The effect of land use on the formation of the metabolome of typical Chernozem is studied. Typical Chernozems (Haplic Chernozems) of four land uses—55-year-old permanent bare fallow, the plot untilled for 21 years after permanent bare fallow, and 4-year field experiments with zero tillage and traditional tillage—from the long-term field experiments at the Kursk Federal Agricultural Research Center (Cheremushki, Kursk oblast, Russia) are analyzed. To study the soil metabolome, the water extracts of both fumigated and nonfumigated soil samples are assayed for the contents of dissolved organic (DOC) and microbial biomass (Cmic) carbon species using high-temperature catalytic oxidation; the soil metabolites are analyzed using gas chromatography–mass spectrometry. The effect of postagrogenic Chernozem transformation on the accumulation of labile soil carbon species is demonstrated by the case study of the plot untilled for 21 years. Plowing of Chernozems in the absence of plant litter decreases the content of labile carbon. A positive effect of no-till practice on the content of labile carbon species is observable at the level of a trend. According to metabolomic analysis, 21 compounds involved in the metabolism of carbohydrates, lipids, and nitrogenous substances are identified in Chernozems. The Shannon diversity index shows that tillage has a negative effect on the complexity of metabolic profiles in Chernozems. Untilled Chernozems and those under permanent fallow conditions display the most contrasting metabolic compositions with the prevalence of metabolites having plant and microbial origin, respectively. The metabolites of a plant origin tend to accumulate in the chernozem under no-till conditions. The components of the carbohydrate metabolism are prevalent in the metabolomic profile of arable chernozemic soils and the components of nitrogen and lipid metabolism predominate in the untilled soils.

The results of research on the example of southern chernozem and chestnut soil are presented. Long-term use of plowing with rotation of the soil layer and the use of fallows leads to a critical state of the soil in terms of the content of aggregates measuring >10 mm and >1 mm. The introduction of notill on old arable soils leads to a general increase in the mean weighted diameter of aggregates (MWD). The intensity of restoration of the structural state of the soil during no-till in southern chernozem occurs more intensively than in chestnut soil, and the main changes are recorded in the fractions of agronomically valuable aggregates. In southern chernozem there is an increase in diameter from 6.0 mm to 9.5 mm, while in chestnut soil the MWD increases only to 7 mm. The content of erosion-susceptible aggregates <1 mm and their change depending on the intensity of agricultural cultivation in southern chernozem and chestnut soil indicates a tendency to restore the structure in the no-till variant. In southern chernozem, the content of particles of 1–0.5 mm size decreased by 1.2%, and in chestnut soil – by 6.2%. Refusal of mechanical tillage showed that, in contrast to dry aggregates, the influence of no-till on the water stability of the structure of the arable horizon is more significant and is presented in the form of fractions rearrangement. The use of no-till technology results in a reduction in the content of erosion-susceptible aggregates and increases the water stability of the structure of the arable horizon, which, together with the influence of crop residues on the soil surface, provides an anti-erosion effect. The restoration of the structural state of the soil during notill in southern chernozem proceeds more intensively than in chestnut soil. The main changes in the form of rearrangement occur in fractions of agronomically valuable aggregates.

The methodological possibilities of micromorphological soil research making it possible to analyze digital images of soil thin sections at a quantitative level are presented in this study. A new software Thixomet Pro has been tested for quantitative micromorphological study of sail on the example of soil thin sections from the surface horizons of Haplic Chernozem. Soil samples for preparing thin sections were collected on the territory of scientific and industrial field test plot for assessing the impact of agro technologies in grain crop rotation on soil properties (Kursk region, Russia). In the field test plot, conventional agro technology (real tillage) and no-till are compared. Soil sampling was carried out in two replications from depth of 10–15 cm. The analysis revealed the variability of microstructure of Haplic Chernozem in the size, shape and orientation of aggregates associated with the use of agricultural technologies with and without plowing in grain crop rotation. In the Сhernozem with no–till, aggregates are generally larger compared to the aggregates of Сhernozem with conventional agro technology. This is noted at all levels of comparison of direct seeding and conventional agricultural technology: in the minimum diameter, the fraction 1–2 mm prevails against 0.25–0.5 mm, respectively, in the average diameter, fractions 1–2, 2–3 and 3–5 mm prevail against 0.5–1 and 0.25–0.5 mm, respectively, in the maximum diameter, fractions 1–2, 2–3 and 3–5 mm prevail against 0.5–1, 0.25–0.5 and 1–2 mm, respectively. It is also shown that less rounded and isometric aggregates are formed during direct seeding. With direct seeding, the proportion of aggregates with a form factor of 0.2–0.4 is higher and the proportion of aggregates with a form factor of 0.4–0.6 is lower than with traditional technology. The proportion of subhorizontal aggregates in direct seeding is higher compared to traditional processing (54.3 and 34.1% respectively).

In recent years, research has been conducted in scientific institutions of the Ministry of Agriculture of the Russian Federation and the Russian Academy of Sciences on introducing new technologies for the use of aerospace information in agriculture. This article, using the example of Stavropol krai, considers the possibility of using cloud services such as Google Earth Engine (GEE) and Kaggle machine learning systems for mapping agricultural fields using deep learning methods based on remote sensing data. Median images of the Sentinel 2 space system for the 2022 growing season are used as data for the selection of training and validation samples. The total volume of the prepared training samples is 3998 images. One problem for researchers and manufacturers in the field of agriculture is a lack of centralized and verified sources of geospatial data. Deep learning methods are able to solve this problem by automating the task of digitizing the geometries of agricultural fields based on remote sensing data. One of the limitations in the widespread use of deep learning is its high demand for computing resources, which are not always available to a researcher or manufacturer in the field of agriculture. This paper describes the process of preparing the necessary data for working with a neural network, including correcting and obtaining satellite images using GEE, their standardization for training a neural network in Kaggle, and further use locally. A neural network of the U-net architecture is used as part of the study. The final classification quality is 97%. The threshold of division into classes according to the classification results is established empirically and amounts to 0.62. The proposed approach makes it possible to significantly reduce the requirements for the local use of PC computing power. All the most resource-intensive processes related to the processing of satellite images are performed in the GEE system, and the learning process is transferred to the resources of the Kaggle system. The proposed combination of cloud services and deep learning methods can contribute to a wider spread of the use of modern technologies in agricultural production and scientific research.

The results of the field experiment have been analyzed, it was set up on two experimental fields (with an area of 2.4 hectares each), where two different agricultural techniques – traditional and no-till – were applied. Diagnostics of morphometric parameters of typical chernozems such as: the thickness of the A1 horizon, A1 + AB horizons and the depth of carbonates reaction with 10% HCl, has shown that some changes in soils and soil cover had occurred in the fields over 8 years. The integral indicator of soil productivity is the thickness of the humus horizon, it demonstrated trends to decrease and increase in the soil cover structure of the experimental fields with different compositions of chernozem subtypes. The trends result from both climate change and periodic dry periods, which are not typical of the region, and from the change of traditional technology to no-till. The carbonates leaching from chernozem profiles in all variants of the experiment decreased, which correlates well with climatic indicators, changing with the seasons of the year. Chernozems with thin humus layaer and reacting with HCl close to the surface do not require liming. The revealed changes are not statistically significant, they reflect the resistance of chernozems to the variability of natural and anthropogenic factors of soil formation. Crop residues on the soil surface under no-tillage reduce physical evaporation, which contributes to moisture accumulation in the soil. The use of cover crops in winter also increases the moisture reserves, which are consumed by the plants during the summer growing season. Information on the transformation of morphometric parameters allows making temporal and spatial corrections in the applied agricultural practices (crop rotation, fertilization, the use of cover crops, herbicides and pesticides).

The key feature of the no-till technology is the preservation of crop residues on the soil surface. Crop residues quantitative assessment is an important task when introducing technology into production. On the basis of field and remote sensing data, different approaches to this assessment are considered. The research was carried out in the Budennovsky district of the Stavropol Territory in the fields of farms using both traditional technology (TT) and no-till (ПП). Images of the Sentinel-2 system were used as remote sensing data, on the basis of which the spectral indices NDTI and NDVI were calculated. Three methods were used to estimate the projective cover by plant residues: 1) weight accounting of plant residues per unit area; 2) field determination of the projective cover by the method of line transects; 3) desk analysis of photographs of the soil surface. Based on the obtained results, models of the linear dependence of NDTI values on the projective cover of the soil surface with plant residues were constructed. The possibility of quantitative accounting of plant residues only on the basis of remote sensing data was also analyzed. The highest coefficient of determination (R2 = 0.97) with the smallest square root of the standard error (RMSE = 7.93) was obtained by modeling based on the analysis of photographs of the soil surface covered with plant residues. Based on the model of the dependence of NDTI values on the projective cover of plant residues obtained as a result of the analysis of photographs based on Sentinel -2 satellite data for the growing season 2020–2021, data were obtained on the dynamics of soil coverage with plant residues (CRC) on the scale of a single field an d different tillage technologies. As an approbation of the approach and an assessment of its use for solving production problems, the dynamics of the projective cover with plant residues was analyzed under different crops and different relief conditions. An analysis of the dynamics of CRC values made it possible to distinguish between different stages of crop cultivation under traditional technology (TT) and no-till (ПП), and also on the scale of an individual field revealed the heterogeneity of the projective soil cover with plant residues associated with the features of the mesorelief.

No-till technology has proven itself in world agriculture as an antierosion system that preserves and restores soil fertility by slowing down degradation processes, dehumification in particular. The variability of humus content with time (after rotation) and in space (soil cover of experimental fields, each with an area of 2.4 ha) by the example of a field experiment for minimizing tillage and the use of no-till on typical chernozems in a four-field grain crop rotation has been analyzed. The humus content increased during the rotation in all four variants of the experiment (plowing with a layer turnover, combined processing (chiselling + disking), minimal processing (disking), and no-till), which was related to favorable natural conditions. The differences were at the trend level between the variants of plowing and no-till but were statistically significant between no-till on the one hand and combined and minimal tillage on the other hand. In the space of fields with different soil cover pattern, the increase in the humus content was the largest in the field with a high (23

Reducing the amount of precipitation in summer in the Chernozems area alters soil organic matter (SOM). To compensate for the lack of moisture, farmers are introducing new agricultural technologies such as no-till cultivation. In turn, no-till practices influence the composition of SOM. We examined the impacts of the rise of aridity and no-till technology on the chemical composition of bioavailable and recalcitrant pools of OM. The properties of SOM were assessed using double-shot pyrolysis with gas chromatography/mass spectrometry (GC/MS). The thermolabile substances that are volatilised in the first stage of pyrolysis (300°C) are considered the bioavailable pool. Accordingly, substances are obtained in the second pyrolysis stage (500°C) were attributed to the recalcitrant pool. Identified in both steps of pyrolysis, products were assigned to different chemical groups (lignin-derivative, polysaccharide-fragments, indoles, etc.) and relative abundances were calculated. In work for the separation of substances, a polar column was used for chromatography of the thermolabile fraction. With an increase in aridity in Сhernozems, the content in the bioavailable pool of polysaccharide fragments decreased and the proportion of indoles increased. In the recalcitrant pool, the abundance of six-membered rings with nitrogen and aromatic compounds decreases at the same time the contents of unsubstituted and O-substituted acyclic compounds as well as pyridine increases. The influence of the NT was more noticeable in the recalcitrant OM. The NT practice promotes biological activity and to rich in nitrogen compounds the bioavailable OM; this process contributes to the accumulation of carbon in the recalcitrant OM.

The specific features in accumulation and distribution of organic carbon and nitrogen in the aggregates of typical, ordinary, and southern chernozems (Protocalcic Chernozems, Endocalcic Chernozems, and Pantocalcic Chernozems, respectively) during the transition from conventional farming to a no-till system are evaluated. For this purpose, the contents of organic carbon and nitrogen were determined in different aggregate size fractions (>10, 10–2, 2–1, 1–0.25, and <0.25 mm). All three chernozem subtypes differ in the content of organic carbon in a statistically significant manner. The carbon content in all no-till chernozems is higher as compared with the control (conventionally tilled chernozems). The no-till and conventional variants display no statistically significant differences in the nitrogen content. However, the nitrogen content statistically significantly depends on the aggregate size in no-till variants in contrast to conventional farming. In Protocalcic Chernozems, the higher nitrogen content is observed in all agronomically valuable aggregate size fractions (10–0.25 mm); in Endocalcic Chernozems, in the fractions of 2–0.25 mm; and in Pantocalcic Chernozems, in the fractions of <0.25 mm and 2–1 mm. In addition, characteristic of no-till Endocalcic Chernozem is the dependence of carbon content on the aggregate size. The use of no-till system significantly changes the transformation patterns of soil organic matter and biological activity in chernozems.

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.

Intensification of agriculture leads to development and implementation of new soil conservation technologies that reduce degradation processes, as well as the development of methods for monitoring and controlling these technologies. Spectral indexes method as one of the methods of remote sensing is one of the most modern methods for solving this problem. This research was conducted on three production fields located in the territory of the Budenovsky district of the Stavropol territory, where plowing with the layer turnover and no-till technology were used. Aim of this research is analysis of the possibility of using 8 spectral indices to identify different types of soil cultivation. The study found that the most informative differences between tillage systems are provided by NDTI, STI and NDI7, which use the SWIR 2 spectral range for calculations. In addition, the classification of objects based on these indexes by the K-means method gives the highest accuracy.

This article presents the results of research on the impact of no-till technology on the natural bulk density and macro- and microaggregate composition of the topsoil (0–20 cm) in different subtypes of chernozems before sowing and during the growing season. Haplic Chernozems (Loamic, Aric, Pachic) and Haplic Chernozems (Loamic, Aric) were studied. For all chernozems, improvement of physical properties was recorded when no-till was introduced in comparison with the control. Four and six years of crop growing without tillage did not cause any compaction of Haplic Chernozems (typical and ordinary subtypes). On the plots with direct sowing, the microaggregate composition of typical chernozems was characterized by a higher proportion of coarse fractions (>50 µm) in comparison with the control. Probably, this indicates the development of microaggregation similar to that under natural cenoses, which are characterized by a relatively high content of the fraction 50–250 µm, upon the transition to no-till. In all subtypes of chernozems under no-till, the water stability of aggregates increased. The share of agronomically valuable aggregates in typical chernozem also increased, which may be associated with an increase in the input of water-soluble organic matter into the soil during no-till, because this technology excludes translocation of plant residues into the soil. In southern chernozems, this effect was manifested only for fractions >7 mm, while water stability of finer aggregates was mainly due to the calcium content regardless of the type of tillage.

The application of direct seeding technology on typical and ordinary chernozems in the European territory for four years has resulted in a significant increase in the content of soil organic matter in regions with sufficient moisture supply and some tendency of its in regions with insufficient moisture supply (Stavropol region). A tendency for an increase in the available phosphorus and exchangeable potassium contents has also been observed. The yield of crops and profitability of production in the course of long-term (> 7 yr) application of direct seeding are approximately 30% higher than in the case of traditional technologies. Application rates of glyphosate-containing herbicides to control weeds can be significantly reduced in the case of using cover crops, modern biochemical methods, and strict compliance with the technology of herbicide application. Taken together, these measures ensure an increase in the number and species diversity of microorganisms that can suppress pathogenic microflora significantly reducing the damage to plants from diseases and pests.

A comparative assessment of the morphological properties of typical and ordinary chernozems using traditional technology of field crops cultivation with soil treatment and no-till revealed trends in morphological properties changing over time and space. After using no-till on typical chernozems of the Kursk region for 4 years, there was a tendency to increase in humus horizons A and A + AB thickness and in the level of carbonate detection line (10% HCl reaction), which uprose closer to the soil surface. In ordinary chernozems of Stavropol after 7 years of using no-till, this trend is typical only of A + AB horizon. When plowing chernozems, there is a trend to deeper carbonate accumulation level. The gradual accumulation and decomposition of crop residues on the soil surface, which play an important role in wind erosion protection, and less intensive evaporation over time leads to an increase in the thickness of humus horizons and the content of organic matter. The results obtained are indicative of the initialization of morphological properties transformation in chernozems when no-till is used. The decrease in the thickness of the humus horizon on arable lands in Stavropol region results from deflation caused by both numerous soil treatments and a specific wind regime, and direct sowing has demonstrated positive results in the fight against wind erosion processes. When no-till technology is used, chernozems acquire natural features typical of them – variability of properties, i. e. the initial heterogeneity of soil cover, which determines the sustainability of soils in natural ecosystem.