized. It is shown that the conditions of soil formation on the floodplain of the Zavkhan River are specified by the mountainous topography, the effect of the large Mongol Els sand massif, the character of the alluviation processes, the groundwater level and salinity, and the regime of floods. The position of the floodplain in the system of altitudinal zones largely dictates the character of the soil cover pattern. In terms of the new Russian soil classification system, the soils studied belong to three trunks, four orders, and seven types: stratified humus alluvial soils, light-humus alluvial soils, light-humus quasigley alluvial soils, light-humus stratozems, and solonchaks. The soils of floodplain ecosystems in arid regions are characterized by low fertility. For their efficient use for pasturing and crop growing, the ecologically balanced differentiated application of manure, mineral fertilizers (NPK), and some microelements is required.