Double-shot pyrolysis with gas chromatography and mass detection (Double-shot GC MS) was conducted for a sample of typical chernozem and humic acids separated from it. The humic acids preparations were pyrolyzed at 500, 600 and 700°C. The data were compared with the lignin pyrograms witch were obtained under similar conditions. It was shown that 500°C is the optimum temperature for pyrolysis of humic acids obtained from Chernozems. Toluene in pyrolysis products may be considered as a marker of excessively high temperature occurring during the experiment. The results of a Doubleshot pyrolysis for the soil itself and the humic acids which were extracted from it were compared. Eight products of the soil pyrolysis coincided with substances determined in humic acids (with a total of 41). In the case of thermal desorption of the soil, there were only three such substances, and they also were detected during subsequent pyrolysis of the soil sample. The data obtained speak about the predominantly macromolecular composition of humic substances. The conducted works demonstrate the posibility and perspective for using the Doubleshot pyrolysis GC MS for in situ investigation of soil organic matter, humus matter in general and humic acids in particular.

The current state of irrigated soils’ salinity at the key plot located along the buried irrigation channel within the irrigated plot Chervlenoye of the Svetloyar Irrigation System (Volgograd Region) was studied. In the 1990-s a strong sec-ondary soil salinization was detected during the aerial survey. Its boundaries were clearly observed on the image. After the irrigation had been ceased, a par-tial soluble salts leaching from the soil took place at the key plot as a result of precipitation and decrease of the groundwater table. Basing on the field data obtained in 2017 a model of two-dimensional distribution (depth, distance from the irrigation channel) of the ion activity (Ca2+, Cl–, Na+) was created. It was found that sulfate-chloride-sodium type of salinization prevails which is typical for natural soils at the studied territory. However, the traces of secondary sali-nization expressed by the presence of calcium chloride in soil solution are pre-served in a number of soil horizons. According to the depth of the upper saline horizon, the soils belong to solonchakous type, the distribution of salts is medi-ocre-accumulative, maximum of salts is located at a depth of 100–150 cm.

The paper presents the results of the of the country's plowed area assessment on the basis of the Unified State Register of Soil Resources of Russia, a digital land cover map created on the basis of MODIS satellite data, and study of plowed land areas according to the data of the Internet service Google Earth. Information on the plowing of soils is tied to the soil-geographical units. The map shows the actually plowed soils and soils under the layland. Independent verification of the plowland soil digital map of Russia showed its high enough accuracy (an error of about 8–9%). The share of all plowed soils of the Unified State Register of Soil Resources in Russia has been determined. It is found that chernozem soils predominate on the arable land of Russia, from the northernmost subtypes to the most southern ones. Somewhat unexpected is the presence in this list of meadow chernozem solonetzic and solonchak soils. The map is intended for applied analysis and accounting of soil resources at the national level.

Ecophysiological features of the transit (passed through the intestinal lacune) bacterial hydrolytic complex Aporrectodea caliginosa were studied: a comparison of biodiversity was made in the soil and coprolites, the prevailing ecological strategy and physiological states among its members. The study was conducted by a complex structural and functional method based on the succession kinetic analysis of initiated hydrolytic bacterial communities that occur after the inoculation of a set of selective liquid nutrient media with a suspension of the test samples. In addition to hydrolytic microorganisms, non-hydrolytic bacterial satellites (oligotrophs and copyotropes) are included in initiated communities. The growth of initiated bacterial communities on eight media with biopolymers (chitin, cellulose, pectin, starch, xylan, dextran 500, tween 20, casein) was measured by optical density. It was described by two kinetic parameters used to describe the pure cultures of microorganisms: the maximum specific growth rate and the initial physiological state. The biodiversity of the initiated communities was de-termined according to the planting from liquid nutrient media with polymers on the agar medium. Rank distributions of the studied indicators were abnormal, therefore, median and nonparametric dispersion analyzes were used, as well as a direct analysis of rank distributions. The bacterial community from coprolites acquires greater sustainability - the species composition becomes more leveled (the Berger-Parker index, showing the degree of dominance of the most abundant species, decreases after the passage) and diverse (the Shannon index becomes higher after passage). The hydrolytic bacterial complex is activated at passage, as the median value of the initial physiological state of the initiated communities increases. In the bacterial block, the proportion of fast-growing bacteria of r-strategists increases (on liquid media with polymers, the share of initiated hydrolytic associations increases with large values of the maximum specific growth rate).

A comparative analysis of microspecificities of agrogenic soils of solonetzic com-plexes of inclined plain was conducted to create trends of elementary soil-forming processes under different types of anthropogenic changes (for plowing and irrigation). The task is solved with the help of Olympus BХ51 polarization microscope equipped with Olympus DP26 digital camera and Stream Basic software, which allows us to visualize the results of modern and/or relict process better. The investiga-tion objects are the soils of kastanozem-solonetz complexes of the Stavropol inclined plains of the bogharic and irrigated area. Common microspecificities for all studied soils are numerous carbon particles, humus-ferruginous micronodules and ring-shaped orientation of fine-silt and fine-sandy silicate particles. The first two microspecificities allow us to propose there a weak manifestation of the quasi-gley process that probably was inherited from the pre-agrogenic development of the investigated soils. The ring-shaped orientation of large fractions speak about the cryogenic textural reconstructions of loess-like loam. The impact of irrigation is more clearly manifested in the micro-structure of the arable horizons of irrigated soils: platy organization of surface layers; increased content of fine-dispersed brown humus; increased activity of soil micro- and mesobiota (well-aggregated lumpy-granular microstructure) in the lower parts of the arable horizon. In the subsoil horizon of the residual solonetsic kastanozem under ir-rigation, a decrease in the amount of clay coatings occurred, which was manifested as a decrease in the intensity of the solonetzic process. There also occurred some decrease in the total content of clayey particles, which was a consequence of the process of their eluviation acceleration. There was also observed the reduction of birefringent effect of finely dispersed material, which was a consequence of the process of clay plasma deferrization occurrence. There was also observed the increase in the number of pe-dotubules, bioaggregates, coprolites, biochannels, which were the consequence of the increased biogenic processing. In the subsoil of meadow-chestnut soils under the impact of irrigation, a change in the structure from angular-block to lumpy-grained is revealed. Which was a result of increasing biogenicity. New formations appear within the calcareous horizons due to irrigation. For example, in the upper parts, clayey coatings occurring along the pore walls are the result of eluvial-illuvial redistribution of silt due to migration from the upper horizons. In the lower parts, there is significant recrystallization of carbonate rock grains, destruction of the white soft spot and the formation of micrital hypocoatings in the near-pore space of the pedal mass.

The investigations were conducted on the gray forest heavy clay loamy soils, formed on the loess-like loams, which are widely spread on the territory of Vladimir Opolye. The eluvial-illuvial profile differentiation, its different intensity and the specificity of illuvial coatings (fine dispersed clayey and humus-clayey coatings with sparse skeletal content of soil) is confirmed. The presence of the coarse wooden plant residues, thick humus-clayey illuvial coatings within the illuvial horizons speak about the forest origin of the grey forest soils in Vladimir Opolye. The micromorphology of humus horizon reflects the direction of the soil forming process and the ecological status of soils. The illimerization is the main process of the matter migration and soil profile differentiation. The mixed-layer formations prevail in the clayey fraction. Mica, quartz, and K-feldspars are the prevailing compounds of the fine and medium silt within the gray forest soils. In the silt fraction of the second humus horizon prevail quartz and feld-spar. The most of the nutrients is concentrated in the clayey and fine-silt frac-tion. The micromorphological investigations confirmed the theory, which speaks about the presence of forest (the presence of illuvial coatings) as well as steppe soils (mull humus type in the SHH, the presence of primary and newly formed carbonates) specificities in the modern soil forming process within the gray forest soil of Vladimir Opolye.

The necessity of the doctrine for the soil as a plants habitat environment revival, which appeared in the early stages of the agriculture development, is substanti-ated. The conditions which ensure sustainable growth and high productivity of various crops were determined. First of all, we studied the specificities which determine the ability of soil to provide plants with nutrients and moisture, largely due to the composition and structure (topography) of the soil-forming rocks, their texture (due to the different mineral composition of different size particles) and therefore largely determines soil fertility. The main credo of this scientific approach is the study of soil properties in relation to plant life (P. A. Kostychev). V.V. Dokuchaev determined soils as a special natural body, which requires corresponding approach to their study, regardless of the vegetation, which cover the soil surface. Emerging on these principles, a new direction of soil science, which later obtained the name of genetic, concentrating on the study of the soil itself, moved away from the demands of agricultural produc-tion, entering into the category of academic sciences. The principles and achievements of the ecological school of forest typology, which studies soils from the position of the unity of both directions, are characterized on the basis of N.М. Sibirtsev suggestions which were described in his classification of 1895. This allowed researchers to bring into a strict system the whole diversity of forests from different natural zones, and made it possible to predict their composition and productivity. At the same time, the number and ratio of three limiting ecological resources: heat, moisture, and food — which determine the composition and productivity of vegetation and the productivity of soils — prevail in the classification. This made it possible to characterize the main regulations of the relationship between living and inorganic nature, which V.V. Dokuchaev called the essence, the core of natural science. The soil science otains the opportunity to enter on the position of the basic theoretical base of agriculture. These principles exist in the community of US soil scientists for a long time. Developing global classification constructions (approximations), American soil scientists distinguish the main taxa (soil series) at the local agricultural level by primary rocks, taking into account their availability of food, moisture, and sometimes heat.