No 12 (2024)

This year marks the 125th anniversary of the journal “Pochvovedenie” – the first journal in the world fully devoted to soil science. This is a unique journal, which was based on the fundamental ideas of genetic soil science, a science created by the Russian scientist V.V. Dokuchaev. The article summarizes the history of the journal, the stages of its development. The main topics and directions that have been developed in the journal over the last 5–10 years are disclosed, examples of the most interesting cited publications during this time are given. It is shown that the journal develops dynamically and harmoniously in current conditions.

Numerical values of baseline evaluations of soil organic carbon (SOC) content, storages, soil bulk density, characteristics of their spatial variability and differential vertical distribution within layer 0–40 cm characterized the whole humus layer for the monitoring test polygon at the territory of experimental station “Oroshaemaya” in Volgograd Region (Russia) at the south of Volga Upland are submitted. Mentioned indicators characterize arable land in crop rotations on rain-fed and irrigated soils and 50-year fallow at 7 dynamic plots with loamic agrochestnut soils and accumulative-carbonate agrozems formed from pale-brown sandy loams (Haplic Kastanozems (Loamic, Aric)). To select monitoring objects, a multi-time soil line coefficient map and a retrospective analysis of remote sensing data for 40 years and soil survey were used. Each dynamic plot 30 × 30 m includes 9 individual points with differential soil sampling by depth from thin 5- or 10-cm layers. Variation coefficient in space increases from 5–10 to 30–40% due to increasing of the layer depth. On arable land, a uniform vertical distribution of SOC content within arable topsoil is justified. On fallow, accumulative type of vertical distribution SOC content with maximum near surface in light-humus postagrogenic horizon with sod is regenerated. Experimental evaluations of SOC content and storages are comparable with existing materials on light-chestnut soils at interfluve of Volga and Don. The selected objects are representative for monitoring. For the 0-30 cm layer, the minimum significant difference in SOC storages averages 3.4 t/ha with a variation from 2.7 to 4.6 t/ha. The comparison of SOC stocks of different dynamic plots is significantly influenced by the vertical distribution of soil bulk density, which depends on anthropogenic impact.

Results of baseline evaluations of soil organic carbon (SOC) content, storages, soil bulk density, characteristics of their spatial variability and differential vertical distribution within layer 0–40 cm in agrosoddy-podzolic soils formed from till (Albic Gleyic Retisols (Episiltic, Anoloamic, Aric, Ochric)) and agrosoddy-podzols formed from sands (Albic Podzols (Arenic, Aric, Ochric)) at drained arable lands, hayfield and agricultural fallow lands using 13 dynamic plots of the VNIIMZ test polygon in Tver Region (Russia) are submitted. SOC content has high spatial variability at small distance (plot 30 × 30 m) that is 5–10 times larger than reproducibility of SOM determination by dry combustion. Evaluations of standard deviation of SOC storages nonlinear are increased as the layer thickness increasing from 1–5 t/ ha for 5-cm-layer till 10–20 t/ha for 40-cm-layer. Based on differentiated sampling of soils by depth from thin layers within the 0–40 cm layer, the following was established. Uniform vertical distribution of SOC content within plow horizon and statistically insignificant differences in SOC storages in 0–10 and 10–20 cm layers are found in soils at arable lands with crop rotation. Turf about 3-10 cm thickness, accumulative vertical distribution of SOC content with maximum near soil surface and absence of significant difference between SOC storages in upper and bottom parts of former plow horizon are formed in soils from till after perennial herbs vegetation during 6 years and agricultural fallows during 5–10 years. In soils on sand, similar patterns were revealed against the general background of lower SOC content and storages.

The properties of forest litter of artificial plantations of European larch within the specially protected natural area “Izmailovsky park” in Moscow were studied. The objects of the study were two sites of larch plantations 100–120 years old on typical sandy loam sod-eluvozems on sandy deposits underlain by moraine (Leptic Cambisols). One of the sites was a control, and the other was subject to anthropogenic impacts typical of park areas as a result of recreation. A significant two-fold decrease in the thickness and reserves of litter during recreation was established, with a significant simplification of the structure and changes in the typology of litter, which is especially pronounced in the conditions of near-trunk zones. A grouping of indicators of the structure and functioning of litter was proposed, which made it possible to assess the phased transformation of organic matter corresponding to different time periods of litter functioning. In seasonal dynamics, a uniform decrease in reserves of litter during the year was revealed for control plantations, while the most significant decrease in reserves in the November-June period was noted for disturbed ones. In the annual cycle, a significant decrease in the reserves of the active fraction was established, which indicates an intensive biological cycle in the studied larch woods. Differences in the dynamics of stocks of litter fractions were revealed. Recreational load in larch woods determines the decrease in the carbon sequestration of litter organic matter and affects the dynamics of this process. Indicators of the structural and functional organization of larch woods are informative criteria characterizing the features of biogeochemical cycles of organic matter, and can be used in other types of plantings in a megapolis.

The study of changes in humus content in Haplic Chernozems (Clayic, Pachic) under the influence of field-protective oak-maple forest belt was conducted at the soil-ecological monitoring polygon of Volgograd region. The polygon is located in the Kozlovskaya forest belt, which was established in 1896 on arable land. The influence of the forest belt on changes in the humus state of Haplic Chernozems (Pachic) was considered in the following aspects: spatial and temporal variability of soil properties and humus content, humus content and reserves in arable and forest soils, soil changes under the influence of old and middle-aged forest belt. Spatial variability of soils was investigated on two transects crossing the forest belt and adjacent agricultural lands. The method of retrospective monitoring was applied to analyze the medium- and long-term variability of humus content. Data on the dynamics of humus content for 125 years were obtained on the basis of comparison with buried soil and materials of stationary studies in 1950s by the team of the V.V. Dokuchaev Soil Science Institute. Conjugate studies of soil typomorphic characteristics of soils under the forest belt and agricultural lands were carried out. They included determination of humus content and its reserves, granulometric and aggregate compositions, density of composition, soil solution reaction, content of soluble salts and calcium carbonates. The features of spatial and temporal variability of humus content and its reserves in Haplic Chernozems (Clayic, Pachic) under different types of land use were established.

This study proposes a new approach for analyzing images of the internal structure of soil (microtomograms) and modeling key hydrophysical functions based on the tomographic characteristics of the pore space. The approach is based on constructing a series of closed shells (α-shapes) around the studied three-dimensional section of the tomogram. These shells are capable of penetrating into the pores of the object with a diameter greater than a specified value. The dependence of the internal volume of the shells on the minimum pore size is analyzed. The algorithm of α-shapes construction simulates the process of drying pores connected to the surface and allows for analyzing the anisotropy of pore connectivity by limiting the permeability of a part of the object’s surface. The constructed α-shapes model the surface of the liquid phase, and the maximum curvature of the surface corresponds to the capillary pressure. The approach is applied to analyze samples of the soil microprofile of a crusty solonetz with a contrasting pore space structure. The microhorizons of the solonetz demonstrate pronounced closed porosity and anisotropy of pore connectivity. The approach allows for estimating the Water Retention Curve (WRC), pore connectivity, and anisotropy. The results were compared with typical known WRCs of solonetzic soil horizons in soils of Russia. A comparison of WRC models obtained based on 2D and 3D images was conducted. The method was also tested on tomograms of samples of aeolian laminated sandstone, for which both tomograms and direct WRC measurements were simultaneously available.

In this work, a comparative analysis of the chemical and microbiological properties of soils profile (Urbic Technosol) in Murmansk was carried out in comparison with podzol (Albic Podzol) in the background area. In urban soils, an increase in pH values and the content of main nutrients (C, N, P, K), especially noticeable for subsoil horizons, was revealed. In the topsoil horizons, an increase in the number of bacteria was noted (saprotrophs – up to 3–6 mln CFU/g, oligotrophs up to 4.5–8 mln CFU/g) and a decrease in the number of culturable microscopic fungi by 2 orders of magnitude (up to 10³ CFU) compared to natural podzols, while in the urban subsoil horizons an increase in the number of all groups of microorganisms was revealed compared to the background. The same pattern is characteristic of the microfungi diversity in the urban area. In the urban topsoil horizons, spatial heterogeneity of the species composition and structure of microfungal complexes was noted, while in subsoil horizons there was a relative homogeneity of the dominant species composition: Trichocladium griseum, relative abundance 41–77%. There was an increase in the proportion and abundance of opportunistic fungi of BSL-1 and BSL-2 groups 50–60% in the urban topsoil horizons compared to natural podzols 30%. The degree of mycological danger of urban soils varied from dangerous to safe (index mycological Im values varied from 7–20 in the city center to 1.5–3.6 on the outskirts). The results showed that urbanization in the Arctic not only leads to changes in the chemical properties of soils, but also creates a new niche for microorganisms in subsoil horizons.

The profile distribution of the organic matter (C_org), microbial biomass (C_mic) and basal CO₂ respiration (BR) of Chernozems of different granulometry was studied. It’s important for monitoring their ecosystem functions and developing approaches for decarbonization. Objects: sub-mound chernozems, buried 1.2, 1.8 and ~4 thousand years ago (ka), and their pasture analogues (background) of insufficiently studied regions: Chelyabinsk, Voronezh and Samara regions. 12 of ¹⁴C dates were received, including 7 AMS ones. The C_org loss of the 0–10 cm layer heavy-textured paleosols compared to the background reaches 47% after burial 1.2 ka, 58% – 1.8 ka, 62% – ~4 ka, for light paleosols aged ~4 ka – 24–40%. The BR and C_mic values of the 0–10 cm layer of modern heavy-textured soils are 4 times greater than those of light varieties; in paleosols of different ages they are 5–7 times less than the background; these differences are leveled out with depth. A decrease in the C_org, BR and C_mic values of paleosols occurs due to the processes of C_org mineralization in the absence of the new plant residues input, lack of oxygen and nutrients. In buried soils the stratification of С_org and С_mic distribution weakens within the profile (С_org content of the 0–10 cm layer to each underlying one). C_mic and BR of the 0–20 cm layer of modern heavy loamy soils are 70% of their sum of the 0–50 cm layer, and in light varieties and paleosols – 50–60%. С_org is maximally saturated with microbial carbon at a depth of 0–10 cm in background heavy loamy soils – 1.6–3.0, in the rest – 0.3–1.1. The BR/C_mic ratio is close in modern and ancient soils; the highest values were in sandy loam chernozems, indicating a greater lack of available C_org for microbes. This is also indicated by the fact that paleosols buried 1.2, 1.8 and ~4 ka, C_mic and BR values up to a 60 cm depth are comparable regardless of texture, except for sandy loam one. For the 0–10 cm layer, the coefficients of variation in different objects were: for С_org 9–15%, BR 8–19%, С_mic 13–31%; they increased slightly down the soil profile, a significant correlation was noted between microbiological parameters and С_org, r = 0.54–0.97.

The period from the mid–1970s is distinguished as the period of modern global warming, and 1976 is conventionally taken as its beginning. The territories of southern and arid regions are especially sensitive to climatic changes, so the aim of the work was to identify the peculiarities of climate warming in the territory of the Dzhanybek plain and changes in soil properties associated with the established climatic trends. The object of the study is a microcatena of chestnut solonetzic soils (Someric Calcic Luvic Kastanozem (Loamic, Sodic) and Mollic Salic Calcic Solonetz (Loamic)) on the territory of Dzhanybek station of the Institute of Forestry Science of the Russian Academy of Sciences. Data on the climate of the study area for the period 1914–2021 are summarized. It is revealed that in the period 1976–2021 compared to the period 1914–1975 increased: the average annual T (temperature) of the air by 1° C and Σp (sum of precipitation) by 18.3 mm; the average annual T of the cold period by 1.5° C; the average annual Σp of the warm period by 39.5 mm. Using field, micromorphological, chemical methods it was established that for the last 54 years the groundwater table has risen by 1 m, groundwater mineralization and salinity has increased at least 2 times, salinization and carbonatization of the studied soils have increased, the depth of processing by soil mesofauna and the depth of root penetration have increased, which has not yet been reflected in the content of organic carbon. If the identified climate trends continue, the studied soils are expected to become saline and carbonate from the surface and increase in carbon content and stock, but continued and expanded stationary observations are required to confirm such changes.

The change in the gross content of potassium its easily mobile (extract 0.01 M CaCl₂), mobile (according to Kirsanov) and non-exchangeable (according to Gedroits) compounds in a meter-long layer of soddy-podzolic heavy loamy soil (Albiс Retisol (Abruptic, Aric, Loamic)) during long-term extensive cultivation was studied crops and fertilizer application. The studies were carried out in a long-term stationary experiment established in 1968 in the Perm region. We experimentally studied organic (cattle manure), mineral and organomineral fertilizer systems, leveled by nutrients (control – without fertilizers, manure 10 and 20 t/ha per year, NPK equivalent to 10 and 20 t of manure, manure 5, 10 and 20 t/ ha + NPK equivalent to manure). Eight-field fallow-grain-row crop rotation. An assessment of changes in the potassium regime of arable soil was carried out in comparison with a virgin analogue (grass-forb meadow). It was established that long-term cultivation of agricultural crops (almost 50 years) without the use of fertilizers led to a decrease in the gross reserves of potassium (by 13%), its mobile compounds (by 43%) in the 0–20 cm layer, and the reserves of easily mobile compounds (by 40%) in a meter layer. The saturation of arable land with fertilizers and the type of fertilizer system influenced the direction of changes in the potassium regime of the soil. The accumulation of easily mobile, mobile and non-exchangeable potassium compounds as a result of long-term use of fertilizers was noted maximum in the 0–40 cm layer; in deeper layers (40–100 cm), on the contrary, a tendency was observed to decrease the content of these forms of potassium (relative to the option without fertilizers). Maintenance of gross potassium reserves in the soil in a layer of 0–20 cm at the level of the virgin analogue (46 t/ha) was noted when using an organomineral fertilizer system with a manure saturation of 10 t/ha per year + NPK equivalent to manure, an increase in reserves to 49 t/ha with manure saturation 20 t/ha per year + NPK equivalent to manure.

Ecosystem services are a modern tool of environmental assessment, planning and design, especially in large cities. In urban forest parks of Moscow (Aleshkinsky, Bitsevsky, Lesnaya experimental dacha, Troparevsky, Lianozovsky, Yugo-Zapadny) and suburban (background) forests, samples of the upper 10 cm layer of sod-podzolic soil (Albic Retisols) were taken. In forest parks, 30 samples (6×5 sites) were selected, in background areas – 20 (4×5 sites), a total of 50. The content of carbon (C), nitrogen (N), phosphorus (P), and heavy metals (TM: Pb, Cu, Ni, Zn), nitrate nitrogen (N–NO₃^–); C, N, P of microbial biomass (C_mic, N_mic, P_mic) by fumigation-extraction method and basal (microbial) respiration (BR). The proportion of C_mic, N_mic, and P_mic in the content of these elements in the soil was calculated (C_mic/C, N_mic/N, P_mic/P). The BR, C_mic/C, N_mic/N and P_mic/P), which can characterize the cycles of biophilic elements in the soil, are proposed to be associated with supporting ecosystem services, and pollution (HM, N–NO₃^–) – with ecosystem disservice. It was revealed that the BR, C_mic/C, N_mic/N and P_mic/P of each studied forest park were on average 4–72% less than the background analogue, and chemical (Pb, Cu, Ni, Zn, N–NO₃^–) – on the contrary, more by 14–194%. To quantify these ecologically multidirectional soil properties, the calculation of the integral index (II, in points) of the soil was proposed, which in urban forest parks was 32–72% less than the background analogue (it is taken as one). It turned out that the value of soil II in the Bitsevsky forest park (area, 2208 ha) was the largest (0.68 points), and in Lianozovsky (44 hectares) it was the smallest (0.28 points).

The change in the chemical composition of the upper soil horizons (Albic Podzol) of lichen pine forests affected by a runaway ground fire in the middle taiga of the Komi Republic was studied. It was revealed that two days after the fire, the total carbon content in the pyrogenic horizon (Q_pyr) increases by 1.3 times compared to the litter of the conditionally background area. During further post-pyrogenic succession, the total carbon content in the upper pyrogenic horizon decreases. Immediately after the fire, an increase in the content of benzenepolycarboxylic acids in the pyrogenic horizon was revealed by 14.5 times compared with the litter of the conditionally background area. The concentration of polycyclic aromatic hydrocarbons is 7 times higher than their content in the litter of the original forest. It has been shown that in the first 10 days after a fire, a “volley” removal of carbon—4 g/m² and PAHs—11.5 μg/m²—occurs from under the pyrogenic horizon. Increased removal compared to the conventionally background area can be observed in the first three months. In the course of further evolution, the chemical composition of lysimetric waters approaches conditionally background values, and after two years the concentration of both carbon and PAHs is close to conditionally background values.