Chernozem-like Soils Research Articles

Assessment of the abiotic and anthropogenic factors influence on soybean nutrition and yield

The research was carried out in a long-term stationary experiment with mineral fertilizers, laid in 1962-1964 on meadow chernozem-like soil in Sadovoye village of the Tambov district of the Amur region, in 2020-2022. The object of the study was the crops of the precocious soybean variety Sentyabrinka, which is the fourth crop of the five-field crop rotation. The aim of the research was to study the influence of external factors on the intake and content of nutrients, productivity and biological yield of soybean seeds in the system of long-term use of fertilizers. Of the abiotic factors, the accumulation of heat and precipitation had a positive effect on the growth and development of soybean plants of the September variety, the intake of mineral nutrition elements from the soil. The most favorable conditions for the formation of a high yield were formed in 2021, due to sufficient precipitation in July (104 mm) and August (194 mm), which contributed to the active formation of beans and seeds in early-ripening plants. The anthropogenic factor of fertilization had a positive effect on the number and weight of seeds from one plant. The average annual loads of N24P30K24, N42P48 and N24P30 + manure 4.8 t/ha provide an increase in the number of seeds by 3.6-3.7 compared to the control, and the weight by 2.3-3.4%, depending on the average annual load of fertilizers. At the same time, the mass of 1000 seeds was greater than in the control by 0.9-4.8 g. The positive effect of fertilizers on plant nutrition led to an increase in the biological yield of seeds, which was the highest in the weather conditions of 2020 and 2021. On average, over 3 years of research, there was a stable tendency to increase biological yield against the background of the action and aftereffect of fertilizers by 0.23-0.68 t/ha with coefficients varying by years from 2.1 to 10.4%, depending on the average annual load of fertilizers.

Evidence and mineralogical and physico-chemical properties of chernozem and chernozem-like soils in Croatia

The aim was to determine possible local differences between the parent materials of recent leoss-derived soils in eastern Croatia (Dalj, Zmajevac). Furthermore, it highlights the existence of chernozem and chernozem-like soils in Croatia and describes their basic physical, chemical and mineral properties. For this purpose, two soil profiles (P-3 and P-6) south of the Dalj settlement and one soil profile (P-10) near the Zmajevac settlement were excavated. The investigation included a detailed pedological analysis, a modal analysis of the heavy and light mineral fraction and a mineralogical analysis of bulk samples (the < 2 mm fraction) and the fraction < 2 μm. By comparing the obtained results with the criteria of the Croatian Soil Classification and the World Reference Base for Soil Resources, the soil profiles P-3 and P-6 can be defined as Chernozem on Loess or Hortic Calcic chernozem (Epiloamic, Endosiltic, Aric, Humic). The systematic unit for profile P-10 was defined as Rendzina according to the Croatian Soil Classification or Calcic Chernozem (Siltic) according to the WRB. Based on the results of the pedological analysis of the soil profile horizons, a gradual degradation of the chernozem was observed as a result of anthropogenic influence, but also due to recent climate change. The degradation is particularly evident in the form of a reduction in organic matter and the relocation of carbonates from the surface to deeper zones. Due to the increasing degree of weathering caused by recent climate changes, some differences in the mineralogical composition of the studied soils were also observed. The progressive degradation of the chernozem due to the effects of recent weathering processes is indicated mainly by the presence of goethite in the fraction < 2 μm as a weathering product of iron minerals (magnetite, pyroxenes…). Although the parent material of all three profiles is loess sediments, the reason why the soil material of profile P-10 has not developed a chernic horizon is the constant contribution of aeolian material and a short period of exposure to pedogenetic processes.

The Effect of Differentiated Nitrogen Fertilization using Satellite Navigation Systems on the Spring Wheat (Triticum aestivum L.) Crop Yield in the Conditions of Chernozem-Like Soils in the Northern Forest Steppe of the Tyumen Region of Russia

Soil cultivation without layers turnover impeded the process of nitrate nitrogen accumulation compared with plowing. The traditional scheme of mineral fertilization applying the averaged standard did not create a heterogeneous level of nutrient supply in primary soil cultivation systems. These factors set them in unequal conditions by default in terms of nitrogen supply to crops. Solid mineral fertilization with the use of precision farming systems in subcompartments, taking into consideration nutrient concentration in soil and the estimated crop yield changes the function of nitrogen status formation. The aim was to study nitrogen status while applying an innovative approach to primary soil cultivation using satellite navigation systems. The experiments were carried out on meadow-chernozem, and nitrogen status was studied in plowing, differentiated, subsurface tillage, and soil cultivation without layers turnover. Nitrate nitrogen was defined by the ionometric method. Moderate supply was registered in plowing and differentiated tillage in the 0-20 cm layer with 10.1-11.8 mg/kg. During the tillering phase, N-NО3 supply amounted to 16.6-15.2 mg/kg which indicated a high supply of crop plants. On fields with subsurface tillage and no primary soil cultivation, a moderate supply of nitrate nitrogen was observed-10.1-10.8 mg/kg. Innovative technology including differentiated mineral fertilization decreased spatial variability of N-NO3 supply to 8.2-10.4 mg/kg before spring wheat (Triticum aestivum L.) seeding, during tillering phase its variability dropped to 15.3%, having the benefit of accumulation with resource-saving tillage: 11.9-12.7 mg/kg. Optimization of nitrogenous nutrition in the case of differentiated mineral fertilization with precision farming systems application in off-line mode helped achieve the maximum spring wheat yield-3.63-4.03 t/ha in soil cultivation without turning over layers.

State of water-stable soil structure in the Central Forest-Steppe under agrogenic and postagrogenic maintenance

Aim. To determine the regularities in the formation of water-stable structure and to obtain the objective integral information about the process of break-up and consolidation of the water-stable structure under agrogenic and postagrogenic load on the main soil types of the Central Forest-Steppe of Ukraine. Methods. The field method – the soils of chernozem type were investigated (seven chernozem-like soil types of different granulometric composition and humus content) in the central part of the Forest-Steppe of Ukraine, the laboratory analytical method (wet sieving of soil structure), the mathematical-statistical method (non-parametric statistics, factor, cluster, and fractal analyses). Results. The analysis of the water stability of the structure of chernozem-like soils in the Forest-Steppe demonstrates the perspectives of using modern statistical methods: fractal, factor, cluster methods, and the method of non-parametric statistics, which demonstrates their sensitivity to insignificant changes in the distribution of water-stable aggregates within the agronomically valuable interval. The soil types of postagrogenic maintenance form the distribution of water-stable aggregates, making up “prevailing” sizes of aggregates in the interval of sizes of 5–3 and 2–1 mm, which ensures the persistent state of the re-distribution where the index of Hurst has the values of H > 0.75. The agrogenic impact on soils changes the re-distribution of water-stable aggregates, destroying their natural distribution and ensuring the antipersistent state of the distribution with low stability (D > 1.43 and Н < 0.58). Under postagrogenic maintenance of soil types, there is a stable mutual connection between water-stable aggregates, structural units, and ESP (R = +0.78), and in the total of correlation relations, the direct and inverse correlation relations of R> ± 0.55 level are >30 % with the 1.5 to 1 ratio in favor of inverse proportion relations which ensures a high level of self-regulation for the hierarchical organization of the structural and water stable state. Conclusions. The determining index, characterizing the stability level of the water-stable structure, was found to be the content of water-stable aggregates of 3–1 mm and > 0.25 mm and the weighted average diameter of water-stable aggregates within the agronomically valuable interval of sizes that demonstrated a strong correlation (R = ± 0.76–0.96 ± 0.02) with fractal dimensionality (D > 1.4) and the index of Hurst (Н) which allowed for forming a gradation scale for the evaluation of the water-stable structure and the degree of agrogenesis manifestation of soils in the Forest-Steppe of Ukraine. In terms of the rate of agrogenesis manifestation via the formation of the degree of the water-stable structure, the soils of chernozem type were divided as follows: gray forest low-humus heavy-loamy light-clay soil on carbonate loess-like clay < typical low-humus heavy-loamy light-clay chernozem on loess-like clay < meadow-chernozem low-humus carbonate heavy- loamy soil on loess-like clay < typical medium-humus heavy-clay chernozem on loess.

Influence of terms and methods of storage on changes in enzyme activity of meadow chernozem-like soil on Zeya-Bureya plain

The analysis of the biological and enzymatic properties of soils is an important aspect of soil ecology, but the results of studies can be strongly influenced by the storage conditions of the samples. Variation in storage methods and duration studies reduces the ability to accurately interpret data and compare results. This work presents a study of the influence of various storage conditions and time on the results of the activity of enzymes of hydrolase class (urease, phosphatase), and oxidoreductases class (catalase, peroxidase and polyphenoloxidase) of meadow chernozem-like soil of the Zeya-Bureya plain. For the research, a laboratory experiment was performed, in which naturally moist and air-dry samples were taken and stored under various conditions: room temperature (+23 – +25 °С), low positive temperature (refrigerator, +10 °C), negative temperature (freezer, –10 °С) within 7, 28, 90 and 365 days. As a result, we found that drying soil samples immediately after sampling increases the activity of urease, phosphatase, peroxidase and polyphenoloxidase. Storage conditions do not significantly affect the activity of enzymes. To assess the actual enzymatic activity, we recommend using naturally moist soil samples immediatel y after sampling; to assess potential enzymatic activity, drying the soil and storing it for no more than 7 days are recommended. The results of this study provide useful information on the impact of sample storage conditions for researchers of enzyme activity in similar climates and contribute to further consideration and discussion of the implications of sample storage.

Экологически безопасные концентрации никеля в почвах Центрального Предкавказья и Кавказа

An extensive number of enterprises are located on the territory of the Central Ciscaucasia and the Caucasus. Emissions from these industrial facilities enter the atmosphere, settle on the soil, drain into reservoirs. Among the main pollutants is the heavy metal nickel (Ni). Nickel is at the same time a vital chemical element, and, at the same time, it can act as a toxicant metal that can cause mutations. Its biological role depends on the concentration of metal in the soil. The aim of the study is to establish ecologically safe concentrations of nickel for the soils of the Central Ciscaucasia and the Caucasus. Materials and methods of research. Nickel oxides were added to soil samples at a dose of 100, 1000, and 10000 mg/ kg and incubated in plastic vessels at a temperature of 20-22 °C and 55-60% soil moisture. In this work, the biological parameters of soils were determined on the basis of methods generally accepted in soil science and ecology (phytotoxicity of soils, total number of bacteria, catalase activity, dehydrogenase activity, abundance of Azotobacter bacteria, changes in cellulolytic activity). According to the indicators of microbiological, biochemical and phytotoxic parameters, we calculated IIBS - an integral indicator of the biological state of the soil The results obtained and their discussion. Based on the analysis of the soils of the Central Ciscaucasia and the Caucasus, the following were ranked according to their resistance to nickel contamination: ordinary chernozem (91) >chernozem podzolized (mountain) (84) ≥ chernozem typical (mountain) (83) ≥ chernozems leached (mountain) (82) = mountain-meadow chernozem-likes (82) ≥ mountain-meadow sod-peaty (80) ≥ mountain meadow-steppe (78) ≥ sod-calcareouses (76) ≥ dark gray forest(75) ≥ mountain-meadow soddy (71) ≥ brown forest weakly unsaturated(68).The greater the soil IPBS, the more resistant the biological indicators of this type of soil are to nickel contamination. The study made it possible to calculate the regional maximum permissible concentrations (rMPC) of Ni in the soils of the Сentral Ciscaucasia and the Caucasus. For this purpose, regression equations were constructed reflecting the dependence of the IIBS of each studied soil on the content of Ni in it. The rMPC of Ni in ordinary chernozem is 170 mg/kg, in typical chernozem (mountain) and mountain meadow chernozem-like soil — 160 mg/kg, in podzolized chernozem (mountain) — 150 mg/kg, in leached chernozem and mountain meadow turf-peat soil — 130 mg/kg, in sod—carbonate and dark gray forest — 120 mg/ kg, in mountain meadow-steppe — 145 mg/kg, in mountain meadow turf — 140 mg/kg, in brown forest slightly unsaturated — 100 mg/kg.

Influence of Fertilizer Systems on Soil Organic Carbon Content and Crop Yield: Results of Long-Term Field Experiments at the Geographical Network of Research Stations in Russia

The results of long-term experiments (LTEs) performed at the Geographical Network of experimental stations encompassing major soil types in Russia (soddy-podzolic (Retisols, Luvisols, and Podzols); gray forest (Luvic Greyzemic Phaeozems); leached, typical, and southern chernozems (Chernozems); chestnut soils (Kastanozems); meadow brown soils (Albic Stagnic Luvisols); and meadow chernozem-like soils (Luvic Greyzemic Stagnic Phaeozems)) within the entire country (from the north to the south of the European part of Russia, Siberia, and the south of the Far East region (Amur oblast, Khabarovsk, and Primorskii regions)) are summarized. Most of the stationary LTEs were lasting 20–45 years; ten LTEs lasted from 50 to 81 years. It was found that the organomineral fertilizer system (OMFS) exceeded the mineral fertilizer system (MFS) in its effect on the yield by 1–40% in 18 experiments, while the MFS was more efficient than the OMFS by 2–3% in only three LTEs. For the same soil type, the differences in Corg content between unfertilized trials reach 0.56–1.55% for soddy-podzolic soils and 1.58–3.93% for chernozems. Differences in soil Corg content between the unfertilized and OMFS (manure + NPK) trials were less than 10% in four LTEs, 11–20% in six LTEs, and >20% in ten LTEs; the average difference reached 0.27% of Corg. The levels of minimum (Cmin) and optimum (Copt) organic carbon content have been determined with due account for the soil types, soil texture classes, and the applied fertilizer system. They can be used as reference values for the studied soils.

Активность оксидоредуктаз семян и проростков сои в условиях грибковой инфекции Septoria glycines Hemmi

Abstract. The study is aimed at analyzing the oxidoreductase activity of seeds and seedlings of soybean infected with a fungal infection of Septoria glycines Hemmi. Research Methods. The object of the study was seeds collected from soybean plants (Glycine max (L.) Merr) of the Lydia cultivar grown on meadow chernozem-like soil of the experimental field of the All-Russian Research Institute of Soybean in s. Garden of the Amur Region in 2019. The content of malondialdehyde was determined using thiobarbituric acid. The activity of superoxide dismutase and catalase was determined spectrophotometrically, and the activity of peroxidase and polyphenol oxidase was determined by the colorimetric method. Electrophoretic spectra of the studied enzymes were detected by electrophoresis on columns of a 7.5% polyacrylamide gel. Detection on a gel of zones with enzymatic activity was carried out by appropriate histochemical methods. Results. As a result of studies, it was found that on the 10th day the infection of the seedlings was 8.75 %. In this case, under the influence of Septoria glycines Hemmi, a slowdown in growth processes was observed, the level of malondialdehyde increased, which indicates an increase in oxidative processes. The length of seedlings infected with septoria was 2.7 % less compared to uninfected ones; the mass of infected seedlings decreased by 0.15 g. When soybean infection with Septoria was detected, soybean seeds and seedlings responded, expressed in a change in the specific activity of the studied enzymes and their rearrangement multiple forms. Reduction of oxidative stress in the seeds occurred due to an increase in the activity of superoxide dismutase, peroxidase and polyphenol oxidase, for seedlings – due to an increase in the activity of peroxidase only. Scientific novelty. It has been established that superoxide dismutase in soybean seeds has a high responsiveness to the pathogen. This is expressed in increased specific activity and significant polymorphism of the enzyme, which allows it to be used as a molecular marker for increasing soy resistance to the pathogen.

Role of soil liming in increasing crop yields in crop rotation

These studies were conducted on the effects of new converter slag fertilizer (complex mineral fertilizer, limestone, soil ameliorant) for land reclamation, provided by the Japanese agricultural chemical manufacturer, containing 37.3% of CaO and 18.0% of MgO, on two types of soil in the Amur Region (Russia). About 85% of arable land has a high acidity (pHKCl ≤ 5.5) in the region. Therefore, the need for the use of land reclamation in the region is high. Studies aimed to establish the effect of various doses of the slag fertilizer on the change in the acidity of brown forest and meadow chernozem-like (Amur prairie) soils, as well as increase the yield of soybean and wheat in crop rotation. The experimental scheme was tested in doses of the limestone from 1 to 4 t/ha on the background of nitrogen-phosphorus fertilizer. The application of studied mineral fertilizer ensured a decrease in soil acidity by 0.05-0.30 (pHKCl) units by increasing of exchangeable Ca2+ and Mg2+ ions in soil exchange complex. The result was an increase in soybean yield by 0.18-0.45 t/ha and an increase in seed quality. Based on the results, fertilizer was recommended in doses of 2 to 4 t/ha, depending on the type of soil.

Comparative Characteristics of Mountain-Forest and Mountain-Meadow Soils of Dolgorukovskaya Yayla (the Crimean Mountains)

A comparative study of mountain-meadow and mountain-forest soils was performed within the entire Dolgorukovskaya Yayla—a plateau on the northern macroslope of the Main Ridge of the Crimean Mountains—in the altitudinal range from 560 to 975 m a.s.l. Soil morphology, texture, acidity, exchangeable cations, nonsilicate iron content, parameters of the humus status, and optical characteristics of soils were studied. Forest soils on the entire slope are assigned to acid and dark burozems (Cambisols, Luvisols); they are characterized by similar morphological properties and profile patterns of clay, humus, and nonsilicate iron. Mountain-meadow, mountain-meadow chernozem-like, and residual-carbonate soils (Phaeozems) are formed under meadow vegetation in the upper part of the plateau, and soils transitional to piedmont chernozems (Chernozems) are located in its lower part. Humus reserves in the 0- to 50-cm-thick soil layer varied from 16.6 to 42.2 kg/m2 under meadows and from 10.7 to 18.8 kg/m2 under forests. Soils under forest and meadow vegetation were characterized by an increase in acidity and a decrease in base saturation with the increase in the altitude. Acidity was generally higher in forest soils, while the difference in this parameter between forest and meadow soils in the upper part of the plateau was minimal. In soils under meadows, the content of oxalate-extractable iron also increased with the altitude, and its mean content in the A horizon (226 ± 67 mg/100) was higher than that in forest soils (183 ± 41 mg/100 g). More intense color of soils under grass vegetation as compared to soils under forests is mainly explained by the differences in the rate of organic matter humification and optical density of humic acids, the total humus content being similar in both groups of soils.

Chernozem relics in the Hellweg Loess Belt (Westphalia, NW Germany) – Natural or man-made?

Chernozems and Chernozem-like soils are widespread e.g. in Central Germany but its formation is still controversially discussed. Clustered findings of Luvic Phaeozems and buried dark soil horizons in the Westphalian Hellweg Loess Belt (North Rhine-Westphalia) are traditionally interpreted as relics of early Holocene Chernozems. More recent research raised the question whether these soils are of (pre-) historic anthropogenic origin.Field observations in the east of Dortmund revealed the existence of buried black horizons in hillslope hollows. The underlying Stagnic Luvisol was penetrated by darkish clay illuviation veins forming a polygonal pattern. This feature was also found below the plough horizon in Luvisols beyond the hillslope hollows. A multi-analytical approach was used in order to clarify whether the black soil horizons are natural relics or man-made. In order to identify fire-derived black carbon (microcharcoal), benzenepolycarboxylic acids were used as molecular markers.Beside the position of the fossil black horizons on top of a well-developed Stagnic Luvisol, micromorphological thin section analysis confirmed the colluvial origin of the black horizons. Total organic carbon contents of the black horizons were only ∼1%, whereas high black carbon concentrations indicate large amounts of fire derived organic matter. High concentrations of black carbon were also found in the clay illuviation veins, testifying to a formerly more widespread occurrence of black carbon enriched soils.Radiocarbon ages of charcoal particles from the black horizons prove fire activities during the late Neolithic and Bronze Age (e.g. slash-and-burn). Finally, our results strongly indicate that the Chernozem-like soils in the study area are man-made and natural Chernozem formation can be excluded.

Содержание микроэлементов в чернозёмовидных почвах Зейско-Буреинской равнины

Содержание микроэлементов в чернозёмовидных почвах Зейско-Буреинской равнины

Separation of peroxidases from Miscanthus x giganteus, their partial characterisation and application for degradation of dyes

Due to wide applicative potential of peroxidases (POXs), the search for novel sources and forms, possibly with better characteristics and performances, is justified. In this study, POXs from Miscanthus x giganteus rhizomes grown in chernozem-like soil and mine tailings were examined. Higher activity of POXs in samples originating from the metal-contaminated soil was found. The quantity of acidic isoforms was much greater than basic. The rates of reactions catalysed by acidic POX isoforms decreased slightly at 50 °C, whereas stability of basic isoforms was affected at 40 °C. Concentrations of Zn, Mn and Fe were higher in rhizomes grown in mine tailings, and negatively correlated with the concentration of proteins. Basic POX isoforms effectively degraded CBB R250, while Amidoblack 10b was predominantly degraded by acidic isoforms. Thus, Miscanthus x giganteus can be used as a source of POXs which can be applied for dye decomposition and, possibly, waste water management.

Relationships between parameters of the humus status of forest and meadow soils and their altitudinal position on the main Crimean range

The influence of bioclimatic conditions related to the elevation above sea level on the quantitative and qualitative parameters of humus in mountain soils has been studied. It is shown that changes in the water and temperature conditions with the altitude do not exert significant effect on the humus content in mountain- forest soils, because the total amount of soil organic matter mainly depends on the composition and state of the vegetation cover. The humus content is the highest in meadow soils formed on mountain plateau with excessive moistening, which determines the formation of dense grass cover and the temperature regime favorable for humification. The percentage of Cha in the composition of Corg and the optical density of humic acids (HAs) are the qualitative parameters of the soil humus status changing with the altitude. The intensity of humus coloring of the soil depends on the content and optical density of HAs. A comparison of color intensity in the mountainous meadow chernozemlike soils and plain chernozems has shown its significant dependence on the hydrothermic conditions.

Stable carbon compounds in soils: Their origin and functions

The sources, formation conditions, and composition of stable carbon compounds in soils are considered in this review. It has been shown that the stable carbon compounds contain lithogenic carbon-containing components and pyrogenic material, as well as some stable compounds resulting from the biochemical transformation of biomass in the soil. The presented data indicate that pyrogenic components (black carbon) play the major role in the formation of stable carbon compounds in the soil; in most soils, the products of biomass combustion prevail over the technogenic emissions resulting from the combustion of fossil fuel. Methods for the separation and analysis of stable carbon compounds have been considered; the specificity of markers used for the diagnostics of carbon compounds of different genesis has been discussed. A tentative scheme has been proposed for the classification of carbon compounds in the soil depending on their genesis and stability. The contribution of black carbon to the development of soil morphology and properties has been discussed; the hypothesis about the deciding role of pyrogenic components in the formation of chernozemlike soils in Middle Europe has been challenged. The suitability of biocarbon application to soils for improving their properties and fixing carbon in the soil has been shown.

Preliminary results on sediment and settlement dynamics in the environs of the fortification enclosure Corneşti-Iarcuri, western Romania

Cornesti-Iarcuri is the largest known fortification enclosure of prehistoric Europe. The site is located in the Romanian Banat, at the southeastern edge of the Mures alluvial fan (Fig. 1). Four earth filled wooden ramparts with a total length of about 33 km enclose an area of more than 17.2 km². Even today, after centuries of intensive arable farming, these walls represent significant obstacles in the undulating landscape of the Vinga plain. Radiocarbon dates, most recently achieved by ongoing archaeological research date the construction to the Late Bronze Age (Szentmiklosi et al. 2011, Heeb et al. 2008, Micle et al. 2009). The Mures alluvial fan started to develop in the Pliocene and with its extent of about 10.000 km² it is one of the most extensive landscape features of the eastern Pannonian Basin (Urdea et al. 2012). Extensive parts of the fan are covered with Quaternary loess and loess-like deposits. Thick chernozem or chernozem-like soils have developed in these sediments (Borsy 1990).

Concretions in typical chernozem, gleyed chernozem-like, and solonetzic chernozem-like soils of the southern Tambov Lowland

A system for the diagnostics of chernozemic soils of the Tambov Lowland based on concretions is proposed for agricultural and reclamation purposes. The relationships between the structure and composition of the carbonate concretions, the long-term water regime of the soils, and the productivity of the crops have been established. The dense concretions in the typical chernozem testify to the depth of the seasonal wetting; the angular-rounded concretions in the deeply gleyed chernozem-like soil, to the upper boundary of the capillary fringe; and the angular concretions with sharp edges and cavities in the gleyic chernozem-like soils, to the groundwater table. In the chernozem-like soils that were waterlogged with bicarbonate-sodium water, the black angular concretions were formed in the solonetzic horizons, while the weakly compacted light-colored ones, in the zone of the capillary fringe. Humic acids were responsible for the color of the dark neoformations, and fulvic acids predominated in the light-colored ones. The appearance of black fine nodules indicated periodic surface water stagnation. Manganese predominantly accumulates in these nodules. The structure of the Mn-Fe concretions in the plow horizon observed at a magnification of 40–50 times has a diagnostic importance. The short-term (2–3 weeks) water stagnation leads to the formation of fine-stratified concretions, and the long-term (up to 1.5 months) stagnation promotes the formation of uniform porous ones. The solonetzic process induced by the bicarbonate-sodium water results in the appearance of mottled concretions.

The genesis, classification, and melioration of gleyed podzolic chernozem-like soils in the north of the forest-steppe zone of European Russia

Chernozem-like soils with light-colored acid eluvial horizons are widespread in the forest-steppe zone of European Russia. Their formation is related to gleying under the conditions of a stagnant-percolative water regime on leached rocks. It is closely associated with the evolution of salinized soils (Gedroits’s scheme). However, these soils have not been included in the soil classifications of the Soviet Union and Russia. Based on the principles of substantial-genetic classification, one of the authors of this article [3–5, 10] referred them to gleyed podzolic chernozem-like soils, which are considered as an individual genetic soil type. With respect to agroecological aspects, they are different from the leached chernozems in their low productivity and difficulty of tillage. This article covers the problems of genesis, classification, and melioration of gleyed podzolic chernozem-like soils in the north of the forest-steppe zone of European Russia and their possible association with dark-colored podbels.

Site-specific variability of loess and palaeosols (Ruma, Vojvodina, northern Serbia)

The study of temporal variations in soil intensity has mostly been limited to specific sites. However, it is important for correctly interpreting the stratigraphy and palaeoclimatic significance of loess and palaeosols series to understand the reasons for the spatial variability. More specifically, pedogenetic and sedimentological properties should be evaluated separately. This is particularly well illustrated at the Ruma site (Serbia). In this paper we focus on macroscopic soil characteristics and sediment grain-size properties. The type-succession shows three interglacial pedocomplexes (V-S1,V-S2 and V-S3) separated by loess layers that include at least one interstadial pedocomplex in the uppermost loess layer. All sediments show a bipartite grain-size distribution (a coarser-grained silt-dominated one and a fine-grained one (<16 μm)). The interglacial palaeosols show a slightly finer-grained mean grain size than the interstadial soils and loess layers, which is entirely determined by the higher proportion of the fine subpopulation. Laterally, the palaeosols vary from a black organic, chernozem-like soil to a brown-coloured inorganic soil. There are no significant differences in grain size between the two soil types. In the vertical succession, the jumps in grain-size do not correspond always with the soil colour. Furthermore, there is no clay illuviation. It may be concluded from this multi-proxy study that the locally higher amount of the fine-grained component seems corresponding with a more humid depositional environment. Another important conclusion is that all loess shows identical grain-size composition and thus that interglacial loess with distinct finer grain-size as is the case in Asian loess (also in the coarser subpopulation) is clearly absent.

Mobile forms of phosphorus and iron compounds in chernozem-like soils in the northern part of the Tambov plain

Moisture content and redox conditions are factors determining the dynamics of the content of mobile phosphorus in chernozem-like soils moistened and waterlogged by groundwater and surface water. When the moisture content increases and oxidizing conditions are still present in soils belonging to the chernozem type that contain a high concentration of calcium phosphates, the latter transform from apatite into more mobile forms, Ca-PI and Ca-PII. In chernozem-like soils with a high concentration of iron phosphates under reducing conditions, the amount of phosphorus extracted with 0.1 N H2SO4 increases owing to the transition of iron phosphates into a mobile state. Precipitations enriching the soil with atmospheric oxygen promote the increase in the value of the oxidation-reduction potential (Eh), thereby decreasing the mobility of iron phosphates.