Gley Soils Research Articles

Aggregate structure of agro-gray soils of Vladimir Opolye: composition and strength of aggregates

A complex of soils characteristic of the Vladimir Opole region was studied: agro-gray typical deep-arable soil, tongue-shaped agrozem and agro-gray gleyic soil. The high contrast of soil properties, which is due to the genesis of field landscapes, can be traced in the differences in the arable and subarable horizons of agro-gray soils at the aggregate and microaggregate levels. The soils have an excellent structural condition, high water resistance and mechanical strength of aggregates. In the aggregate structure of arable horizons, dependences on the position in the relief were found: down the slope the content of agronomically valuable aggregates decreases, the weighted average diameter of aggregates increases, the water resistance of aggregates and the mechanical strength of aggregates at capillary saturation decreases. However, the distribution and size of microaggregates, as well as the strength of aggregates in an air-dry state, reflects the complex genesis of the landscape and retains the influence of paleorelief with depressions and elevations. The weighted average diameter of microaggregates of arable horizons of the soils of the Vladimir Opole region is close to the chernozems of the Kursk region. The granulometric composition of the studied soils is typical of Vladimir Opolye soils and close to each other. In accordance with the classification of N.A. Kachinsky arable horizons are medium loamy, coarse silt, BT horizons are heavy loamy, coarse silt. The most structural is the arable horizon of agro-gray typical deep-arable soil, it has large microaggregates, it also has high water resistance and the highest content of agronomically valuable aggregates. The most homogeneous in terms of aggregate composition is tongue-shaped agrozem; the average diameter of aggregates and microaggregates in the arable and subarable horizons are equal and similar in the content of microaggregates and agronomically valuable aggregates. This soil is also highly water resistant. Agro-gray gleyic soil contains fewer agronomically valuable aggregates and its water stability is unsatisfactory.

Soil development and ancient Maya land use in the tropical karst landscape: Case of Busiljá, Chiapas, México

AbstractThe soil mantle of the tropical karstic landscapes of Southern Mexico was shaped by specific processes of pedogenesis and long‐term human impacts of ancient Maya agriculture. To understand the interaction between natural and human‐induced soil‐forming processes in the calcareous mountains of Chiapas state, we studied soil toposequences around the Classic Maya site of Budsilhá and related them to the archaeological evidence of settlement and land‐use distribution. Soil chemical analysis, micromorphological observations, and clay mineral identification were carried out in key soil profiles at the main geoforms. Limestone hills are occupied by shallow Rendolls which are usually perceived as incipient soils. However, high content of silicate clay composed of kaolinite and vermiculite and ferruginous clayey soil material observed at macro‐ and microscale backed the hypothesis that these soils were formed from the residues of thick Terra Rossa after their erosion. Swampy lowlands are occupied by thick clayey gleyic soils with clay mineral assemblages similar to those in the upland Rendolls. We suppose that the mineral matrix of the lowland soils is largely derived from the pedosediments of eroded upland Terra Rossa, which lost original ferruginous pigmentation and aggregation due to redoximorphic processes. Some wetland soils contain neoformed gypsum that is atypical for humid tropics; sulfide‐sulfate transformation under fluctuating redox conditions could promote gypsum synthesis. Ancient Maya land use was closely related to soil‐geomorphic conditions: settlements with homegardens occupied calcareous hills, whereas the primary agricultural domain was developed on lowland soils after their drainage by artificial canals.

Podzolic-brown soils of the Far East on the Soil map of Russian Federation, scale 1 : 2.5 M, and their correlation with soils in the Russian soil classification

Podzolic-brown forest soils on the Soil Map of Russian Federation, scale 1 : 2.5 M, are widespread on the plains and plateaus of the Far East, referred to the Eastern brown-forest-soil area in the scheme of soil-geographical zoning. There, in Primorye and Priamurye regions, they are confined to various parent rocks and to different climatic and biota conditions. In the Classification of Soils of Russia (2004, 2008), there are no direct analogues of podzolic-brown soils in the map legend. To name these soils in the Russian classification system, regional publications (N.A. Kreida, G.I. Ivanov, V.I. Roslikova et al., N.M. Kostenkov, E.A. Zharikova) were reviewed: morphological and physicochemical properties of podzolic-brown soils were assessed in terms of their compliance with the diagnostic criteria of their possible analogues in the Russian system. The comparison has shown that in Primorye, on stony-loamy-clayey derivates of hard rocks, podzolic-brown soils correspond to soddy-pale-eluvial-metamorphic soils with textural differentiation, on loamy-clayey lacustrine-alluvial and colluvial deposits – as dark-humus podbels. In the north, in Priamurye region, podzolic-brown gley soils have properties of both texture-differentiated soils with the BT diagnostic horizon and of soils with a specific cryogenic structure in the middle cryometamorphic horizon. In the ideology and nomenclature of the Russian classification system, the former are defined as mucky-podzolic gleyic soils, the latter soils, as depending on the intensity of surface gley and structure development, can be defined as cryometamorphic podzolized gleyzems, eluvial-metamorphic cryometamorphic gleyic soils, or gleyic svetlozems.

Soil contamination by plastic particles in the floodplain of the small Danilikha River in an urbanized area

The aim of the study. To assess the content, morphology and surface degradation degree of plastic particles in the Danilikha river floodplain soils in an urbanized area. Location and time of the study. The study was conducted in a recreational area in the projected “Kamensky Square”, located on the left bank of the low floodplain of the small Danilikha River (a left-bank tributary of the Kama River) in the city of Perm. Urban-alluvial gray-humus gley soils were identified in the area. Soil samples were taken from surface horizons in July 2023. Methods. To extract plastic particles from soil we used visual selection, sieving, and flotation in a saturated NaCl solution. The shape and type of plastic particles were determined visually by external features. Natural organic matter was removed with Fenton's reagent. Surface morphology of the of plastic particles and their number were determined using a stereomicroscope. Information-logical analysis was used to determine the relationship between the shape of plastic particles and their sizes. Results. In the combined soil sample from the surface horizons, the number of plastic particles reached 177 pieces/kg (excluding fibers). The mass of plastic particles, including fibers, was 0.7 g/kg. Films prevailed quantitatively among the forms of plastic particles (62%), whereas foam and foam balls made up 34% and 4%, respectively. By mass, particles predominated in the following sequence: foam balls ˃ film ˃ fiber ˃ foam. The size range was dominated by large plastic particles from 1.1 to 15 mm. Specific sizes of plastic particles for different shapes were established. Conclusions. For the first time, the content of plastic particles in the surface soil horizons of the Danilikha river floodplain in an urbanized territory was studied using the case of a recreational zone in the projected Kamensky Square. Plastic particles had different sizes and shapes, which indicated a variety of contamination sources. Contamination of the studied soils with plastic particles can be regarded as moderate. The surface degradation degree of plastic particles indicated their active weathering, which occurs in soil under neutral reaction. The surface degradation of the plastic particles was also actively influenced by external factors that act before plastics enter alluvial soils. To detect soil contamination with plastic particles, we recommend Perm municipal authorities to organize monitoring of plastics content in areas with high anthropogenic pressure.

Mycological and toxicological analysis of soil under the influence of crop cultivation technologies

The purpose of the research is to study the influence of various crop cultivation technologies on the structure of micromycete complexes and the level of microbial soil toxicosis. Extensive, organic and intensive crop cultivation technologiesin a six-field crop rotation on soddy-podzolic gleyic soil for 2021–2022 have been studied. To study the structure of the micromycete complex the deep seeding method, the spatial occurrence index of species, the Syorensen-Chekanovsky similarity coefficient and the significance indexwere used. To determine the microbial toxicosis, the method of the initiated microbial community according to V.S. Guzev was used. According to the results of the experiments, fungi from the departments of Zygomycota and Ascomycota were discovered, in 2021 – 10 species, in 2022 – 16 species. In 2022, the largest number of micromycetes was recorded under cereals with extensive and intensive technologies, in 2021, a high number of fungi was recorded in variants with annual and perennial grasses using the same technologies. The greatest manifestation of microbial toxicosis was noted in 2021: the germinating ability of test crop seeds on control variants –76.67-92.67%, when initiating a microbial community – 44.67-76.67%. The cultivation of grain crops by extensive and intensive technologies contributed to the greater manifestation of soil microbial toxicosis.

The effect of drainage, fertilizers, and agro-reclamation techniques on spring wheat productivity

The current study was conducted at the agricultural site ‘Gubino’ of the All-Russian Research Institute of Reclaimed Lands (Tver Region) in 2011–2022. The purpose was to study the efficiency of drainage of waterlogged soils, fertilizers and agro-reclamation techniques when growing spring wheat in the conditions of the North-Western part of the Non-Blackearth region. The soil of the agricultural site was soddy-podzolic, light loamy and gleyic sandy loam, drained by closed drainage. The field trials have established the influence of drainage of gleyic soils, the use of fertilizers, volumetric slotting of the soil to a depth of 45–50 cm, ridge plowing and ridge belt-scattering method of sowing on spring wheat productivity. Drainage increased wheat productivity on the extensive background by 17.8 % (0.34 t/ha), on the medium-intensive and intensive background by 16.9–19.4 % (0.56–0.60 t/ha). Mineral fertilizers improved productivity more significantly, against a drained background, wheat productivity increase at medium fertilizer rates (N45Р15K45) was 1.20 t/ha (53.3 %) and at high fertilizer rates (N90Р30K90) it was 1.91 t/ha (84.9 %). The combined effect of drainage and fertilizers improved spring wheat productivity on waterlogged soil by 2.2 times (by 2.25 t/ha). The highest payback of 1 kg of fertilizers by a spring wheat yield was obtained on a drained plot with average fertilizer application rates of 9.8 kg of grain. A high effect was obtained from agro-reclamation techniques aimed at improving the water-air regime of soil. With volumetric slotting of the soil, spring wheat productivity raised by 0.50–0.97 t/ha (13.2–26.4 %), with ridge plowing by 0.36 t/ha (12.0 %), with ridge belt-scattering method of sowing with growing spring wheat on ridges 40–80 mm high by 0.45 t/ha or 13.7 %, in relation to the existing technology of row sowing. The study results can be used in the development of adaptive agricultural technologies for cultivating spring wheat on drained lands.

Influence of agromelioration and drainage methods on the field crops productivity

The effectiveness of ameliorative strip loosening to a depth of 50-60 cm and volumetric soil slotting to 45-50 cm, their influence on the productivity of field crops and agrophysical properties of drained soils with different ameliorative systems (interdrainage distance of 18 and 28 m) was studied. The experiment was carried out in the period 2015-2021. at the Gubino agricultural polygon of the All-Russian Research Institute of Reclaimed Lands (Tver Region). The soil is soddy-podzolic cultivated light loamy gleyic, drained by closed pottery drainage, formed on a moraine. Volumetric slotting was carried out with a specially designed tool with filling the subarable part of the slot with crushed straw and plant residues mixed with a humus layer. Ameliorative loosening (MR) was carried out with a converted chisel plow. The pitch of slotting and MP is 140 cm. According to the generalized data, the best results on both drainage systems were obtained in the variant with volume slotting. Ameliorative loosening increased the yield of grain crops, on average over 5 years, by 0.60 t/ha (17.0%) and 0.79 t/ha (20.7%), slotting by 0.90 and 1.02 t/ha ha (25.6 and 26.7%), respectively. Additional grain harvest for the five-year period of MR action on the estimated drainage was 3.0, on sparse - 3.95 t/ha, and with volumetric slotting of the soil - 4.5 and 5.1 t/ha, respectively. On spring rapeseed, the best results were also obtained in the variant with sparse drainage and volumetric slotting of the soil. The increase in the yield of green mass in this variant, on average over 3 years, amounted to 3.6 t/ha of green mass, or 19.0%. It has been established that on soddy-podzolic light loamy gleyic soils with an atmospheric type of water supply, when designing ameliorative systems for field crop rotations, it is possible to use drainage systems with extended, compared to the calculated, interdrainage distances, which helps to reduce the cost of drainage. The use of land reclamation techniques increases the efficiency of sparse drainage.

Cereals-goat's rue agrocenoses in the conditions of the Upper Volga region

During 2015–2021 at the Gubino agro-polygon VNIIMZ, studies were carried out on hay-grass-goat-rue grass stands depending on the composition of the grass mixture and soil difference in the conditions of the Upper Volga region. Varieties of oriental goat's rue (Galega orientalis Lam.) - Gale, Yubilyar, Krivich and seeded cereal grasses - meadow timothy grass (Phleum pratense L.) Vic 9, awnless rump (Bromus inermis L.) Vegur, reed dwarf grass (Phalaris arundinacea L.) Ural. Sowing methods of grass stands are single-species and mixed - legumes, legumes-cereals and cereals. The research methodology included phenological observations, determining the density and height of herbage, studying the structure of the crop, the dynamics of the accumulation of dry and green mass, and processing statistical data. It has been established that, on average, over a seven-year observation period, the yield of legume-grass grass stands varied within 5.1-7.9 t/ha of dry weight. The maximum productivity was noted in 2017 - up to 11.7 t/ha of dried mass. The stem density of the sown legume component - oriental goat's rue, depending on the grass mixture and the year of the study, varied from 17 to 149 pcs/m2. The height of goat's rue plants on average for long-term observations with two-cutting use was 63-93 cm, for grass seeded grasses - 78-108 cm. Goat's rue had good foliage, the average share of leaves in the structure of the Eastern goat's rue crop for all years of research varied from 50.6 to 58.2%. The stem content was 41.4-48.9%. In single-species crops, the leaf content of eastern goat's rue reached 43.6-66.8% on average for 2 cuttings, and in a mixture with cereal grasses - 42.6-69.0%. The most productive were legume-cereal agrocenoses on gleyic soil.

Features of soils of the natural park “Scherbakovsky” Volgograd region

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.

Cellulose‐Based Hydrogel as a Natural Medium for Paddy Seed Germination

AbstractCellulose hydrogel derived from cellulose fibers extracted from printed paper waste is prepared. The hydrogel derived from 3 wt% of the cellulose concentration exhibits a maximum water absorption capacity of 465.5%. The effects of the cellulose hydrogel on the soil moisture are evaluated using four types of soils namely river sand, clayey soil, loamy soil, and gley soil (the wetland soil). The potential application of cellulose‐based hydrogel as an eco‐friendly seed germination media of the paddy seeds under the soil‐less condition is evaluated. This study shows that paddy seeds exhibit a higher seed germination rate of 53% when cellulose hydrogel is used as a seed germination media as compared to seed germination rate ranging from 14% to 35% when various types of soil are used as the germination media. The prepared cellulose hydrogel could be applied as an eco‐friendly and cost‐effective seed germination media to enhance the paddy seeds' germination rate.

Bacterial Community Composition Under Paddy Conditions Is More Strongly Affected by the Difference in Soil Type than by Field Management.

In this study, we aimed to investigate the effects of soil type and field management on bacterial communities in paddy soils, taking into account the differences in soil physicochemical properties. We collected soil samples from 51 paddy fields in six prefectures in Japan. The paddy fields were managed under organic regimes (26 fields), natural-farming regimes (12 fields), or conventional regimes (13 fields). The paddy fields were classified into four soil types: andosol, gray lowland soil, gley soil, and gray upland soil. Soil DNA was extracted from the soil samples collected 2 to 10 weeks after the flooding, and the 16S rRNA gene amplicon sequencing analysis was performed. The bacterial community compositions were dominated by the phylum Proteobacteria, Chloroflexi, Actinobacteria, Acidobacteria, and Firmicutes in all fields. The difference in soil type had significant effects on α-diversities of the bacterial communities, although the field management had no effect. The soil bacterial communities in the gley soils and gray upland soils individually formed different groups from those in the other soils, while the andosol and gray lowland soils tended to form relatively similar bacterial communities. On the other hand, the effects of the field management were estimated to be smaller than those of soil type. The β-diversity of the bacterial community compositions were significantly correlated with soil pH, total nitrogen content, total carbon content, and divalent iron content. Our results suggest that the soil microbial community in paddy fields may be strongly influenced by soil physiochemical properties derived from differences in soil type.

Establishing the origin of aromatic products from vascular and non-vascular vegetation inputs in surficial peats using 13C-labelled tetramethylammonium hydroxide (TMAH) thermochemolysis

Six cambic stagnohumic gley soil profiles located on marginal peatland between a gymnosperm plantation (Sitka spruce (Picea sitchensis (Bong.) Carr.)) and heather grassland in Wark Forest (northeast England), were analysed using 13C labelled tetramethylammonium hydroxide (TMAH) thermochemolysis to yield methylated phenolic and oxygenated aromatic products. The identification of aromatic compounds derived from the thermally assisted hydrolysis and methylation (THM) of vascular plant, Sphagnum and non-Sphagnum spp. allowed changes in vegetation both within the top 50 cm of peat (surficial peat) and across the site to be explored. Four sphagnum acid pyrolysis products reflected the presence of Sphagnum spp.; lignin phenols reflected the presence of vascular inputs; whilst 3,4-dimethoxybenzenepropanoic acid methyl ester reflected the presence of the non-Sphagnum moss Polytrichum commune. 210Pb dating of the surficial peat suggests that a historic change in vegetation identified by the changes in aromatic compound distribution with depth, coincide with the adjacent plantation of coniferous woodland. The peat closest to the plantation has seen a shift from grass dominated vegetation, to a species diverse vegetation cover, including Sphagnum spp. and vascular vegetation. These results suggest that Sphagnum spp. are able to survive not only perturbing environmental conditions, but are also able to establish themselves amongst non-Sphagnum species. This study demonstrates the ability of 13C-TMAH THM to be utilised as a screening method for the rapid characterisation of aromatic biomacromolecules in peat to identify key historic and current vegetation inputs. This technique in combination with peat dating helps identify the degradation patterns of these inputs and associated carbon dynamics, providing information on the resilience of current peat deposits to climate change and changing peat conditions.

Influence of tillage and fertilizers on the fauna of sodpodzolic gleyic soil and the yield of field crops

The results of the study of the mouldboard, surface-mouldboard and surface soil treatment systems, as well as straw-based fertilizer systems used both separately and in combination with full mineral fertilizer are presented. Data for 2019-2021 on soil fauna, yield of perennial grasses of the 1st and 2nd years of use and spring wheat are given. The studies were conducted on sod-podzolic gleyic middle-loamy soils (experimental field of the Yaroslavl State Agricultural Academy). During the period under study, the highest abundance of beneficial soil fauna (earthworms (Lumbricina), ladybugs (Coccinellidae) and carabid beetles (Carabidae) was observed during surface-mouldboard treatment which indicates that this system has favorable feeding conditions for these organisms. The number of nematodes (Nematoda) in this variant decreased with significant changes recorded in different soil layers depending on the year, which may be associated with stronger plant growth and an increase in their ability to resist helminths. It was found that the greatest impact on the beneficial fauna had a combined application of straw and total mineral fertilizer: an increase in the beneficial soil fauna and a decrease in the population of nematodes were observed, which can be explained by the reduction of bacterio- and mycotrophs. In all the years of research the surface-mouldboard treatment provided the yield of field crops at the level of the mouldboard tillage or slightly lower. Application of straw together with full norm of mineral fertilizers caused the highest values of the above-mentioned indicator.

Soils of the Krestovsky and Chetyryokhstolbovoy islands in the National Nature Reserve “Bear Islands” (East Siberian Sea)

This paper presents an investigation of previously unstudied soils of the Arctic islands (Krestovsky and Chetyryokhstolbovoy), which gained the status of a new protected area “Bear Islands” (70°37′–70°60′ N, 160°23′–162°33′ E). Their soils were formed mainly under permafrost conditions (approximately 1 m), with a seasonal thawing depth of 0.3–0.6 cm. The territory of Krestovsky Island is a combination of several landscapes characterized by various types of permafrost soils. Primitive gravelly soils (A–BC(C)) are exposed in mountainous areas. Permafrost tundra low-gley soils (OT–Bg–BCg(C)) are formed on the gentle long slopes under hummocky moss-herbaceous tundra. In natural depressions on cryogenic forms of surface, the soil cover represents a combination of permafrost arctotundra gleyic (O–B–Bg(BC)┴) and humus-gley soils (O–AH–AB–BG┴). Marsh soils (Ad–C(AC)–C′) occur along the low flooded gently sloping coasts of the island. All soils are acidic. Zonal types are characterized by gleying, which brings them closer to the soils of the mainland. The soil cover of Chetyryokhstolbovoy Island, with the most fully developed shrublichen-moss or forb-moss soils, is rather monotonous. Namely it is represented by arctotundra gleyic soils with a profile of the same type in terms of morphological features and physicochemical properties (О–Аd–АВ(g)–Вg(BCg)). The main features of this soil type include the thinness of the surface organogenic horizon, good decomposition of organic matter, high and medium content of humus in the soddy-humus horizon, the absence of surface gleying or its weak severity due to drying out in summer.

СТРУКТУРНО-АГРЕГАТНЫЙ СОСТАВ РАЗНОВОЗРАСТНЫХ ЗАЛЕЖНЫХ ОСУШЕННЫХ ПОЧВ ЕВРЕЙСКОЙ АВТОНОМНОЙ ОБЛАСТИ

Involving new virgin soils in agricultural use requires huge capital investments and significant labor resources. The secondary return to agricultural use of fallow reclaimed lands not used in agriculture can become a less costly method of increasing the area of agricultural arable land. In the Middle Amur Lowland, the issues of environmental assessment of fallow drained soils, re-involved in agricultural use, remain poorly studied and practically there are no materials devoted to this issue. To study the ecological state of abandoned drained soils in the Jewish Autonomous region, the authors were carrying out a field research from July to September 2022. The studies showed that drained soils of agrocenoses after being out of agricultural use enter a complex process of self-healing. In fallow soils, the density of the top layer of soil decreases, which has a beneficial effect on the structure of the soil. With the fallow age increasing in drained meadow sod-gley soils, a decrease in the structure coefficient is observed to values close to the lower limit of “good” structure. In brown 20-year-old fallow mountain-forest soils it is observed a noticeable increase in the proportion of macro aggregates, including agronomically valuable ones, which indicates an improvement in the agronomic properties of fallow soils. The condition of the examined different age meadow gley soils deposits, which form the regional arable fund basis, makes it possible to classify them as suitable for agricultural use.

The Role and Frequency of Wildfires in the Shaping of the Late Glacial Inland Dunes – A Case Study from the Korzeniew Site (Central Poland)

Abstract The study examines sedimentology, stratigraphy, and the impact of wildfires on aeolian and soil processes during the Late Glacial Termination in the Korzeniew site, central Poland. The site, within a parabolic dune's central and lee-slope area, presents stacked aeolian sand units intermixed with six charcoal-enriched palaeosols. Thirteen optically stimulated luminescence (OSL) dates on quartz and six radiocarbon dates establish the chronological framework, dating deposition processes. Initial aeolian sand deposition occurred towards the Late Pleniglacial's end. Climate amelioration during the Bølling interstadial led to permafrost thaw and gleyic soil formation, later overlain by migrating parabolic dunes from the older Allerød interstadial. Wildfires, influenced by vegetation cover, deposited charcoals on the dune's lee slope. These charcoals underwent pedogenic reworking amid episodes of aeolian sand deposition during the Allerød interstadial and Younger Dryas, stabilizing in the earliest Holocene. Wildfires significantly impacted local vegetation development and aeolian activity. Despite the warmth of the Allerød interstadial, increased fires correlated with expanding pine forests and their heightened fire susceptibility. Short-term climate shifts likely destabilized vegetation, fostering fire occurrences during the Allerød interstadial.

Floodplain soils on the soil map of the Russian Federation, scale 1 : 2.5 M, 1988, in the Russian soil classification, 2004

The largest area of taiga gley-differentiated soils on the Soil map of Russian Federation, scale 1:2.5 M, is located in the north of West Siberia. Small areas are dispersed over the northwestern European Russia, Eastern Siberia and the North-East. Interpretation of taiga gley-differentiated soils in terms of Russian soil classification system (2004) is rather ambiguous owing to high diversity of ecological conditions where these soils occur, аs well as variability of soil morphological, chemical, and physicochemical properties in diverse mapping units. Comparing properties of taiga gley-differentiated soils described in the Program of the map (1972) and in regional publications with the diagnostic criteria for soil types in some orders of the Russian classification system made it possible to find adequate names and taxonomic position for these soils. Thus, taiga gley-differentiated soils in the middle and northern taiga of Western Siberia proved to be allocated to several orders: weakly differentiated and gleyed soils with a brown profile were referred to the order of organo-accumulative soils as shallow-peat gleyic soils; their more hydromorphic variants – taiga gley-differentiated shallow-peat soils were defined in the order of gleyzems, as peat gleyzems, soil with morphologically differentiated profile having a particular cryogenic structure were qualified for svetlozems and iron-illuvial gleyic svetlozems in the order of cryometamorpic soils, and for eluvial-metamorphic soils of the same order in case of cryogenic structure was absent. Taiga gley-differentiated soils in their northwestern area are confined to varved clays and correspond to (soddy-)eluvial-metamorphic gleyic soils.

Биологическая доступность 137Cs и 90Sr в дерново-подзолистых почвах в отдаленный период аварии на Чернобыльской АЭС

The content of 137Cs and 90Sr forms in soddy-podzolic automorphic and gleyic soils of different textures (loamy, sandy loamy, sandy) was studied. It has been established that over a long post-accident period, the physical and chemical forms of 137Cs and 90Sr have been transformed in soils, and a dynamic balance has come in their content. 137Cs compounds have undergone non-exchange fixation, and their content in the form available to plants is currently an insignificant fraction -5-15 %. 90Sr compounds, on the contrary, are predominantly in easily accessible forms, which make up from 60 to 75 % in soddy-podzolic soils, 67 % on average. The transfer factor of 137Cs, depending on the granulometric composition of soils, decreased on average in grain crops by 3.0-6.7 times, in potato tubers - by 5.0-7.5 times. The parameters of 90Sr intake into plants decreased most intensively in the first 1-2 years after the accidental fallout, which was mainly due to the transformation of its water-soluble compounds into exchangeable forms, and over the past 30-36 years they have not practically decreased. Due to the high mobility of 90Sr in the soil, the transfer factor into agricultural crops are significantly higher compared to 137Cs - into grain crops by more than an order of magnitude, into potatoes - by an average of 5 times. Currently, the bioavailability parameters of 137Cs and 90Sr have stabilized and no significant changes are observed. Therefore, based on the current situation and the transfer coefficients of these radionuclides from soil to plants, it can be concluded that the main problems associated with obtaining standard clean crop products can occur on soils contaminated with 90Sr.

Rationalizing mottling and gleying in the characterization and classification of Canadian soils

Mottling and gleying remain important characteristics for the classification of soils in Canada. The development of criteria for the morphological description of these redoximorphic soil features, for soil horizon nomenclature, for the taxonomy of gleysolic and gleyed soils, as well as for soil drainage classification, began in the mid-1940s and continued for the next four decades. Despite advancements elsewhere, notably with Soil Taxonomy and the World Reference Base, there have been minimal refinements made in Canada, during the past quarter century. Various issues are identified, including the need for more succinct and clearer definitions, a revision of standards for the field characterization of redoximorphic features, as well as more consistency in the application of concepts across existing taxa and systems. A taxonomic framework to more effectively reflect redoximorphic features, such as a new “Redoximorphic Phase” is also discussed. Ultimately, it is recommended that a special committee to be established to conduct a thorough study and present recommendations.

Influence of carbonate rocks on soil hydromorphism in mining activity zone

Operation of mining and processing plants violates the hydrogeological conditions of the land, which can contribute to the hydrogenous transformation of landscapes and soils. The geological feature of the Belgorod Region is the presence of chalk eluvium as soil-forming rocks on hill slopes (3.6% of the territory). Soils are often underlain by chalk deposits which are characterized by significant microporosity and microfracturing. Five soil profiles were studied using the profile-genetic and morphological methods. The morphological indicators of the process of gleying are the color of the soil and the presence of glandular neoplasms. The catena included soils: gray forest soil-contact-gley on mantle loam underlain by chalk eluvium; soddy underdeveloped on eluvium chalk; soddy-carbonate medium washed out on the eluvium of chalk; soddy-reclaimed thin humus soil-gley on deluvial deposit. The appearance of gray forest gley soils nearby groundwater occurrence in flat areas in the upper parts of the slopes is due to the fact that the soils are underlain by carbonate rocks, which can contribute to moisture stagnation. The main cause of formation of hydromorphic soils on the upland slope is the occurrence and weathering of carbonates in combination with their water-lifting capacity. This leads to a violation of the law of similar topographic series. Thus, Cretaceous rocks make significant adjustments to the formation of soils and their distribution over the relief. When anomalous soil properties are detected, even in the industrial zones of mining plants, a detailed consideration of all possible causes of the observed phenomena, not only anthropogenic, but also natural, is necessary.