Subtypes Of Chernozems Research Articles

Сравнительная характеристика литохимических особенностей черноземов северного Приазовья и Крыма

The article discusses modern approaches to the study of weathering and soil formation processes in soils. It offers comparative characteristics of migration-segregation (ordinary carbonate) chernozems and textural-calcareous (southern) chernozems formed under conditions of the steppe regions in the Crimea and Rostov region. Lithochemical indices were used to determine the relative age of soils and establish the relationship between soil formation and weathering. CIA index characterizes the degree of soil weathering and its mineralogical features, while CIW index determines the degree of maturity of fine aluminosiliciclastics. The determined gross chemical (elemental) composition of soils and rocks formed the initial data for such reconstructions. In addition, the research included calculations of the molar ratios of silica to sesquioxides (SiO2:R2O3) and the eluviation coefficient (Ke) (excluding sodium) in soils and soil-forming rocks. It has been established that the relative age of chernozems in the Crimean Peninsula is less compared to the similar subtypes of chernozems in the Rostov region. This is due to the peculiarities of the soil-forming material. In the Rostov region, chernozems are formed on more weathered clay parent rocks, while the formation of Crimean chernozems is confined mainly to the eluvium of sedimentary rocks. Down the profile, the intensity of soil formation and weathering processes in the soils of the South and South-East of the East European Plain noticeably decreases due to a lower rate of secondary weathering of minerals. This can be explained by the limited energy characteristics of the environment in which these processes occur. Among such limiting environmental factors, on the major factors are an insufficient amount of moisture in the spring-summer period.

ОСОБЕННОСТИ СТРУКТУРЫ ПОЧВЕННОГО ПОКРОВА СЕВЕРНОЙ ЧАСТИ АКТАЙ-ШЕНТАЛИНСКОГО ЛАНДШАФТНОГО НИЗМЕННОГО РАЙОНА

The results of the analysis of materials of a large-scale soil and agrochemical survey, morphological structure and properties of representatives of forest-steppe soils of the northern part of the Aktay-Shentalinsky landscape lowland region of the Republic of Tatarstan are shown. The territory is a poorly divided polygenetic plain with absolute heights of 140-150 m. The bedrock deposits have sandy-loamy layers of the Neogene and Pleistocene, overlain by cloaks of Quaternary deluvial loams, up to 20-21 m thick. The soil cover is dominated by leached medium–sized chernozems, which is 52.6% of the area, typical low–power and medium-sized chernozems - 39.6%, podzolized medium-sized chernozems - 2.7%, gray forest – 4.8%. The humus content in the agrogenic horizon of typical chernozems is average – 4.2-5.2%, and in leached chernozems ranges from 4.6% in a slightly washed analogue to 5.4% in full-profile representatives, where the humus content gradually decreases to the soil-forming rock. The potential reserves of humus of the studied subtypes of chernozems according to typical sections are in the range from 230 t/ha to 462 t/ha. According to the materials of the agrochemical survey for 1972-2021, the dynamics of the content of mobile forms of phosphorus in the arable horizon ranged from 103 mg/kg to 158 mg/kg. The weighted average amount of mobile potassium gradually decreased from 140 mg/kg to 101 mg/kg of soil. The actual yield of spring wheat and the dynamics of the content of mobile forms of potassium over the years of observation have a reliable correlation between each other. The obtained regression equations can be used to predict the yield of spring wheat in a given area. According to the results obtained, for each hectare of arable land for 51 years, about 149.9 kg of phosphorus was received with organic and mineral fertilizers, and since it is sedentary and difficult to dissolve, this led to its accumulation in the soils of the territory. The potassium balance is negative and amounted to -775.9 kg.

The Effect of Long-Term Agricultural Use on the Bacterial Microbiota of Chernozems of the Forest-Steppe Zone

The structure of soil microbial communities and the factors that control it are still poorly understood and cause ongoing interest. The diversity of soil bacteria reflects the diversity of existing ecological niches and trophic connections between them and with other components of the ecosystem. The presence of certain taxa with their own characteristic properties depends on the specific environmental conditions. Analysis of the composition of soil microbiota in various physicochemical conditions allows identify landmarks for understanding the principles by which it is formed. Of particular interest in this regard are the features of cultivated fertile soils that assist agricultural production. In this paper, we have assessed the occurrence of representatives of different families of bacteria in arable and nonarable chernozems of three subtypes. The methodology of 16S microbial profiling was used. The general features of the taxonomic structure of bacterial communities of chernozem remain similar, with a high occurrence of the families Sphingomonadaceae, Xanthobacteraceae, Rubrobacteraceae and Chitinophagaceae. Notably, Gemmatimonadaceae, one of the most commonly occurring families, is approximately twice as represented in arable soils as in nonarable ones. Differences between subtypes of chernozem and between arable and nonarable areas concerned different sets of bacterial families. Among others, the occurrence of representatives of families characterized by nitrogen fixation, nitrite oxidation and reduction, ethanol oxidation, biodegradation and microbial predation is touched upon. The obtained results raise the question of the factors limiting the number of certain groups of bacteria in various soil conditions and so limiting their contribution to the properties of the ecosystem.

Wind resistance of southern carbonate and ordinary сhernozems in agroforest landscapes of the steppe zone of Russia

Relevance. The rate of destruction of chernozems in the steppe zone as a result of deflation is very high. There is a threat of their loss of the humus horizon. To optimize the complex of protective measures, it is necessary to establish the regularities of the formation of wind resistance of these soils.Methods. The seasonal dynamics of the structure of the upper layer (0–5 cm) of chernozems of the steppe zone of the Lower Volga region and the Central Pre-Caucasus in the network of forest belts is studied. The aggregate composition was determined by fractionation of an air dry sample. The wind resistance of the soil was assessed by the total content of particles with a diameter of less than 1 mm.Results. It has been established that the open surface of southern carbonate chernozems is deflationary dangerous at any time of the year. Two spraying peaks were revealed — in early spring and before harvesting grain crops. In the first period, the content of particles with a diameter of less than 1 mm was 33–47%, in the second — 60–61%. Shelter forest belts reduced soil spraying in the zone of effective influence. A change in the internal structure of the deflationally dangerous fraction was detected during the year. The disintegration of large aggregates and an increase in the volume of smaller ones were observed. By the harvesting period, the number of particles with a diameter of 0.5–1.0 mm decreased by 1.7–2.6 times compared to the spring. Number of aggregates with a diameter of 0.1–0.5 mm, most strongly blown by the wind, increased by 1.3–1.8 times. The total dispersion of ordinary chernozem is almost two times lower than that of southern chernozem. However, the amount of particles with a diameter of 0.1–0.5 mm in the deflationary dangerous fraction of southern carbonate chernozem in the spring period is 37%, during the harvesting period — 50–56%. And in ordinary chernozem, already since the spring, there are more than 55% of such particles, in the future their number increases to 60%. As a result, by the harvesting period, the danger of a fraction with a diameter of less than 1 mm becomes the same for both subtypes of chernozems. This requires adjusting the complex of protective measures.

Influence of the anti-erosion complex on erosion-hydrological indicators and productivity of cultivated crops

An assessment of the impact of the anti-erosion complex on the productivity of cultivated crops has presented on the example of many years of experience in contour-ameliorative agriculture of the Kursk FARC located in the northern part of the Medvensky district of the Kursk region. Two subtypes of chernozem represent the soil of the experiment: typical and leached. As anti-erosion measures, narrow-row stock-regulating poplar forest belts, reinforced by a simple hydraulic structure (ditch and rampart along the lower edge), have designed and planted along the contour at a distance of 216 m. There are no anti-erosion measures in the control catchment. Analysis of long-term data showed a decrease in runoff and the absence of soil washout in the catchment area with a system of narrow-row forest belts 38 years after the experiment has laid in comparison with the control. For the control catchment, a maximum soil washing of 22 t/ha recorded which significantly exceeds the permissible standards of flush. A significant increase in crop productivity averaged 5.2 feed units. The profitability of growing crops in fields with forest belts exceeds the control by almost 50%. The anti-erosion complex performs the task of strengthening the soil-protective role of the farming system.

Changes in Physical Properties of Chernozems under the Impact of No-Till Technology

This article presents the results of research on the impact of no-till technology on the natural bulk density and macro- and microaggregate composition of the topsoil (0–20 cm) in different subtypes of chernozems before sowing and during the growing season. Haplic Chernozems (Loamic, Aric, Pachic) and Haplic Chernozems (Loamic, Aric) were studied. For all chernozems, improvement of physical properties was recorded when no-till was introduced in comparison with the control. Four and six years of crop growing without tillage did not cause any compaction of Haplic Chernozems (typical and ordinary subtypes). On the plots with direct sowing, the microaggregate composition of typical chernozems was characterized by a higher proportion of coarse fractions (>50 µm) in comparison with the control. Probably, this indicates the development of microaggregation similar to that under natural cenoses, which are characterized by a relatively high content of the fraction 50–250 µm, upon the transition to no-till. In all subtypes of chernozems under no-till, the water stability of aggregates increased. The share of agronomically valuable aggregates in typical chernozem also increased, which may be associated with an increase in the input of water-soluble organic matter into the soil during no-till, because this technology excludes translocation of plant residues into the soil. In southern chernozems, this effect was manifested only for fractions >7 mm, while water stability of finer aggregates was mainly due to the calcium content regardless of the type of tillage.

The efficiency of rhizobia use in the soybean cultivation on chernozem of the Western Ciscaucasia

In the period of 2008-2014, we carried out the field experiments to evaluate the efficiency of soybean inoculation with Russian and foreign preparations of nodule bacteria on various subtypes of chernozem of the Western Ciscaucasia. All studied inoculants ensured an increase of soybean yield: on ordinary chernozem – on average, by 18.8 % (0.34 t/ha), on leached and typical chernozems – by 14.9 % (0.30 t/ha), on meadow chernozem of rice fields – by 59.1 % (1.04 t/ha). The protein content from inoculation increased by 1.7-1.9 %, in rice crop rotations – by 4.0-4.9 %. There was no significant difference in efficiency between Russian and foreign inoculants. In 2018-2019, in a field experiment on leached chernozem we established the varietal specificity by reaction to inoculation with various strains of rhizobia in new soybean varieties Bars and Irbis, confirming the expediency of selecting complementary pairs in the system soybean variety – rhizobia strain.

Influence of various systems of soil tillage on agrophysical properties of leached chernozem

The paper presents the results of research into the effect of different soil tillage systems on soil density and structure. The research was conducted in a long-term stationary experiment on the crops of Nikita spring barley. The soil of the experimental plot is classifi ed as leached, mediumtextured, medium-humus, heavy-loam chernozem. The following soil tillage systems with peas as a forecrop were studied: deep moldboard, deep combined, minimum combined and zero. The years of research (2015-2018) differed in heat availability and amount of precipitation. This allowed to study and carry out comparative assessment of the effect of various soil tillage systems of leached chernozem on agrophysical properties of soil. Yearly weather conditions had no signifi cant effect on soil density with all the studied soil tillage systems in single and binary crops of spring barley, whereby the indicators varied from 1.87 to 6.72%. Compared to deep moldboard tillage (control), there was an increase in soil density with zero tillage in singlecrop sowings of spring barley by 6.2%, and in binary crops – by 9.4%. However, the indices were not beyond optimum values of 1.02-1.05 g/ cm3. The optimum equilibrium soil density for the main subtypes of chernozems is 1.0-1.25 g/cm3. Minimum combined soil tillage system resulted in the stable content of valuable structural soil units 0.25-10 mm both in single-crop and binary sowings of spring barley at 68.3% and 68.9%, and the coeffi cient of soil structural properties – 2.15 and 2.21 respectively. It was established that the effect of soil tillage system on the creation of valuable structural units in soil was 21.4%, yearly weather conditions – 11.8%, type of crops – 25.5%.

Nitrogen in Chernozems under Traditional and Direct Seeding Cropping Systems: A Review

The functional role of nitrogen in the formation of crop yield on chernozems under conditions of traditional and direct seeding (DS) cropping systems is considered. In the course of long-term experimental studies of DS cropping system on chernozems, considerable experience has been gained and has found efficient practical application. It is shown that the effect of nitrogen as the most important element in the composition of humic substances influencing the fertility of chernozems depends on the variability of environmental factors, the forms and rates of nitrogen fertilizers, the rotation systems, and the soil treatment technologies. The DS cropping system has been tested for 4–10 years on experimental fields of the Stavropol Agricultural Research Institute and in a number of farms in Stavropol region. The obtained data on the yields of cereal crops and the application of fertilizers attest to the importance of the formation of a mulching layer of plant residues on the surface of ordinary and southern chernozems in the DS systems. This layer contributes to a gradual accumulation of nitrogen, protects the soil from erosion, and increases the number and mass of earthworms. Nitrogen in the DS cropping systems on chernozems in Russia is characterized by the high mobility and the capacity for considerable transformation. In this context, further investigations and special experiments are necessary to gain better knowledge of the behavior of nitrogen in different cropping systems. In particular, the relationships between nitrogen fluxes, agrophysical soil properties (aggregate-size distribution at the macro and micro levels), and specificity of the organic matter in different subtypes of chernozems under different cultivation technologies have to be clarified. In general, the role of DS cropping systems in farming practices has become more significant in the recent years; application of the DS cropping system is considered a positive factor in maintaining and restoring soil fertility.

Особенности латерального и радиального распределения металлов в почвах агроландшафтов Самарской области

Одним из факторов, изменяющим структуру и функции почв агроландшафтов, являются соединения металлов. В работе выявлены и оценены особенности латерального и радиального накопления тяжелых металлов (Pb, Cd, Zn, Cu, Mn, Cr, Fe) в темно-каштановых, темно-серых лесных типах почвах, а также во всех основных подтипах черноземов (южном, обыкновенном, типичном, выщелоченном, оподзоленном) в условиях Самарской области. Почвенные образцы анализировали методом атомно-абсорбционной спектрометрии с пламенной и беспламенной атомизацией. Установлено, что содержание Pb, Cd, Zn, Cu, Mn, Cr, Fe в гумусовых горизонтах темно-каштановых, темно-серых лесных почв и в подтипах черноземов не выходит за пределы ПДК. Превышение над кларками земной коры выявлено для Pb в темно-серых лесных и темно-каштановых почвах, для Cd — в черноземах типичных и выщелоченных, для Mn и Pb — в темно-серых лесных почвах, черноземе южном, для Zn — в темно-серых лесных почвах. Коэффициенты накопления, показывающие превышение над фоновым значением, в почвах агроландшафтов представлены следующим убывающим рядом: Fe(1,9) > Zn(1,7) > Cu(1,5) > Mn(1,4) > Cr(1,4) > Pb(0,9) > Cd(0,2). По суммарному показателю загрязнения исследованные почвы образуют ряд (в порядке снижения концентрации): темно-серые лесные (16,15) > чернозем южный (9,81) > чернозем выщелоченный (8,72) > чернозем обыкновенный (8,64) > чернозем типичный (8,12) > темно-каштановые (7,83) > чернозем оподзоленный (4,79). Распределение металлов в почвенных горизонтах равномерно-аккумулятивное. Элементами выноса во всех изученных почвах являются Cr(0,42), Fe(0,43), Cu(0,66); Cd активно накапливается в выщелоченных (3,55) и типичных (2,17) черноземах, Mn — в темно-серых лесных почвах (2,04); Pb равномерно распределен в профиле почв и аккумулируется в профиле серых лесных (1,24) и темно-каштановых (0,94) почв; Cd, Zn, Cu, Cr накапливаются в верхнем пахотном горизонте; Fe и Mn мигрируют в нижележащие слои почвы.

Variation in main morphometric parameters of chernozems under anthropogenic impact

Data characterizing the distribution pattern of the main morphometric parameters of chernozems in the Kamennaya Steppe are given. Variable thickness of humus horizon within a flat test plot typical for the central part of the chernozemic zone of Russia is shown. It has been revealed that annually exerted strong anthropogenic impact causes a pronounced drop in the thickness of humus horizon. The investigated objects on the test plot—fallow land, plowed filed, and forest shelter belt—were situated side by side. The statistical parameters of the thickness of humus horizon in different subtypes of chernozems have been calculated. They mainly differ by the depth of continuous impregnation with calcium carbonate (effervescence depth varies from 1 to 95 cm). The deepest effervescence is seen in the soils of the fallow and under the forest belt (68 and 63 cm, respectively).

Vztahy mezi respirací, kvalitou humusu a kationtovou výměnnou kapacitou u vybraných subtypů černozemí jižní Moravy

Soil organic matter (SOM) undergoes short and long-term transformation in the soil. Microorganisms through their enzymes are able to mineralize organic carbon while the rate of this process is different. Biological test though referred to one of the main diagnostic methods for evaluating soil qualit­y/health. The aim of our work was to determine basal respiration, total carbon content, fractio­nal composition of humus and basic parameters of soil colloidal complex in selected subtypes of chernozem in South Moravia region. Basal respiration was measured using Vaisala GMT220 apparatus. Total carbon content was determined by oxidimetric titration and basic parameters of soil colloidal according to Mehlich. Results showed that production of carbon dioxide varied from 0.09 to 0.27 mg CO2/100g/h. Linear correlation between basal respiration and humification degree was found. Humus content varied from 2.15% to 4.6%. No correlation between quantity of humus and basal respiration was observed. Higher values of basal respiration were connected with higher quality of HS. Significant linear correlation between total carbon content (TOC) and cation exchange capacity (CEC) was found.

Productivity of black locust (Robinia pseudoacacia L.) stands on chernozem in Vojvodina

This paper presents the elements of growth of black locust trees and stands in 15 sample plots in Vojvodina, at the age of 21-68 years. In each sample plot, based on soil profile horizons the determined soil type was chernozem as well as its lower systematic units (subtype, variety and form), according to the Skoric et al. (1985) classification. On the basis of the mean stand heights (hL), the stands on the subtype of chernozem on loess and loesslike sediments belong to height classes I-IV, and stands on calcareous aeolian sand to classes II-V (according to R e d e i et al. 2014), which indicates their considerable variability with respect to productivity within the determined subtypes of chernozem. Significant differences at the level of chernozem subtypes were found between the mean heights (p = 0.032), but not between the mean diameters (p = 0.083). The mean diameters at breast height in the studied black locust stands were on average lower than the models of diameter growth for the appropriate height classes and determined by a larger number of trees per hectare than in the tables (R e d e i et al, 2014). The volume per hectare is higher than in the tables also being conditioned by the large number of trees per hectare.

Валовий хімічний склад чорноземів Сокальсько-Торчинської пасмової височини

The results are given on total chemical composition of podzolic and typical chernozems of the Socal-Tortchin range upland. The geographical features of forming of morphological profile of chernozems of Volyn upland are educed. Connection is shown between different genetic subtypes of chernozems and chemical composition them silicate part. The cultural constituent of soil formation is educed in forming of morphological profile of deep chernozems on terrace localities of Volyn Pobuzia. Key words: chernozems, total chemical composition, structure of the soil profile, morphological signs, cultural evolution of soils.

The development of chernozems on the Dniester-Prut interfluve in the Holocene

The development of foreststeppe and steppe ch ernozems on the Dniester-Prut interfluve in the Holocene was studied on the basis of data on the paleosols buried under archaeological monuments of differ� ent ages. The parameters of the mathematic models of the development of the soil humus horizons in differ� ent subtypes of chernozems were calculated. They were used to determine the rate of this process and the age of the soils formed on the surface of Trajan's lower rampart. The climatecontrolled changes in the character of the soil's development in the Late Holocene were differently pronounced in the different subtypes of cher� nozems. The suggested differentiation of the trends in the development of the humus horizon in the studied chernozems corresponds to the differences in the soilforming potential of particular areas (as judged from the energy consumption for pedogenesis).

Changes in the enzymatic activity of soil samples upon their storage

The influence of the duration and conditions of storage of soil samples on the activity of soil enzymes (catalase, β-fructofuranosidase, and dehydrogenase) was studied for the main soils of southern Russia (different subtypes of chernozems, chestnut soils, brown forest soils, gray forest soils, solonetzes, and solonchaks). The following soil storage conditions were tested: (1) the air-dry state at room temperature, (2) the airdry state at a low positive (in a refrigerator, +4°C) temperature, (3) naturally moist samples at a low positive temperature, and (4) naturally moist samples at a negative (in a freezer, −5°C) temperature. It was found that the sample storing caused significant changes in the enzymatic activities, which depended on the soil type, the land use, the type of enzyme, and the duration and conditions of the sample storage. In the course of the storage, the changes in the enzymatic activity had a nonlinear character. The maximum changes were observed in the initial period (up to 12 weeks). Then, a very gradual decrease in the activity of the studied enzymes was observed. Upon the long-term (>12 weeks) storage under the different conditions, the difference in the activities of the soil enzymes became less pronounced. The storage of soil samples in the air-dried state at room temperature can be recommended for mass investigations.