Ecological aspect of the development of soil-forming processes at the post-technogenic stage

The relevance of the study is caused by the problem of the global anthropogenic transformation of natural landscapes in Kuzbass as a result of the development of mining. The rate of reclamation of disturbed lands lags behind the rate and scale of their formation, and most of the territory is self-recovering. This paper is aimed at studying the ecological conditions of the natural environment and technogenic factors affecting the dynamics of soil-forming processes and the formation of phytocenoses in disturbed territories, which differ in the way of formation at the technogenic stage. For the first time, some physicochemical parameters of technozems were obtained. Like ebriozems, they are formed in the post-technogenic phase of the development of a technogenic landscape under the conditions of its self-growth. The similarities and differences in the properties of technozems and ebriozems formed in the same natural and climatic conditions of the southern forest-steppe zone of Kuzbass have been revealed. It was found that the rate of their transformation, expressed in the formation of the soil profile, depends on the conditions of the relief and underlying rocks created at the technogenic stage. The presence of a preserved layer of potentially fertile rocks and the absence of slope surfaces led to the formation of the frontal soil and vegetation cover of the technozem; under other conditions, the formation of soils and plant groups occurs fragmentarily, which leads to the asynchronous development of the functions and modes of the technogenic landscape.

The study of plants and embryozem soils on the technogenic dumps aimed to the improvement of the monitoring and remediation in industrial zones

In the soil cover of technogenic territories (Usolye-Sibirskoye, Irkutsk Region, Eastern Siberia, Russia) the initial, organo-accumulative, soddy, and humus-accumulative embryozems were identified. The period of soil formation was established: from 20 years (organo-accumulative) to 40 years (humus-accumulative embryozems). The relationship between regenerative successions of vegetation and stages of the soil-forming process was found. Each stage of post-technogenic soil formation (type of embryozem) corresponds to a certain type of plant communities possessing a clear discrepancy in the species composition. The first stage is represented by plant communities comprising few ruderal species on the initial embryozem. The more advanced stage is characterized by complex communities consisting of grasses, shrubs, and trees on the humus-accumulative soil. It has been shown that the humus content determines the degree of natural restoration of biocenotic functions in the post-technogenic ecosystem. Plants-concentrators that can be effectively used in phytoextraction of metals for decontamination of embryozems have been studied. Natural renewal of vegetation and the development of soil-forming processes serve as the best option for the rational use of nature management in comparison with the artificial restoration of natural landscapes in technogenic territories.

Soil Formation, Subaerial Sedimentation Processes and Ancient Cultures during MIS 2 and the Deglaciation Phase MIS 1 in the Baikal–Yenisei Siberia (Russia)

The time of Sartan glaciation in the Baikal–Yenisei Siberia, is comparable with that of MIS 2 and the deglaciation phase MIS 1. Loess loams, aeolian–colluvial sands and sandy loams represent subaerial sediments. There are four subhorizons (sr1, sr2, sr3 and sr4) in the Sartan horizon (sr). Sedimentary and soil-forming processes at different stratigraphic levels are considered. Differing soil formation types of cold periods are distinguished. Soils of the interstadial type with the A-C profile are represented only in the Early Sartan section of this paper. The soils of the pleniglacial type are discussed throughout the section. Their initial profile is O-C, TJ-C and W-C. Plant detritus remnants or poor thin humus horizons are preserved in places from the upper horizons. We propose for the first time for the interphasial soil formation type of cold stages to be distinguished. This is represented in the sections by the preserved BCm, BCg, Cm and Cg horizons of 15–20 cm thick. The upper horizons are absent in most sections. According to the surviving fragments, these were organogenous (O, TJ and T) and organomineral (AO and W) horizons. The sedimentation and soil formation features are considered from the perspective reconstruction of the Sartan natural and climatic conditions. Buried Sartan soils often contain cultural layers. Soil formation shows a well-defined periodicity of natural condition stabilization, which allowed ancient populations to adapt actively to various situations. Archaeologists’ interest in fossil soils is based on the ability of soils to “record” information about the natural and climatic conditions of human habitation.

Available for plants phosphorus in the floodplain catenas of the Amur River

This work was carried out to study the content and distribution of available for plants phosphorus in different types of floodplain soils along five catenas located in the upper and the middle Amur. It was found that the available for plants phosphorus forms in the soils of floodplains are influenced by the following factors: the structure of the river system, the type of floodplain, the type of vegetation cover, and soil-forming processes. During the long-term transportation of alluvium along the river bed, its hydrogenic weathering occurs with the release of phosphorus into river waters. In the absence of tributaries serving as additional sources of alluvium, the phosphorus content decreases downstream. More intense floodplain and alluvial processes in small floodplains provide renewal of the soil profile and replenishment of phosphorus reserves. In the soils under the birch forest, there is a significant accumulation of phosphorus, in comparison with the soils under meadow vegetation. The development of gley processes leads to active mobilization of phosphorus, but the long-term exposure leads to the depletion of its total reserves. The illimerization processes, initiated and developing when the floodplain hydrological regime of alluvial soils is changed to another one, promote the migration of iron oxides and phosphorus, adsorbed by the former, beyond the soil profile. To summarize, the average content of available for plants phosphorus, depending on the type of soil, decreases downstream from 300–100 mg/kg in the upper Amur to 170–20 mg/kg in the middle Amur. Available for plants of phosphorus are best provided in primitive alluvial layered soils, while in residual floodplain brunezems the lowest content is recorded.

Influence of prokaryotic microorganisms on initial soil formation along a glacier forefield on King George Island, maritime Antarctica

Compared to the 1970s, the edge of the Ecology Glacier on King George Island, maritime Antarctica, is positioned more than 500 m inwards, exposing a large area of new terrain to soil-forming processes and periglacial climate for more than 40 years. To gain information on the state of soil formation and its interplay with microbial activity, three hyperskeletic Cryosols (vegetation cover of 0–80%) deglaciated after 1979 in the foreland of the Ecology Glacier and a Cambic Cryosol (vegetation cover of 100%) distal to the lateral moraine deglaciated before 1956 were investigated by combining soil chemical and microbiological methods. In the upper part of all soils, a decrease in soil pH was observed, but only the Cambic Cryosol showed a clear direction of pedogenic and weathering processes, such as initial silicate weathering indicated by a decreasing Chemical Index of Alteration with depth. Differences in the development of these initial soils could be related to different microbial community compositions and vegetation coverage, despite the short distance among them. We observed—decreasing with depth—the highest bacterial abundances and microbial diversity at vegetated sites. Multiple clusters of abundant amplicon sequence variants were found depending on the site-specific characteristics as well as a distinct shift in the microbial community structure towards more similar communities at soil depths > 10 cm. In the foreland of the Ecology Glacier, the main soil-forming processes on a decadal timescale are acidification and accumulation of soil organic carbon and nitrogen, accompanied by changes in microbial abundances, microbial community compositions, and plant coverage, whereas quantifiable silicate weathering and the formation of pedogenic oxides occur on a centennial to a millennial timescale after deglaciation.

The Evolution of the Chernozems in the Central Part of Russia and their Complex Analysis in Modern Conditions

An increasing anthropogenic impact on soils leads to qualitative and quantitative changes in chernozems, the richest soils on Earth. In this regard, the understanding of modern soil-forming processes is undoubtedly relevant because it will allow predicting the future state of not only soils, but also nature as a whole. The methodology for studying the evolution of chernozems is based on a process-factor analysis of genetically conjugated and agrogenic series of chernozems of different taxonomic levels. The objects of the study were system complexes of soil series, including subtypes of virgin, arable, and irrigated chernozems in the central regions of Russia. The data obtained made it possible to identify patterns of variation in the composition and properties of virgin chernozems in a genetically conjugated series at a subtype level and in the series virgin land – arable land – irrigated arable land; we also detected the processes and factors that determine the nature and direction of changes in the composition and properties of chernozems in the studied series and determined the direction of anthropogenic evolution of chernozems. The main provisions of the work conceptually develop the theory of the chernozem-forming process and serve as a theoretical basis for the development of models for the formation of the chernozem profile. Established quantitative and qualitative indicators of humus profiles of chernozems are important diagnostic features in the classification of these soils. The nature and direction of the chernozem evolution disclosed in the work can serve as the basis for long-term forecasting of the state of these soils and the development of a set of measures for their rational use and protection.’’

Problems of agroecological assessment of soil fertility

The paper proves the need to clarify the agroecological assessment of soils, taking into account the migration of substances, the non-exchange fixation of biophilic elements by the soil, the relationship between the properties of soils, the intensity and speed of soil-forming processes, and the manifestation of the law of decreasing fertility. It is shown that on well-cultivated sod-podzolic soils of the Moscow region, the losses of elements with high water and ground water averaged 19.3 and 6.9 kg/ha of N-NO3, 0.7 and 1.2 N-NH4 in the crop rotation. Losses with surface-runoff waters were: nitrogen-2.2 kg / ha, potassium-7.0; calcium-11.0; magnesium-6.0; phosphorus-0.9 kg / ha per year. When the Ca/K ratio in the soil solution of this soil was 0.44±0.03 and 2.7±0.1, the content of water – soluble iron was 57.9±7.4 and 5.3±0.7 mg/l, respectively; manganese-2.3±0.4 and 1.1±0.2 mg/l. It is shown that plants consume biophilic elements from different soil horizons, which must be taken into account in the balance of biophilic elements. It is shown that the optimal soil properties differ depending on the hydrothermal conditions of the territory, the combination of soil properties. It is proved that in order to choose the optimal crops for growing on certain soils, it is necessary to take into account the alienation of energy with the crop. Keywords: SOIL FERTILITY, FERTILIZERS, BALANCE, ECONOMIC EFFICIENCY

Studying and mapping the soils of the southern part Sea of Okhotsk sector of the Kunashir island, Kuril islands

The paper deals with compilation of a large-scale soil map for the site of “Kurilsky” nature reserve, located in the southern part of Kunashir island, the Greater Kuril ridge. The islands make a remote and poorly studied area, and the soil is one of the least examined components of the local geosystems. The zonal soils here are cambisoil, but the variety of soil-forming processes characteristic of the island provides a comparative diversity of the cover. Modern volcanism affects the formation process significantly, although its role is sometimes overestimated. The study is based on field surveys performed in the considered area in 2014–2019, during which descriptions of soils were compiled according to standard methods. The map was compiled using a multispectral image of high spatial resolution from the Pleiades-1B satellite and topographic maps. Thus, the abundance of soils from different levels and divisions does not make a significant effect on the general heterogeneity of the territory soil cover due to the small area of intrazonal soils.