Genetic Horizons Research Articles

Reserves of nutrients and soil organic components of Haplic Chernozems

The focus of this investigation is to present the reserves, soil nutrients and organic matter components along the profile depth of Haplic Chernozems near village Krupen, Kavarna municipality, South Dobrudzha region. The data confirm our previous investigations that they are one of the most fertility soils in Bulgaria. The profile is also marked by a variation of nutrients reserves according to the genetic horizon. All investigated reserves gradually decreased which is typical for the group of izohumic soils. The Ntotal reserves varied from 66.37% in Аhorizon to 8.86% in Сhorizon of the total stocks counting to 3.247 kg/ha. The reserves of total phosphorus in А0-84 cm add up to 1.723 kg/m2, which is 45.94% from the total reserves of through profile, while in soil formation material horizon (Сhorizon) they reached to 0.782 kg/m2 (20.85%). The Corg reserves in the study profile (0-195 cm) are 326.131 kg/m2 and 67.50% of the stocks are concentrated in the humus accumulative horizon. In transition horizon (В84-152) all nutrient reserves gradually decreased and reached lowest values in soil formation material horizon (С152-195). These two genetic horizons have a higher degree of enrichment of humus with nitrogen compared to the humus-accumulative horizon. Throughout the depth of the profile, the degree of enrichment of humus with nitrogen is defined as average. We established essential correlations between the investigated indices as follows: Reserves of C-total are in a strong correlation with reserves of N-total (0.993**); Cres. (0.982**); C-THS (0.949**); Mineralization ability after 56 days incubation (0.665**) and exchable potassium.

Shifting prokaryotic communities along a soil formation chronosequence and across soil horizons in a South Taiga ecosystem

The study of chronosequences allows the analysis of the temporal and spatial dynamics of ecogenesis, soil microbiome and soil development. Here, we investigated the taxonomic diversity of bacterial and archaeal communities along a chronosequence of soils that formed on four Lake Ladoga coastal bars in the Nizhnesvirsky Nature Reserve (Leningrad region, north-west Russian Federation). We analyzed two factors: the age of sampled solum (ranging from 70 to 1,590 years) and the soil horizons that differ in terms of morphology and genesis.We observed a relationship between podzolisation, typical major soil-forming processes of the southern taiga zone, and the taxonomic structure of prokaryotic communities. The most pronounced differences between microbial communities were associated with the vertical heterogeneity of soil profile. Phyla associated with copiotrophic habits (Proteobacteria, Actinobacteria and Bacteroidetes) were more frequent in topsoil. Podzolic eluvial (E) horizons had higher frequencies of the genus Mycobacterium (Actinobacteria). In deeper horizons, we observed lower frequencies of copiotrophic phyla and increased frequencies of phyla associated with oligotrophic habits (Nitrospirae, Gemmatomonadetes, Planctomycetes, Chloroflexi, etc.), as well as archaeal lineages. The lowest (gleyic, G) horizons had high frequencies of anaerobic and methane-producing bacteria.Therefore, the relationship between microbial community structure and the continuous development of the soil profile was revealed. Shifting physico-chemical were identified as key factors associated with variation in prokaryotic communities. The older coastal bar demonstrated the clearer signs of podzol formation, increased thickness of the E horizon, and increased differentiation among microbial communities in different genetic horizons.

Rapid Determination of Soil Class Based on Visible-Near Infrared, Mid-Infrared Spectroscopy and Data Fusion

Wise soil management requires detailed soil information, but conventional soil class mapping in a rather coarse spatial resolution cannot meet the demand for precision agriculture. With the advantages of non-destructiveness, rapid cost-efficiency, and labor savings, the spectroscopic technique has proved its high potential for success in soil classification. Previous studies mainly focused on predicting soil classes using a single sensor. In this study, we attempted to compare the predictive ability of visible near infrared (vis-NIR) spectra, mid-infrared (MIR) spectra, and their fused spectra for soil classification. A total of 146 soil profiles were collected from Zhejiang, China, and the soil properties and spectra were measured by their genetic horizons. Along with easy-to-measure auxiliary soil information (soil organic matter, soil texture, color and pH), four spectral data, including vis-NIR, MIR, their simple combination (vis-NIR-MIR), and outer product analysis (OPA) fused spectra, were used for soil classification using a multiple objectives mixed support vector machine model. The independent validation results showed that the classification model using MIR (accuracy of 64.5%) was slightly better than that using vis-NIR (accuracy of 64.2%). The predictive model built on vis-NIR-MIR did not improve the classification accuracy, having the lowest accuracy of 61.1%, which likely resulted from an over-fitting problem. The model based on OPA fused spectra performed best with an accuracy of 68.4%. Our results prove the potential of fusing vis-NIR and MIR using OPA for improving prediction ability for soil classification.

Geochemical pollution of trace metals in permafrost-affected soil in the Russian Arctic marginal environment.

The Arctic marginal environment has been considered as far from industrial areas and low population. During June-July of 2016 "Russian High Latitude" expedition, 93 samples of soil genetic horizon from 25 soil profiles dug till frozen ground were sampled from 8 islands and 2 capes of the Russian Arctic without direct anthropogenic influences. Nine trace metals (Pb, Cd, Cu, Ni, Co, Zn, Fe, Mn and Hg) were measured and quantified by energy-dispersive X-ray analysis for elemental concentrations. Through analysis of divided soil groups (Haplothels, Turbels, Historthels), the factors of organic matter and cryoturbation had a significant influence on metals' distribution except for Fe and Mn. From summarized soil master horizons (O, A, B, C), Fe and Mn are abundant in all horizons suggesting as geochemical background values. Cu, Pb, Co and Ni are distributed specifically in different horizons with leaching and accumulation process, whereas Hg is evenly disturbed in all horizons. The correlation analysis reveals that distribution of most metals in present soils is highly depended on soil properties (pH, TOC, clay and silt). Li was selected as normalizing element for metals' concentrations from mineral layers to establish geochemical baseline concentrations. The concentrations of trace metals have been assessed by geoaccumulation index (Igeo) and enrichment factor, showing only Co and Zn are moderately polluted and slightly polluted, and Co, Cu, Zn and Pb are enriched in topsoil. Other indices as modified degree of contamination (mCdegree) and pollution load index (PLI), mCdegree show moderate degree of pollution and PLI shows unpolluted to moderate pollution load. The ecological risk indices, e.g., ecological risk factor (Er) and potential ecological risk index, show low ecological risk potential.

Importance of lisimetric research in the ecological-agrochemical evaluation of agricultural technologies

To identify regional technology models capable of reducing non-productive losses of biogenic elements and increasing the level of their utilization by cultivated plants. Agrochemical, lysimetric (stationary lysimetric unit with 48 concrete sections-lysimeters filled with sod-podzolic sandy loam soil including the parent rock and taking into account the thickness of each genetic horizon of the soil in its natural state; soil layer — 155 m, mass — 10.5 tons). Losses of labile nitrogen, calcium and magnesium compounds in the form of their oxides can vary several times depending on the type of crops. Thus, nitrogen losses in winter wheat averaged 25 kg/ha, while in corn the values were as much as 77.5 kg/ha. In organic fertilization system, calcium losses in winter wheat crops were in the range of 44 kg/ha, while in corn they account for 101 kg/ha. The introduction of cover crops into the crop rotation system reduces nutrient losses from the soil due to the utilization of mineral compounds by cover crops for constructive metabolism during their active growth and development. Following green manure mineralization during the spring-summer period nutrients become available for the following crop in rotation assuring minimal nutrient losses. Besides the reduction of nutrient losses, the use of green manure have ensured higher efficiency of pre-sowing seeds bacterization. The loss of biogenic elements increases with the application of calcium-containing materials in the norms, calculated for the full hydrolytic acidity. The most effective and resource-saving both for a single (once every 5 years) and for periodic use of soil amendments (every second year) is the use of 1/4 hydrolytic acidity dose of calcium. This reduces the leaching of calcium, nitrogen and other biogenic elements. It is recommended to use lysimetric studies as a tool to trace the migration of moisture, humic substances and compounds of biogenic elements beyond the root layer of soil, depending on the amount of rainfall and the fertilizer systems used and to determine the optimal ways to regulate these processes, which is important for the evaluation of different crop growing technologies.

Profile Distribution and Migration of Heavy Metals in the Soils of the Kursk Agglomeration (Model Experiments)

Aim. Laboratory evaluation of the characteristics of spatial distribution and migration of heavy metals (HM) in model soil profiles of varied genesis through measurement of the electrokinetic potential of soil solutions. Material and Methods. Undisturbed soils of forest parks landscapes and continental floodplain meadows of the Kursk agglomeration were studied. Experiments were carried out in laboratory conditions. The short‐term temporal dynamics were studied of vertical distribution and migration of the introduced HMs in model soil columns which imitated soil profiles. Results. Analysis of the kinetics of soil solutions and of lysimeter waters of control and polluted samples showed that the model profile of typical dark‐gray soil has the least capacity to capture lead ions from polluted soil solutions. Minimum sorption capacity with respect to zinc was found to be characteristic of sod‐podzol illuvialferruginous soil profiles. Maximum ability to deposit the HMs under analysis (Zn and Pb) was shown in leached chernozem medium loamy soils. Conclusion. The dynamics and kinetics of lead and zinc in soils of the Kursk agglomeration differ significantly and depend on a number of soil factors. In the soils studied, the spatial distribution and the intensity of migration of lead and zinc were determined by the capacity and contrast indices of the internal soil geochemical barriers. Inhibition of the processes of vertical migration of Pb and Zn in the model soil profiles was observed in those rich in humusified humus‐accumulative genetic horizons as well as in mineral horizons with highly contrasting acid‐base and redox conditions. Adsorption zones of lead and zinc are formed with a significant increase in granulometric texture and a decrease in pHKCl.

Specificity of genetic nature and classification characteristics of Zmiiny Island chernozem soils

Even the first researchers of the nature of the small (20.5 hectares) rocky Zmiiny Island in the northwestern Black Sea region visually diagnosed the soil there with black earth. Since 2003, the staff of the Department of Soil Science and Soil Geography of the Odessa National University named by I.U.Mechnikov ONU began the study of factors and processes of soil formation, soils and soil cover of Zmiiny Island territory. It was found out that on the inter-rocky areas of the island un- der the steppe grassy vegetation on the gravelly-stony eluvium or eluvium-deluvium of dense rocks formed unusually high humus (up to 14-18%) undeveloped and short-profile chernozem soils. However, the diagnostic and classification of these soils remains unclear. The purpose is to characterize the specificity of the genetic nature of the island soils and to determine their diagnostic and classification affiliation, including the World Reference Base for Soil Resources WRB.The materials presented in this article are obtained as a result of our extensive fieldwork and laboratory analysis, research and mapping of soils and soil cover of Zmiiny Island with the application of methodological principles of the process-genetic paradigm.Chernozem soils on the island are formed on a low-strength (25-40, up to 50 cm) rocky-gravelly crust of weathering of dense acidic rocks under the cover of almost virgin steppe herbaceous vegetation and year-round salting from the sea, mainly chlorides and Na sulfates. The soils are short-profile, typical chernozem humus-accumulative type with typical for the chernozem profile genetic horizons, gravel-stony, non-carbonate, almost non-structural, acidic, varyingly saline and solonetinous, but without solonets-ileuvial profile differentiation. The humus content in the upper horizons is very high (10-12, up to 15-18%), it is typical of the chernozem composition of the Chumic acid : Сfulvic acid (2,5-3,3), but with a sharp dominance of the HA-1 fraction (70% and more) and very low content (1-2, up to 3-4%) or lack of typical chernozem HA-2fraction. It is established that there is a tendency to an irreversible constant increase of the chernozem properties and characteristics in soils as the bioproductivity of herbal vegetation increases.For the first time their diagnostic and classification dependence on the system of both domestic and World WRB soil classifications has been determined. The WRB system proposes to refer these soils to the Phaeozem abstract group, with clarification of the classifiers Leptic and Skeletic. The work is practically significant in terms of the integration the Ukrainian soil science in the system of the current international standard of soil classification WRB.

Stocks of organic substance in post-agrogenic lands in Leningrad region

We have analysed factors affecting the formation of organic matter stocks in sod-podzolic soils and post-agrogenic lands in the south-western part of the Leningrad region. There are many factors influencing the process of humus formation, which does not allow to reliably simulate the process of transformation of organic residues and the accumulation of humus in areas previously used for agricultural production. There is a connection in the differences in the specific density of the soil and the unequal content of humus in the genetic horizons of fallow soil compared to the arable layer of the field, where these horizons are mixed into a homogeneous mass. The data obtained show a high correlation between the humus content in the former arable horizon of soil with a clay fraction and pHKCI. At different successional stages of accumulation of organic matter in post-agrogenic lands is not the same, as the formation of different species composition of vegetation makes adjustments to this process. When determining humus stock in post-agrogenic lands, an error can reach to 30%. The main reason is the differences in the specific density of the soil and the unequal content of humus in the genetic horizons of fallow soil compared to the arable layer of the field, where these horizons are mixed into a homogeneous mass. The conclusion was made about different methods of soil sampling from arable lands and from post-agrogenic lands.

Changes in Soil Organic Carbon Fractions Across a Loess Toposequence

Soil organic carbon fractions may vary with soil development and soil genesis controls its vertical distribution. The objectives of this study were to determine organic carbon fractions in soil derived from loess parent material and the role of relief in its vertical distribution. Five soil pedons, i.e., Typic Ustorthents (Rajar), Typic Calciustepts (Missa), Udic Calciustepts (Basal), Udic Haplustalfs (Guliana), and Typic Hapludalfs (Mansehra), were selected along a loess toposequence and sampled at genetic horizon level. Soils were characterized for texture, pH, calcium carbonate (CaCO3), and organic carbon fractions including total organic carbon (TOC), dissolved organic carbon (DOC), particulate organic carbon (POC), HCl-insoluble organic carbon, and density fractions, i.e., heavy fraction (HF) and light fraction (LF). Total organic carbon content ranged from 0.03 to 0.98% in these soils and significantly differed with soil depth within each soil and soil type. Mansehra and Guliana had 0.04 and 0.031% POC, respectively, which was greater compared to remaining soils. Dissolved organic carbon was greater in the Basal followed by Mansehra, Rajar, Missa, and Guliana soil profiles, and distribution remains uniform throughout the profile’s depth. Insoluble C fraction was 0.214% in Mansehra profiles followed by 0.156% in Rajar, 0.078% in Basal, 0.063% in Guliana, and 0.091% in Missa soil profiles. The Mansehra soil profiles had the highest (0.008 and 0.30%) content of both light and heavy fractions. Total organic carbon had little correlation with clay. Particulate organic carbon, DOC, and HCl-insoluble organic carbon had a significant correlation with TOC. The HF had the strongest correlation with TOC, while LF had a negative correlation. The soil organic fractions significantly differed with soil type and soil genesis. The soils at gentle slopes are dominant in most of the organic carbon fractions due to higher development stage.

Classification and fertility status of soils on slopes of varying orientations in Umuahia area of Abia State, Nigeria

The slope orientation and position of toposequence influence soil properties along the landscape. The study classified and evaluated the fertility status of soils on slopes of varying orientations in Umudike (East-lying Toposequence) and Itu (West-lying Toposequence) located in Olokoro Umuahia, Abia State southeastern Nigeria. Transect soil sampling technique was employed in locating 3 distinct top units (Summit, Midslope and Footslope) along each of the toposequence. Soil profile pit was dug at each top unit, described using FAO guidelines and sampled according to genetic horizons. Soil samples collected were subjected to routine laboratory analyses. Pedons were classified using the USDA Soil Taxonomy System and correlated with World Reference Base while the fertility status was evaluated using elemental ratios. The results indicated that soils of the two toposequence were dominated by sandy clay loam texture. Consistency of the pedons generally varied from very friable (Vfr) to very firm (Vfi) in the two toposequence. Soil pH was very strongly acidic (4.58-4.78) in the east lying toposequence but varied from very strongly acidic to strongly acidic (4.52-5.30) in the west lying toposequence. Organic matter concentration was higher at the epipedons and ranged from 26.44 to 23.36 g kg -1 and 18.9 to 30.64 g kg -1 in soils of east-lying and west-lying slopes, respectively. K: Mg ratio varied from 0.01- 0.12 and 0.01-0.08 at the east and west lying slopes, respectively. The pedons of the summit, midslope and footslope were as classified Grossarenic Paleudalfs, Typic Paleudalfs and Arenic Hapludalfs for respectively for the east-lying slope and Arenic Glossudalfs, Typic Paleudalfs and Typic Ferrudalfs, respectively for the west-lying slope. Generally, the two toposequences were of poor fertility status.

Lead isotope ratios in Podzol profiles as a tracer of pollution source in the subalpine zone of the Karkonosze National Park, Sudety Mts (south-western Poland)

The Karkonosze National Park (south-western Poland) represent central European medium-elevation mountains. At the end of the twentieth century, an ecological disaster was observed in this nature reserve, resulting in the defoliation of large areas of spruce forest. One of the considered reasons for this phenomenon was contamination with heavy metals. The aim of this study was to determine the origin of lead (lithogenic versus several specific anthropogenic sources) occurring in the soils of the highest located parts of the Karkonosze Mts. Lead concentrations and its isotope ratios were investigated in nine Podzol profiles located in the subalpine zone (1200–1400 m a.s.L.) of the Karkonosze Mts. Concentrations of total lead and its isotopes were measured in particular genetic horizons; then lead isotope ratios were calculated. On the basis of lead isotope signatures known from literature data, different anthropogenic sources of this element have been assessed (emissions from coal combustion, mining, metallurgy, and fuel combustion). The results obtained revealed the highest Pb concentrations (121.0–353.0 mg kg−1) in the surface horizons. The podzolization process, differentiating soil profiles into eluvial (Es) and illuvial (Bh and Bs) horizons, has contributed to different concentration of lead through the profile. The concentrations of this element in eluvial, illuvial Bh, and parent material horizons were 15.5–28.4 mg kg−1, 25.8–55.6 mg kg−1, and 8.7–29.6 mg kg−1, respectively. The Pb isotope composition determined in the ectohumus horizons and eluvial horizons showed that about 86–95% of lead existing in these surface horizons originated from emissions resulting from the burning of coal exploited in Poland and the Czech Republic. The Pb isotope signatures of lead present in the illuvial horizon (Bs) and parent material (C) pointed to the lithogenic origin of this element. The results obtained indicated that higher-elevation areas of the Karkonosze National Park have been contaminated with lead from long distance emissions. Pollution with lead has been limited only to ectohumus and eluvial horizons, although the soil-forming process contributed to translocation of lithogenic lead down the soil profile to the illuvial Bh horizon.

ВПЛИВ ШТУЧНИХ ЛІСОНАСАДЖЕНЬ НА ЕЛЕКТРОФІЗИЧНІ ПОКАЗНИКИ ЧОРНОЗЕМУ ЗВИЧАЙНОГО

The effect of artificial forest plantations on electrical resistance, electrical conductivity (Cond), mineralization (TDS), salinity (Salt) and dielectric constant of ordinary chornozem in the conditions of Pyatikhatsky forest range (Dnipropetrovsk region, Ukraine) was studied. Determination of the electrical resistance of the soil paste was performed using a four-electrode installation with planar electrodes. The determination of the electrophysical index of the soil suspension (conductivity, mineralization and salinity) was performed using an Ezodo-7021 –conductometer-salimeter-thermometer. Determination of the dielectric constant of the soil was performed using a CM-9601A – digital capacitance meter. It has been established that the upper genetic horizons of chernozem under the steppe vegetation and the planting of robinia are characterized by increased electrical resistance as compared with the upper horizons of the chornozem under the oak plantation. The upper horizons of chornozem under steppe vegetation and robinia plantation are also distinguished by reduced values of electrical conductivity, mineralization and salinity compared to the upper horizons of chornozem under oak plantation. This pattern of distribution of the studied parameters may indicate the removal of water-soluble and nutritive compounds from chornozem under the steppe vegetation (used for growing agricultural plants) and robinia plantation, while their accumulation is observed under the oak plantation. The upper horizons of the chornozem under the steppe vegetation are distinguished by increased values of the dielectric constant compared with the upper horizons of chornozem under the plantations of robinia and oak. This indicates the compaction of chornozem under the steppe vegetation, which occurs as a result of its depletion on the content of organic substances and the decline of the structural-aggregative state. The results obtained suggest that artificial forest plantations have a favorable effect on the properties of ordinary chornozem, and the electrophysical index can quite fairly be used as certain «markers» of the state of chornozem.

Ecological Stoichiometry of Carbon, Nitrogen, and Phosphorus in Subtropical Paddy Soils

This study aims to understand the existence of stable soil organic carbon (C), nitrogen (N), and phosphorus (P) ratios in paddy soil. Based on a field soil survey database, the ecological stoichiometry of the C:N:P ratio of 110 subtropical paddy soil profiles and 587 genetic horizons were analyzed at a regional scale. Relevant analysis and redundancy analysis (RDA) are used to study the relationships between C:N:P ratios and soil-environmental factors (topography, parent materials, soil genetic horizons, soil groups, soil physical, and chemical properties). The results showed that the weighted averages of C:N, C:P, and N:P in paddy soils of subtropical regions were 12.6, 49, and 3.9, respectively, and C:N:P was 38:3.2:1. The C:N of paddy soil did not vary significantly with parent materials, soil groups, or genetic horizons. However, the C:P and N:P variations were significantly different, and the mean values of the two were much lower than global ratios (186 and 13.1) and average levels of C:P and N:P in Chinese soils (136 and 9.3). Although the C:N:P ratio in the paddy soil profile was relatively unstable, the topsoil C:N (14.2) was relatively stable due to the strong interaction between the topsoil and the environment. This reflects the close coupling of C and N in the topsoil of paddy fields under long-term anthrostagnic maturation. However, in the paddy soil profile, C:P and N:P were not stable, and there was no significant correlation between soil organic carbon (SOC) and total P content, total N, or total P content, which suggests that environmental changes may lead to soil C:N:P decoupling. It was found that topography, soil texture, iron oxide, and bulk density are all key soil-environmental factors that regulate the soil profile of rice paddy C:N:P.

Modelling soil properties from horizon depth functions and terrain attributes: An example with cation exchange capacity

The objective of this study was to, through the distribution of some soil properties, model cation exchange capacity (CEC) in soils formed on gently undulating coastal plain sands of southeastern Nigeria using genetic horizon functions and terrain attributes. A total of 19 profile pits were prepared, described and 104 genetic horizons were identified and sampled, processed and analysed in the laboratory. Data were generated on the soil characteristics, including particle size fractions, hydraulic conductivity, bulk density, organic carbon, pH and electrical conductivity. Terrain attributes that were generated from digital elevation model include aspect, compound topographic index (CTI), Flow direction, curvatures, slope and stream power index (SPI). Data generated were analysed using descriptive statistics, correlation and regression. The terrain attributes were modified with genetic horizon depths, bulk density and clay content for the modelling process. Sand content, bulk density and cation exchange capacity possess geogenic rather than pedogenic characteristics and were normally distributed. The indication is that the two groups of terrain attributes depended on the mass per unit area of soil and clay content in their influence on these ultisol profiles. Paired comparison, root mean square error and normalized root mean square error indicated that the model was a good fit and could be useful in the prediction of soil properties and management of coastal plain sands.

Особливості голоценового педогенезу поселення доби ранньої бронзи неподалік с. Мальчівці (Барський район Вінниччини)

The paper concerns the issue of using paleopedological data in order to reconstruct the ancient Man environments during the different periods of the Holocene. The soil sections, located within the ancient settlement (the excavation №1) and outside it (the excavation №2, the modern soil), have been studied at the archeological site of the Early Bronze Age in the Bar district of the Vinnytsia region, 150 m SW of the Murafa River and 1 km SW of the Malchivtsi village. The samples were taken for grain-size, bulk chemical, and micromorphological analyses, and large-scale field sketches with smears of natural material were made. Micromorphology of soil genetic horizons has been analyzed in sections with intact structure. Podzolization, lessivage, and clay weathering were the main processes in the soil formation (excavation №1) that allows to define it as transitional between Greyzem and Luvisol. The fact that the soil profile includes a large number of ‘krotovinas’, and carbonate material is present in some of them indicates that the carbonate horizon was located at a small depth below the soil. The settlement existed under predominance of forest landscapes of a fairly humid climate, as it is evidenced by the soil profile. The modern soil was studied in order to compare it with the paleosol of the settlement. According to macro- and micromorphological features, the modern soil can be defined as brown- podzolic forest, which humus-eluvial horizon is depleted in organic-iron material and it includes a huge number of light “washed” areas without typical complex aggregates. Thus, the features of ancient and modern soils indicate their formation in a humid, moderately warm climate of the forest-steppe zone. However, the profile of the ancient soil of the settlement, formed on the sandy substrate, was better differentiated into the eluvial and illivial genetic horizons. It has a significant number of ‘krotovinas’ and the features typical for cultivated soils. If the ancient soil is more similar to the podzolic soils, which at present spread to the north of the studied area, the modern soil, formed on loamy substrate, is closer to the Luvisol but still with the features of podsolization. This soil type evidences a wetter climate regime as compared to the ancient soil. The features of lessivage may indicate the dominance of deciduous (beech-hornbeam) forests in this area (the composition of their leaf mould is enriched in carbonates).

МАГНІТНІ ДОСЛІДЖЕННЯ ПРИРОДНИХ І ТЕХНОГЕННИХ ПРОЦЕСІВ ОБ'ЄКТІВ КРИТИЧНОЇ ІНФРАСТРУКТУРИ НА ПРИКЛАДІ ДІЛЯНКИ "ГЛИНКА"

The results of magnetic soil and underlying rocks studies at the area near Lake Glinka are considered. This study was performed as a part of the landslide investigation of the urban environment of the Kyiv agglomeration. The aim was to detect the natural and man-made processes affecting critical infrastructure. Under field condition we measured the volume magnetic susceptibility of soil κ (10-3 SI), and sampling was performed. Under laboratory conditions we measured and then calculated the mass-specific magnetic susceptibility χ (10-8 m3/kg), and its frequency dependence χFD (%). The soil of the study area is gray forest (Greyic Phaeozems Albic in WRB) with signs of urban soil. Magnetic studies were conducted at two points on the high landslide bank of the Lake Glinka, as well as on the opposite low bank. On the low bank, we organised measurements and sampling along the micro-catena and at the vertical soil section to study the soil genetic horizons. Magnetic polygons were constructed based on cosmography downloaded by ArcGIS. The classification of the polygons is made by the attracting the magnetic susceptibility and its frequency dependence. We identified the polygon with the highest values of magnetic susceptibility (χ = 54 × 10-8 m3/kg) and the lowest value of frequency dependence (χFD = 3.6 %). This is the soil with man-made pollution. Two polygons with similar values of magnetic parameters were identified: χ = 25-35 × 10-8 m3/kg, χFD = 8-10 %. Such values are related to the natural soils. Three polygons (two on the the low bank and one on the high landslide bank of Glinka) have average intensity values of magnetic parameters: χ=35-40 × 10-8 m3/kg, χFD = 6-7 %. The vertical distribution of soil magnetic parameters in genetic horizons was observed and the redistribution of magnetic matherial was detected. Such kind of the redistribution indicates the erosion processes. The magnetic properties of soils are important for the joint interpretation with electric tomography, GPR measurements, and GIS analysis of the national landslide database of Ukraine. The results are useful for the development of the algorithm for the environmental monitoring of the critical infrastructure at the urban area.

Evaluation of pedotransfer functions to predict saturated hydraulic conductivity of Ukrainian soils

Literature overview. The parameterization of hydrological models requires knowledge of the soil filtration properties. Generally, soil profiles are characterized by properties such as sand, silt and clay content, bulk density, organic carbon fraction or humus content, and no data on filtration properties are available. Ukrainian soil database, created in Geoecophysics of soil laboratory of National Scientific Center “Institute for Soil Science and Agrochemistry Researched named after O.N. Sokolovsky” (Laktionova et al., 2012), among other properties has extensive data on texture and bulk density for more than 2000 profiles, less on organic carbon content, and almost no data on saturated hydraulic conductivity (Ksat). The most probable ranges of Ksat for most types of Ukrainian soils are given in the Atlas of natural conditions and natural resources of the Ukrainian SSR (“Pochvenno-meliorativnoye rayonirovaniye. Masshtab 1:4000000,” 1978), however, the data doesn’t present Ksat for different textures inside one soil type. To fill this gap, the best solution is the applying of pedotransfer function (PTF). The purpose of this work is to synthesize the most realistic Ksat of the main soil groups of Ukraine, corresponding to a scale map of 1:2 500 000 (Krupskiy, 1977), as well as their genetic horizons, on the basis of calculated and experimental values available in the literature. Material and methods. Ten PTFs used in the study are based on regression equations (Cosby et al., 1984; Saxton & Rawls, 2006; Weynants et al., 2009; Wösten et al., 1999), decision tree (Tóth et al., 2015), or neural network (Zhang & Schaap, 2017). Ksat was estimated for 942 horizons of 171 profiles which represented all 40 soil groups (corresponding to the legend of 1:2 500 000 map) of Ukraine according to Dokuchaev classification. Results. Wösten and Rosetta3 PTFs are determined as the most relevant by comparing the calculated Ksat values with the available data of the bottom (horizons A2, B, C) and top (A0, A1) soil layers of Ukraine. In particular, they are relevant for widespread soils such as Soddy podzolic soils (WRB – Eutric podzoluvisols), dark gray podzolized soils (Phaeozems Albic), chernozems podzolized (Chernozems Chernic), chernozems southern (Chernozems Calcic), meadow-chernozemic soils (Phaeozems Haplic), dark chestnut and chestnut soils (Kastanozems Haplic and Kastanozems Luvic), meadow soils (Umbrisols Gleic, Fluvisols Dystrict, Fluvisols Eutryc, Leptosols Umbric), mountain soils (Cambisols), and top layer of Chernozems ordinary (Chernozems Chernic). Unfortunately, all ten PTFs underestimate 2-4 times Ksat of bottom layer of ordinary and typical chernozems (Chernozems Chernic) and overestimate 2-5 times for relatively impermeable horizons (< 2 mm/h). Conclusions. Based on the calculated and experimental values, the map of Ksat of the top and bottom soil layers was obtained. Sandy soils, common in Polissia, have the highest filtration rate. Ksat of loam and clay soils of forest-steppe and steppe can differ between different types by an order. The highest Ksat have soils with high structural properties (Chernozems Luvic, Chernozems Chernic). The lowest Ksat (0.2-3 mm/h) have Phaeozems Sodic, Solonetz, Solonchaks, Planosols Albic, and bottom layer of soddy manly gley (Arenosols Protic/ Haplic) and loamy soddy podzolic soils (Albeluvisols Umbric). The estimated values should be considered as the most probable because Ksat depends on landscape location of soil profile, tillage operations, and soil temperate. The results are acceptable to use in hydrological calculations and modeling.

Anthropogenic dynamics and recovery of disturbed landscapes at the Far East Russia permafrost area

The results of studies of anthropogenic landscapes functioning with an assessment on the processes of natural self revegetation are summarized. The principles of accelerated restoration of the ecological and aesthetic value of disturbed landscapes at the permafrost zone are substantiated, based on the data obtained during studying the selfrevegetation processes on disturbed complexes. Development of placer and ore deposits of mineral resources is leading to deep transformation of landscape and to destruction of soil-vegetable complexes. The processes caused by mining-technical activity are leading to variable mechanisms of degradation of soil and vegetables often having complex impact. Results of study of sustainability of soil-vegetable complexes to the impact of mancaused activity have showed the dependence from the structure of the soil profile and it characteristic, from the character of genetic horizons, frozen status of the landscape elements, form the structure and biomass and productivity of vegetation cover.

Plant Available Water Capacity (PAWC) for Deep-Rooted Crops in Cracking Clay Soils (Vertisols) of Semi-Arid Central India

Smectite is the dominant clay mineral in the cracking clay soils (mainly Vertisols) in the semi-arid tropical (SAT) region (Vidarbha andMarathwada).Amongst the crystalline clay minerals, smectite has the highest soil moisture retention capacity depicted as the available water between field capacity and wilting point, which increases with soil depth. But in SAT Vertisols of Vidarbha and Marathwada regions, the release of this soil water is unavailable to deep-rooted crops, causing loss of crop yield is frequently observed. Thus, the water holding between33 and 1500 kPa tension is not in reality available soil moisture in these soils. The release of soil moisture is, however, seriously constrained by the dispersion of smectitic clay colloids due to the presence of both Mg and Na ions on soil exchange complex. In reality, in calcareous Vertisols of non-sodic nature, soil moisture is held at 100 kPa while in calcareous Vertisols of sodic nature it is held at 300 kPa. Based on this field observation the concept of plant available water content, which relates to profile water content, was adopted earlier to calculate the plant available water capacity (PAWC) considering the soil moisture held between 100-1500 kPa for non-sodic and 300-1500 kPa for sodic soils. This pragmatic PA WC method showed a significant positive correlation between the PA WC and the yield of cotton (lint + seed) of 32 Vertisols of the Vidarbha region, however, it did not address the status of soil moisture release at higher tensions. It is apprehended that at higher tensions, the release of soil moisture is not enough during the dry period of the season that can prevent the extension of vertical cracks in the slickensided horizons at deeper depth of 100 cm and beyond. Less amount of soil water in the subsoils is due to the decrease of saturated hydraulic conductivity(sHC) with depth preventing the free flow of rainwater in the subsoils. This makes subsoils as more water constraint horizons but enriches subsoils with pH > 8.0, more amount of Mg2+ and Na+ ions on soil exchange complex. Such Vertisols do not support the second crop during the winter months. In view of this predicament in agricultural land use plan of SAT Vertisols, the present study was undertaken to understand the cause and effect relationship between soil moisture and relevant soil parameters that prevent the release of soil moisture at higher tensions. In order to find an insight into this queer issue, soil moisture retention and release curves at 33, 100, 300, 500, 800, 1000 and 1500 kPa, were obtained for each genetic horizon of 33 representative Vertisols ofVidarbha andMarathwada region. In Vidarbha, Vertisols are Aridic/Typic/Sodic Haplusterts and Calciusterts, and in Marathwada, they are Typic/Sodic Haplusterts. Moisture tension curves indicate that the release of water beyond 800 kPa is negligible. Failure in the release of soil water beyond 800 kPa is due to the dispersion of fine clay size smectite (< 200 nm) consisting primarily of nano-size smectite (<100 nm), caused by the Mg2+ and Na+ ions present on the soil exchange complex. The dispersed nano-size smectite blocks the macropores and simultaneously increase the micropores, where soil moisture is held very tightly. In the present study, PA WC calculation was done considering the soil water held between 100-800 kPa for soils of non-sodic nature, and for sodic soils, it was between 300-800 kPa. The revised PAWC data showed a better significant positive correlation with yields of cotton on farmers ’field, in comparison to correlation obtained earlier. Thus, it stands as a robust index parameter of soil abiotic stress in SAT environment. This unique parameter having a legacy to major pedogenetic processes in SAT Vertisols. In Indian states under SAT, PAWC emerges as a formidable biophysical parameter for evaluation of rain-fed Vertisols for growing deep-rooted crops.

Physico-chemical properties of peatland located in the impact zone of municipal landfill

The results of studies of peat located in the impact zone of municipal landfill are presented. It is established that according to the peat genetic horizons profile the distribution of the mobile fractions of heavy metals is manifested in a gradual decrease with depth. The content of heavy metals (manganese, copper, zinc, lead, cobalt, mercury) in the peat does not exceed the MAC, except for cadmium, which is spread by waste from the landfill. The source of cadmium in landfills is waste containing lacquers and paints, fluorescent lamps, batteries etc. Cadmium sulfide is the basis for yellow paints used in vehicle dyeing, textile production, soap making. Peat is characterized as very poor in micromycetes distribution. Some micromycetes detected are indicators of high mineral content and low heavy metal content. Analysis of peat micromycetes by growth rate showed that the slowest growing micromycetes owns the largest proportion - 70%. The distribution by color showed that dark-colored micromycetes of the Moniliaceae, characterized by toxicity, predominate. According to the humus reserve, peat is slightly humus. It is not recommended to use such peat for crop cultivation. Instead, peat can be a source of fuel under conditions of industrial development and compliance with existing rules and state standards.