Brown Desert-Steppe Soils

(or brown semidesert soils), low-humus (1.5-2.5 percent), carbonaceous soils, formed under desert-steppe (mostly wormwood) vegetation in the conditions of a temperate cold dry climate. The cross section of such soils is broken into layers: the surface is weakly colored by humus; deeper it is friable and lumpy, then cloddy, lumpy, and saline. As the depth of the cross section increases, the carbonate content rises. Brown desert-steppe soils are further divided into weak-solonets, solonets, and solonchak. These soils form an independent soil zone 150-300 km wide that stretches from the northern Caspian Sea area to the Chinese border and, outside the USSR, to the Gobi Desert (inclusive). In the USSR these soils occupy about 46 million ha. Without irrigation they are usually used as pastures, but with irrigation they yield quite satisfactory harvests of many crops. The protection of brown desert-steppe soils against wind erosion is particularly important.