Articoli di riviste sul tema "Carbonated soils"
Segui questo link per vedere altri tipi di pubblicazioni sul tema: Carbonated soils.
Cita una fonte nei formati APA, MLA, Chicago, Harvard e in molti altri stili
Vedi i top-50 articoli di riviste per l'attività di ricerca sul tema "Carbonated soils".
Accanto a ogni fonte nell'elenco di riferimenti c'è un pulsante "Aggiungi alla bibliografia". Premilo e genereremo automaticamente la citazione bibliografica dell'opera scelta nello stile citazionale di cui hai bisogno: APA, MLA, Harvard, Chicago, Vancouver ecc.
Puoi anche scaricare il testo completo della pubblicazione scientifica nel formato .pdf e leggere online l'abstract (il sommario) dell'opera se è presente nei metadati.
Vedi gli articoli di riviste di molte aree scientifiche e compila una bibliografia corretta.
1
MILLER, J. J., D. F. ACTON e R. J. ST. ARNAUD. "THE EFFECT OF GROUNDWATER ON SOIL FORMATION IN A MORAINAL LANDSCAPE IN SASKATCHEWAN". Canadian Journal of Soil Science 65, n. 2 (1 maggio 1985): 293–307. http://dx.doi.org/10.4141/cjss85-033.
Abstract (sommario):
The results of this study indicate the importance of groundwater flow and water table depth on the genesis, characteristics and distribution of soils within a hummocky morainal landscape. Non-saline and non-carbonated soils in upland depressions can be attributed to "depression-focused" recharge by snowmelt and snowmelt runoff in the spring, as evidenced by deep sola and/or eluvial horizons. Non-saline and carbonated soils on lower slopes adjacent to depressions are associated with local discharge and/or lateral flow from the adjacent groundwater mounds under the depressions in spring, as well as upward flow in the summer resulting from water use by phreatophytes such as willows, creating a water table depression around the slough fringes. Saline and carbonated soils at low elevations are associated with shallow and rather stable water tables, and local discharge from surrounding uplands. Soil types on uplands are more dependent on slope position and infiltration than on depth to water table or groundwater flow. Non-saline soils of different profile types occur on mid- and upper slope positions. These areas have a deep water table with mainly recharge or lateral flow occurring in the saturated zone. The infiltration of surface runoff water in upland depressions is the dominant factor influencing the distribution of soluble salts in this hummocky landscape. Key words: Water table, landscape position, recharge, discharge, soluble salts, soil genesis, morphology, carbonate soil
2
Yi, Yaolin, Martin Liska, Cise Unluer e Abir Al-Tabbaa. "Carbonating magnesia for soil stabilization". Canadian Geotechnical Journal 50, n. 8 (agosto 2013): 899–905. http://dx.doi.org/10.1139/cgj-2012-0364.
Abstract (sommario):
This paper investigates the potential for carbonating reactive magnesia (MgO) to serve as a more sustainable soil stabilization method by providing rapid and significant strength development of the stabilized soil through absorbing substantial quantities of CO2. Gaseous CO2 was forced through laboratory-prepared reactive MgO-treated soil samples in a triaxial cell set-up, and their resulting mechanical and microstructural properties were investigated using unconfined compressive strength, X-ray diffraction, and scanning electron microscopy. The results showed that adequately carbonated MgO-treated soils could, in a few hours, reach a similar strength range to corresponding 28 day Portland cement (PC)-stabilized soils. Hydrated magnesium carbonates, namely nesquehonite and hydromagnesite–dypingite, were the main products of the carbonated MgO in the soil, and were responsible for the significant strength development.
3
Shore, Margaret L., Harrison G. Hughes, Frank D. Moore e Danny H. Smith. "170 DRIP IRRIGATION OF PLASTIC-MULCHED STRAWBERRY USING CARBONATED WATER-A GREENHOUSE STUDY". HortScience 29, n. 5 (maggio 1994): 453c—453. http://dx.doi.org/10.21273/hortsci.29.5.453c.
Abstract (sommario):
Carbonated water (CW) application has enhanced yields of tomato. However, little is known about the mechanism of this response. Our objectives were to determine if strawberry would respond to CW application and the effect of soil pH modification on the expression of a yield response. Two different soils were used; a calcareous soil (5% CaCO3, pH 7.9), with a Zn content 0.8 ppm and a non-calcareous soil (< 1% CaCO3, pH 6.5) with a Zn content 8.8 ppm. The carbonated water temporarily lowered the pH of the calcareous soil to 6.7 and the non-calcareous soil to 5.9, at both extremes of the optimal range (6.0-6.7) for strawberry. Application of carbonated water increased production of marketable fruit as compared to the tap water control on both soils, and the magnitude of the response to CW was similar for both soils. Soil and water treatment effects on leaf tissue Zn levels will also be discussed.
4
Gasanov, Vilayat, e Bahadur Ismailov. "Diagnostics and Soil Forming Characteristics of Alluvial-Meadow Soils of Ganykh-Ayrichay Valley, Azerbaijan". Natural Systems and Resources, n. 1 (luglio 2020): 37–48. http://dx.doi.org/10.15688/nsr.jvolsu.2020.1.5.
Abstract (sommario):
This study is devoted to the influence of ecological conditions on soil forming and improving the nomenclature of alluvial-meadow-forest soils in the flood plains of the subtropical forest-shrubby zone within Azerbaijan. On the basis of detailed soil mapping, the primary areal of soil units and the structure of soil cover were determined in the area of the Ganykh-Ayrichay valley. The spatial distribution of primary soil units, genetic features and diagnostic indexes (extend of bedding and development of the soil profile, thickness of the decomposedaccumulative layer, content of humus, total nitrogen, base saturation, particle size distribution, etc.) of stratified and typical suborders of alluvial-meadow-forest soils are identified. The turbidity and content of the weighted deposits of stream water is determined using regime-measurements. The weighted deposits contain a considerable amount of humus (1.2–1.8%) and its water soluble part, total nitrogen (0.09–0.13%) which significantly affects the morphogenetic diagnostics of the above described soils. The status of the humus content is characterized by a high activity, in which humic acid (15.3–20.8%) and fulvic acid (16.2–22.5%) dominate significantly, while the third fraction riches to 1.23–2.30% in the selective-group content. The ratio of Ch.a.:Cf.a. reaches to 0.88–0.93 in the leached soil profile (5.8–6.0), while reaching to 1.19–1.32 in carbonated soils (7.3–7.5). The total chemical composition of soils shows that the profile of leached soil is characterized by increasing the SiO2 (60.2–64.0%) content and sesquioxides (Al2O3=17.6–19.5%, Fe2O3=8.5–10.3%) and the carbonated suborders contain more CaO (7.1–9.2%). The active form of iron (Fe3+=182–496; Fe2+=56–123 mg 100 g soil) hints the insufficiency content in carbonated soils.
5
Liu, Song-Yu, Guang-Hua Cai, Guang-Yin Du, Liang Wang, Jiang-Shan Li e Xing-Chen Qian. "Field investigation of shallow soft-soil highway subgrade treated by mass carbonation technology". Canadian Geotechnical Journal 58, n. 1 (gennaio 2021): 97–113. http://dx.doi.org/10.1139/cgj-2020-0008.
Abstract (sommario):
The innovative carbonation technique based on reactive MgO and CO2 has been identified as an environmentally friendly and efficient method in the improvement of weak soils. Previous laboratory studies have indicated that carbonated MgO-admixed soils had significant improvement in mechanical properties. However, there are to date limited investigations on the soft-soil field application of this technique. In this study, a field trial was conducted to ascertain the feasibility of the MgO mass carbonation technique in improving shallow soft-soil subgrades. A series of field tests, including temperature, dynamic cone penetrometer, and light-weight deflectometer tests, were undertaken. The results indicated that compared with uncarbonated soil layers, there was two to three times increase in dynamic resilient moduli and soil resistances of carbonated MgO-admixed soils. The outcomes of this field investigation will contribute to the utilization of the combined stabilizer of MgO and CO2 and the mass carbonation technology in subgrade improvement.
6
Bouajila, A., e T. Gallali. "Soil Organic Carbon Fractions and Aggregate Stability in Carbonated and No Carbonated Soils in Tunisia". Journal of Agronomy 7, n. 2 (15 marzo 2008): 127–37. http://dx.doi.org/10.3923/ja.2008.127.137.
7
Cai, G. H., Y. J. Du, S. Y. Liu e D. N. Singh. "Physical properties, electrical resistivity, and strength characteristics of carbonated silty soil admixed with reactive magnesia". Canadian Geotechnical Journal 52, n. 11 (novembre 2015): 1699–713. http://dx.doi.org/10.1139/cgj-2015-0053.
Abstract (sommario):
Soil electrical resistivity has been used quite extensively for assessing mechanical properties of chemically treated soils in the recent past. One of the most innovative applications of this technique could be in the field of ground improvement wherein carbonated reactive magnesia (MgO) is employed for treating soils. With this in view, a systematic study that targets the application of electrical resistivity to correlate physical and strength characteristics of the carbonated reactive MgO-admixed silty soil is initiated, and its details are presented in this manuscript. To achieve this, reactive MgO-admixed soils were carbonized by exposing them to CO2 for different durations, and subsequently their electrical resistivity and unconfined compressive strength were measured. In this context, the role of a parameter, the ratio of the initial water content of the virgin soil to reactive MgO content (designated as w0/c), has been highlighted. It has also been demonstrated that w0/c is able to correlate, uniquely and precisely, with the physicochemical parameters of the soils (viz., unit weight, water content at failure, porosity, degree of saturation, and soil pH), electrical resistivity, and unconfined compressive strength at various carbonation times. In addition, microstructural properties have been obtained from the X-ray diffraction, scanning electron microscopy, and mercury intrusion porosimetry analyses. These properties have been used to substantiate the findings related to the carbonation of the reactive MgO-admixed soils.
8
Kyrylchuk, Andrii, Roman Malik e Sergiy Doroshkevich. ". MORPHOLOGICAL CHARACTERISTICS SOILS OF THE BELIGATIVE STRUCTURES OF THE KAMIANETS-PODILSKYI KAMIANETS-PODILSKYI STATE HISTORICAL RESERVE MUSEUM". SCIENTIFIC ISSUES OF TERNOPIL VOLODYMYR HNATIUK NATIONAL PEDAGOGICAL UNIVERSITY. SERIES: GEOGRAPHY 51, n. 2 (5 dicembre 2021): 30–38. http://dx.doi.org/10.25128/2519-4577.21.2.4.
Abstract (sommario):
The article presents micromorphological descriptions of soil profiles of key areas of the research territory. The results of micromorphological analysis and synthesis of selected soil samples are illustrated. For the first time the process-and-genetic features of urborendzins of beligerative structures were studied through the evaluation of their micromorphological structure.
Urborendzins of the beligerative landscape complex of the Kamianets-Podilskyi State Historical Preserve Museum are intrazonal biolithogenic polygenetic soils with complex phylogeny exposed to a long-term anthropogenic influence. It is important to establish their genesis, which is accompanied by a number of obstacles caused by the significant amplitude of the soil profile, morphological features, physical-and-chemical features and the presence of buried horizons in such soils. To solve the problem of age and ontogenesis staging of urborendzins, along with comparative-and-geographical, we use a complex paleopedological method with active application of micromorphological analysis, which allows to establish process-and-genetic features of soils by diagnosing elementary soil processes according to sustainable features at the micro level of solid phase formation.
Micromorphological structure evaluation makes it possible to consider soil as a system at the microscopic level and observe the natural flow of soil-forming processes in their interaction and ratio at all morphological levels - from microscopically small volumes of soil mass to soil profile in general. Consequently, micromorphological analysis is a unique one and possesses significant advantages over other methods of physical geography.
Urborendzins of the object under study have a complex problematic genesis and the use of micromorphological analysis and micromorphological synthesis is acceptable to solve these problems. The evaluation of the micromorphological structure of these soils was carried out for the first time, their micromorphological features were not previously determined as well as the genesis in general. Our micromorphological analysis allowed us to establish the process-and-diagnostic features of the studied soils and shows that in comparison with the background soil, the deposits of the «Day Tower» are more carbonated. Under the conditions of the washing regime, fragments of limestone deposits provide constant involvement of new weathered carbonated material in soil formation processes, which promotes saturation of soil solutions with calcium cations and, accordingly, formation of more stable microaggregation of soil mass and reduction of mobility of silty particles downwards the profile, fixed through by micromorphological researches in the form of the presence of high-order microaggregates. Comparing the background soil with the sediments of the «Day Tower», it can be stated that the agrorendzin typical, in contrast to urborendzin, leached from carbonates, is characterized by the practical absence of microorshteins, humic substances are mainly in a dispersed state and signs of movement of organo-clay substances downwards the profile can be traced much more clearly. This indicates that the background agrorendzin is formed under conditions of active biogenic and accumulative processes, carbonate leaching and illimerization.
Key words: micromorphological analysis, synthesis, soil, beligerative complex.
9
Filippov, D. V., I. N. Chursin, A. D. Boyarenkova e D. D. Rulev. "Results of soil carbonate enrichment research in irrigated areas using remote sensing data". Geodesy and Cartography 986, n. 8 (20 settembre 2022): 39–44. http://dx.doi.org/10.22389/0016-7126-2022-986-8-39-44.
Abstract (sommario):
The authors discuss a soil carbonate enrichment problem in the Volgograd region. These processes cause a decrease in yield and require timely identification and assessment of manifestation extent. Observing of large irrigated areas is very difficult. Therefore, the possibilities of monitoring soil carbonate enrichment processes using the analysis of Earth remote sensing data are becoming relevant. The aim of this work is to research the relationship of soil carbonate enrichment with the spectral characteristics of the surface obtained from the data of the “Resurs-P” ultra-high resolution satellite. Using the image from “Resurs-P”, the standard spectral indices were calculated. Most effective ones were selected, having the highest correlation with the degree of soil carbonization, determined from the compared field samples. Through geographic information systems, space images were marked with areas at the sampling points. Information from those sites was then analyzed using graphical visualization and regression analysis. As a result, a relationship was established between the values of the areas’ spectral brightness in the image from the “Resurs-P” and the level of carbonate enrichment. Based on the identified relationships, the Random Forest classifier was trained, using which a map of carbonated soils distribution in the irrigated territory of the Svetloyarsk irrigation system’s test site was created.
10
Lampreave, Miriam, Assumpta Mateos, Josep Valls, Montserrat Nadal e Antoni Sánchez-Ortiz. "Carbonated Irrigation Assessment of Grapevine Growth, Nutrient Absorption, and Sugar Accumulation in a Tempranillo (Vitis vinifera L.) Vineyard". Agriculture 12, n. 6 (30 maggio 2022): 792. http://dx.doi.org/10.3390/agriculture12060792.
Abstract (sommario):
Iron chlorosis is common in vineyards grown on calcareous soils, and consists of a chlorophyll deficiency caused by a disorder in iron nutrition. It is manifested by interveinal yellowing of the youngest leaves and decreased growth and production. Most of the vineyards in Spain are planted on calcareous soils, so iron chlorosis is frequent, even in tolerant rootstocks. In the case of Spain, Tempranillo accounts for 20.8% of the total Spanish wine area, with this red variety being the most planted. The study of iron chlorosis and the availability of nutrients is essential for improving the qualitative balance of the wine, as it is one of the most representative in our country. The aim of this work was to evaluate how carbonated irrigation modifies soil pH and increases the absorption of nutrients, as well as to assess the impact of chlorosis on the physiology of the variety and the composition of the grape. In the first instance, a test was carried out on bare soil of calcareous composition, evaluating three different levels of carbonated water, and seeing what response it gave to the pH level. The result showed that the dose of 400 ppm of CO2 provided the optimal pH. Subsequently, in a potted soil, the dose of 400 ppm of CO2 was evaluated on the variety cv. Tempranillo, in three different compositions of calcareous soil. Results showed that carbonated irrigation increased the levels of chlorophyll impacting on primary metabolism (acids and sugar), plant growth, and higher crop yield, improving the optimal grape ripeness. Given that irrigation with 400 ppm CO2 increased the ability to control ferric chlorosis, this strategy could be an easy-to-use alternative to iron-based chelates for preventing Fe deficiency in the grapevine as well as moderating the different levels of iron chlorosis. This strategy could be an alternative to the use of synthetic Fe chelates as EDTA or o,o-EDDHA for preventing Fe chlorosis in susceptible Tempranillo (Vitis vinifera L.) vineyard in calcareous soils, with less of a risk to the environment.
11
Solodov, I. N., e M. V. Nesterova. "Occurrence of Carbonated Groundwater and Hydrocarbons at the Uranium Deposits of the Khiagda Ore Field (Republic of Buryatia)". Геология рудных месторождений 65, n. 6 (1 novembre 2023): 495–508. http://dx.doi.org/10.31857/s0016777023060096.
Abstract (sommario):
A generalization of unpublished and published data since 1985 on biogeochemical, hydrogeochemical, geochemical, mineralogical studies and soil geochemistry at uranium deposits of the Khiagda ore field in the Vitim uranium ore district made it possible to reveal a genetic relation of deep cold carbonated hydrocarbonate–magnesium groundwater containing dissolved hydrocarbons (HCs) to uranium mineralization and ore preservation. The through penetration of epigenetic HCs was traced from the disintegration zone of basement granitoids through overlying sedimentary ore-bearing and volcanosedimentary rocks up to overlying fractured basalts. The assemblage of clarified rocks–HCs–siderites–uranium phosphates U(IV) was commonly found. Carbonated hydrocarbonate–magnesium groundwater and anomalous HC contents in soils can be additional criteria for identifying the Vitim-type uranium deposits in the Trans-Baikal region.
12
Comino, Francisco, Víctor Aranda, María J. Ayora-Cañada, Antonio Díaz e Ana Domínguez-Vidal. "Effect of irrigation water quality on soil properties and infrared spectroscopic signatures". Spanish Journal of Agricultural Research 17, n. 4 (13 febbraio 2020): e1105. http://dx.doi.org/10.5424/sjar/2019174-14920.
Abstract (sommario):
Aim of study: To study the effect of irrigation with medium-to-low-quality water on an olive farm that seems to be causing salinity and/or sodicity problems in soils, and the ability of infrared spectroscopy to detect this problem.Area of study: The study was conducted in an olive (Olea europaea L.) grove located in Guarromán (Jaen, Spain), on the boundary of the Sierra Morena Mountains and the Guadalquivir Depression.Material and methods: The olive farm is cultivated over two soil typologies, a calcareous area (carbonated) dominated by Regosols and a siliceous area with Leptosols. Typical soil physical and chemical parameters were determined, as well as near and mid infrared spectra were collected for analysis.Main results: Soil physical properties were affected by irrigation, with low infiltration rates and symptoms of structural degradation. Chemical properties were also altered, showing high pH, low amounts of organic carbon and N, and high sodium concentrations. These effects were stronger in the samples directly affected by the irrigation bulb, with the siliceous soils more affected than carbonated, probably due to the positive effect of the higher amounts of calcium in the latter. Using infrared spectroscopy, it was possible to discriminate the samples of this farm affected by sodicity from similar soil samples in Jaen province not affected.Research highlights: the use of medium-to-low quality irrigation water affected soil physical and chemical properties. Infrared spectroscopy could be useful for quick assessment of soil quality and soil degradation from salinity and sodicity.
13
Bedard-Haughn, Angela. "Gleysolic soils of Canada: Genesis, distribution, and classification". Canadian Journal of Soil Science 91, n. 5 (ottobre 2011): 763–79. http://dx.doi.org/10.4141/cjss10030.
Abstract (sommario):
Bedard-Haughn, A. 2011. Gleysolic soils of Canada: Genesis, distribution, and classification. Can. J. Soil Sci. 91: 763–779. This review examines the pedogenesis of Gleysolic soils, including how they affect and are affected by land use and climate change. In the Canadian System of Soil Classification, the Gleysolic Order includes all those soils with morphologic features that provide dominant physical evidence of oxidation-reduction processes or gleying. Gley features include dull coloured soil matrices and/or brightly coloured mottles, which arise due to periodic or permanently saturated conditions. Under saturated conditions, oxygen is rapidly depleted and alternative terminal electron acceptors (such as iron, Fe3+) are used by microorganisms in the decomposition of organic matter. Gleysolic soils are found throughout Canada, either in low-lying landscape positions in association with better-drained soil orders (e.g., Prairie Pothole region), or as the dominant soil type where topography and/or a slowly permeable substrate prolong the period of saturation (e.g., Clay Belt of northern Ontario and Quebec). These soils are often highly fertile agricultural land and are commonly drained for production, altering the soil-forming environment. Gleysolic soils have also been found to be potentially significant sources of greenhouse gas emissions due to high levels of denitrification and methanogenesis under their characteristic reducing conditions. Given their economic, ecologic, and environmental significance, further research is required to refine our understanding and classification of Gleysolic soils, particularly with respect to (1) how Gleysols are affected by human- or climate-change-induced changes to the drainage regime (either progressing towards reducing conditions or regressing to a non-redoximorphic state), (2) classification of carbonated and saline Gleysols, and (3) pseudogley versus groundwater Gleysols.
14
Chimitdorzhieva, E. O., Ts D.-Ts Korsunova e G. D. Chimitdorzhieva. "Microbiocenosis of Cryofrost Soils in the South of the Vitim Plateau". Агрохимия, n. 8 (1 agosto 2023): 68–74. http://dx.doi.org/10.31857/s0002188123060078.
Abstract (sommario):
The microbial communities in soils of cryomorphoses in the south of the Vitim Plateau have been studied. The objects of study were gley cryoturbated chernozems and humus-quasi-gley carbonated soils. In the course of the study, experimental sites with pronounced cryogenic phenomena were selected. The intensity of microbiological activity was determined by the carbon content of microbial biomass, the number of microorganisms in the dominant groups of microbial communities. Determination of the number of microorganisms in soils was carried out by direct microscopy, which makes it possible to carry out a more accurate count of bacteria in the soil, taking into account adsorbed cells. Cells were preliminarily desorbed on an ultrasonic disperser. The carbon of microbial biomass was determined by the rehydration method. Data were obtained characterizing the direction and intensity of microbiological processes along the horizons of soil profiles of heaving mounds and thermokarst depressions. The number of microorganisms and the dominant groups of bacterial communities of soils formed under the conditions of the ultracontinental climate of Buryatia and relatively close-lying permafrost are presented. It was revealed that bacterial microflora predominates in the soils of heaving mounds and thermokarst depressions. The intra-profile heterogeneity in the distribution of soil microorganisms indicates that, as a habitat, the soil is strongly differentiated in all directions. This differentiation along the vertical of heaving mound and thermokarst depression was reflected in the concept of soil horizons as special ecological niches and the possibility of using microbiological indications of heaving and subsidence occurring during heaving.
15
Nakvasina, E. N., T. A. Parinova, A. G. Volkov e L. V. Golubeva. "Soil and Vegetation Heterogeneity in Postagrogenic Restorative Succession in the Middle Taiga Subzone". Экология, n. 1 (1 gennaio 2023): 22–34. http://dx.doi.org/10.31857/s0367059723010080.
Abstract (sommario):
The specific features of the soil–vegetation heterogeneity at the early stages of restorative succession have been studied. These features are determined by biotic and bioinert conditions that were influenced by anthropogenic factors during long-term plowing on azonal carbonated soils in the middle taiga subzone (Kargopol district, Arkhangelsk Oblast, Russia). In total, 25 full-profile soil sections, 500 soil samples, 125 sites for counting tree and shrub species, 25 standard geobotanical plots, and 250 plots for counting herbaceous species have been studied and analyzed. During the first 15 years of restorative succession on fallow agricultural land, herbaceous vegetation has the highest phytocenotic significance. On the residual calcareous soils of the forest zone, the specialization of ecological properties, i.e., the confinement of species to certain factors is weakly pronounced only in some herbaceous species. The mosaic structure of vegetation cover on a 15-yearold fallow is determined not by the variability of soil properties and the influence of growing tree and shrub species, but by the biological properties of herbaceous plants and their specific requirements for environmental factors. Soil fertility and soil moisture are the main factors that determine the variations of vegetation at this stage.
16
Korsunova, Tsypilma, Erzhena Chimitdorzhieva, Galina Chimitdorzhieva, Maria Merkusheva, Yurii Tsybenov, Elena Valova e Nimbu Baldanov. "Microbiocenosis of the Permafrost Soils of Transbaikalia under Agriculture Use". Agronomy 13, n. 11 (30 ottobre 2023): 2740. http://dx.doi.org/10.3390/agronomy13112740.
Abstract (sommario):
An understanding of how the involvement of soils in agricultural turnover affects soil microbiocenosis has been attained. The aims of this study were to investigate the number of the main groups of microorganisms in microbial complexes, the carbon of microbial biomass and the enzymatic activity in permafrost soils under the influence of tillage. The presented data can provide an insight into the stability of the microbiome in region’s soils under agricultural influence. The significance of the study lies in obtaining new data on the microbiocenosis of permafrost soils, which will make it possible to reveal the orientation and intensity of microbiological processes during their agricultural use. The study uses the classical methods used in soil science and soil microbiology, which are characterized by accuracy and reliability. The general characteristics of the microbiocenosis of different types of the studied region’s soils have been revealed. The quantity of bacteria, including actinomycetes and fungi, in the studied soils was determined. The variability of indicators in time and space is shown. The number of bacteria was revealed to reach its maximum in the autumn period in grey forest non-podzolised soils, and the indicator decreases in the following manner: forest—10.6 billion cells/g, arable land—5.1 billion cells/g, virgin land—2.6 billion cells/g. The lowest indicator of bacterial abundance—0.5 billion cells/g was found on arable permafrost meadow chernozemic soil. A comparatively low bacterial content is characteristic of chernozem meal-carbonated: 1.9 billion cells/g on virgin land and 2.1 billion cells/g on arable land. The length of actinomycete mycelium is dynamic according to the seasons of the year. The maximum length of actinomycete mycelium was observed in grey forest non-podzolised soil (forest) in the autumn period—830 m/g. The maximum length of fungal mycelium was also observed in grey forest non-podzolised soil (forest) in autumn—1200 m/g. In arable variants, the length of fungal mycelium is high in grey forest non-podzolised soils and meadow permafrost soils. In chernozems and permafrost meadow chernozemic soils (virgin and arable) the index is much lower. Assessment of catalase activity showed that the studied soils are poor or moderately enriched in this enzyme. Relatively high invertase activity was found in all variants.
17
Virto, Iñigo, Maria José Imaz, Alberto Enrique, Willem Hoogmoed e Paloma Bescansa. "Burning crop residues under no-till in semi-arid land, Northern Spain—effects on soil organic matter, aggregation, and earthworm populations". Soil Research 45, n. 6 (2007): 414. http://dx.doi.org/10.1071/sr07021.
Abstract (sommario):
Stubble burning has traditionally been used in semi-arid land for pest and weed control, and to remove the excess of crop residues before seeding in no-tillage systems. We compared differences in soil properties in a long-term (10 years) tillage trial on a carbonated soil in semi-arid north-east Spain under no-tillage with stubble returned and stubble burnt, with the conventional tillage system (mouldboard plough, stubble returned) as a reference. Differences in total soil organic C and C in particulate organic matter, mineralisation potential, soil physical properties (bulk density, penetration resistance, and aggregate size distribution and stability), and earthworm populations were quantified. The effect of stubble burning was absent or insignificant compared with that of tillage in most of the parameters studied. The most significant effect of stubble burning was the change in soil organic matter quality in the topsoil and penetration resistance. No-till plus stubble burning stocked an amount of organic C in the soil similar to no-till without burning, but the particulate organic matter content and mineralisation potential were smaller. Earthworm activity was similar under the 2 no-till systems, although a trend towards bigger earthworms with increasing penetration resistance was observed under the system with burning. Our results indicate that the role of burnt plant residues and earthworms in organic matter accumulation and soil aggregation in Mediterranean carbonated soils under no tillage is of major importance, meriting further attention and research.
18
LIU, Jiangying, Dimin XU, Lan XIONG, Colin HILLS, Paula CAREY e Kevin GARDNER. "Comparison of properties of traditional and accelerated carbonated solidified/stabilized contaminated soils". Journal of Environmental Sciences 20, n. 5 (gennaio 2008): 593–98. http://dx.doi.org/10.1016/s1001-0742(08)62099-9.
19
Achour, Yosra, Radhia Souissi, Haifa Tlil, Fouad Souissi e Mikael Motelica-Heino. "Mobility of Potentially Toxic Elements (Pb, Zn, Cd, As, Sb) in Agricultural Carbonated Soils Contaminated by Mine Tailings (Northern Tunisia): A New Kinetic Leaching Approach with Organic Acids". Water 14, n. 20 (21 ottobre 2022): 3337. http://dx.doi.org/10.3390/w14203337.
Abstract (sommario):
The present study was carried out to show the potential of root exudates to mobilize potentially toxic elements (PTE) present in rhizospheric carbonated soils. Five different contaminated rhizospheric soils were collected from five former mining districts of northern Tunisia (Jebel Hallouf (H3), Sidi-Bouaouane (B1), Jebel Ghozlane (G7), Hammam Zriba (Z2) and Jalta (J2)). The abundant minerals in these soils are quartz, calcite and clays. These soils contain significant PTE amounts compared to the local geochemical background (LGB). The important concentrations of Pb, Zn, Cd, As and Sb are, respectively, in the order of 17,350 mg·kg−1 in B1, 37,000 mg·kg−1 in G7, 205 mg·kg−1 in G7, 683 mg·kg−1 in B1 and 145 mg·kg−1 in B1. Kinetic leaching tests were conducted with a mixture of low molecular weight organic acids (LMWAOs) for increasing times up to 16 h (initial pH = 2.8) to study the mobility of PTE in the rhizospheric soils. The results showed an increase in the pH of the solution (2.8) to values up to neutrality together with the increase in Ca and Mg concentrations in the leachate, resulting from the dissolution of carbonates (calcite and dolomite). Additionally, leaching tests showed important extractions of Cd and Zn (25% for Cd and 11% for Zn). Pb was also mobilized but to a lesser extent (5%). The extractability of metalloids (As and Sb) was, in contrast, relatively low, except for Jebel Hallouf and Sidi Bouaouane soils, with an extraction percentage of no more than 1% for Sb and 0.1% for As, respectively. The mobility of Zn, Pb and Cd was thought to be controlled by both the solubility of their host minerals (e.g., sphalerite, hemimorphite, cerussite and jordanite) and the high pH. In contrast, As and Sb mobility was dependent on secondary carrier phases such as iron oxyhydroxides.
20
Haq, Farid Ul, Faridullah Faridullah, Muhammad Irshad, Aziz Ur Rahim Bacha, Farhan Hafeez, Zahid Ullah, Akhtar Iqbal et al. "Fractionation and Characterization of Metallic Elements in Soils in Land Use Systems". Toxics 12, n. 2 (28 gennaio 2024): 110. http://dx.doi.org/10.3390/toxics12020110.
Abstract (sommario):
Land use has a great impact on soil dynamics. The soils of various land use systems in Central Karakoram have been under immense pressure in the recent past due to certain anthropogenic activities such as land use practices and land use cover changes. These influences have an impact on the spatial distribution of metallic elements (MEs) in the soils of various land uses. Herein, we investigated the occurrence of the MEs, copper (Cu), zinc (Zn), and nickel (Ni), in soils of various land uses such as the permafrost, pasture, forest, and agricultural lands of the Central Karakorum region. The MEs were extracted in exchangeable, adsorbed, organically bound, carbonated, precipitated, and residual forms. The concentrations of MEs showed a significant dependence on the extraction method used, and the extraction trend followed the order of EDTA > HNO3 > KNO3 > NaOH > H2O. Zn showed the highest concentration compared to Ni and Cu in all extractions, whereas the land uses’ ME concentration followed the order of agricultural land > permafrost > forest > pasturelands. The highest values of total Zn, Ni, and Cu were 712 ± 01 mg/kg, 656 ± 02 mg/kg, and 163 ± 02 mg/kg, respectively, in agricultural soil. The ME concentration showed significant variations between different land uses, and the highest concentration was noted in agricultural soil. Zn was found to be a dominant ME compared to Ni and Cu. We believe this effort will provide opportunities for scholars to investigate MEs around the globe.
21
Martín-Sanz, Juan Pedro, Ana de Santiago-Martín, Inmaculada Valverde-Asenjo, José Ramón Quintana-Nieto, Concepción González-Huecas e Antonio L. López-Lafuente. "Comparison of soil quality indexes calculated by network and principal component analysis for carbonated soils under different uses". Ecological Indicators 143 (ottobre 2022): 109374. http://dx.doi.org/10.1016/j.ecolind.2022.109374.
22
Aguilar, Manuel Jimenez. "Adsorption and Sequestration of Dissolved Carbon and Nitrogen from Carbonated Urine to Mineral Soils". Research Journal of Environmental Sciences 12, n. 2 (1 febbraio 2018): 90–97. http://dx.doi.org/10.3923/rjes.2018.90.97.
23
Yu, Chunyang, Chunyi Cui, Yu Wang, Jiuye Zhao e Yajun Wu. "Strength performance and microstructural evolution of carbonated steel slag stabilized soils in the laboratory scale". Engineering Geology 295 (dicembre 2021): 106410. http://dx.doi.org/10.1016/j.enggeo.2021.106410.
24
Choi, Jiyeon, e Won Sik Shin. "Application of aqueous carbonated slags in the immobilization of heavy metals in field-contaminated soils". Environmental Engineering Research 25, n. 3 (18 maggio 2019): 356–65. http://dx.doi.org/10.4491/eer.2019.101.
25
Wang, Dunling, e Darwin W. Anderson. "Pedogenic carbonate in Chernozemic soils and landscapes of southeastern Saskatchewan". Canadian Journal of Soil Science 80, n. 2 (1 maggio 2000): 251–61. http://dx.doi.org/10.4141/s99-063.
Abstract (sommario):
The objective of this study was to characterize soil carbonates and estimate their accumulation by using a method based on δ13C values of soil carbonate in pedons and landscapes. Dark Brown Chernozem soils of the Amulet Association (with mixed C3 and C4 plants) and native Black Chernozem soils of the Oxbow Association (with a pure C3 plants) were included. Six soil samples representing the Cca and Ck horizons of the Oxbow and Amulet Associations were chosen for detailed pedogenic carbonate studies, which include particle size fractionation, mineralogical identification, surface morphology examination, and stable carbon isotopic compositions analysis on the particle size fractions.X-ray diffraction (XRD) and scanning electron microscopy (SEM) analyses of the fractionated particle sizes indicated that dolomite dominates the carbonate occurring in the Ck horizons, and is mainly in medium and coarse silt fractions. In the Cca horizons, carbonate in clay and fine silt fractions is mostly calcite, whereas dolomite dominates the carbonates in medium and coarse silt fractions. Calcitic coatings on the surfaces of both silt and sand particles were observed. Stable carbon isotope ratio (δ13Cvalue) of carbonate was −8‰ in the clay fraction of Cca horizons in which carbonate is dominated by calcite. Carbonate in the fine particle size fractions of the Cca horizons is dominated by calcite and has the most depleted δ13C values, indicating that pedogenic carbonate occurs as calcite and mainly in the fine particle size fractions. In contrast, carbonates from coarse silts of Ck horizons were composed solely of dolomite and had the most enriched δ13C values (−1.1 to −1.4‰), a character of lithogenic carbonate. On a landscape basis, carbonate occurs mainly in the Cca horizons in mid- and upper slope soils as a result of moisture movement and ground water fluxes. Soils in the depressions were more leached and contained small amounts of carbonate, mostly in the 60- to 90-cm depth. Calculations from the δ13C values of soil carbonates indicate that about 50–68% of the carbonate in the Cca horizons of middle slope soils is of pedogenic origin, which is equivalent to a CaCO3 storage of 136–188 kg m−2. In contrast, 5 to 39% (0–36 kg m−2 CaCO3) of carbonate stored in the lower slope soils is of pedogenic origin. Thirty-one to fifty percent of the carbonate (equivalent to 100–134 kg m CaCO3) in upper slope soils is of pedogenic origin. Key words: Carbonate, pedogenic, calcite, dolomite, δ13C value, XRD, SEM, landscape
26
Yu, Chunyang, Jia Yuan, Chunyi Cui, Jiuye Zhao, Fang Liu e Gang Li. "Ontology Framework for Sustainability Evaluation of Cement–Steel-Slag-Stabilized Soft Soil Based on Life Cycle Assessment Approach". Journal of Marine Science and Engineering 11, n. 7 (14 luglio 2023): 1418. http://dx.doi.org/10.3390/jmse11071418.
Abstract (sommario):
Steel slag has become a promising supplementary cementitious material for soft soil stabilization. However, there is a lack of research on the integrated assessment of cement–steel-slag-stabilized soft soils (SCSs) from the performance, environmental, and economic perspectives. In this study, an ontology framework for the sustainable evaluation of SCSs was developed based on the life cycle assessment (LCA) approach, which combined a knowledge base with semantic web rules to achieve an automated decision design for soft soil stabilization, considering comprehensive benefits. The ontology framework was applied to a marine soft soil stabilization case to verify its scientificity and practicability and to evaluate the influence of the fineness, carbonation degree, and substitution ratio of steel slag on the sustainability of SCSs. The results show that, when compared to pure-cement-stabilized soil (S-C), using 10% and 20% of fine steel slag carbonated for 18 h (FSS-C-18h) as cement substitutes can significantly reduce carbon emissions and costs while achieving a similar strength performance as S-C, demonstrating the feasibility of steel slag as a sustainable supplementary cementitious material for soft soil stabilization.
27
SEİTKALİ, Nurzikhan, Askhat NAUSHABAYEV, Shynar MAZKİRAT e Tursunay VASSİLİNA. "Assessing the efficacy of ameliorants on saline-sodic soils: Laboratory insights for reclamation strategies". EURASIAN JOURNAL OF SOIL SCIENCE (EJSS) 12, n. 4 (17 luglio 2023): 328–34. http://dx.doi.org/10.18393/ejss.1331960.
Abstract (sommario):
This study presents the combined findings of laboratory experiments conducted to assess the efficacy of various ameliorants on saline-sodic soils in the foothill plain of Ile Alatau in the Northern Tianshan region. The investigation focused on the influence of phosphogypsum, elemental sulfur, nano sulfur, and sulfuric acid on the ionic composition of the soil solution and their impact on the soil-absorbing complex. Different doses of these ameliorants were applied to saline-sodic soil samples, and their incubation period was observed. The analysis of the aqueous extract of the soil emphasized the presence of bicarbonate, carbonate, sulfate, calcium, and sodium ions. The results revealed that sulfuric acid was the most effective ameliorant, rapidly neutralizing extreme alkalinity, reducing bicarbonate and carbonate ion content, and increasing sulfate and sodium ion concentrations. Elemental sulfur ranked second in effectiveness, significantly decreasing bicarbonate and carbonate ions and increasing sulfate and sodium ions. Phosphogypsum exhibited the lowest effectiveness, causing reductions in bicarbonate and carbonate ions and modest increases in sulfate and calcium ions. The study demonstrated that the introduction of phosphogypsum led to an increase in calcium and sulfate ions in the soil solution, while elemental sulfur and sulfuric acid significantly increased the sulfate ion content. Sulfuric acid exhibited the highest efficacy among the ameliorants, completely neutralizing normal carbonates and reducing alkalinity in the soil solution. The formation of subsoil gypsum through the interaction of sulfuric acid with calcium carbonates facilitated the displacement of sodium from the soil-absorbing complex. These findings contribute to our understanding of the processes involved in the amelioration of saline-sodic soils and provide insights into effective soil management practices. They serve as a theoretical basis for developing strategies for the reclamation of such soils worldwide. The research highlights sulfuric acid as the most effective ameliorant for saline-sodic soils, resulting in a significant rearrangement of the soil's ionic composition. Further research and field studies are necessary to validate and refine these laboratory findings for practical applications in soil improvement methods.
28
Dubé, Jean-Sébastien, Rosa Galvez-Cloutier e Thierry Winiarski. "Heavy metal transport in soil contaminated by residual light non-aqueous phase liquids (LNAPLs)". Canadian Geotechnical Journal 39, n. 2 (1 aprile 2002): 279–92. http://dx.doi.org/10.1139/t01-113.
Abstract (sommario):
This paper presents an experimental study on mixed soil contamination, more specifically on heavy metal behaviour in soil contaminated by residual non-aqueous phase liquids (NAPLs). Remediation of mixed contaminated sites is a complex technical goal because of the presence of physically and chemically different contaminants and potential interactions between them. Commonly encountered contaminants in mixed contaminated soils include light and dense organic liquids (LNAPLs, DNAPLs) and heavy metals. This study investigated interactions between three residual LNAPLs and three heavy metals (Cd, Cu, Pb) in a carbonated soil. The objectives of the study were to (i) establish the presence of interactive processes in the behaviour of the contaminants, with a focus on the influence of residual LNAPL on heavy metal transport and retention; and (ii) determine the nature of these interactions. Results showed that the LNAPL having the highest residual saturation enhanced heavy metal mobility and decreased heavy metal retention by the soil. On the other hand, the geochemical distribution of heavy metals was not significantly modified by chemical interactions with the residual LNAPLs. Specific modifications of Pb and Cu geochemical distributions rather appeared to be the result of modifications of soil hydrodynamics by residual LNAPL.Key words: contaminated soil, mixed contamination, heavy metals, LNAPL, preferential flow, contaminant mobility.
29
Daldoul, Ghassen, Radhia Souissi, Fouad Souissi, Nejib Jemmali e Hedi Karim Chakroun. "Assessment and mobility of heavy metals in carbonated soils contaminated by old mine tailings in North Tunisia". Journal of African Earth Sciences 110 (ottobre 2015): 150–59. http://dx.doi.org/10.1016/j.jafrearsci.2015.06.004.
30
Filippov, D. V., I. N. Chursin, D. D. Rulev e A. D. Boyarenkova. "Implementation of complex methods of earth’s remote sensing data processing for studying carbonation processes of soils with artificial irrigation". Vestnik SSUGT (Siberian State University of Geosystems and Technologies) 28, n. 1 (2023): 80–91. http://dx.doi.org/10.33764/2411-1759-2023-28-1-80-91.
Abstract (sommario):
The article represents methodical researh of carbonation processes of agricultural lands based on Earth’s remote sensing data. The research is carried out on the territory of Svetloyarsk irrigationsystem located in Volgograd region. The article considered a set of methodical approaches for complex digital processing of multispectral space survey data and field results. The material on the deciphering features of carbonized lands is generalized and the relationship between the spectral brightness of pixels and the level of carbonation in the fields is established using scatter diagrams. Methods for collecting field data for complex processing together with high-resolution satellite images are determined. The test plots of soils are identified by the level of carbonation with their graphical display on cartographic schemes. The reliability of identifying zones of pixel display of carbonated agricultural lands was determined at the level of 75 %.
31
El Howayek, Alain, Antonio Bobet e Marika Santagata. "Microstructure and cementation of two carbonatic fine-grained soils". Canadian Geotechnical Journal 56, n. 3 (marzo 2019): 320–34. http://dx.doi.org/10.1139/cgj-2018-0059.
Abstract (sommario):
This paper presents an investigation of the microstructure and cementation of two carbonatic fine-grained soils obtained from a deposit of lacustrine origin formed during the Wisconsin glaciation. The two soils differ in the degree of cementation (with average total carbonate contents of ∼55% and ∼38%), the dominating carbonate mineral (calcite versus dolomite), and the forms of carbonates present. The study is founded on observations of the microstructure using scanning electron microscopy (SEM) equipped with energy-dispersive X-ray (EDX) spectrometry, and examination of the effects of carbonate dissolution on Atterberg limits and particle-size distribution. In both soils, the majority of the carbonate is in the form of a coating layer on the clay and silt particles, with a thickness less than 2–3 μm, and decreasing in the sample with lower carbonate content. This coating layer “networks” particles and groups of particles. Carbonate cementation impacts the engineering properties of both soils, and the site’s overconsolidation ratio (OCR) profile clearly reflects changes in carbonate content and microstructure. One-dimensional compression tests show that cementation is associated with a moderate degree of structuring, and that the resulting structure is stable, with no complete destructuration occurring even after the effective stress exceeds 10 times the preconsolidation stress.
32
García-Montero, L. G., I. Valverde-Asenjo, P. Díaz e C. Pascual. "Statistical patterns of carbonates and total organic carbon on soils of Tuber rufum and T. melanosporum (black truffle) brûlés". Soil Research 47, n. 2 (2009): 206. http://dx.doi.org/10.1071/sr08084.
Abstract (sommario):
The ascocarps of several truffle species, such as Tuber rufum, are harvested in T. melanosporum brûlés; these species reduce T. melanosporum production. Some authors argue that this competition might be due to the evolution of organic matter in the soil. However, soil conditions in brûlés have yet to be clarified, and most studies on T. melanosporum fail to supply statistical data. We propose a study of 40 soils to compare the values for total organic carbon (TOC), pH, and carbonates inside the brûlés with the values for the outer edges of the same brûlés, where T. rufum ascocarps are collected. A principal component analysis relates the soils from the inner brûlés with high active carbonate content and soils outside the brûlés with high TOC and total carbonate content. ANOVA analyses indicate that the mean concentration of active carbonate, total CO32–, and % active/total carbonate differ significantly depending on soil location, but there are no significant differences for pH and TOC. These results lead us to propose a new hypothesis: T. melanosporum mycelia may solubilise active carbonate (<50 μm) and the other carbonate fractions (>50 μm) inside the brûlés; however the environmental conditions of the brûlés could favour a secondary carbonate precipitation with a net increase in active carbonate. This increase would counterbalance carbonate losses from leaching, which would in turn favour T. melanosporum mycelia, suggesting a feedback process.
33
Oganesyan, M. S., e A. A. Mуkhailichenko. "Features of the content of carbonates in the ordinary chernozem improved by forest under plantings of false acacia (Robinia pseudoacacia L.)". Fundamental and Applied Soil Science 16, n. 3-4 (14 novembre 2015): 25–30. http://dx.doi.org/10.15421/041514.
Abstract (sommario):
Carbonate neoplasms are the characteristic feature of the black soil profile. The study of morphological and micromorphological characteristics and chemical composition gives an idea of the black soil genesis and serves as the diagnostic feature of classification units of them. The study of migration carbonate in the chernozem are of great scientific and practical interest (Afanasyeva, 1996). Nowadays the issues of migration carbonates, as well as the extent of the manifestation of this process in the soil profile need further researching, which is important as carbonates has one of the main role in basic soil processes, in particular, they affect the concentration and activity of calcium ions in the soil solution, the composition of the soil absorbing complex and pH in the soil solution. Carbonate neoplasms contribute to the formation of strong coagulation structures, which increases soil fertility and harvest agricultural crops, provides resistance against the wind, prevents reduction of the upper fertile soil layer, increases mobility of some chemical elements and improves such physical characteristics of soil as density, permeability and porosity (Goncharova, 1983). The aim of our work was to study the content of calcium carbonate in the soil profile of the test section 201–L under of the acacia plantations crops of forest ecosystems and to determine of their distribution in the soil genetic horizons. According to the aim of our work of we has the following tasks: to give a general characterization of carbonates of calcium in Chernozem usual, to perform sampling of the genetic horizons of the soil profile of test section 201–L, to determine the content of carbonates by conventional gravimetric methods; to study the features of the content of carbonates in soil profiles of test section 201–L; to conduct statistical processing of the obtained data; to formulate conclusions of the performed research. Soil samples were selected according to the standard technique in genetic horizons of the soil profile on three times (Fedorets, 2009). Determination of the percentage content of carbonates in the soil was performed by the gravimetric method, which is based on weight loss of soil due to discharge of CO2 during the destruction of carbonates with acid. It should be noted that the method can be applied in the case of the carbonates content up to 70 % (Travleev et al., 2009). The average coefficient of variation of carbonates of calcium content in genetic horizons of the soil profile is 77.5 %. This is quite a high rate, so as General it is considered that if the value of the coefficient of variation is less than 33 %, the result is considered homogeneous if more than 33 %, it is inhomogeneous. Based on this observation, we conclude that carbonate calcium has inhomogeneous redistribution of genetic horizons of test section 201–L. Regarding the reliability of the obtained data, we can see that the standard error calculations for each of the horizons does not exceed 0,34, which in turn confirms the accuracy of the our data. According to our calculations the lowest content of calcium carbonate is 1.47 % in the first horizon, and biggest – 16,07 % in the genetic horizon Ph (70–90 cm). These results are extending the current understanding of the processes of formation and distribution of calcium carbonate in the genetic horizons of the soil profile of the Chernozem ordinary. The data of percentage of calcium carbonate may be used in the solution of the question of the genesis, evolution and classification of soils, the obtained data can serve as the basis of the research the conditions of pedogenesis under the influence of natural climatic fluctuations and anthropogenic factors.
34
Boussen, Salma, Marilyne Soubrand, Hubert Bril, Kamel Ouerfelli e Saâdi Abdeljaouad. "Transfer of lead, zinc and cadmium from mine tailings to wheat (Triticum aestivum) in carbonated Mediterranean (Northern Tunisia) soils". Geoderma 192 (gennaio 2013): 227–36. http://dx.doi.org/10.1016/j.geoderma.2012.08.029.
35
Gordienko, O. A., e E. A. Ivantsova. "Morphological features of the soil cover of slope lands in the south of the Volga uplands within the urban landscapes of Volgograd". Dokuchaev Soil Bulletin, n. 106 (27 marzo 2021): 77–104. http://dx.doi.org/10.19047/0136-1694-2021-106-77-104.
Abstract (sommario):
The paper deals with morphological properties of agrogenically transformed chestnut soils of slope lands in the south of the Volga upland within the urban landscape of Volgograd. It is established that as a result of agrogenesis, erosion, land use change, as well as of agroforestry reclamation measures performed, both anthropogenic deeply transformed and postagrogenic soils have been formed. The greatest changes under the influence of agrogenesis are noted in morphological structure of profiles. Agrogenesis results in degradation of soils involved in active agricultural use due to intensified sheet and rill erosion. In eroded soils there is noticed a decrease in the thickness of agrohumic layer, formation of furrow bottom compaction and changes in structure. Their characteristic feature is the presence on the surface of a homogeneous agro-abraded horizon with lumpy structure, in the lower part of which secondary carbonates inherited from the carbonate horizon and resulted from deep plowing may occur. Soils slightly exposed and not exposed to erosion processes have an agrohumus horizon on the surface, which depending on soil tillage can have thickness from 19 to 36 cm. At present, the annual agricultural practices at the plot include mowing of weeds and disk plowing to 20 cm depth. Earlier moldboard plowing to 40 cm depth was performed. All agrogenically-modified soils are characterized by HCl reaction with carbonates from the surface. Carbonate accumulations in agrogenic soils, as a rule, have a segregated form that indicates rapid summer drying of the profile and short period of soil solutions migration. Upper boundary of accumulative-carbonate horizons of agrogenic soils on the average is at 42 cm depth. Such occurrence of carbonate horizons in general is typical both of natural non-eroded soils of dry-steppe zone and of soils involved in agricultural land use. Under forest plantations the original chestnut soils were transformed into turbated agrozems due to deep ameliorative cultivation preceded planting of woody and shrub vegetation. Soil preparation practices applied before tree species planting resulted in transformation of original chestnut soils into turbated agrozems, which is due to deep (up to 60 cm) soil reclamation. The forest belt, being a “barrier” between the field parts, contributed to the formation of a stratified small horizon (trait) of 10 cm thickness for more than 70 years due to the constant inflow of fine-grained soil and decay of leaf and herbaceous debris.
36
Almanova, Zh S., S. O. Kenzhegulova, R. Kizilkaya, A. T. Zhakenova, D. Yerzhan e K. Harrison Diri. "MODERN ASSESSMENT OF FERTILITY OF DARK CHESTNUT SOILS OF KAMYSTINSKY DISTRICT OF KOSTANAY REGION". HERALD OF SCIENCE OF S SEIFULLIN KAZAKH AGRO TECHNICAL RESEARCH UNIVERSITY, n. 4(119) (25 dicembre 2023): 97–105. http://dx.doi.org/10.51452/kazatu.2023.4(119).1576.
Abstract (sommario):
The article presents the results of a study on the morphological, nutritional characteristics of arable dark chestnut soils in the Kamystinsky district of the Kostanay region. According to the structure of the morphological profile, dark chestnut soils belonged to medium and low thickness types, where the thickness of the humus horizon A + B1 is noted within the range of 29 - 45 cm in depth. The accumulation of carbonates and ready soluble salts depends on the parent rocks and the grain-size distribution of dark chestnut soils. In dark chestnut immature soil, there are no carbonates along the soil profile, but gypsum is found at a depth of 36 cm. The line of bubbling from hydrochloric acid is different in ordinary and carbonate genus of dark chestnut soil. The humus content is low, in the plough-layer of soils it ranges 1.10 - 3.05%, the supply of nitrate nitrogen is very low, moving forms of phosphorus are medium and low, while potassium content is very high and elevated.
37
Ahmad, Waqar, Balwant Singh, Ram C. Dalal e Feike A. Dijkstra. "Carbon dynamics from carbonate dissolution in Australian agricultural soils". Soil Research 53, n. 2 (2015): 144. http://dx.doi.org/10.1071/sr14060.
Abstract (sommario):
Land-use and management practices on limed acidic and carbonate-bearing soils can fundamentally alter carbon (C) dynamics, creating an important feedback to atmospheric carbon dioxide (CO2) concentrations. Transformation of carbonates in such soils and its implication for C sequestration with climate change are largely unknown and there is much speculation about inorganic C sequestration via bicarbonates. Soil carbonate equilibrium is complicated, and all reactants and reaction products need to be accounted for fully to assess whether specific processes lead to a net removal of atmospheric CO2. Data are scarce on the estimates of CaCO3 stocks and the effect of land-use management practices on these stocks, and there is a lack of understanding on the fate of CO2 released from carbonates. We estimated carbonate stocks from four major soil types in Australia (Calcarosols, Vertosols, Kandosols and Chromosols). In >200-mm rainfall zone, which is important for Australian agriculture, the CaCO3-C stocks ranged from 60.7 to 2542 Mt at 0–0.3 m depth (dissolution zone), and from 260 to 15 660 Mt at 0–1.0 m depth. The combined CaCO3-C stocks in Vertosols, Kandosols and Chromosols were about 30% of those in Calcarosols. Total average CaCO3-C stocks in the dissolution zone represented 11–23% of the stocks present at 0–1.0 m depth, across the four soil types. These estimates provide a realistic picture of the current variation of CaCO3-C stocks in Australia while offering a baseline to estimate potential CO2 emission–sequestration through land-use changes for these soil types. In addition, we provide an overview of the uncertainties in accounting for CO2 emission from soil carbonate dissolution and major inorganic C transformations in soils as affected by land-use change and management practices, including liming of acidic soils and its secondary effects on the mobility of dissolved organic C. We also consider impacts of liming on mineralisation of the native soil C, and when these transformations should be considered a net atmospheric CO2 source or sink.
38
Ramnarine, R., R. P. Voroney, C. Wagner-Riddle e K. E. Dunfield. "Carbonate removal by acid fumigation for measuring the δ13C of soil organic carbon". Canadian Journal of Soil Science 91, n. 2 (maggio 2011): 247–50. http://dx.doi.org/10.4141/cjss10066.
Abstract (sommario):
Ramnarine, R., Voroney, R. P., Wagner-Riddle, C. and Dunfield. K. E. 2011. Carbonate removal by acid fumigation for measuring the δ 13 C of soil organic carbon. Can. J. Soil Sci. 91: 247–250. Complete removal of carbonates from calcareous soil samples is critical for accurate measurement of the quantity and isotopic signature (δ13C) of soil organic carbon (SOC). Carbonates confound SOC and δ13C measurements because they have δ13C values ranging from −10‰ to +2‰, whereas those of soil organic carbon range from −27‰ to −13‰, depending on the source of plant residues. Commonly used methods for removing carbonates involve treatment with acid followed by repeated water washings; however, these methods are time consuming, labour-intensive and lead to losses of acid- and water-soluble organic carbon. Fumigation of soil samples with HCl was evaluated as an alternative method, and the time required for complete carbonate removal was determined in this study. Moistened soil samples, taken from 0- to 10-cm and 30- to 50-cm depths, were exposed to HCl vapours for periods of 0, 6, 12, 24, 48, 72, and 96 h, followed by measurements of total C and δ13C using coupled elemental analyzer-isotope ratio mass spectrometry. The minimum time required to remove all carbonates was ca. 30 h and 56 h for surface and subsurface soils containing 0.80 and 1.94% inorganic C, respectively. Therefore, the fumigation period required is dependent on the total carbonate content of the sample and the nature of the carbonate (pedogenic vs lithogenic). In our study, the rate of removal of inorganic carbon was 0.08–0.10 mg h−1 for soil samples sizes with 2.4 to 5.8 mg of carbonate-C, a rate similar to previous studies on acid fumigation. A “correction factor” was used to account for a change in sample mass due to fumigation and is necessary for accurate determination of SOC concentration using our proposed methodology.
39
Leah, Tamara. "Assessment of Microelements Soil Pollution with Ecological Indicators". Chemistry Journal of Moldova 7, n. 1 (giugno 2012): 45–49. http://dx.doi.org/10.19261/cjm.2012.07(1).06.
Abstract (sommario):
Trace elements soil pollution leads to degradation of structure and aggregates stability which promotes the soil erosion and compaction. For more efficient management of the results on the content of trace elements in eroded soils is used the ecological indicators for characterization the accumulation in genetic horizons. The data confirms the soil pollution by erosion, the losses of humus, carbonates, and trace elements in arable carbonatic chernozems of catena. The humus losses in eroded soils consists 52%, the trace elements - 33-35%.
40
Fishtik, Ilie. "Thermodynamic Stability Relations in the C-H-O System". Chemistry Journal of Moldova 7, n. 2 (dicembre 2012): 12–20. http://dx.doi.org/10.19261/cjm.2012.07(2).19.
Abstract (sommario):
Trace elements soil pollution leads to degradation of structure and aggregates stability which promotes the soil erosion and compaction. For more efficient management of the results on the content of trace elements in eroded soils is used the ecological indicators for characterization the accumulation in genetic horizons. The data confirms the soil pollution by erosion, the losses of humus, carbonates, and trace elements in arable carbonatic chernozems of catena. The humus losses in eroded soils consists 52%, the trace elements - 33-35%.
41
Fayyadh, M. A., e S. A. F. Rekani. "Distribution Path of Total and Active Carbonates, and Iron Oxides under Two Different Forest Tree Species". IOP Conference Series: Earth and Environmental Science 1120, n. 1 (1 dicembre 2022): 012038. http://dx.doi.org/10.1088/1755-1315/1120/1/012038.
Abstract (sommario):
Abstract The research area was in Iraq’s Kurdistan region’s Duhok province. Oak and pine were chosen as the two woodland tree species. At each location, five pedons were dug, and soil horizons were then sampled. Because both types of forest soil were formed from limestone parent materials and the soil of Pine trees was substantially more carbonate than the soil of oak trees, and the calcium carbonate concentration of both forest types increased. The active carbonate varies from horizon to horizon, but it is often lower on the surface horizons, and its distribution pattern matches that of clay. Iron oxides in soils generally fluctuated between increasing and decreasing in the studied pedons, with the highest value of iron oxides in soil being discovered at the Sarke location. In contrast, the distribution pattern of iron oxides in clay fraction increased with increasing depth and was correlated with an increase in clay content. This study came to the conclusion that the distribution of active carbonate follows a similar pattern to that of total carbonate and is consistent with that of clay. The movement from surface soil horizons to subsurface due to gain was associated with the translocation of iron oxides in the investigated soils. The purpose of this study was to clarify the distribution pathways of free iron oxides, total and active carbonates in soil, under two different tree species.
42
Zamanian, Kazem, Konstantin Pustovoytov e Yakov Kuzyakov. "Carbon Sources in Fruit Carbonate of Buglossoides arvensis and Consequences for 14C Dating". Radiocarbon 59, n. 1 (31 gennaio 2017): 141–50. http://dx.doi.org/10.1017/rdc.2016.123.
Abstract (sommario):
AbstractFruit carbonate of Buglossoides arvensis (syn. Lithospermum arvense) is a valuable dating and paleoenvironmental proxy for late Quaternary deposits and cultural layers because CaCO3 in fruit is assumed to be accumulated from photosynthetic carbon (C). However, considering the uptake of HCO3– by roots from soil solution, the estimated age could be too old depending on the source of HCO3– allocated in fruit carbonate. Until now, no studies have assessed the contributions of photosynthetic and soil C to the fruit carbonate. To evaluate this, the allocation of photo-assimilated carbon and root uptake of HCO3– was examined by radiocarbon (14C) labeling and tracing. B. arvensis was grown in carbonate-free and carbonate-containing soils (sand and loess, respectively), where 14C was provided as (1) 14CO2 in the atmosphere (5 times shoot pulse labeling), or (2) Na214CO3 in soil solution (root-labeling; 5 times by injecting labeled solution into the soil) during one month of fruit development. Distinctly different patterns of 14C distribution in plant organs after root- and shoot labeling showed the ability of B. arvensis to take up HCO3– from soil solution. The highest 14C activity from root labeling was recovered in roots, followed by shoots, fruit organics, and fruit carbonate. In contrast, 14C activity after shoot labeling was the highest in shoots, followed by fruit organics, roots and fruit carbonate. Total photo-assimilated C incorporated via shoot labeling in loess-grown plants was 1.51 mg lower than in sand, reflecting the presence of dissolved carbonate (i.e. CaCO3) in loess. Loess carbonate dissolution and root-respired CO2 in soil solution are both sources of HCO3– for root uptake. Considering this dilution effect by carbonates, the total incorporated HCO3– comprised 0.15% of C in fruit carbonate after 10 hr of shoot labeling. However, if the incorporated HCO3– during 10 hr of shoot labeling is extrapolated for the whole month of fruit development (i.e. 420-hr photoperiod), fruit carbonate in loess-grown plants incorporated approximately 6.3% more HCO3– than in sand. Therefore, fruit carbonates from plants grown on calcareous soils may yield overestimated 14C ages around 500 yr because of a few percentage uptake of HCO3– by roots. However, the age overestimation because of HCO3– uptake becomes insignificant in fruits older than approximately 11,000 yr due to increasing uncertainties in age determination.
43
Lechler, Alex R., Katharine W. Huntington, Daniel O. Breecker, Mark R. Sweeney e Andrew J. Schauer. "Loess–paleosol carbonate clumped isotope record of late Pleistocene–Holocene climate change in the Palouse region, Washington State, USA". Quaternary Research 90, n. 2 (5 luglio 2018): 331–47. http://dx.doi.org/10.1017/qua.2018.47.
Abstract (sommario):
AbstractThe Channeled Scabland–Palouse region of the Pacific Northwest (PNW) of the United States preserves geomorphic and pedosedimentary records that inform understanding of late Pleistocene–Holocene paleoclimate change in a region proximal to the last glacial period Cordilleran Ice Sheet. We present a clumped (Δ47) and conventional (δ18O, δ13C) isotopic study of Palouse loess–paleosol carbonates in combination with carbonate radiocarbon (14C) dating to provide new measures of regional late–last glacial (~31–20 cal ka BP) and Holocene soil conditions. Average clumped isotope temperatures (T(Δ47)) for last glacial Palouse loess–paleosol carbonates (9±4°C) are significantly lower than those for Holocene-aged carbonates (T(Δ47)=18±2°C) in study sections. Calculated soil water δ18OVSMOWvalues (−16±2‰) for last glacial carbonates are also offset relative to those for Holocene-aged samples (−11±1‰), whereas calculated soil CO2δ13CVPDBvalues are similar for the Holocene (−16.9±0.2‰) and late–last glacial (−16.7±1.1‰) periods. Together, these paleoclimate metrics indicate late–last glacial conditions of pedogenic carbonate formation in the C3grassland soils of the Palouse were measurably colder (9±5°C) than during the Holocene and potentially reflect a more arid last glacial paleoclimate across the Palouse, findings in agreement with previous proxy studies and climate model simulations for the region.
44
Stietiya, Mohammed Hashem, Mohammad Duqqah, Theophilus Udeigwe, Ruba Zubi e Tarek Ammari. "Fate and Distribution of Heavy Metals in Wastewater Irrigated Calcareous Soils". Scientific World Journal 2014 (2014): 1–11. http://dx.doi.org/10.1155/2014/865934.
Abstract (sommario):
Accumulation of heavy metals in Jordanian soils irrigated with treated wastewater threatens agricultural sustainability. This study was carried out to investigate the environmental fate of Zn, Ni, and Cd in calcareous soils irrigated with treated wastewater and to elucidate the impact of hydrous ferric oxide (HFO) amendment on metal redistribution among soil fractions. Results showed that sorption capacity for Zarqa River (ZR1) soil was higher than Wadi Dhuleil (WD1) soil for all metals. The order of sorption affinity for WD1 was in the decreasing order of Ni > Zn > Cd, consistent with electrostatic attraction and indication of weak association with soil constituents. Following metal addition, Zn and Ni were distributed among the carbonate and Fe/Mn oxide fractions, while Cd was distributed among the exchangeable and carbonate fractions in both soils. Amending soils with 3% HFO did not increase the concentration of metals associated with the Fe/Mn oxide fraction or impact metal redistribution. The study suggests that carbonates control the mobility and bioavailability of Zn, Ni, and Cd in these calcareous soils, even in presence of a strong adsorbent such as HFO. Thus, it can be inferred that in situ heavy metal remediation of these highly calcareous soils using iron oxide compounds could be ineffective.
45
Shilova, Irina V., Alena S. Parkhomenko, Anton A. Denisov, Anna O. Kondratieva e Alexandr S. Kashin. "Ecological features of plant communities containing Globularia bisnagarica L. in the Middle and Lower Volga Region". Izvestiya of Saratov University. New Series. Series: Chemistry. Biology. Ecology 21, n. 1 (24 febbraio 2021): 99–113. http://dx.doi.org/10.18500/1816-9775-2021-21-1-99-113.
Abstract (sommario):
The present article investigates the plant communities of the Middle and Lower Volga region that contain Globularia bisnagarica L. (G. punctate Lapeyr., G. willkommii Nylan) – the species listed in the Red Book of the Russian Federation, the Republic of Bashkortostan, the Republic of Tatarstan, the Stavropol Krai, the Orenburg, Samara, Saratov and Ulyanovsk Province, and Kazakhstan. The paper provides the geo-botanical description as well as the ecological and coenotic properties of 13 plant communities located in the Middle and Lower Volga region (the Ulyanovsk, Saratov and Samara Provinces). It is shown that the studied communities are confined to the elevated elements of relief where soil erosion usually takes place and bedrock gets exposed. Most communities grow on proto-soils – namely, carbonated. In general, the communities under study include 141 vascular species. In individual communities, the total projective cover fluctuates from 25 to 90%; the number of species varies from 29 to 43. Furthermore, the study subdivides the communities containing G. bisnagarica into 10 types. The level of set similarity is rather low (IBD is mere 19.5%). Finally, based on the bio-morphological content, most species in the studied communities are classified as hemicryptophytes, which is typical for the moderately cold zones of the Holarctic realm. Among trophomorphs, mesotrophs are predominant (62%); while oligotrophs are a third as many.
46
DEGTYAREVA, Tatyana, Yuri KARAEV, Andrey LIKHOVID e Alexey LYSENKO. "MICROELEMENT COMPOSITION OF SOD-CARBONATE SOILS OF THE NORTH-WEST CAUCASUS". Sustainable Development of Mountain Territories 13, n. 1 (27 marzo 2021): 25–34. http://dx.doi.org/10.21177/1998-4502-2021-13-1-25-34.
Abstract (sommario):
The aim of the work is to study the peculiarities of the formation of the microelement composition of sod-carbonate soils of the North-West Caucasus. Methods: Determination of the features of the formation of the microelement composition of sod-carbonate soils was carried out in the western part of the Labino-Malkinsky landscape district of forest-steppes and settled meadows. The Kuestov District occupies a band of ridges of the North-western Caucasus, composed of limestones, dolomites and sandstones of the Jurassic (K) and Cretaceous (k) periods. Chemical analysis of the soil was performed by conventional methods. The content of strongly bound compounds Pb, Cu, Zn, and Cd by acid decomposition using 5 M HNO3 was analyzed in the humus horizon of soils. The metal content was determined by the methods of inversion volt-amperometric and atomic absorption analyses. Results: In most cases, the microelement composition of sod-carbonate soils is characterized by the enrichment of Pb, Cu, Cd and depletion of Zn in comparison with the Clark soils. The constant anthropogenic input of pollutants into the soil as a depositing medium directly affects the trace element composition-the soils are intensively enriched with all the elements considered, especially strongly accumulated on CD and PB. In the radial distribution of trace elements between sod-carbonate soils and the soil-forming rock, a high intensity of accumulation of chemical elements in the humus horizon of soils was revealed. The intensity of the redistribution of trace elements in soils is largely determined by the position in the terrain. Within the Cretaceous cuesta, high Cd contents are typical for plakor soils, Cu and Zn-for the soils of the slope of the beam. On the slope of the Jurassic questi higher contents of Pb, Cd and Cu are typical for soils of placorestan cavage array Zn for soils of steep hillside with oak and beech forests. Conclusions: The microelement composition of sod-carbonate soils is a consequence of such soil-forming processes as humification, humus accumulation, leaching, glinting, and loess age, the specifics of which are largely determined by calcium carbonates. The microelement composition of sod-carbonate soils reflects the most significant features of the microelement composition of soil-forming rocks, which are characterized by low Zn content. The possible aerotechnogenic intake of trace elements affects the intensity of the radial accumulation of trace elements in the soil relative to the rocks. The degree of transformation of the microelement composition of anthropogenic disturbed soils depends on the intensity of anthropogenic impact on the soil. The conducted research is important in the aspect of revealing the regularities of the formation of the microelement composition of the soil as a depositing component of the landscape in modern conditions of anthropogenic pressure.
47
Gaultier, Jeanette, Annemieke Farenhorst e Gary Crow. "Spatial variability of soil properties and 2,4-D sorption in a hummocky field as affected by landscape position and soil depth". Canadian Journal of Soil Science 86, n. 1 (1 febbraio 2006): 89–95. http://dx.doi.org/10.4141/s04-074.
Abstract (sommario):
Since pesticide fate and leaching models increasingly incorporate spatial variability, the objective of this study was to quantify the variability of soil properties and 2,4-D sorption within a hummocky field as affected by landscape position and soil depth. Seventy-two soil cores collected at 5-m intervals along a transect were segmented by soil horizon (A, B and C) and landscape position (upper, mid, lower and depression). As expected, soil organic carbon content significantly decreased, and soil pH and soil carbonate content significantly increased with soil depth, while clay content was significantly greater in the B horizon than the A and C horizon. Soils from the depressional area generally had higher soil organic carbon content, soil carbonate content, clay content and soil pH than soil samples from other slope positions. The sorption of 2,4-D by soil was positively correlated with soil organic matter content and negatively correlated with soil carbonate content. These soil properties and herbicide sorption varied along the transect and with soil depth. Regardless of whether or not the landscape was segmented by landscape position, for both the A and C horizon, predictions of 2,4-D sorption by soil were generally good using simple regression models that contained soil organic carbon content and carbonate content as the only parameters. However, for the B horizon, the prediction of 2,4-D sorption by soil was very poor when all sampling points along the transect were considered, but greatly improved for the mid- and depressional slope positions when soils were segmented by landscape position. We conclude that segmentation by slope position could be a useful additional tool when predicting pesticide fate and leaching at the large-scale. As well, the negative association between soil carbonate content and 2,4-D sorption warrants further attention as a large portion of Canadian agriculture encompasses calcareous soils. Key words: 2,4-D, sorption, soil organic carbon, carbonates, landscape position, soil depth
48
Sorokina, V. V., e E. G. Aleshina. "EXPERIMENTAL STUDIES OF THE BEHAVIOR OF ELEMENTS OF THE CARBONATE SYSTEM OF SEA WATERS AS A RESULT OF THE ARRIVAL OF COASTAL ABRASION MATERIAL". Ecology. Economy. Informatics.System analysis and mathematical modeling of ecological and economic systems 1, n. 6 (2021): 167–72. http://dx.doi.org/10.23885/2500-395x-2021-1-6-167-172.
Abstract (sommario):
. The assessment of the intake of carbonates into the Sea of Azov in the process of coastal destruction is carried out based on data on the volumes of abrasive material entering the sea and the content of carbonate material in rocks in different periods of the twentieth century. The following relations can be stated: the share of abrasive material in the supply of solid terrigenous matter to the Sea of Azov in the last period is more than 50%, and in the supply of carbonate material – does not exceed 10% compared to other sources. A method was developed, experimental studies were performed and the first quantitative estimates of changes in the elements of the carbonate system (active reaction of the medium (pH) and total alkalinity) in the water of the Sea of Azov with different salinity as a result of soil (abrasive material containing carbonates) entering it during active wave action on the shores were obtained. The results of experimental studies can be considered from the point of view of identifying the main trends in the behavior of elements of the carbonate water system when soil enters it. We can draw a preliminary conclusion that the coastal abrasive material that has entered the seawater should be considered, first of all, as a source of calcium carbonate in bottom sediments due to the mechanism of adsorption of bicarbonate ion on solid particles of suspension (crystallization centers), as well as due to simple deposition on the bottom, since calcium and magnesium carbonates of soils are poorly soluble compounds.
49
Smirnova, M. A., A. N. Gennadiev e Yu G. Chendev. "Short–Range Variation of Humus and Carbonate Profiles of Arable Chernozems (Key Site in Belgorod Region)". Почвоведение, n. 3 (1 marzo 2023): 300–311. http://dx.doi.org/10.31857/s0032180x22601086.
Abstract (sommario):
The short-range variation of soil properties is a particular expression of the spatial soil variability; it is non-directional short-periodic (in the range of a few meters) changes in soil-profile features. The short-range variation of soil properties is aimed to characterize the continuum nature of soil cover instead of the discrete (as in the soil cover pattern theory), thus the soil cover is presented by a continuum field of various soil properties, and the boundaries of the selected soil properties ranges may or may not coincide with the soil taxonomic boundaries. The study is based on soil data of three parallel transects (length 240 m) in the watershed, perpendicularly crossing the 60-year-old shelterbelt in their central part. The sampling step was 10 m on agricultural fields, 6 – under the shelterbelt; In total, the features of the humus (the content of organic carbon in the 0–20 cm layer, the thickness of the humus horizon and profile) and carbonate (the effervescence depth, the carbonate content in the effervescence layer and the horizon of maximum accumulation of carbonates) profiles were studied at 75 points. It was revealed that the parameters of the humus and carbonate profiles of soils have periodic changes with a step of 6–10 meters. The parameters of the humus profile are characterized by lower coefficients of variation (less than 30%) than the parameters of the carbonate profile of soils (more than 50%). The growth of trees on agrochernozems (Haplic Chernozem (Aric)) for 60 years led to the formation of new taxonomic components (postagrogenic agrochernozems (Haplic Chernozem)), characterized by a smaller lateral variation in soil properties compared to arable soils. In total, 3 types of soils are found within the studied area: agrochernozem (64 points; Haplic Chernozem (Aric, Loamic, Pachic)), clay-illuvial agrochernozem (7 points; Luvic Chernozem (Aric, Loamic, Pachic) and Luvic Chernic Phaeozem (Aric, Loamic, Pachic, Loamic, Pachic)) and agrochernozems, clay-illuvial quasigley (4 points; Luvic Stagnic Chernic Phaeozem (Aric, Loamic, Pachic)), including 8 subtypes.
50
Luo, W. T., P. N. Nelson, M. H. Li, J. P. Cai, Y. Y. Zhang, Y. G. Zhang, S. Yang et al. "Contrasting pH buffering patterns in neutral-alkaline soils along a 3600 km transect in northern China". Biogeosciences 12, n. 23 (7 dicembre 2015): 7047–56. http://dx.doi.org/10.5194/bg-12-7047-2015.
Abstract (sommario):
Abstract. Soil pH buffering capacity (pHBC) plays a crucial role in predicting acidification rates, yet its large-scale patterns and controls are poorly understood, especially for neutral-alkaline soils. Here, we evaluated the spatial patterns and drivers of pHBC along a 3600 km long transect (1900 km sub-transect with carbonate-containing soils and 1700 km sub-transect with non-carbonate-containing soils) across northern China. Soil pHBC was greater in the carbonate-containing soils than in the non-carbonate-containing soils. Acid addition decreased soil pH in the non-carbonate-containing soils more markedly than in the carbonate-containing soils. Within the carbonate soil sub-transect, soil pHBC was positively correlated with cation exchange capacity (CEC), carbonate content and exchangeable sodium (Na) concentration, but negatively correlated with initial pH and clay content, and not correlated with soil organic carbon (SOC) content. Within the non-carbonate sub-transect, soil pHBC was positively related to initial pH, clay content, CEC and exchangeable Na concentration, but not related to SOC content. Carbonate content was the primary determinant of pHBC in the carbonate-containing soils and CEC was the main determinant of buffering capacity in the non-carbonate-containing soils. Along the transect, soil pHBC was different in regions with different aridity index. Soil pHBC was positively related to aridity index and carbonate content across the carbonate-containing soil sub-transect. Our results indicated that mechanisms controlling pHBC differ among neutral-alkaline soils of northern China, especially between carbonate- and non-carbonate-containing soils. This understanding should be incorporated into the acidification risk assessment and landscape management in a changing world.