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 paper presents the results of a study of the soil cover of the Shcherbakovsky Nature Park in the Kamyshinsky district of the Volgograd region. To achieve the results 12 soil sections were laid along the studied soil catena (1.5 km), so that morphological and chemical features of the soils of the study area were investigated. Variety and diversity are due to vertical zonality and geological and hydrological peculiarities. So, in the gullies and in massive forest plantations various dark humus and gley soils have become widespread. On steppe, slope and watershed areas lithosolic light humus luvisols and light humus lithozems were formed. On areas with open sand surface, humus psammozems with protohumus horizons W, as well as light humus (AJ-C) and humus soils (A-C), and a variety of soil-forming rocks of the natural park were found. In relief depressions they are represented mainly by gleyed sandy, as well as proluvial-deluvial deposits with inclusions of large fragments of opokas. On steppe and steep-slope areas, the soil-forming rocks are thick layers of opoka deposits. Their upper boundary varies from 20 to 60 cm depth depending on the meso- and microrelief. On the watersheds, the soilforming rocks are represented by sandy, ferruginous deposits with new formations of clay and pseudofibres. The parent rock is registered starting from 100 cm depth and consists of large blocks of hardened sandstone. The chemical properties of the studied soils are characterized by a neutral or slightly acidic pH. Easily soluble salts are leached from all soil horizons. The maximum values of Сorg are typical of humus and transitional horizons. The studies conducted in the Shcherbakovsky Nature Park are of greatest importance for monitoring the state of soils, and also allowed us to identify the features of the genesis of underdeveloped soils and luvisols of the dry-steppe natural zone.

Data on total non-silicate iron (Fe_d) content in mineral-associated organic matter (MAOM) of agro-chernozems of different localization on the slope are presented. The distribution of total non-silicate iron in soil profile follows that of organic carbon (OC): the maximum values are confined to the surface horizons, and decrease down the profile. It has been revealed that the change in the content of non-silicate iron in the MAOM of the clay fraction in arable horizons of eroded agro-chernozems is a result of erosion processes, including their intensity, which also depends, among other things, on the slope steepness. A lower slope steepness (4°) contributes to an increase in the organic carbon loading on iron oxides, resulting in an increased in iron desorption capacity, while a higher slope steepness (6°) results in lower iron desorption capacity. The OC/Fe_d molar ratio is suggested as an additional indicator of the degree of soil erosion. In clay fractions, of both their position in the soil profile and their position on the slope, the predominant mechanism of organic matter stabilization was the formation of organic-iron complexes (OC/Fe_d > 10). In the Residue fraction of humus horizons, non-silicate iron seems to be presented mainly as iron carbonates (FeCO₃), while the proportion of microaggregates (stable under the sonication), where OM is mainly humin, is relatively low against the background of the absolute dominance of primary minerals in this fraction (weight %). Most of the non-silicate iron of mineralassociated OM extracted by dithionite-citrate-hydrocarbonate is localized in the clay fraction – 2/3 or more.

Elementary soil particles are the first soil-specific level in the soil structure hierarchy, which is also the object of the soil texture analysis. To disperse soil solids to elementary soil particles (ESP), it is necessary to break the strong bonds between particles by physical action. An effective way of physical dispersion is to treat soil suspensions with ultrasound. However, depending on the type of soil, the required energy level varies, as it is determined by the stability of the soil structure. In this work the experiment with increasing energy (from 65 to 1 101 J·mL^-1) of ultrasonic dispersion at constant power equal to 32.4 W is described. Soil samples from the upper horizons of three types of loamy soils (Retisol, Phaeozem, Chernozem) were used in the experiment. For this purpose, a horn-type ultrasonic disruptor Digital Sonifier S-250D (Branson Ultrasonics, USA) with a stepped solid horn tip (13 mm) was used. It was found that the value of the total energy of dispersion E_t required for complete destruction of soil aggregates to ESP depends on soil type and varies within 200–800 J·mL^-1 for loamy soils with an organic matter content of 1.8–4.6 g. 100 g^-1 soil. For sample preparation of soils for grain-size analysis with a subsequent determination of soil texture class according to Kachinsky classification, the value E_t = 250 J·mL^-1 is sufficient, as it allows obtaining the maximum amount of physical clay (<10 µm) at the minimum duration of sample preparation.

The dynamics of the physical properties and reserves of humus in saline soils of an arid semi-desert zone is presented. The basis for the research was observational data for 2010-2022. in a typical hilly landscape of the Astrakhan region. A grid of 100 × 100 m was laid. Soil studies were carried out at the grid nodes along the sampling layers. We studied the change in physical properties (soil moisture; salt content according to the amount of dense residue; soil density; filtration coefficient; soil porosity; moisture reserve), humus reserves and salt state of saline soils under desertification. Comparative analysis showed that negative changes have taken place in the study area and it can be stated that the processes of soil degradation and desertification are intensively developing. It has been established that in the soil layer of 0–40 cm there was a significant reduction in soil moisture reserves against the background of an increase in maximum air and soil surface temperatures, as well as changes in the hydrological regime because of the embankment of the territory. Dehumification processes are observed. The most clearly negative trend was revealed for meadow solonchaks. The change in the hydrological regime of the territory because of embankment contributes to an increase in the areas of automorphic soils in the landscape and a reduction in the areas of meadow soils. An increase in the degree of salinity and compaction was recorded for automorphic zonal soils. The physical destruction of the Baer's hills exacerbates the processes of degradation and the development of desertification in such conditions.

Satellite data have been used for a long time to assess various properties of arable soils. At the same time, there are certain difficulties associated with the fact that a number of agronomically important soil properties do not directly affect spectral reflectance of their surface, which complicates the remote assessment of such properties. In addition, to obtain reproducible models, it is necessary to take into account the state of the open soil surface during the survey. The aim of the study was to demonstrate a method for detecting agronomically important properties of arable soils based on Landsat 8-9 OLI satellite data and including information about the state of their open surface using the example of a test field in the Serebryano-Prudsky district of the Moscow region. Depending on the soil property, R²cv of the models developed based on Landsat 8-9 OLI satellite data varied from 0.57 to 0.91. The best models with R²cv>0.8 were obtained for organic matter and properties higly correlated with it such as the content of exchangeable calcium and magnesium cations, the content of total nitrogen, pH of water and salt extracts. The involvement of information on the state of the open surface of arable soils for most properties made it possible to obtain models of higher quality and predictive ability, regardless of the survey period. Based on the models obtained, maps of the spatial variation of agronomically important properties of arable soils were constructed as part of the demonstration of the method. The resulting models can be used for remote monitoring of the analyzed properties of arable soils of the test field. At the same time, for such properties as the content of exchangeable potassium and phosphorus compounds, it is necessary to search for the approaches that will take into account their high variability, as well as to perform a prior assessment of the informativity of the survey periods in which the open soil surface is not transformed.

Chicken manure and composts derived from it are valuable organic fertilizers that have a positive impact on soil fertility and significantly enhance crop yields. However, the application of fresh manure can lead to excessive concentrations of nitrogen and other nutrients in the soil, as well as contamination of the soil with microorganisms that are pathogenic to humans and animals. Therefore, it is recommended to compost chicken manure prior to its use in agriculture. This review examines the composition and properties of chicken manure, the techniques involved in its composting, and its influence on the physical, chemical, and biological properties of the soil. The utilization of composted manure results in increased levels of organic carbon (on average by 1–1.5%), nitrogen (by 0.1–0.2%), and other biophilic elements. Moreover, it improves various physical properties of the soil, such as porosity, aeration, and density. Levels of pH increase (by 0.2–0.4), as well as electrical conductivity (by 2–2.5 times), and the quantity of water-resistant aggregates (by 5–10%). The application of these fertilizers also promotes biological activity, microbial diversity, microbial biomass carbon (by 25–75%), and soil enzymatic activity (phosphatase and catalase increase by 5–7 times, and urease by 3–5 times). When chicken manure is incorporated into the soil, a significant (2–4 times) increase in the population of bacteria from the phyla Firmicutes, Bacteroidetes, and Actinobacteria is observed. The necessity of investigating the effects of compost derived from chicken manure on the chemical composition and storage of soil organic matter, pore space, and the ecotrophic structure of the soil microbiome is also discussed.

It is known that one and the same corn plant material can be used to produce silage, cornage, milled grain, or grain for fodder. Each of them contains completely different amounts of nutrients and a wide range of gross yield of fodder units. The results of the research show the direct dependence of the choice of corn use on zonal features of the soil cover and the existing level of chemicalization of agricultural formations of the Republic of Tatarstan, which are considered in detail in this paper. Thus, in order to produce the ploughed grain or corn with the gross harvest of fodder units 7.94–8.82 t/ha and profitability of 78.7% on leached chernozems, which account for 38% of soils of the Republic of Tatarstan, it is recommended to cultivate corn using the complex application of agromeliorants and calculated norms of mineral fertilizers. Liming of acidic dark gray and gray forest soils with phosphorite and zeolite application in combination with NPK provides increase in gross harvest of fodder units of corn silage from 4.22 to 6.13 and 3.34 to 5.86 t/ha respectively. The high efficiency of agrochemicals application on corn crops and forage harvesting of different types of fodder taking into account zonal features of soil cover of the Republic of Tatarstan is also confirmed by economic indicators. The profitability of production of rolled grain reaches the maximum value (78.8%) in the variant with liming and phosphating of leached chernozem combined with the application of mineral fertilizers in rates calculated for obtaining the planned 35 t/ha of green mass. At the same time, on dark gray and gray forest soils as the yield of green mass increases under the influence of agromeliorants the total costs of silage production increases by 13.1 and 16.5 thousand rubles/ha compared with the control variants of the experiment (without agrochemicals). However, the costs of production of 1 000 fodder units are reduced to 9.9 and 10.4 thousand rubles respectively, provided that the sale price is about14 thousand rubles.