The paper presents theoretical basis of the methods for determining the content of soil organic carbon (SOC) both by direct dry combustion using automated analyzers and indirectly – by I.V. Tyurin and Walkley–Black oxidation. Author's and literature experimental data of SOC analyses in various soils by these methods are presented. Comparative analysis of the above data showed that in some cases the content of SOC determined by oxidability is lower than the one obtained by dry combustion (in most cases), while in others, on the contrary, the content of SOC is higher. This conclusion fully complies with the theoretical views of I.V. Tyurin on the chemical nature of soil organic matter (SOM). A schematic description of determining the content of total (organic) carbon in non-carbonate soils by dry combustion method using automated analyzers Leco (USA) and AH-7529 (Gomel, Belarus) is given. It was pointed out that it is difficult to determine SOC content by dry combustion method with automated analyzers in carbonate soils. For these soils it is recommended to determine the content of inorganic carbon by decomposition of carbonates with HClO₄ solution using express analyzer AN-7529. The direct method of determining the content of SOC has the best metrological characteristics compared to ones of the indirect method, which convincingly confirms the authoritative opinions of Schollenberg and Tyurin about the inaccuracy of the latter. It is concluded that the indicators determined by the methods of Tyurin and Walkley–Black and dry combustion are chemically independent, characterizing, respectively, the oxidability and organic carbon content of SOM. It is recommended to use dry combustion method with automated analyzers when monitoring the content and stocks of organic carbon in soils. 

At the end of the 20^th century, a geoinformation database on soil degradation in Russia, relied on the soil map of Russia at a scale of 1 : 5 million, was developed under the leadership of V.S. Stolbovoy. As part of the development of this problem and in the course of obtaining new information on soil degradation, an attempt was made to refine and supplement this database, that relies on the soil map of the Russian Federation 1 : 2.5 million scale. Soil degradation resulted from the impact of various types of pollution was taken into account, including industrial emissions, leakage of oil products, excessive application of pesticides, the impact of vehicles and radiation pollution. Each soil polygon of the soil map exposed to the pollution was characterized by the degree and area of pollution in accordance with the developed scales. The results of the analysis were used to construct cartograms illustrating the spatial distribution of chemical and radiation degradation of the country soils. According to the data obtained, in the zone of pollution derived from industrial enterprises and oil pollution, 20% of the soil-geographic polygons of the map are characterized by a strong degree of pollution, and 30% and 50% – by weak and medium, respectively. Agricultural pollution due to excessive use of plant protection products in Russia does not exceed 10% of the area of polygons and is characterized by a low degree. About 10% of the soil polygons of the basic soil map are heavily contaminated with radioactive contamination, while 40% and 50% of the polygons are moderately and weakly contaminated, respectively. Pollution from vehicles is weak and generally has low level. At the same time, megacities and highways with heavy traffic are distinguished by relatively high level of pollution.

Soils of archaeological sites are highly interesting objects for multidisciplinary research in various fields of soil science, ecology, archaeology, anthropology and other sciences. Currently, the soils of archaeological sites in the Arctic regions have not been studied sufficiently, although many ancient monuments beyond the polar circle have been found. This work is devoted to the study of morphological and chemical properties of soils of the archaeological site “Settlement Labytnangi 1”, which is located beyond the northern polar circle, near the cities of Labytnangi and Salekhard (Yamal-Nenets Autonomous Okrug). Development of these territories (according to archaeological research) began in the Eneolithic (Late IV – III millennia BC) and continues to the present day. Soil types on the territory of the monument are represented by soil-like bodies (urbikvazizems), podzols, turbozems, urbo-agrozems and peat soils with inclusions of archaeological and anthropogenic artifacts dating back to the XX century. Most of the studied soils were previously subjected to the processes of cryoturbation, although at present the lower boundary of the active layer of permafrost lies at a depth of 120–130 cm, according to the conducted electrophysical sounding. Significant changes occurred in the acid-base properties of the studied soils. In addition, anthropogenic activity entailed the introduction of biophilic elements and organic matter into the soil profile, in particular phosphorus, which is concentrated in the urbanized soil horizons (phosphorus concentrations above 2 800 mg/kg were recorded). The concentrations of heavy metals in the soils are at/below the conventional background (vicinity of Salekhard and Labytnangi). However, some excess concentrations of copper (up to 87.5 mg/kg), zinc (up to 303.3 mg/kg), lead (up to 76.1 mg/kg), and cadmium (up to 2.1 mg/kg) in the urbanized soil horizons have been detected. According to the results of the work, we can conclude that the soils of the archaeological site were formed under the strong influence of modern and past anthropogenic activity, which determined their morphological structure and chemical characteristics at present.

The article presents the developed soil maps and maps of spatial variability of soil properties (pH, total salt and carbonate content, organic carbon, density) in some recreational areas of Volgograd. The anthropogenic soils in the studied recreational areas include various urbostratozems (Urbic Technosols (Transportic)), Ekranic Technosols (Transportic), as well as quasizems (Phaeozems (Tehnic)), among the agrogenic ones – accumulation-carbonate agrozems (Cambisols (Aric, Protocalcic). Natural soils are represented by light and dark humus soils, chestnut soils, solonetz, as well as stratozems and psammozems. According to the data of isolinear mapping, it was found that acid-alkaline properties of soils of green zones vary from slightly alkaline to alkaline depending on the soil horizon and anthropogenic load. The mapping did not reveal salinization of the upper 0–30 cm layer. Values of organic carbon vary greatly (1–10%) and are conditioned by the presence or absence of meliorative artificial layers, as well as by the character of territory use. The content of calcium carbonates in the upper 30 cm is small and varies from 0.7 to 5%. It is established that the physical properties (density) directly depend on the level of anthropogenic load, increasing in footpaths and lawns. Spatial assessment of the properties of urban soils is important for identifying areas with an excess or on the contrary – low content of certain chemical and physical indicators for the planning of landscaping and gardening of urban areas.

Konstantin Dmitrievich Glinka made a major contribution to the development of such areas of soil science as genesis, geography, cartography and mineralogy of soils. He made the first world soil maps (1908, 1915, 1927), the first soil map of the Asian part of Russia (1927, jointly with L.I. Prasolov), classic studies of weathering processes and transformation of primary minerals into secondary, first studies of buried and relic soils, which laid the foundation for paleosoil science. Fundamental, encyclopedic textbook, written by K.D. Glinka “Soil science” went through six editions (1908–1936) and became a basic guide for many generations of soil scientists. The ideas of K.D. Glinka in the genesis of different types of soils, including gray forest soils, podzols, red earths, burozems (brown soils) have not lost their scientific value until the present day. His outstanding scientific, organizational and pedagogical contribution to the development of genetic soil science has earned K.D. Glinka a well-deserved fame as a scientist of world class.