Interrelation of climatic factors of soil formation with the formation of chemical and physical-chemical properties of soil cover in agricultural landscapes of the Central Chernozem Region of Russia

Aim. To assess the interrelations of chemical and physical-chemical parameters of soil cover properties with climatic factors of soil formation in agricultural landscapes of the Central Chernozem Region (CCR) of Russia.Materials and Methods. The research was carried out using a systemic analysis of the complex of agroclimatic and soil parameters. Soil properties were assessed by the weighted average characteristics of arable soils for the areas of the Central Chernozem Region. Hydrothermal conditions were taken into account by rainfall, temperature and the amount of active temperatures for the period 1960-2000.Results. Estimated excess of annual precipitation (440-640 mm) over evaporation (407-500 mm) in the average annual cycle ensures the formation of total runoff and soil washability in the amount of 40-150 and 17-104 mm. This determines soil acidity (pHKCL, R2 = 0.36...0.73). Optimal conditions of humus accumulation are formed when the humidity factor is 0.8-0.9. Mesorelief is a factor of spatial heterogeneity of the total soil composition with which 85% of physical-chemical properties and up to 70% of nutrient availability are associated.Conclusion. The differences in the hydration of the territories both at the scale of the CCR and local levels determine the intensity of geochemical runoff, the oxidation-reduction regime and total chemical soil composition which constitute the basis of heterogeneity in the content of organic matter, acidic-base and other properties.

SOIL CLASSIFICATION HAS YET TO BE CREATED

The thesis is put forward that all the classifications of soils existing in the world do not possess the attributes of such a concept accepted in science and its technical applications but are only lists of author's names of soils. The names are substantiated mainly by factors of soil formation (natural zoning, vegetation, series, etc.), on weakly reasoned genetic horizons and small unformalized aggregates of soil properties. At the Soil Institute Named After V.V. Dokuchaev of the Russian Academy of Science, a mathematical apparatus for the development and use of digital soil classifications was created.

Landscape-dynamic aspects of soil formation in the Lena River Delta

This article provides data on the study of pedodiversity and pecularities of soils and their spatial distribution in the territory of the Lena River Delta (Siberia, Russia). Special reference to geogenic factors of soil formation in the pedoenvironment are made. The main patterns of soil distribution in different geomorphic positions for Samoilovsky, Arga-Belir-Aryta, Kurungnakh and Hardang islands are discussed. The soil catenas of the 4 investigated islands are given as a reliable representation of the formation of soils and the development of soil-forming processes in various types of relief and geomorphological features. Soils are represented mainly by the following groups: Fluvisols, Umbrisols, Podzols, Cryosols, Histosols, Gleysols, which are closely related to the geomorphic terraces of the delta.

Mapping and spatial distribution of the natural and transformed soils of Osa river basin (Irkutsk region)

The soil cover of Osa river basin is described in the article, its variety caused by features of a geological structure, relief, climate, vegetation and anthropogenous impact is revealed. Set of factors of soil formation which gives prerequisites for forming of special types of the soils which aren’t fitting into traditional representations of zone types of a taiga and forest zone – chernozems, dark-humic and other soils under steppe vegetation is studied. In total three trunks, nine departments, 27 types and 46 subtypes of soils are allocated. It is established that the main area (more than 7 0 %) is provided by the soils entering into departments of the accumulative and humic, organo-accumulative and textural differentiated soils, agrozyom, and the insignificant territories are busy with full-height types of soils of structural and metamorphic department, litozyom, abrazyom, alluvial. 37,3 % of the general territory of a research occupy agricultural holdings, from them about 12,8 % are used now, 87,2 % are in abandon condition. The map «Soils of Osa River Basin» is provided in the article.

Physical properties of soils as a component of the characteristics of forest-growing conditions in the steppe zone of Ukraine

Steppe zone of Ukraine is characterized by a significant predominance of artificial forest plantations over natural forests, which is associated with the peculiarities of the steppe environment. Since forests in the steppe play a number of important ecological functions, in particular, protect the soil from erosion, it becomes necessary to conserve and create new forest plantations. To solve this problem successfully, a practical and theoretical scientific justification is needed, which was developed by A. L. Belgard, creating a typology of artificial steppe zone forests. One of the main components of the developed typology is the type of forest-growing conditions, characterized by presence of a floodplain, fertility and humidification against a specific geographical area. A. L. Belgard (1971) noted that there is a significant difference between the floodplain and non-floodplain habitats. Floodplain habitats, even in the case of short floods, differ from the outland by the presence of alluvial deposits, relatively shallow groundwater occurrence, abrupt changes in seasonal moistening, and significant development of salinization processes. Also, scientists emphasize the need to distinguish soil formations depending on their mechanical or granulometric composition, which predetermines the specific physical properties of soils and the chemical processes that occur in them. A. L. Belgard (1971) divided all the soils of the steppe zone according to the granulometric composition into three groups: sandy, sandy loamy and loamy. This division is based on the binary classification of soils according to the granulometric composition developed by N. A. Kachinskiy (1958), which provides for the separation of classes according to the content of physical clay and physical sand. In the future, it may be necessary to more detailed this graduation, given the fact that the world is widely used three-member classification, developed in the USA. In this classification, soil groups are distinguished by the ratio of sand, dust and clay (Medvedev, Laktionova, 2011). Considering the fertility of soils as a gradation of forest-steppe conditions of the steppe zone, A. L. Belgard (1971) primarily pays attention to the presence or absence of salinization processes. At the same time, the scientist notes that the granulometric composition of the soil of one or another type of forest growing conditions, taking into account salinity, gives an idea primarily of the chemical fertility of the habitat. At the same time, it must be taken into account that the complex of physical properties of soils is also important, and in some cases crucial for the normal existence and reproduction of forest biogeocenosis in steppe conditions. Humidification in the steppe zone of Ukraine is an important limiting factor that determines the possibility of growing forest stands. As it was emphasized by A. L. Belgard (1971), even minor changes in hydration lead to significant changes in the forest-growing effect. The scientist noted that within the steppe zone growths can be represented by the following gradations: very dry, dry, dryish, fresh, damp, moist and wet. L. P. Traveleyev (1976) detailed the moisture gradation and proposed quantitative indicators – local moisture coefficients. The scientist noted that in its origin and the formation of moistening of soils, it could be atmospheric, soil, atmospheric-soil and transit, each of which has its own characteristics. As it is known, soils are formed as a result of interaction of five factors of soil formation-climate, plant and animal organisms, rocks, relief and time (Dokuchaev, 1952). It is the result of the interaction of all factors of soil formation and their changes in time that are the patterns of spatial distribution of soils (Dobrovolsky, Urusevskaia, 2004). Moreover, each soil zone or subzone is characterized by a specific set of soil formation factors, due to which the soils of a certain territory acquire their own special properties. Very often, when determining the complex of soil properties with a certain probability, one can say in which soil zone or subzone they were formed. Physical properties are no exception to this statement. The most informative physical properties of soils from the point of view of the characteristics of the forest-growing conditions in the steppe zone of Ukraine are the granulometric composition, structural state, the density of addition, the density of the solid phase, wilting moisture, water capacity, water permeability, and electrical conductivity.