Pub Date : 2024-06-03DOI: 10.1134/s1064229324600209
D. G. Polyakov, A. G. Ryabukha, T. A. Arkhangelskaya, I. V. Kovda
Abstract
The temperature dynamics of conjugated soils of a paleocryogenic soil complex on chalk deposits in the Orenburg oblast is studied. Temperature measurements are combined with the study of cryogenic characteristics. The freezing point of soil moisture has been measured in laboratory. The temperature field within the soil complex is most heterogeneous. In the fall–winter season, the soil of microhighs is colder than the soils of microlows and microslopes; however, the microslope warms up faster than the microelevation and microlow in the spring–summer season. The differences between the temperature of soils in the frozen layer of microhighs and microlows reach –4.5°C at the beginning of freezing (December 15, 2019 at a depth of 15 cm), –4.0°C at the end of winter (February 10–11, 2020 at a depth of 5 cm), and –6.5°C during thawing (March 21–23, 2020 at a depth of 5 cm). The differences in the temperature regime along the microrelief are accompanied by the differences in the moisture distribution along the profile and determine the manifestation of cryogenic processes. The soils of microhighs freeze deeper and lens-type cryostructure forms in the entire frozen layer; this is accompanied by frost heaving, cryogenic sorting of coarse fragments, and formation of a crust on the soil surface ensuring preservation of the microtopography and soil cover pattern of chalk polygons. Cryogenic processes determine the formation of a platy soil structure in microhighs. Freezing in microlows is blocked in the middle part of the profile because of relatively high soil temperatures and low soil freezing points. The cryogenic characteristics and processes described in microhighs are unobservable in microlows.
{"title":"Freezing of Chalk Cryomorphic Soil Complexes of the Orenburg Oblast: Temperature Regime and Cryogenic Processes in Soil Profile","authors":"D. G. Polyakov, A. G. Ryabukha, T. A. Arkhangelskaya, I. V. Kovda","doi":"10.1134/s1064229324600209","DOIUrl":"https://doi.org/10.1134/s1064229324600209","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>The temperature dynamics of conjugated soils of a paleocryogenic soil complex on chalk deposits in the Orenburg oblast is studied. Temperature measurements are combined with the study of cryogenic characteristics. The freezing point of soil moisture has been measured in laboratory. The temperature field within the soil complex is most heterogeneous. In the fall–winter season, the soil of microhighs is colder than the soils of microlows and microslopes; however, the microslope warms up faster than the microelevation and microlow in the spring–summer season. The differences between the temperature of soils in the frozen layer of microhighs and microlows reach –4.5°C at the beginning of freezing (December 15, 2019 at a depth of 15 cm), –4.0°C at the end of winter (February 10–11, 2020 at a depth of 5 cm), and –6.5°C during thawing (March 21–23, 2020 at a depth of 5 cm). The differences in the temperature regime along the microrelief are accompanied by the differences in the moisture distribution along the profile and determine the manifestation of cryogenic processes. The soils of microhighs freeze deeper and lens-type cryostructure forms in the entire frozen layer; this is accompanied by frost heaving, cryogenic sorting of coarse fragments, and formation of a crust on the soil surface ensuring preservation of the microtopography and soil cover pattern of chalk polygons. Cryogenic processes determine the formation of a platy soil structure in microhighs. Freezing in microlows is blocked in the middle part of the profile because of relatively high soil temperatures and low soil freezing points. The cryogenic characteristics and processes described in microhighs are unobservable in microlows.</p>","PeriodicalId":11892,"journal":{"name":"Eurasian Soil Science","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2024-06-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141255947","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-06-03DOI: 10.1134/s1064229324600167
R. E. Musaelyan, K. N. Abrosimov, K. A. Romanenko
Abstract—
The use of synthetic and natural resins in the fixation of organomineral matter for further studies is common, e.g. in the micromorphological study of soils, since the procedure of making thin sections includes the impregnation of the sample with the filling materials (resins). At the same time, their effect on the soil structure remains poorly known. In this article, an experiment to study the impact of synthetic and natural resins on the nano- and microstructure of soil during impregnation is considered. First data on the characteristics of resins frequently used in laboratories, as well as on their effects on the structure of soil samples have been obtained with small-angle X-ray scattering and computed tomography techniques. The X-ray transparency of fixing materials was detected. Subsequent impregnation of the AU horizon fraction from Haplic Chernozems of Kursk oblast by fixing materials allowed establishing their influence on the change in size of soil nanostructural heterogeneities. The experiment with different horizons of Protosalic Solonetz attests to a decrease in the size of nanoheterogeneities with depth in the impregnated soil as compared with that in the native soil. At the microlevel, a decrease in microporosity within the first percent after polymerization of the fixing material has been proved. As a result of studies of nanoheterogeneities in the soil, scanning parameters have been experimentally selected at the BioSAS station of the Kurchatov`s synchrotron radiation source. The nanostructure of soil core samples and separate fractions has been studied for the first time at this station. The above results can be used in sample preparation and further analysis of organomineral objects (soils, rocks) for a number of studies that require fixation of the substance structure at different dimensional levels.
摘要--合成树脂和天然树脂在固定有机矿物物质以进行进一步研究方面的应用非常普遍，例如在土壤微观形态研究中，因为制作薄片的程序包括用填充材料（树脂）浸渍样品。与此同时，人们对填充材料对土壤结构的影响还知之甚少。本文通过实验研究了合成树脂和天然树脂在浸渍过程中对土壤纳米和微观结构的影响。通过小角 X 射线散射和计算机断层扫描技术，获得了实验室常用树脂特性及其对土壤样本结构影响的第一手数据。检测了固定材料的 X 射线透明度。随后用固定材料浸渍库尔斯克州哈普利克切尔诺泽姆的非盟地层部分，确定了它们对土壤纳米结构异质性大小变化的影响。对不同地层的原盐 Solonetz 进行的实验证明，与原生土壤相比，浸渍土壤中纳米异构体的大小随着深度的增加而减小。在微观层面上，固定材料聚合后的第一个百分点内，微孔减少已得到证实。在对土壤中的纳米异质性进行研究后，在库尔恰托夫同步辐射源的 BioSAS 站对扫描参数进行了实验性选择。在该站首次研究了土壤核心样本和单独馏分的纳米结构。上述结果可用于样品制备和有机矿物物体（土壤、岩石）的进一步分析，以进行一些需要固定不同维度物质结构的研究。
{"title":"Effect of Different Synthetic Resins on Soil Nano- and Microstructure","authors":"R. E. Musaelyan, K. N. Abrosimov, K. A. Romanenko","doi":"10.1134/s1064229324600167","DOIUrl":"https://doi.org/10.1134/s1064229324600167","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">\u0000<b>Abstract</b>—</h3><p>The use of synthetic and natural resins in the fixation of organomineral matter for further studies is common, e.g. in the micromorphological study of soils, since the procedure of making thin sections includes the impregnation of the sample with the filling materials (resins). At the same time, their effect on the soil structure remains poorly known. In this article, an experiment to study the impact of synthetic and natural resins on the nano- and microstructure of soil during impregnation is considered. First data on the characteristics of resins frequently used in laboratories, as well as on their effects on the structure of soil samples have been obtained with small-angle X-ray scattering and computed tomography techniques. The X-ray transparency of fixing materials was detected. Subsequent impregnation of the AU horizon fraction from Haplic Chernozems of Kursk oblast by fixing materials allowed establishing their influence on the change in size of soil nanostructural heterogeneities. The experiment with different horizons of Protosalic Solonetz attests to a decrease in the size of nanoheterogeneities with depth in the impregnated soil as compared with that in the native soil. At the microlevel, a decrease in microporosity within the first percent after polymerization of the fixing material has been proved. As a result of studies of nanoheterogeneities in the soil, scanning parameters have been experimentally selected at the BioSAS station of the Kurchatov`s synchrotron radiation source. The nanostructure of soil core samples and separate fractions has been studied for the first time at this station. The above results can be used in sample preparation and further analysis of organomineral objects (soils, rocks) for a number of studies that require fixation of the substance structure at different dimensional levels.</p>","PeriodicalId":11892,"journal":{"name":"Eurasian Soil Science","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2024-06-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141255949","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-06-03DOI: 10.1134/s1064229324600106
Y. V. Kholopov, D. D. Khaidapova, A. B. Novakovskiy, E. M. Lapteva
Abstract—
The results of rheological studies of semihydromorphic soils of taiga zone in the northeast of the European part of Russia (Komi Republic) on a modular rheometer MCR-302 (Anton Paar, Austria) by an amplitude sweep test (oscillatory method) are considered. Rheological studies of soil samples have been performed with plate–plate measuring systems at maximum capillary water saturation. The strongest interactions between soil particles develop in the horizons with the high content of mobile humus compounds (fulvic acids) and Al–Fe-humus complexes (ELhi,g–ELg–CRM horizons). Increased structural stiffness is due to the binding of soil particles with humus substances and Al–Fe-humus complexes with the development of strong interparticle bonds. Freezing–thawing processes are an important factor of changes in rheological parameters. The impact of seasonal freezing on the rheological behavior is most clearly pronounced in the profile of semihydromorphic svetlozems (Histic Gleyic Stagnosols) in their cryometamorphic (CRM) horizons, where increased stiffness of interparticle bonds is due to condensation compaction of soil particles in the course of the long-term development under temperatures close to 0°С (zero curtain). With an increase in the soil moistening, disaggregation of the mineral mass takes place, which is seen from a significant increase in the plasticity range. Disaggregated soils are more susceptible to erosion, but a thick moss–peat layer forming in the upper part of the profile of semihydromorphic soils protects them from degradation. In the northward direction, from the texturally differentiated soils of southern taiga to the cryomethamorphic soils of forest-tundra, the stiffness and brittleness of interparticle bonds increase, which is associated with a more active input of fulvic acids, including Al–Fe-humus complexes, as well as with a longer freezing of northern soils. It is shown that rheological parameters can be used as additional indicators in the diagnosis and classification of taiga soils.
{"title":"Rheological Properties of Taiga Semihydromorphic Soils: Relationship with Physicochemical Properties and Temperature Conditions","authors":"Y. V. Kholopov, D. D. Khaidapova, A. B. Novakovskiy, E. M. Lapteva","doi":"10.1134/s1064229324600106","DOIUrl":"https://doi.org/10.1134/s1064229324600106","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">\u0000<b>Abstract</b>—</h3><p>The results of rheological studies of semihydromorphic soils of taiga zone in the northeast of the European part of Russia (Komi Republic) on a modular rheometer MCR-302 (Anton Paar, Austria) by an amplitude sweep test (oscillatory method) are considered. Rheological studies of soil samples have been performed with plate–plate measuring systems at maximum capillary water saturation. The strongest interactions between soil particles develop in the horizons with the high content of mobile humus compounds (fulvic acids) and Al–Fe-humus complexes (ELhi,g–ELg–CRM horizons). Increased structural stiffness is due to the binding of soil particles with humus substances and Al–Fe-humus complexes with the development of strong interparticle bonds. Freezing–thawing processes are an important factor of changes in rheological parameters. The impact of seasonal freezing on the rheological behavior is most clearly pronounced in the profile of semihydromorphic svetlozems (Histic Gleyic Stagnosols) in their cryometamorphic (CRM) horizons, where increased stiffness of interparticle bonds is due to condensation compaction of soil particles in the course of the long-term development under temperatures close to 0°С (zero curtain). With an increase in the soil moistening, disaggregation of the mineral mass takes place, which is seen from a significant increase in the plasticity range. Disaggregated soils are more susceptible to erosion, but a thick moss–peat layer forming in the upper part of the profile of semihydromorphic soils protects them from degradation. In the northward direction, from the texturally differentiated soils of southern taiga to the cryomethamorphic soils of forest-tundra, the stiffness and brittleness of interparticle bonds increase, which is associated with a more active input of fulvic acids, including Al–Fe-humus complexes, as well as with a longer freezing of northern soils. It is shown that rheological parameters can be used as additional indicators in the diagnosis and classification of taiga soils.</p>","PeriodicalId":11892,"journal":{"name":"Eurasian Soil Science","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2024-06-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141255857","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-06-03DOI: 10.1134/s1064229324600076
E. V. Chernysheva, F. Fornasier
Abstract
A study of the influence of farming practices in the Middle Ages (X–XV AD) on the activities of 11 hydrolytic enzymes involved in the biogeochemical cycles of major elements in soils has been carried out. Agrostratozems of Medieval agricultural terraces in Dagestan mountains (Plaggic and Hortic Anthrosols) were chosen as objects of study. In all cases, the enzymatic activity of the studied soils decreased in all soil layers in the following sequence: alkaline phosphatase > phosphodiesterase > acid phosphatase > pyrophosphatase ≥ leucine aminopeptidase > arylsulfatase > chitinase > β-glucosidase > xylanase > α-glucosidase > cellobiohydrolase. The enzymatic activity of the studied soils was primarily determined by the amount of microbial biomass (Cmic). Thus, the activity of enzymes of various groups depended on Cmic by 61–94%. Agricultural practices associated with ploughing, manuring, and irrigation induce the convergence in the activity of nitrogen cycle enzymes in soils of the mountain zone, which is associated with similar features of the nitrogen cycle in agrogenic soils, regardless of bioclimatic conditions. The addition of organic materials has led to an increase in the physiological efficiency of microbial communities and the rate of enzyme production, and high levels of biological activity can persist in soil for about 1000 years. Ploughing with the application of organic fertilizers in the past led to an increase in enzymatic activity expressed per unit of microbial biomass (specific activity), therefore, this indicator can be used as an indicator of agrogenic transformation of soils in the past.
{"title":"Specific Features of the Pool of Hydrolytic Enzymes in Soils of Agricultural Terraces in the Eastern Caucasus","authors":"E. V. Chernysheva, F. Fornasier","doi":"10.1134/s1064229324600076","DOIUrl":"https://doi.org/10.1134/s1064229324600076","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>A study of the influence of farming practices in the Middle Ages (X–XV AD) on the activities of 11 hydrolytic enzymes involved in the biogeochemical cycles of major elements in soils has been carried out. Agrostratozems of Medieval agricultural terraces in Dagestan mountains (Plaggic and Hortic Anthrosols) were chosen as objects of study. In all cases, the enzymatic activity of the studied soils decreased in all soil layers in the following sequence: alkaline phosphatase > phosphodiesterase > acid phosphatase > pyrophosphatase ≥ leucine aminopeptidase > arylsulfatase > chitinase > β-glucosidase > xylanase > α-glucosidase > cellobiohydrolase. The enzymatic activity of the studied soils was primarily determined by the amount of microbial biomass (C<sub>mic</sub>). Thus, the activity of enzymes of various groups depended on C<sub>mic</sub> by 61–94%. Agricultural practices associated with ploughing, manuring, and irrigation induce the convergence in the activity of nitrogen cycle enzymes in soils of the mountain zone, which is associated with similar features of the nitrogen cycle in agrogenic soils, regardless of bioclimatic conditions. The addition of organic materials has led to an increase in the physiological efficiency of microbial communities and the rate of enzyme production, and high levels of biological activity can persist in soil for about 1000 years. Ploughing with the application of organic fertilizers in the past led to an increase in enzymatic activity expressed per unit of microbial biomass (specific activity), therefore, this indicator can be used as an indicator of agrogenic transformation of soils in the past.</p>","PeriodicalId":11892,"journal":{"name":"Eurasian Soil Science","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2024-06-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141255855","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-06-03DOI: 10.1134/s106422932460026x
K. S. Boyarshin, V. V. Adamova, W. Zheng, E. V. Nikitinskaya, O. Yu. Obukhova, M. V. Kolkova, V. A. Nesterenko, O. S. Bespalova, V. V. Klyueva, K. A. Degtyareva, L. V. Nesteruk, Yu. N. Kurkina, O. A. Makanina, E. S. Ivanova, Zh. Li, I. V. Batlutskaya
Abstract
Families and genera of bacteria that predominate in chernozems of the forest-steppe zone have been identified. Microbiological profiling of samples of plowed and unplowed chernozems is performed, using the 16S rRNA gene sequencing, at different phases of the growing period: in June and August. Changes in the proportion of individual bacterial families, depending on land use and time, are shown. Correlations between the occurrence of bacterial families and chemical parameters of soil have been revealed. The predominant role of nitrates in the formation of the community structure and the important contribution of the organic carbon content, soil moisture, and pH in this process are shown. Despite the revealed differences in the proportions of the studied families, depending on land use and the sampling period, the set of dominant bacterial families in the studied samples remains stable. The first six dominant families comprise about 1/4 of the entire community, and the first 20 ones make up about 40%. The obtained results create prerequisites for further study of the variability of the taxonomic composition of the bacterial community in chernozems under various biotic and agrochemical conditions.
{"title":"Dominant Bacterial Taxa in Chernozems and Factors Affecting Their Abundance in the Bacterial Community","authors":"K. S. Boyarshin, V. V. Adamova, W. Zheng, E. V. Nikitinskaya, O. Yu. Obukhova, M. V. Kolkova, V. A. Nesterenko, O. S. Bespalova, V. V. Klyueva, K. A. Degtyareva, L. V. Nesteruk, Yu. N. Kurkina, O. A. Makanina, E. S. Ivanova, Zh. Li, I. V. Batlutskaya","doi":"10.1134/s106422932460026x","DOIUrl":"https://doi.org/10.1134/s106422932460026x","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>Families and genera of bacteria that predominate in chernozems of the forest-steppe zone have been identified. Microbiological profiling of samples of plowed and unplowed chernozems is performed, using the 16S rRNA gene sequencing, at different phases of the growing period: in June and August. Changes in the proportion of individual bacterial families, depending on land use and time, are shown. Correlations between the occurrence of bacterial families and chemical parameters of soil have been revealed. The predominant role of nitrates in the formation of the community structure and the important contribution of the organic carbon content, soil moisture, and pH in this process are shown. Despite the revealed differences in the proportions of the studied families, depending on land use and the sampling period, the set of dominant bacterial families in the studied samples remains stable. The first six dominant families comprise about 1/4 of the entire community, and the first 20 ones make up about 40%. The obtained results create prerequisites for further study of the variability of the taxonomic composition of the bacterial community in chernozems under various biotic and agrochemical conditions.</p>","PeriodicalId":11892,"journal":{"name":"Eurasian Soil Science","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2024-06-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141255742","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-06-03DOI: 10.1134/s1064229323603359
V. S. Anisimov, S. V. Fesenko, G. P. Glazunov, L. N. Anisimova, A. I. Sanzharov, S. V. Korovin, D. V. Krylenkin, Yu. N. Korneev, N. V. Novikova, M. V. Mezina, D. A. Zheltov
Abstract
The ecological and toxicological assessment of the soil and plant cover of a key site in the Streletskaya Steppe in the V.V. Alekhin Central Chernozem Reserve is presented. The content of heavy metals (HMs) and radionuclides in typical chernozem is determined. The clarkes of concentration of HMs (Cc); geoaccumulation lithogeochemical indices (Igeo) for As, Cd, Co, Cs, Cu, K, Pb, Sr, Zn, 232Th, and 238U; and pollution indices (PI) for individual HMs in chernozem have been calculated. It is shown that the pedogeochemical background is higher in comparison with the lithosphere clarkes only for Cd and As. In may be concluded that soils are not polluted with the studied HMs, namely, As, Cd, Cu, Pb, and Zn. The content of radionuclides (40K, 137Cs, 232Th, and 238U), HMs, and potassium in various types of natural steppe vegetation has been determined. Based on the plant accumulation coefficients of HMs and radionuclides, the biophilicity of radionuclides and HMs was estimated. The transfer factors (TFs) of 137Cs and 40K from soil to plants have been calculated, and a comparative analysis of the bioavailability of cesium and potassium during root uptake is performed. The vertical distribution of 137Cs and 40K radionuclides in the root-inhabited soil layer from 0- to 20-cm-thick is studied. It is shown that 40K is evenly distributed in the root-inhabited layer. The vertical distribution of 137Cs in the soil profile is characterized by the shift of the maximum from a depth of 0–5 to that of 5–10-cm. Based on the data obtained, the migration coefficient of 137Cs is calculated, taking into account the convective and diffusion components of the radionuclide translocation in typical chernozem.
{"title":"Ecological and Toxicological Assessment of the Soil-Plant Cover of Unmown Streletskaya Steppe in the V.V. Alekhin Central Chernozem Reserve","authors":"V. S. Anisimov, S. V. Fesenko, G. P. Glazunov, L. N. Anisimova, A. I. Sanzharov, S. V. Korovin, D. V. Krylenkin, Yu. N. Korneev, N. V. Novikova, M. V. Mezina, D. A. Zheltov","doi":"10.1134/s1064229323603359","DOIUrl":"https://doi.org/10.1134/s1064229323603359","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>The ecological and toxicological assessment of the soil and plant cover of a key site in the Streletskaya Steppe in the V.V. Alekhin Central Chernozem Reserve is presented. The content of heavy metals (HMs) and radionuclides in typical chernozem is determined. The clarkes of concentration of HMs (<i>C</i><sub>c</sub>); geoaccumulation lithogeochemical indices (<i>I</i><sub>geo</sub>) for As, Cd, Co, Cs, Cu, K, Pb, Sr, Zn, <sup>232</sup>Th, and <sup>238</sup>U; and pollution indices (PI) for individual HMs in chernozem have been calculated. It is shown that the pedogeochemical background is higher in comparison with the lithosphere clarkes only for Cd and As. In may be concluded that soils are not polluted with the studied HMs, namely, As, Cd, Cu, Pb, and Zn. The content of radionuclides (<sup>40</sup>K, <sup>137</sup>Cs, <sup>232</sup>Th, and <sup>238</sup>U), HMs, and potassium in various types of natural steppe vegetation has been determined. Based on the plant accumulation coefficients of HMs and radionuclides, the biophilicity of radionuclides and HMs was estimated. The transfer factors (TFs) of <sup>137</sup>Cs and <sup>40</sup>K from soil to plants have been calculated, and a comparative analysis of the bioavailability of cesium and potassium during root uptake is performed. The vertical distribution of <sup>137</sup>Cs and <sup>40</sup>K radionuclides in the root-inhabited soil layer from 0- to 20-cm-thick is studied. It is shown that <sup>40</sup>K is evenly distributed in the root-inhabited layer. The vertical distribution of <sup>137</sup>Cs in the soil profile is characterized by the shift of the maximum from a depth of 0–5 to that of 5–10-cm. Based on the data obtained, the migration coefficient of <sup>137</sup>Cs is calculated, taking into account the convective and diffusion components of the radionuclide translocation in typical chernozem.</p>","PeriodicalId":11892,"journal":{"name":"Eurasian Soil Science","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2024-06-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141255741","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-05-29DOI: 10.1134/s1064229323603530
D. Mrad, S. Boukhari, S. Dairi, Y. Djebbar
Abstract
Soil erosion poses a significant problem in the Mediterranean region, posing serious threats to the environment and natural resources. The objective of this study is to identify and evaluate the risks associated with gully erosion in the Medjerda watershed in the northeastern part of Algeria. To accomplish this goal, two models were utilized: the fuzzy analytic hierarchy process (F-AHP) and the frequency ratio (FR). Twelve factors that contribute to soil erosion were considered in the study: slope, elevation, distance to streams, land use and land cover, drainage density (DD), topographic wetness index (TWI), rainfall, soil groups, lineament density, soil power index (SPI), sediment transport index (STI), and plan curvature. The results indicate that sediment transport index (STI), rainfall, and slope are the most influential factors in predicting erosion in the Medjerda Basin. To validate the models used, the area under the receiver operating characteristics curve (AUC) was employed. The AUC values obtained for the FR and F-AHP models were 75.5 and 73.7%, respectively, indicating their excellent accuracy in identifying the erosion susceptibility area. The accuracy ratings of both models demonstrate their outstanding predictive capabilities. Thus, the results of soil erosion susceptibility maps with a better success rate and forecast could be beneficial and effective for implementing various policy measures to safeguard soil. They could be useful for managing gully erosion risks in different parts of the river basin.
{"title":"Mapping the Potential for Erosion Gullies Using Frequency Ratio and Fuzzy Analytical Hierarchy Process: Case Study Medjerda Basin, Northeast Algeria","authors":"D. Mrad, S. Boukhari, S. Dairi, Y. Djebbar","doi":"10.1134/s1064229323603530","DOIUrl":"https://doi.org/10.1134/s1064229323603530","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>Soil erosion poses a significant problem in the Mediterranean region, posing serious threats to the environment and natural resources. The objective of this study is to identify and evaluate the risks associated with gully erosion in the Medjerda watershed in the northeastern part of Algeria. To accomplish this goal, two models were utilized: the fuzzy analytic hierarchy process (F-AHP) and the frequency ratio (FR). Twelve factors that contribute to soil erosion were considered in the study: slope, elevation, distance to streams, land use and land cover, drainage density (DD), topographic wetness index (TWI), rainfall, soil groups, lineament density, soil power index (SPI), sediment transport index (STI), and plan curvature. The results indicate that sediment transport index (STI), rainfall, and slope are the most influential factors in predicting erosion in the Medjerda Basin. To validate the models used, the area under the receiver operating characteristics curve (AUC) was employed. The AUC values obtained for the FR and F-AHP models were 75.5 and 73.7%, respectively, indicating their excellent accuracy in identifying the erosion susceptibility area. The accuracy ratings of both models demonstrate their outstanding predictive capabilities. Thus, the results of soil erosion susceptibility maps with a better success rate and forecast could be beneficial and effective for implementing various policy measures to safeguard soil. They could be useful for managing gully erosion risks in different parts of the river basin.</p>","PeriodicalId":11892,"journal":{"name":"Eurasian Soil Science","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2024-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141198005","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-05-29DOI: 10.1134/s1064229324600258
F. F. Pan, S. Pan, J. Tang, B. H. Chen
Abstract
Biogas slurry is increasingly adopted as a substitute for chemical fertilizer to improve soil fertility and control soil degradation. But little is known about its long-term effects on different soil layers. This study aims to test if biogas slurry substitution alters soil nutrients and aggregates differently in different layers and how the effects are influenced by straw return. A five-year field trial of a winter wheat–summer maize rotation was established to evaluate the effects of biogas slurry substitution [treatments: control without fertilizer (CK); chemical fertilizer (CF); 50% biogas slurry substitution (BSCF); 100% biogas slurry substitution (BS)] on two soil layers (0–20 and 20–40 cm) under equal N, P, and K fertilization in a Fluvisol. The result showed that compared with CK, fertilization was necessary to maintain soil available nitrogen (AN) and available potassium (AK) in the 0–20 cm layer. Also, fertilization had positive effects on soil EC, TN, and AP, especially in the topsoil. In terms of increasing the degree of water-stable macroaggregation, improving aggregate stability and reducing their crushing rates, CF was superior to biogas slurry substitution because of the greater accumulations of soil N, the most important physicochemical factor regulating soil macroaggregation and stability. The effects of biogas slurry substitution changed with soil layers. In surface soil, BD, water-stable macroaggregates, and aggregate stability significantly increased due to the positive regulatory effects of straw, AP, and EC; whereas in subsoil, they decreased. Inorganic fertilization with straw return functions well in soil structural degradation control and N fertility improvement, especially in the topsoil. Whereas in fields without straw return, biogas slurry substitution may be a feasible and economical choice to improve topsoil structure and also an excellent supplement to provide P and K.
摘要沼气浆越来越多地被用作化肥的替代品，以提高土壤肥力和控制土壤退化。但人们对其对不同土层的长期影响知之甚少。本研究旨在检验沼气泥浆替代物是否会对不同土层的土壤养分和团聚体产生不同的影响，以及秸秆还田对这些影响有何影响。研究人员对冬小麦-夏玉米轮作进行了为期五年的田间试验，以评估沼液替代物[处理：无肥对照（CK）；化肥（CF）；50%沼液替代物（BSCF）；100%沼液替代物（BS）]在Fluvisol中同等氮、磷、钾施肥条件下对两个土层（0-20厘米和20-40厘米）的影响。结果表明，与 CK 相比，施肥对维持 0-20 厘米土层的土壤可用氮（AN）和可用钾（AK）是必要的。此外，施肥对土壤 EC、TN 和 AP 有积极影响，尤其是在表层土壤中。在提高水稳性大团聚程度、改善团聚体稳定性和降低其破碎率方面，CF 优于沼气浆替代物，因为土壤氮的积累更多，而土壤氮是调节土壤大团聚和稳定性的最重要的物理化学因素。沼气浆替代物的效果随土壤层的变化而变化。在表层土壤中，由于秸秆、AP 和 EC 的正向调节作用，BD、水稳大团聚物和团聚稳定性显著增加；而在底层土壤中，它们则有所减少。使用秸秆还田的无机肥能很好地控制土壤结构退化和提高氮肥，尤其是在表层土壤中。而在没有秸秆还田的田块中，沼气浆替代物可能是改善表土结构的一种可行且经济的选择，同时也是提供磷和钾的最佳补充物。
{"title":"Continuous Biogas Slurry Substitution of Chemical Fertilizer with Wheat/Maize Straw Return Alters Surface and Subsoil Physicochemical and Aggregate Properties Differently","authors":"F. F. Pan, S. Pan, J. Tang, B. H. Chen","doi":"10.1134/s1064229324600258","DOIUrl":"https://doi.org/10.1134/s1064229324600258","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>Biogas slurry is increasingly adopted as a substitute for chemical fertilizer to improve soil fertility and control soil degradation. But little is known about its long-term effects on different soil layers. This study aims to test if biogas slurry substitution alters soil nutrients and aggregates differently in different layers and how the effects are influenced by straw return. A five-year field trial of a winter wheat–summer maize rotation was established to evaluate the effects of biogas slurry substitution [treatments: control without fertilizer (CK); chemical fertilizer (CF); 50% biogas slurry substitution (BSCF); 100% biogas slurry substitution (BS)] on two soil layers (0–20 and 20–40 cm) under equal N, P, and K fertilization in a Fluvisol. The result showed that compared with CK, fertilization was necessary to maintain soil available nitrogen (AN) and available potassium (AK) in the 0–20 cm layer. Also, fertilization had positive effects on soil EC, TN, and AP, especially in the topsoil. In terms of increasing the degree of water-stable macroaggregation, improving aggregate stability and reducing their crushing rates, CF was superior to biogas slurry substitution because of the greater accumulations of soil N, the most important physicochemical factor regulating soil macroaggregation and stability. The effects of biogas slurry substitution changed with soil layers. In surface soil, BD, water-stable macroaggregates, and aggregate stability significantly increased due to the positive regulatory effects of straw, AP, and EC; whereas in subsoil, they decreased. Inorganic fertilization with straw return functions well in soil structural degradation control and N fertility improvement, especially in the topsoil. Whereas in fields without straw return, biogas slurry substitution may be a feasible and economical choice to improve topsoil structure and also an excellent supplement to provide P and K.</p>","PeriodicalId":11892,"journal":{"name":"Eurasian Soil Science","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2024-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141198012","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-05-13DOI: 10.1134/s1064229323603426
Qiankun Tan, Siyuan Huo, Deng Wang, Ming Wen, Mantian Xing, Mengyi Lu
Abstract
The hysteresis effect of water retention curve (WRC) has significant implications for comprehending soil water and salt transport, especially in areas with soil salinization. This study evaluates the hysteresis of WRC in saline soils by measuring the drying and wetting WRC of silty clay loam exposed to different salinities using a tension meter. We find that WRC is influenced by the superposition coupling effect of salinity and dry density, which results in an upward shift of WRC and increases the soil water holding capacity. In addition, soil matrix suction also rises with the increasing salt concentration, leading to a gradual upward shift in WRC. The presence of salt in pore spaces weakens the “ink-bottle” effect, disjoining pressure and air entrapment effect, results in a 30.9% reduction in hysteresis of WRC with increasing salinity. Additionally, the volumetric shrinkage of low dry density silty clay loam also weakens the WRC hysteresis. Furthermore, we utilized a WRC hysteresis model that considers the “ink-bottle” effect and entrapped air, which reasonably predicts the main wetting WRC of saline silty clay loam. The root-mean-square error and mean absolute error between predicted and measured values are 0.027–0.039 and 0.036–0.060, respectively. These findings are significant to the research and guidance of salinization in expansive soil and heavy textured soil area where salinization occurs.
{"title":"Hysteresis of Water Retention Curve of the Capillarimetric Diapason in Saline Soils","authors":"Qiankun Tan, Siyuan Huo, Deng Wang, Ming Wen, Mantian Xing, Mengyi Lu","doi":"10.1134/s1064229323603426","DOIUrl":"https://doi.org/10.1134/s1064229323603426","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>The hysteresis effect of water retention curve (WRC) has significant implications for comprehending soil water and salt transport, especially in areas with soil salinization. This study evaluates the hysteresis of WRC in saline soils by measuring the drying and wetting WRC of silty clay loam exposed to different salinities using a tension meter. We find that WRC is influenced by the superposition coupling effect of salinity and dry density, which results in an upward shift of WRC and increases the soil water holding capacity. In addition, soil matrix suction also rises with the increasing salt concentration, leading to a gradual upward shift in WRC. The presence of salt in pore spaces weakens the “ink-bottle” effect, disjoining pressure and air entrapment effect, results in a 30.9% reduction in hysteresis of WRC with increasing salinity. Additionally, the volumetric shrinkage of low dry density silty clay loam also weakens the WRC hysteresis. Furthermore, we utilized a WRC hysteresis model that considers the “ink-bottle” effect and entrapped air, which reasonably predicts the main wetting WRC of saline silty clay loam. The root-mean-square error and mean absolute error between predicted and measured values are 0.027–0.039 and 0.036–0.060, respectively. These findings are significant to the research and guidance of salinization in expansive soil and heavy textured soil area where salinization occurs.</p>","PeriodicalId":11892,"journal":{"name":"Eurasian Soil Science","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2024-05-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140936755","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-05-13DOI: 10.1134/s1064229323603384
P. Kunmala, W. Jindaluang, T. Darunsontaya
Abstract
Evidence has suggested that either labile organic carbon (OC) or stable OC play a role in improving aggregate stability. Therefore, this study determined the OC fractions in water stable aggregates (WSA) and their contribution to the formation of the WSA in paddy soils, on the Central Plain of Thailand. Analysis of the OC fractions in the WSA was determined using wet oxidation with hydrogen peroxide (H2O2). The chemical composition of the organic compounds in the WSA was investigated using Fourier transform mid-infrared (FT-IR) spectroscopy. The results showed that the WSA content of the studied soils significantly increased with increasing organic and inorganic cementing/flocculating agents, such as soil organic carbon, clay, polyvalent cations, and sesquioxides. The labile OC and stable OC contents in the WSA also significantly increased with increased WSA content, suggesting the physical protection of OC fractions against microbial decomposition. The FT-IR analysis revealed that labile OC in the WSA, both before and after wet oxidation with H2O2, was dominated by polysaccharides, supporting the physical protection of labile OC by the WSA. Paddy soils containing higher organic and inorganic cementing/flocculating agents had higher stable OC, such as hydrophobic aromatic compounds, in the WSA, compared to paddy soils containing lower organic and inorganic cementing/flocculating agents. In turn, the WSA content of the soils in this study significantly increased with increases in the hydrophobic aromatic compounds in the WSA, suggesting the important role of stable hydrophobic organic compounds in enhancing the formation and stabilization of soil aggregates in these paddy soils.
{"title":"Labile and Stable Organic Carbon Fractions in Water Stable Aggregates and Their Contribution to Aggregate Stability in Paddy Soils","authors":"P. Kunmala, W. Jindaluang, T. Darunsontaya","doi":"10.1134/s1064229323603384","DOIUrl":"https://doi.org/10.1134/s1064229323603384","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>Evidence has suggested that either labile organic carbon (OC) or stable OC play a role in improving aggregate stability. Therefore, this study determined the OC fractions in water stable aggregates (WSA) and their contribution to the formation of the WSA in paddy soils, on the Central Plain of Thailand. Analysis of the OC fractions in the WSA was determined using wet oxidation with hydrogen peroxide (H<sub>2</sub>O<sub>2</sub>). The chemical composition of the organic compounds in the WSA was investigated using Fourier transform mid-infrared (FT-IR) spectroscopy. The results showed that the WSA content of the studied soils significantly increased with increasing organic and inorganic cementing/flocculating agents, such as soil organic carbon, clay, polyvalent cations, and sesquioxides. The labile OC and stable OC contents in the WSA also significantly increased with increased WSA content, suggesting the physical protection of OC fractions against microbial decomposition. The FT-IR analysis revealed that labile OC in the WSA, both before and after wet oxidation with H<sub>2</sub>O<sub>2</sub>, was dominated by polysaccharides, supporting the physical protection of labile OC by the WSA. Paddy soils containing higher organic and inorganic cementing/flocculating agents had higher stable OC, such as hydrophobic aromatic compounds, in the WSA, compared to paddy soils containing lower organic and inorganic cementing/flocculating agents. In turn, the WSA content of the soils in this study significantly increased with increases in the hydrophobic aromatic compounds in the WSA, suggesting the important role of stable hydrophobic organic compounds in enhancing the formation and stabilization of soil aggregates in these paddy soils.</p>","PeriodicalId":11892,"journal":{"name":"Eurasian Soil Science","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2024-05-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140942087","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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