The identification of factor and indicational features, which are characterized by the high informativity and field of view in relation to the soil cover organization, plays a very important role in the soil mapping. Such characteristics are more common for Unmanned Aerial Vehicles (UAV), which include spectrazonal imagery and digital elevation model (DEM) with ultrahigh spatial resolution, necessary for obtaining fine and large scale images. However, the agrogenic micro- and nanotopography is considered as a noise during the studies of the soil cover topographic differentiation under the conditions of plowland, as the genetic soil properties correlate with natural micro- and mesotopography. A filtration algorithm for the land surface roughness, which is not related to the spatial organization of the objective soil properties, is suggested in the paper. The stages of linear dimension identification for self-similar structures of the glacial and agrogenic topography based on two-dimensional Fourier decomposition are demonstrated using the example of a field topography digital model for the area of 125 hectares. Filtering in the frequency domain allowed restoring the natural field topography and substantiating the effective resolution of the DEM and the size of the area to calculate local morphometric specificities of the topography for digital soil mapping.

A multi-sided study of the interactions between forest and soil requires choosing sample plots in such a way when their soil characteristics are as similar as possible but the types of biocoenoses are different. This study employed materials from the database “Soils of Karelia”, which has pooled together long-term data on soils of the Republic of Karelia. The aim of the analysis was to identify the soil traits that are the most sensitive to the type of biocoenosis. The biocoenoses chosen for the analysis were automorphic pine, spruce and birch communities, collectively accounting for 99 % of forest stands in Karelia, growing on podzolic-type Al-Fe-humus soils with sandy texture over sandy or loamy-sand till, which represent the most widespread type of soils in the study area. The analysis was performed for the following soil horizons: forest floor (O), eluvial (E) and illuvial (B). In order to characterize the soil horizons the physico-chemical parameters were used: рН (KCl), total С and N content, labile P₂0₅ and K20 compounds content, and gross content of SiO₂, TiO₂, Al₂O₃, Fe₂O₃, MnO, MgO, CaO, Na₂O, K₂O, P₂O₅. Discriminant analysis was employed to determine the traits contributing the most to the differentiation of biocoenosis types. The contribution of the traits to differentiation between groups was measured by Wilks’ lambda. Overall, the analysis has shown that N and C content the most significantly reflect the changes happening under the effect of the forest, both in the organic and in the mineral parts of the soil, as corroborated by the findings of numerous Russian and foreign researchers.

The analysis of the Landsat 5 satellite data helped to study the processes of soil changes which took place from 1991 to 2011 inclusively at the test site located in the south-west of the Belgorod Region. As a result, it was found that despite intensive agricultural land use the proportion of soils, the properties of which have changed over the past 20 years, within the total area studied is quite small. The changes of soil erosion status were recorded within the territory of no more than 1 % of the total area; the territories characterized by soil humus losses on subhorizontal surfaces cover no more than 2 % of considered area. The most intensive process among the others is humus accumulation in the soil, the increase in humus content is noted on 5.6 % of the analyzed area. The identified tendencies in soil changes may be due to both the specifics of agricultural land use and climate changes.

Diatomites of the Paleocene-Eocene age are widespread in the Trans-Urals and act as soil-forming rocks in river valleys. At the same time the direction and nature of the processes of soil formation on such deposits are practically not studied. The paper presents the results of studying soil formation on diatomites for the territory of the Middle Trans-Ural region within the Sverdlovsk region. The main methods used for studying the soil formation process on diatomites were the soil-morphological and micromorphological ones. The studied soils, formed under pine forests on the indigenous banks of the river, can be classified as sod-podzolic (Albic Luvisols). They are characterized by the presence of-the strong bleached eluvial strata, with a characteristic structure and visually diagnosed traces of dissolution of the original rock. When studying in thin sections and using a scanning electron microscope, it is found that the processes of soil formation occur synchronously with the dissolution and destruction of silicon microfossils. The preliminary results obtained indicate that soils on diatomites and other rocks enriched with biogenic silica are unique natural objects, and their study can be useful for understanding the role of the lithogenic base in the formation of the silicon cycle and the contribution of biogenic silicon to soil formation.

The article presents data on how bentonite clay (applied at reclamation rates) affects acid-alkaline characteristics and fertility indicators of soil (sod-podsolic sandy loamy soil - retisols). The experiment was conducted in the Nizhny Novgorod region. Physical and chemical properties of the used bentonite clay were preliminary studied. It is characterized by alkaline reaction of aqueous solution (pH 10.9) and of salt extract as well (pH 9.8) and undergoes electrolytic dissociation. The micro-plot field experiment which lasted over 3 years revealed some positive effect of bentonite application. As a result, the lowering of exchangeable soil acidity (by 0.31. pHKci units) and hydrolytic soil acidity (by 0.20 mg-eqv./100 g) was recorded, substantial reduction of aluminium soluble forms content (up to 48 %) was noticed as well, meanwhile the content of exchangeable Ca²⁺ and Mg²⁺ increased by 0.70 and 0.24 mg-eqv./100 g correspondingly. Bentonite application contributed to humus preservation in the soil and humus content was maintained at 1.221.28 % level. Moreover, this practice helped to increase the content of soluble (available) phosphorus and potassium compounds (on average by 27-30 % depending on experiment trial). The studied bentonite clay was proved to have stabilizing effect on acid-alkaline and nutrition balances in the soil. Some interaction between mineral soil part and bentonite clay is supposed to take place which results in the reconstruction of chemically-active fine particles (so-called active mineral centers) in soil adsorption complex.

The polygenetic nature and polymorphism of the soils of kastanozems-solonetz complexes determine the difficulty of their field diagnostics and further genetic interpretations. In the current study, micromorphological features are used as additional diagnostic characteristics, specifying genetic interpretations for the soils of the kastanozems (chesynut)-solonetz complex (chestnut solonetz, chestnut solonetzic soil, chestnut soil, chestnut-like meadow soil) used in agriculture (dryland farming) within the Apanasenkovsky District of Stavropol region. An attempt has been made to correlate the results of micromorphological research, which was performed to evaluate the role of micromorphologycal investigation in clarification of macromorphological description, with data obtained through physical and chemical analyses. First, this study reveals that the Kastanozem (Chestnut) soil have the best correlation between macromorphological description and data of micromorphological investigation. In meadow-chestnut, solonetzic-type and solonetz soils micromorphological investigation helps to realize a set of pedofeatures such as complex multilayered coatings with layers of different genesis, Red-Ox features, etc. Finally, micromorphological investigation allows better interpretation and understanding of physico-chemical data.

This study performs a methodical experiment on adaptation and unification of soil dry sieving analysis. The analysis is based on the Savvinov dry sieving method that uses 0.5-1.5 kg air-dried soil samples which are passed through the 10, 7, 5, 3, 2, 1, 0.5, 0.25 mm sieves. The studied soils are silt loam Eutric Retisol and Haplic Chernozem. From each object, 50 kg of fresh soil was sampled from the plow layer (lm² area). Air-dried soil subsamples of 500 ± 0.5 g were used for analysis, clods bigger than 50 mm were gently crushed by pestle with rubber tip. The sieving parameters were the following: 50 Hz vibration frequency - 3000 rpm (depend on current), from 0.5 to 2.5 mm vibration amplitude and from 0.5 to 5 minutes sieving time. Sieve shaker mechanical work (J) was calculated for each mode. The data approximation was carried out by means of the asymptotic regression function. An optimal dry sieving mode was defined for each soil: Eutric Retisol - 1 mm vibration amplitude during 1 minute, Haplic Chernozem - 2.5 mm vibration amplitude during 2 minutes. In the case of sandy soils dry sieving doesn't require much effort. Therefore, in this experiment only fine macrostructure soils were selected (11-16 % < 2 um clay by laser diffraction method). As a result, the unified dry sieving mode of vibratory sieve shakers was developed which is applicable for all studied soils: 2.5 mm vibration amplitude during 2 minutes and 50 Hz frequency when 500 g air-dried soil sample is used.

The world-class geologist and petrographer - Frants Yul’evich Levinson-Lessing (1861-1939) was one of the followers and apprentices of V.V. Dokuchaev, the founder of the Soil Science. In 1882-1892 he took part in Dokuchaev’s expeditions. Thereafter, Levinson -Lessing carried out research in the field of petrography; he assumed various administrative positions and constantly lent support to his teacher’s life-work. He was the chairman of the Soil Commission of the Russian Free Economic Society (1905-1912), one of the founders of Dokuchaev Soil Committee and its council member (1912-1916), headed Soil Science Department and Soil Science Institute of the Commission on Natural Production Forces affiliated with Academy of Sciences of the USSR (1917-1925), V.V. Dokuchaev Soil Science Institute (1926-1929). In 1927 in cooperation with V.I. Vernadskiy and K.D. Glinka he gained recognition of the Soil Science as a fundamental science in Academy of Sciences of the USSR, which resulted in establishment of special Soil Science Institute of Academy of Sciences of the USSR.