Intermountain depressions (depressions) are a characteristic feature of Zaaltai Gobi landscapes in Mongolia. There are three types of depressions, each of which is characterized by peculiarities of soil structure and specificity of soil salinity. The first type is low intermountain depressions - zones of accumulation of modern flood waters. Takyrs are formed at the bottom of depressions. The second type is the salt marshes, the formation of which is determined by the seepage of ground (ground) waters. The bottom is occupied by saline soils, sandy soils, takyrs and takyr-like soils. These are zones of modern salt accumulation. The third type is the highest absolute levels of dry depressions, filled mainly with ancient melpaleogene salt rocks, often washed away by the Saur channels. Ancient saline rocks (reddish flowers) form lithogenic solonchaks, the salinity of which is associated with the salinity of soil-forming rocks.

On the basis of experimental and literary data the assessment of humus state of arable layer of differently cultivated typical agrarian-grey heavy loamy non-eroidated soils of the center of the Non-Black Earth zone of Russia was carried out. The gradations of humus content corresponding to the different level of soil fertility were determined. The optimal interval of humus content is calculated on the basis of its minimal value in non-erodized agrarian soils of the region and optimal limits of transforming organic matter. It is shown that at development of grey soils under forest in arable horizon
The content of humus, fulvic acids, mobile humic acids, extracted 0.1 n. NaOH, decreases, and the amount of humic acids associated with Ca sharply increases with the increase of their optical density and ratio to mobile humic acids to the level in agronomic black soil. Further domestication of agrarian soils on the background of systematic application of increased doses of organic fertilizers, along with increasing the content of humus, there are reverse changes in the ratio of these fractions of humic acids. At the same time, the optical density of humic acids associated with clay minerals decreases significantly, which indicates the processes of their renewal and enrichment by aliphatic structures. Criteria of difference between agrarian soils and podzolic soils and agronomic chernozems by quality of humus in arable horizon are discussed.

Soils formed on eluvium of Triassic sediments and their derivatives are characterized by a sharp predominance of smectite group minerals with an admixture of palygorskite in the mud fraction and feldspars in dusty ones. The composition of minerals predetermines high soil fertility.

The distribution of clay minerals of the fraction less than 1 micron, extracted from typical, alkaline, podzolized agronomic black earths, depends on the type of soil, lithology of soil-forming rocks and relief. The silt fraction of agrochernozems developed on the quaternary loess-like heavy loam consists of smectite phase, represented by complex disordered mica-smectite formations, di-trioctahedral mica, kaolinite, chlorite. Agroblack soils formed on sediments in which include Neogene eluvium, contain a smectite phase represented by montmorillonite itself and badelyte with clinoptylolites in it. Erosion-resistant the material is represented by rounded aggregates, the structure of which was determined by micromorphological analysis. In the composition of micaceous micaceous fraction, extracted from this material, is dominated by micaceous mectritic formation. The conclusion is made about the demolition of the most valuable fertility of aggregated material - product of interaction smectite phase with organic matter.

Expert assessment of methods for determining soil content Phosphorus and potassium used in soil science and agrochemistry to assess changes in the phosphate and potassium state of soils under anthropogenic impact. The principle of selection of methods was based on the necessity of strict coordination of research task, object of study (soil diversity) with real possibilities for analysis methods.

With the help of X-ray radiometric method modified for diagnostics of superheavy metals Ba, La, Ce, their content in soils of Cherepovets geochemical anomaly is studied. Values Ultra-heavy metal technogeneities reach their maximum nearness of the Severstal mill. This is especially true for La and Ce, the share of whose technogenicity reaches up to 30-43%. This reflects the accumulative nature of the profile distribution of La and Ce, while in the background areas in humidal landscapes the distribution is eluvial.

The laws of zinc and copper absorption by agrarian and carbonate soils in the area of Cherepovets Steel Mill are described. Sorption isotherms demonstrate high affinity of PPK of the studied soils to zinc and copper. Approximation of experimentally obtained isotherms by three methods: Freindlich, Lengmyur, Dabinin-Radushkevich. It is shown that Langmur's model cannot to be applied to most isotherms. The Dibininin model -Raduskevich well approximates the obtained data and enables thermodynamic characteristics of the adsorption process. According to the obtained indicators, the most significant contribution to sorption processes is made by minerals of iron oxides and hydroxides. Coefficients of approximation of isotherms of adsorption by different equations are analyzed. It is recommended to use the Dibininin-Radushkevich equation when the equation Langemura is inapplicable.

In the Khibinsko-Lovozero district of the Kola Peninsula, the territory is divided into three geochemically different areas. In the background area near Umbozero, both mineral and peated samples contain all rare metals below clark: lanthanides and actinides are leaching heavily from acidic podzolic soils. В in the area of weak geochemical anomaly (near Lovozero), all lanthanides are inherited from the loparite-containing rock, and all actinides - Th: their content is 1.3-5.4 times higher than the clark value. In the zone of a strong geochemical anomaly (on the northern shore of Seidozero and on the
The concentration of lanthanides and actinides is even higher: 4-9 times higher than the clark value. There is an impact of a biological barrier that prevents excessive accumulation of of heavy metals in the mosses of a geochemical anomaly.