Abstract <p>The arid lands of the Caspian Lowland are part of the global arid climate zone and reflect changes in natural processes, primarily in the soil cover. The total area of arid lands is more than 90% of the territory of the region and is affected by progressively increasing droughts, moisture deficit, and a decrease in precipitation and surface water (Kovda, 1977). In the context of changes occurring in desertification processes, there is a need to mobilize available types of water resources, including nontraditional water sources. The most important of these are the migration reserves of water obtained from atmospheric precipitation and accumulated in soil horizons during interseasonal transition periods. They have a migratory ability that depends on the changing seasons. The change of seasons is accompanied by a change in the amount of precipitation and the ratio of heat and moisture (Akaev, 1996). The accumulation of maximum moisture reserves coincides in time with the period characterized by the parameters of winter dormancy (anabiosis) conditions of plants. The stage of moisture accumulation in the root layer occurs under conditions of weakened evaporation, characteristic of the initial period of vegetation (<i>Agroklimaticheskii spravochnik…</i>, 1963).</p>