The analysis of long-term observations in the Kamennaya Steppe (over 125 years) for climatic parameters (air temperature and precipitation), ground water level, vegetation species composition revealed the main trends in their variability. Since 1969 there has been an increase in temperature and a reduction in temperature fluctuation during the year. Over the last 30 years, the difference has reached 1.90, and over the last decade it has grown by 0.40 due to the cold season. The amount of precipitation over the same 50-year period has not changed much. In total, an increase of 45 mm was observed over the decade (1999-2008). In the XXI century, there has been registered an increase in the amount of precipitation in the cold season by 12.7% and a decrease in the warm season, which creates certain prerequisites for climate continentality mitigation during the annual cycle. During the first 70 years of observations, the groundwater level in the well No. 1 was on average at the depth of 6.5 m (5.7-7.3 m). At the end of the XX century and at the beginning of the XXI century, there was marked a pronounced rise in the ground water level, the average depth was 3.8 m, which coincided with the growth of average annual temperature and an increase in total rainfall. In this period changes in the long-term regime of ground and surface soil moisture resultedin expanding the area of wetlands and hydromorphic soils on the territory of the steppe. The period of 2009-2018 is characterized by a continued increase in average annual temperatures and a decrease in precipitation, which may lead to a seasonal change in temperature and precipitation to milder and wetter winters and warmer and drier summers. Transformation of vegetation for 100 years of observations had several stages with a general trend to change the steppe grasslands to meadow-steppe, shrubs and woody species.

The study presents three groups of Soil Quality Indicators (SQI) of arable lands in the Russian Federation, such as agroclimate conditions, soil parameters and negative soil characteristics. The selection of SQI meets the requirements of the crop growth model for calculating the standard crop yield. The application of SQI in the Grain Equivalent Model allows ranking quality of the soils of agricultural lands in the country. The share of the best quality Chernozems with the standard yield of grain crops exceeding 4 t/ha is about 10%. At the same time, arable Chernozems occupy nearly 66% of total area of agricultural lands. More than 74% of the arable lands including podzolized and leached Chernozems in the northern part and Chernozems southern in the southern part of the agricultural zone are characterized by medium quality with the standard yield of grain crops 2-4 t/ha. About 10% of the arable land occupied by Chestnut solonetzic and saline soils are of poorer quality with the standard yield of grain crops less than 1 t/ha. The proposed indicators are included in the government programs for valuating and monitoring the quality of agricultural lands. The universal validity of indicators is a basis for the development of a new generation of standards for the protection and rational use of soils based on modern digital technologies and GIS approaches.

The goal is to assess the impact of 50-year irrigation by sprinkling on soil processes occurring in the light-chestnut soils (Luvic Kastanozem (Loamic, Aric, Protosodic, Bathysalic)) of the southern slopes of the Volga upland at the Volga-Don interfluve (FSUE “Oroshaemoe”, the Volgograd region) with deep ground water. Water for irrigation is supplied from the Varvarovsky reservoir of the Volga-Don Canal system. It is characterized by a total dissolved salts of about 1 g/l, a bicarbonate-chloride-sulfate compositionwith an increased sodium content. Detailed morphological description of soil profiles, granulometric composition, content of soluble salts in soils and sediments of the vadoze zone up to the depth of 3.5 m, dynamics of salts in the layer of 0-50 cm for 2011-2019 are presented. Until the autumn of 2015, the studied soils were deep saline, being no saline in the layer of 0-100 cm. In recent years, a weak salinity degree of soda-chloride sodium chemistry has been observed in the 0-50 cm layer as a result of gradual accumulation of irrigation water salts during irrigation organized according to water consumption of agricultural crops. Irrigated soils have acquired a complex of signs of secondary salinity: (1) the presence of light accumulations of sandy and silt mineral grains in the arable horizon, resulting from the destructive effect of irrigation water drops during sprinkling; (2) toxic alkalinity associated with sodium (residual sodium carbonate), according to water extraction 1 : 5 (soil : water), in the horizons from the depth of 10-20 to 60100 cm; (3) abundant humus-clay cutans on the lateral side faces of prismatic structural units in the undisturbed part of the soil profile from 30 to 100 cm.

The article presents a scientific literature review in the field of modern methods of monitoring wind erosion of soils such as: visual indicators of erosion, erosion bridge, close-range photogrammetry, cesium-137 and remote sensing cover. The brief description of each method, advantages and disadvantages, conditions and limitations of their applicability are given. When choosing the method, it is necessary to take into account the monitoring conditions, the area of the territory under consideration and the scale of research, time frames, financial and labor resources. It has been established that the most relevant, economically justified and promising, especially on large territories, are the remote sensing methods, which allow monitoring on different scales, and not only estimating the erosion activity, but also predicting it, thus providing the parties concerned with the necessary information for making right, prompt and timely economic decisions, aimed both at combating wind erosion and elimination of its consequences, and for organizing preventive measures as well. To improve the effectiveness of these methods it is also necessary to create databases, expand and accumulate soil information that can help verify, refine, process and calibrate the satellite data obtained. In order to understand aeolian processes and dust particle transport mechanisms one should create integrated methods that include remote sensing data, meteorological data, on the basis of which the improved models and maps would be developed, and erosion processes would be predicted. The scientific literature is mostly devoted to the interpretation of wind erosion in arid and semi-arid zones. The possibility of satellite monitoring of soil erosion in arable fields remains poorly studied. There are also practically no research results available on the transport of chemicals with micro-particles due to wind erosion. Both in Russia and abroad the attempts are made in soil erosion modelling, but the quality of the models is very limited by the lack of field data required for their calibration and verification. Eroded soils in the country are still identified using ground-based methods. However, field studies can only be conducted in a very limited area, in a few key points, and as a matter of fact it is quite complicated to conduct field studies on actively used agricultural lands.

Soil degradation resulting from water erosion poses a serious threat to food and environmental security, therefore the research of soil erosion features and soil erosion mapping do not lose their relevance. The paper presents the results of large-scale digital mapping of the erosion degree of the arable soils in the Prokhorovsky district of the Belgorod region (85 thousand hectares), based on two approaches: (1) linking the factors of erosion-accumulative processes and the erosion degree of soil directly (factor -property model), and (2) due to imitation erosion model WaTEM/SEDEM (factor - process - property model). The inclusion of the process component into the digital soil mapping algorithm allows taking into account not only the spatial but also the temporal soil erosion features. It was revealed that the agricultural development of the Prokhorovsky district was primarily carried out on lands that are weakly prone to erosion, with the rate of erosion almost two times lower than on younger arable lands. As a result, the soil erosion maps, based on the factor - process - property model, with and without taking into account the duration of agricultural use, largely correspond to each other. Dominant soil categories (the map pixel corresponds to one soil taxa - noneroded and slightly eroded, medium, highly eroded), mapping by factor -property and factor - process - property models, have a high degree of correspondence to each other (prediction identity for 90% of pixels), while the soil combinations (the map pixel has information on the proportion of soils with different erosion degrees of soil) more significant (identity for less than 60% of pixels). The areas of zonal, erosion-zonal, and weakly eroded soil combinations differ 1.5-2 times, in the direction of a greater degree of soil erosion on the factor - process - property map.

The purpose of this study was to investigate the applicability of semiautomatic segmentation methods for obtaining and evaluating morphometric parameters of soil aggregates in artificially prepared loose samples in soil thin sections. The object of the research is typical arable Chernozem. The aggregates were separated by wet sieving method from loose sample of upper 10 cm of the plowing horizon after erosion by a model shallow water flow on a large erosion tray. The aggregates, loosely scattered on the glass and fixed with polyester resin, were used to produce the thin sections. Images of the thin sections were taken under a polarizing microscope and then were processed using two methods compared: Adobe Photoshop + CTan and Thixomet Pro. Data on morphometric parameters of aggregates were obtained: the shape factor, the degree of roundness and the coefficient of aggregate surface roughness. The convergence of the results obtained using Photoshop + CTan by three researchers was evaluated by comparing samples using the Student's test and the Mann-Whitney test. The convergence of the averaged results obtained using Photoshop + CTan and the results obtained using Thixomet Pro was evaluated using the Mann - Whitney test. No significant differences were found between the parameters of the same aggregates obtained using a combination of Adobe Photoshop and CTan programs by different researchers. No significant differences were found between the parameters of the same aggregates obtained by the compared methods. So, one can conclude that the reliability of determining the morphometric parameters of soil aggregates using Thixomet Pro is comparable to the reliability of results when working with images of sectionsin CTan after binarization in Adobe Photoshop. The method of obtaining data on morphometric parameters of soil aggregates using Thixomet Pro completely eliminates the possibility of subjective error, shows a high degree of automation, reproducibility and reliability of the results obtained, and is faster.

A digital version of the soil map of the Russian Federation, scale 1 : 2.5 M, is being prepared based on the analysis of the attributes of polygons with peat soils in the West-Siberian taiga and sub-taiga zones. The correction was perfomed in 795 polygons (with the total area of 179 483 km²) out of 1 711 polygons considered (with the total area of 262 204 km²). The currently formulated idea of the dominance of oligotrophic bogs in the West Siberian taiga region of mires served as the basis for suggestion to replace the mesotrophic peat soils by oligotrophic ones in 598 polygons of the total area of 87 250 km². Similarly, the polygons of microcatenas comprising oligotrophic and mesotrophic peat soils (57 polygons, total area of 38 405 km²) were modified: only oligotrophic peat soils were considered to be the dominant ones there. At the same time, a number of polygons with prevailing oligotrophic soils, confined mainly to the sub-taiga zone were proposed to be replaced by polygons with mesotrophic peat soils. The thermokarst pools in ridge-hollow mire complexes that were shown on the soil map of Russia beyond the permafrost zone were eliminated from the map database; the mapping of destructive peat soils was rearranged in accordance with the new interpretation of this taxon in the Russian soil classification. This work should improve the quality of research in the field of assessing the resource potential of peat soils in West Siberia.

According to the World Health Organization, more than 80% of urban residents are at risk due to unsatisfactory air quality and air pollution, which causes approximately 4.2 million deaths per year. The purpose of the work is to give an overview of scientific articles related to the dustiness of the city’s natural environments. The articles of foreign and Russian researchers were analyzed - the definition of urban road dust was given; the primary technogenic and natural sources of dust particle generation in the city, thephysical and chemical properties of road dust, their dependence on climate, the type of roads and city architecture, the effect of photolysis on physicalchemical characteristics of dust particles are reviewed as well. Particular attention is paid to the negative impact of dust particles PM2.5 and PM10 on human health and the environment. The question of the absence in Russian scientific practice an officially recognized methodology for the settled dust sampling with updating the regulatory documentation on the methodology for the sampling of fine particles suspended in the air is considered. Recommendations are given on the creation of the regulatory framework governing the sampling and analysis of road dust, which is confirmed by the numerous conclusions of both foreign and some domestic researchers as an environmental geo-indicator.