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Timbal, J. y J. Gelpe. "Croissance juvénile du chêne rouge sur des sols carbonatés à des profondeurs variables". Annales des Sciences Forestières 46, Supplement (1989): 694s—696s. http://dx.doi.org/10.1051/forest:198905art0153.
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Dupla, Jean-Claude, Elisabeth Palix, Guillaume Damblans, Alain Puech, Mathieu Blanc, Christophe Dano, Hussein Mroueh et al. "Le projet ANR SOLCYP+ pour améliorer le dimensionnement des monopieux utilisés comme fondations d’éoliennes marines". Revue Française de Géotechnique, n.º 158 (2019): 4. http://dx.doi.org/10.1051/geotech/2019010.
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La plupart des éoliennes offshore sont fondées sur monopieux. L’augmentation constante de la capacité des turbines et l’insuffisance des procédures évoquées dans les documents normatifs, notamment en ce qui concerne la prise en compte des chargements cycliques, posent des défis pour leur dimensionnement. Dans le cas des sites français, la présence de sols et roches carbonatés, dont le comportement est encore mal connu aujourd’hui, rend la tâche encore plus complexe. Le projet SOLCYP+, lancé en 2017 pour une durée de 3 ans, doit permettre de disposer de nouvelles méthodologies fiables et robustes pour le dimensionnement des monopieux de grand diamètre y compris dans le contexte géotechnique du plateau continental français. Cet article présente une description détaillée du projet ANR SOLCYP+. On aborde, tout d’abord, le contexte, la problématique et les objectifs du projet puis, dans un second temps, on décrit plus en détail les quatre principales tâches scientifiques.
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El Howayek, Alain, Antonio Bobet y Marika Santagata. "Microstructure and cementation of two carbonatic fine-grained soils". Canadian Geotechnical Journal 56, n.º 3 (marzo de 2019): 320–34. http://dx.doi.org/10.1139/cgj-2018-0059.
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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.
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Wang, Dunling y Darwin W. Anderson. "Pedogenic carbonate in Chernozemic soils and landscapes of southeastern Saskatchewan". Canadian Journal of Soil Science 80, n.º 2 (1 de mayo de 2000): 251–61. http://dx.doi.org/10.4141/s99-063.
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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
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MILLER, J. J., D. F. ACTON y R. J. ST. ARNAUD. "THE EFFECT OF GROUNDWATER ON SOIL FORMATION IN A MORAINAL LANDSCAPE IN SASKATCHEWAN". Canadian Journal of Soil Science 65, n.º 2 (1 de mayo de 1985): 293–307. http://dx.doi.org/10.4141/cjss85-033.
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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
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Kassim, Jabbar K. "Method for Estimation of Calcium Carbonate in Soils from Iraq". International Journal of Environment 1, n.º 1 (30 de agosto de 2013): 9–19. http://dx.doi.org/10.3126/ije.v1i1.8524.
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Attempts have been made to evaluate four methods of quantitative determination of soil carbonates. Calcium carbonates equivalent were determined by the acid neutralization, calcimeter and acetic acid methods. Also, it obtains by the fourth methods when the acid neutralization method is corrected against proton adsorption. The acid neutralization method gave significantly higher estimates of total carbonates and different from each of the others. The calcimeter method gave the lower estimates of CaCO3 equivalent. The results showed that the corrected values of CaCO3 equivalent did not differ significantly from other three methods but the overall mean tended to be higher than the acetic acid and calcimeter methods. It may be concluded that the acetic acid method is simple, can reasonably estimate the carbonate content and requires only a pH meter. It can be used for routine determination of soil carbonate. DOI: http://dx.doi.org/10.3126/ije.v1i1.8524 International Journal of Environment Vol.1(1) 2013: 9-19
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Souza, Renato Ferreira de, Valdemar Faquin, Ruy Carvalho, Paulo Rogério Ferreira Torres y Adélia Aziz Alexandre Pozza. "Atributos químicos de solos influenciados pela substituição do carbonato por silicato de cálcio". Revista Brasileira de Ciência do Solo 32, n.º 4 (agosto de 2008): 1563–72. http://dx.doi.org/10.1590/s0100-06832008000400020.
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A aplicação de silicatos pode promover incrementos na capacidade de troca de cátions, favorecer a disponibilização de ânions, especialmente o H2PO4- (fosfato diácido), elevar o pH, amenizar a toxidez de Al e, de maneira geral, incrementar a disponibilidade de nutrientes para as plantas, apresentando, porém, uma eficiência agronômica inferior em comparação aos carbonatos. Com o objetivo de avaliar o efeito da substituição do carbonato de Ca por silicato de Ca sobre as propriedades químicas dos solos, especialmente em relação à disponibilidade de P, foram realizados quatro experimentos em casa de vegetação, num delineamento inteiramente casualizado, com quatro repetições. Os tratamentos consistiram de cinco níveis de substituição (0, 25, 50, 75 e 100 %) do carbonato de Ca por silicato de Ca, mantendo uma relação estequiométrica Ca:Mg de 4:1 e o mesmo conteúdo de CaO, suficientes para elevar V = 60 %. Os tratamentos foram aplicados em amostras de 4 dm³ de Neossolo Quartzarênico órtico, Latossolo Vermelho-Amarelo textura média, Latossolo Vermelho-Amarelo textura argilosa e Latossolo Vermelho textura muito argilosa, sendo cada solo um experimento. Foram determinados os valores dos atributos químicos dos solos: pH em H2O, P, P remanescente (P-rem), K, Ca, Mg, Si, Al, H + Al, matéria orgânica (MO), Cu, Mn, Zn e B, soma de bases (S), a CTC efetiva (t), a CTC em pH 7,0 (T), a saturação por bases (V) e a saturação por Al (m), os quais foram submetidos à analise de variância e ao ajuste de modelos de regressão simples, considerando os níveis de substituição de CaCO3 por CaSiO3. Verificou-se que a substituição de carbonato por silicato promoveu aumentos significativos nos valores de Si, Al, H + Al e m e redução nos valores de P-rem, pH, S, t e V; já os valores de P Mehlich-1, K, Mg, MO, T, Mn, Cu e B não foram influenciados significativamente. Houve declínio na disponibilidade de Zn somente no solo RQo. A eficácia do silicato de Ca foi inferior à de carbonato de Ca na melhoria das condições químicas do solo.
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Jarnuszewski, Grzegorz. "Some physical properties of mursh developed on limnic limestones in NW Poland". Soil Science Annual 68, n.º 3 (1 de septiembre de 2017): 132–39. http://dx.doi.org/10.1515/ssa-2017-0016.
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AbstractPost-bog soils developed on carbonate sediments are closely related to a young-glacial landscape and postglacial lakes. Drainage of biogenic accumulation area leads to a series of transformations in accumulated formations, including the process of decession. The studies conducted in the years 2009–2012 were focused on post-bog soils near lakes: Strzeszowskie, Sitno and Drawskie in Western Pomerania. The examined soils belong to murshic soils and gleysols (The classification of Polish soils). Mursh horizons contained from 0.2 to 43.3% of carbonate and from 27.2 to 77.6% of non-carbonates fractions (Ncf), and varying amount of organic matter depending on the degree of mineralisation. Specific density of surface horizons was in the range from 1.76 to 2.33 Mg·m−3, and bulk density from 0.28 to 0.68 Mg·m−3. Higher porosity was found in mursh organic soils in comparison to gleysols. The studies showed that the content of carbonate fraction was related with specific density, bulk density, porosity and water capacity. Obtained results of physical and physico-chemical analysis indicate that dewatering depth of post-bog soils developed on limnic limestone are reflected in worsened water retention properties and reduced capillary ascent in the upper layers of carbonate formations of gleysols.
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García-Montero, L. G., I. Valverde-Asenjo, P. Díaz y 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.º 2 (2009): 206. http://dx.doi.org/10.1071/sr08084.
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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.
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Gordienko, O. A. y 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.º 106 (27 de marzo de 2021): 77–104. http://dx.doi.org/10.19047/0136-1694-2021-106-77-104.
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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.
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Alcântara, Marco Aurélio Kondracki de y Otávio Antonio de Camargo. "Manipulação de carga e movimento de nitrato em horizontes B de um Latossolo Vermelho". Pesquisa Agropecuária Brasileira 45, n.º 2 (febrero de 2010): 204–12. http://dx.doi.org/10.1590/s0100-204x2010000200012.
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O objetivo deste trabalho foi avaliar a influência do pH e da adição de carbonatos, fosfatos e sulfatos na movimentação do nitrato, em colunas constituídas do horizonte subsuperficial de um Latossolo Vermelho Acriférrico. Os experimentos foram realizados de acordo com a técnica do deslocamento miscível. Utilizaram-se como pulso de nitrato soluções de KNO3 a 10 ou 40 mmol L-1. Em cada coluna, foram obtidas curvas de transposição do elemento. A carga líquida do solo nos diferentes tratamentos variou de - 24,0 a +35,0 mmol c L-1. Nos tratamentos que receberam adição de ácido clorídrico, ácido clorídrico + fosfato, carbonato + fosfato e sulfato, as recuperações de nitrato foram maiores do que o total aplicado no pulso. As adições de carbonatos, fosfato e sulfato favoreceram a lixiviação de nitrato, e deslocaram as curvas de transposição para a esquerda. A acidificação do solo retardou o deslocamento do nitrato, e deslocaram as curvas de transposição para a direita. A movimentação de nitrato no solo foi mais influenciada pelo pH do meio, pela presença de carbonatos, fosfatos e sulfatos, do que pela força iônica do pulso.
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Fernandes, Milena y Evelyn Krull. "How does acid treatment to remove carbonates affect the isotopic and elemental composition of soils and sediments?" Environmental Chemistry 5, n.º 1 (2008): 33. http://dx.doi.org/10.1071/en07070.
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Environmental context. The ability to accurately determine the elemental and isotopic composition of soils and sediments has important implications to our quantitative understanding of global biogeochemical cycles. However, the analysis of organic carbon in solid matrices is a time-consuming task that requires the selective removal of carbonates, a treatment that has the potential to significantly alter the composition of the original sample. In the present work, we compare three of the most common acid treatments used for carbonate removal, and critically evaluate their effect on the content and isotopic signature of organic carbon and nitrogen in both soils and sediments. Abstract. In the present work, we compared the efficacy of three acid treatments in removing carbonates from soils and sediments for elemental and isotopic analysis. The methods tested were (1) refluxing with H2SO3; (2) in situ treatment with H2SO3 in silver capsules; and (3) treatment with HCl followed by rinsing with water. Refluxing with H2SO3 led to substantial losses of organic carbon and nitrogen, but comparatively small nitrogen isotopic shifts. The in situ treatment was inadequate for carbonate-rich samples (contents ≥30%) as a consequence of the formation of a mineral precipitate. Treatment with HCl led to substantial losses of nitrogen from carbonate-rich samples, and deviations in nitrogen isotopic signatures (δ15N) of up to 3.7‰. δ15N values showed no significant difference between acid-treated and untreated samples or between treatments, although variability was high and influenced by sample composition. Carbonate-poor samples showed no statistical difference in δ13C values between treatments, whereas carbonate-rich samples tended to be more 13C-depleted when treated with HCl, potentially suggesting the preferential preservation of 13C-depleted compounds (e.g. lipids or lignin).
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Almanova, Zh S., S. O. Kenzhegulova, R. Kizilkaya, A. T. Zhakenova, D. Yerzhan y 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.º 4(119) (25 de diciembre de 2023): 97–105. http://dx.doi.org/10.51452/kazatu.2023.4(119).1576.
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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.
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Leah, Tamara. "Assessment of Microelements Soil Pollution with Ecological Indicators". Chemistry Journal of Moldova 7, n.º 1 (junio de 2012): 45–49. http://dx.doi.org/10.19261/cjm.2012.07(1).06.
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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%.
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Fishtik, Ilie. "Thermodynamic Stability Relations in the C-H-O System". Chemistry Journal of Moldova 7, n.º 2 (diciembre de 2012): 12–20. http://dx.doi.org/10.19261/cjm.2012.07(2).19.
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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%.
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Yi, Yaolin, Martin Liska, Cise Unluer y Abir Al-Tabbaa. "Carbonating magnesia for soil stabilization". Canadian Geotechnical Journal 50, n.º 8 (agosto de 2013): 899–905. http://dx.doi.org/10.1139/cgj-2012-0364.
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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.
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Sorokina, V. V. y 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.º 6 (2021): 167–72. http://dx.doi.org/10.23885/2500-395x-2021-1-6-167-172.
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. 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.
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Ahmad, Waqar, Balwant Singh, Ram C. Dalal y Feike A. Dijkstra. "Carbon dynamics from carbonate dissolution in Australian agricultural soils". Soil Research 53, n.º 2 (2015): 144. http://dx.doi.org/10.1071/sr14060.
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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.
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SEİTKALİ, Nurzikhan, Askhat NAUSHABAYEV, Shynar MAZKİRAT y Tursunay VASSİLİNA. "Assessing the efficacy of ameliorants on saline-sodic soils: Laboratory insights for reclamation strategies". EURASIAN JOURNAL OF SOIL SCIENCE (EJSS) 12, n.º 4 (17 de julio de 2023): 328–34. http://dx.doi.org/10.18393/ejss.1331960.
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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.
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Kabore, Fidèle, Edmond Hien, Tockville B. Mare, Korodjouma Ouattara y Prosper N. Zombre. "Caractéristiques morpho-pédologiques et potentialités agricoles de sols développés sur roches dolomitiques dans le bassin de Taoudéni au Burkina Faso". International Journal of Biological and Chemical Sciences 14, n.º 6 (7 de octubre de 2020): 2333–51. http://dx.doi.org/10.4314/ijbcs.v14i6.32.
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Dans l’Ouest du Burkina Faso ont été identifiés des sols développés sur des dolomies. L’absence d’étude pédologique antérieure dans la région, traitant de l’implication géochimique des roches dolomitiques sur les propriétés de ces sols, a conduit à la réalisation d’une étude morpho-pédologique. Celle-ci avait pour objectif d’évaluer l’impact des carbonates sur les caractéristiques morphologiques, physiques, chimiques et hydriques des sols en vue d’en dégager les potentialités. Cette prospection menée à partir de trois transects, partant chacun des trois principales collines dolomitiques de la région (Diounkan, Souroukoudinga et Samendéni) indique l’existence d’argiles de type 2/1. Ces argiles interviennent positivement dans la structuration des sols, la rétention de l’eau et des nutriments grâce à leur CEC élevée comprise entre 11 et 20 cmol(+).kg-1. On note, par ailleurs, un déséquilibre cationique entre Ca2+et Mg2+, car le ratio Ca2+/Mg2+>1 dans l’horizon organo-minéral, devient < 1 en profondeur, traduisant ainsi un excès de Mg2+ à ce niveau. Les rapports Mg2+/K+ et Ca2+/K+ parfois > 50 et le ratio K+/CEC < 0,05, indiquent une carence en K+. Par conséquent, le potassium pourrait constituer, avec le phosphore (< 5 mg.kg-1), les principaux facteurs limitant la productivité des sols. L’utilisation durable de ces sols exige un choix judicieux des types de cultures et un mode de fertilisation organo-minérale pour compenser les carences.
Mots clés: Argiles, cations, antagonisme potassium-magnésium, fertilité du sol, roches dolomitiques.
English Title: Morpho-pedological characteristics and agricultural potentialities of soils developed on dolomitic rocks in the Taoudeni basin in Burkina FasoIn western of Burkina Faso, soils developed on dolostones have been identified. Lack of previous soil study in the region, dealing with the geochemical implication of dolomitic rocks on the properties of these soils, led to the realization of a morpho-pedological study. The purpose of this study was to assess the impact of carbonates on the morphological, physical, chemical and water characteristics of the soils in order to identify their potential. This prospecting carried out starting from three transects, starting each from the three main dolomitic hills of the region (Diounkan, Souroukoudinga and Samendeni) indicates the existence of type 2/1 clays. These clays play a positive role in the structuring of soils, the retention of water and nutrients thanks to their high CEC between 11 and 20 cmol(+)kg-1. There is also a cationic imbalance between Ca2+ and Mg2+, because Ca2+/Mg2+ > 1 ratio in the organo-mineral horizon becomes < 1 from the median horizon, thus reflecting an excess of Mg2+ at this level. The Mg2+/K+ and Ca2+/K+ ratios sometimes > 50 and the K+/CEC ratio < 0.05 indicate a deficiency of K+. Consequently, potassium could constitute with phosphorus (<5 mg.kg-1) the main factors limiting the productivity of these soils. The sustainable use of these soils requires a judicious choice of crop types and an organo-mineral fertilization method to compensate for the deficiencies.
Keywords: Clay, cations, potassium-magnesium antagonism, soil fertility, dolostones.
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Silva, Douglas Fernando Ramos da, Juberto Babilonia Sousa y Celia Alves Souza. "SUB-BACIA HIDROGRÁFICA DO CÓRREGO LIMEIRA: CARACTERIZAÇÃO AMBIENTAL E MORFOLÓGICA". REVISTA EQUADOR 12, n.º 3 (2 de abril de 2024): 640–61. http://dx.doi.org/10.26694/equador.v12i3.14261.
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A sub-bacia hidrográfica do córrego Limeira localiza-se na interface geomorfológica da Província Serrana, Baixada Cuiabana e Pantanal Mato-grossense. A região é área de recepção de material sedimentar advindo das adjacências e com altos teores em carbonatos. O objetivo do estudo foi realizar caracterização ambiental e morfológica de solo na sub-bacia hidrográfica do córrego Limeira. Alguns procedimentos foram necessários, tais como atividades de gabinete para construção da base teórica e conceitual; elaboração da base cartográfica no ambiente de Sistemas de Informações Geográficas (SIG), utilizando a extensão ArcMap do software ArcGIS, versão 10.6. Realizou trabalho de campo para observação e descrição morfológica de um perfil de solo pré-selecionado, com influência direta de sedimentos ricos em carbonato. Quanto aos componentes ambientais da sub-bacia, registrou as ocorrências geológicas: Formação Raizama (1,86%), Formação Araras Membro Superior (4,02%), o Grupo Cuiabá (27,13%), Formação Pantanal, com maior área dentro da sub-bacia, representando 67%. Foram identificadas três unidades de relevo: Província Serrana (9,79%), Pantanal de Poconé (22,21%) e Depressão Cuiabana (67,86%). As classes de solos ocorrentes na sub-bacia foram: Plintossolo Argilúvico Distrófico (0,14%), Argissolo Vermelho-Amarelo Eutrófico (24,86%), Argissolo Vermelho Eutrófico (38,45%), Neossolo Litólico Distrófico (4,29%), Planossolo Háplico Eutrófico (0,58%) e Vertissolo Hidromórfico órtico (22,92%). O Vertissolo Hidromórfico Carbonático típico apresentou a consistência seca do solo muito duro, formando torrões compactos.
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Lechler, Alex R., Katharine W. Huntington, Daniel O. Breecker, Mark R. Sweeney y 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.º 2 (5 de julio de 2018): 331–47. http://dx.doi.org/10.1017/qua.2018.47.
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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.
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Ramnarine, R., R. P. Voroney, C. Wagner-Riddle y K. E. Dunfield. "Carbonate removal by acid fumigation for measuring the δ13C of soil organic carbon". Canadian Journal of Soil Science 91, n.º 2 (mayo de 2011): 247–50. http://dx.doi.org/10.4141/cjss10066.
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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.
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Oganesyan, M. S. y 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.º 3-4 (14 de noviembre de 2015): 25–30. http://dx.doi.org/10.15421/041514.
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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.
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Stietiya, Mohammed Hashem, Mohammad Duqqah, Theophilus Udeigwe, Ruba Zubi y 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.
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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.
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Konarbaeva, G. A. y E. N. Smolentseva. "Fluorine and Iodine in Soils of the Kulunda Plain". Почвоведение, n.º 2 (1 de febrero de 2023): 170–83. http://dx.doi.org/10.31857/s0032180x22600792.
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The content and distribution of fluorine (F) and iodine (I) have been studied using the example of a four soils located on the terrace of Kuchukskoye Lake in the Altai kray. Soil sections are located on various elements of the micro relief within the boundaries of the lake terrace. The textural-carbonate stratified chernozem (Calcic Chernozem (Loamic, Areninovic, Bathyraptic)) occupies the top of the micro relief. The Solonchak quasi-gleyed (Calcic Solonchak (Loamic, Sulphatic, Humic) is located in a micro-depression. The absolute difference in elevation between these soils is 1 m. Solonetz dark quasi-gleyed salted (Protosalic Solonetz (Loamic, Humic) and texture-carbonate quasi-gleyed salted (Calcic Gleyic Chernozem (Loamic, Endosalic) are confined to the slope between the Calcic Chernozem and Solonchak. The total content of halogens and their mobile forms were determined: water-soluble for F and salt-soluble for I. The content of total F in soils averaged 277.40 mg/kg (lim 59.83–541.10 mg/kg), water-soluble – 3.47 mg/kg (lim 0.04–16.45 mg/kg). Statistical calculations proved that the content of total F strongly correlates with the content of clay, carbonates and water-soluble sodium-cation, and the value of the correlation coefficient depends on the type of soil and its position on the micro relief. Water-soluble F has a high positive correlation with similar parameters in the Chernozem and in the Solonetz. The results showed that the content of total I in the studied soils is higher than in zonal soils of this territory, averages 13.61 mg/kg of soil (5.27–15.21 mg/kg) and moderately depends on the content of clay and carbonates. The influence of the soil type and its position on the micro relief was not revealed on the content of total I. The average content of salt-soluble I is 0.71 mg/kg (0.01–1.86 mg/kg). For all studied soils except Solonchak the relationship of the content of salt-soluble I with the content of clay, carbonates and water-soluble sodium cation has been established. No significant correlation between the above-mentioned parameters has been established for the Solonchak. The revealed heterogeneity of the spatial distribution of F and I in in the studied soils should be taken into account when conducting regional assessments of the status of these halogens.
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Zamanian, Kazem, Konstantin Pustovoytov y Yakov Kuzyakov. "Carbon Sources in Fruit Carbonate of Buglossoides arvensis and Consequences for 14C Dating". Radiocarbon 59, n.º 1 (31 de enero de 2017): 141–50. http://dx.doi.org/10.1017/rdc.2016.123.
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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.
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Deptula, Andrzej, Wiesława Łada, Tadeusz Olczak, Danuta Wawszczak, Marcin Brykala, Fabio Zaza y Kenneth C. Goretta. "Novel Sol-Gel Synthesis of LiMn2O4 and LiNixCo1-xO2 Powders". Advances in Science and Technology 63 (octubre de 2010): 14–23. http://dx.doi.org/10.4028/www.scientific.net/ast.63.14.
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A modified complex sol-gel process was developed to synthesize LiMn2O4 and LiNixCo1-xO2 powders. Sols were prepared from 1.5 M of Mn2+ or 1 M of xNi2+ and (1-x)Co2+ acetates plus ascorbic acid aqueous solutions by alkalizing them with LiOH and NH4OH. Ascorbic acid was added to prevent precipitation in the precursor solutions. When the sols were concentrated to one-third of their initial volume under reduced pressure and then gelled by drying for 10 days, heat treatment to ≥700 °C was accompanied by foaming, violent self-ignition, and formation of carbonates in the Ni-containing species. Significant improvements to the process and resulting powders were gained by modifying the gelation step. When gelation and drying were carried out under reduced total pressure, subsequent heating produced self-ignition, but no foaming, for all heating rates. The resulting products were determined to be nearly phase pure and carbonate free by thermogravimetric, differential thermal, X-ray, and infrared spectroscopy methods.
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Fayyadh, M. A. y 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.º 1 (1 de diciembre de 2022): 012038. http://dx.doi.org/10.1088/1755-1315/1120/1/012038.
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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.
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DEGTYAREVA, Tatyana, Yuri KARAEV, Andrey LIKHOVID y Alexey LYSENKO. "MICROELEMENT COMPOSITION OF SOD-CARBONATE SOILS OF THE NORTH-WEST CAUCASUS". Sustainable Development of Mountain Territories 13, n.º 1 (27 de marzo de 2021): 25–34. http://dx.doi.org/10.21177/1998-4502-2021-13-1-25-34.
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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.
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Alcântara, Marco Aurélio Kondracki de y Otávio Antonio de Camargo. "Adsorção de nitrato em solos com cargas variáveis". Pesquisa Agropecuária Brasileira 40, n.º 4 (abril de 2005): 369–76. http://dx.doi.org/10.1590/s0100-204x2005000400008.
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O objetivo deste trabalho foi avaliar o comportamento adsortivo do nitrato em relação às modificações da carga líquida do solo decorrentes da adição de ácidos, bases (carbonatos), fosfato e sulfato. Foram utilizadas amostras dos horizontes A e B de dois solos: Latossolo Vermelho acriférrico e Nitossolo Vermelho eutrófico. Para verificar o comportamento adsortivo do nitrato em relação aos tratamentos, ajustaram-se isotermas de adsorção de Freundlich (exponencial). O modelo de Freundlich descreve satisfatoriamente a adsorção do nitrato ao solo em todos os tratamentos. Existe correlação significativa entre o pH e a carga líquida dos solos, considerando-se os tratamentos aplicados ao horizonte B do Latossolo Vermelho. A adsorção do nitrato nos horizontes A e B comporta-se de maneira diferenciada nos dois solos utilizados. No Latossolo Vermelho, a adsorção é maior no horizonte subsuperficial em relação ao superficial. No Nitossolo Vermelho, a adsorção é maior no horizonte superficial em relação ao subsuperficial. As adições de sulfato e de fosfato ao solo resultam em pequena diminuição na adsorção de nitrato em relação ao observado no horizonte B do Latossolo Vermelho acriférrico.
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PARLAK, OSMAN y ALASTAIR ROBERTSON. "The ophiolite-related Mersin Melange, southern Turkey: its role in the tectonic–sedimentary setting of Tethys in the Eastern Mediterranean region". Geological Magazine 141, n.º 3 (mayo de 2004): 257–86. http://dx.doi.org/10.1017/s0016756804009094.
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The Mersin Melange underlies the intact Mersin Ophiolite and its metamorphic sole to the south of the Mesozoic Tauride Carbonate Platform in southern Turkey. The Melange varies from chaotic melange to broken formation, in which some stratigraphic continuity can be recognized. Based on study of the broken formation, four lithological associations are recognized: (1) shallow-water platform association, dominated by Upper Palaeozoic–Lower Cretaceous neritic carbonates; (2) rift-related volcanogenic–terrigenous–pelagic association, mainly Upper Triassic andesitic–acidic volcanogenic rocks, siliciclastic gravity flows, basinal carbonates and radiolarites; (3) within-plate-type basalt–radiolarite–pelagic limestone association, interpreted as Upper Jurassic–Lower Cretaceous seamounts with associated radiolarian sediments and Upper Cretaceous pelagic carbonates; (4) ophiolite-derived association, including fragments of the Upper Cretaceous Mersin Ophiolite and its metamorphic sole. Locally, the ophiolitic melange includes granite that yielded a K/Ar radiometric age of 375.7±10.5 Ma (Late Devonian). This granite appears to be subduction influenced based on ‘immobile’ element composition.The Mersin Melange documents the following history: (1) Triassic rifting of the Tauride continent; (2) Jurassic–Cretaceous passive margin subsidence; (3) oceanic seamount genesis; (4) Cretaceous supra-subduction zone ophiolite genesis; (5) Late Cretaceous intra-oceanic convergence-metamorphic sole formation, and (6) latest Cretaceous emplacement onto the Tauride microcontinent and related backthrusting.Regional comparisons show that the restored Mersin Melange is similar to the Beyşehir–Hoyran Nappes further northwest and a northerly origin best fits the regional geological picture. These remnants of a North-Neotethys (Inner Tauride Ocean) were formed and emplaced to the north of the Tauride Carbonate Platform. They are dissimilar to melanges and related units in northern Syria, western Cyprus and southwestern Turkey, which are interpreted as remnants of a South-Neotethys. Early high-temperature ductile transport lineations within amphibolites of the metamorphic sole of the Mersin ophiolite are generally orientated E–W, possibly resulting from vertical-axis rotation of the ophiolite while still in an oceanic setting. By contrast, the commonly northward-facing later stage brittle structures are explained by backthrusting of the ophiolite and melange related to exhumation of the partially subducted northern leading edge of the Tauride continent.
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Tawfik, Abdelhamid, Issam Etebaai, Yassine Smoh, Youssef Ait Akki, Soukaina Ed-Dakiri y Morad Taher. "Contribution to the physicochemical characterisation of soils in the Beni Boufrah watershed (Central Rif, Morocco)". E3S Web of Conferences 502 (2024): 05003. http://dx.doi.org/10.1051/e3sconf/202450205003.
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As part of the study of soil water erosion in the Beni Boufrah watershed, which forms part of the northern slopes of the Central Rif, generally dipping towards the Mediterranean Sea, we carried out soil analyses to determine certain physicochemical characteristics of the soil. These analyses, which consisted of measuring pH, estimating residual moisture content, organic matter and carbonates, and measuring magnetic susceptibility in the horizons of eight profiles sampled from different soils in the Beni Boufrah watershed, are of great interest in understanding the behaviour of these soils with regard to water erosion. The results obtained show that the soils in this catchment area are alkaline, and that their residual moisture and organic matter content are remarkably low, especially in the surface horizons. The carbonate content is only significant in soils resulting from the alteration of parent rocks belonging to the Bokkoya limestone ridge. Magnetic susceptibility measurements show that the soils studied are disturbed and reworked.
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Alcântara, M. A. K. y O. A. Camargo. "Fator de retardamento e coeficiente de dispersão-difusão para o crômio (III) em solos muito intemperizados, influenciados pelo pH, textura e matéria orgânica". Revista Brasileira de Ciência do Solo 25, n.º 1 (marzo de 2001): 209–16. http://dx.doi.org/10.1590/s0100-06832001000100022.
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O objetivo principal deste trabalho foi analisar a variação dos fatores de retardamento (R) e dos coeficientes de dispersão-difusão (D) para o crômio (III) em dois solos muito intemperizados, considerando diferentes atributos edáficos: textura, pH e matéria orgânica. Utilizaram-se amostras dos horizontes A e B com diferença marcante no teor de matéria orgânica de dois solos coletados no estado de São Paulo: Latossolo Vermelho eutroférrico textura argilosa (LVe) e Latossolo Vermelho-Amarelo distrófico textura média (LVd). A alteração do pH das amostras do horizonte superficial foi realizada com adição de carbonato de cálcio para elevar a saturação por bases a 70%. Foram realizados experimentos de adsorção em condições estáticas e de lixiviação em colunas de solo, utilizando a teoria do deslocamento miscível. Os Rs obtidos para o LVe foram maiores em comparação aos obtidos para o LVd. O aumento do pH do solo propiciado pela adição de carbonato de cálcio resultou em aumento no R. No LVe, a presença significativa de ácidos fúlvicos na matéria orgânica propiciou um R menor no horizonte superficial em relação ao subsuperficial. Não foi evidenciada relação nítida entre D e os diferentes solos, níveis de calagem e horizontes.
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Nunes, José Gustavo Da Silva y Rogério Uagoda. "Solos Em Carste Tropical, Desenvolvimento Pedogenético E Comportamento Hidrológico: Uma Revisão Teórica." Revista Brasileira de Geografia Física 13, n.º 07 (13 de diciembre de 2020): 3498. http://dx.doi.org/10.26848/rbgf.v13.07.p3498-3517.
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Este trabalho teve como objetivo reunir informações sobre comportamento pedogenético e hidrológico em áreas de rochas carbonáticas de clima tropical. A execução desta pesquisa foi embasada em artigos científicos indexados, nacionais e internacionais, como também em livros, teses e dissertações relevantes para o tema proposto. O solo é um sistema multifásico, e os seus aspectos morfológicos e constitucionais atuam facilitando ou dificultando a permeabilidade da água, assim cada horizonte pedológico funciona como um mecanismo em um mesmo perfil de solo. Os fatores físicos/químicos da água também atuarão contribuindo para a classificação dos grupos hidrológicos de solo. No Brasil, a Embrapa realizou classificações dos horizontes diagnósticos, dos grupos hidrológicos e dos tipos de solos, baseada em autores internacionais, adaptadas às condições tropicais. Mas as áreas cársticas, que representam um percentual de 20% da superfície terrestre, podem apresentar condições particulares para a formação de solo e para o comportamento hidrológico, podendo incluir zonas locais de alta permeabilidade, fuga de água subterrânea e eliminação de resíduos insatisfatórios. Solos de ambientes cársticos são mal desenvolvidos, apresentam argilas avermelhadas de baixa atividade normalmente. No Brasil os estudos deste tipo de ambiente são escassos, mas alguns trabalhos desenvolvidos em áreas cársticas trazem algumas informações básicas sobre os solos. As pesquisas encontradas que trouxeram informações dos solos em carstes, foram plotadas no mapa brasileiro. A pesquisa demonstrou que há um gap de informações para o desenvolvimento pedológico em áreas cársticas, mas é possível fazer associações entre estas classes de solo a outros ambientes, incluindo o comportamento hidrológico.Soils In Tropical Karst, Pedogenetic Development And Hydrological Behavior: A Theoretical Review A B S T R A C TThis work aimed to gather information on pedogenetic and hydrological behavior in carbonate rock areas of tropical climate. The execution of this research was based on indexed scientific articles, national and international, as well as on books, theses and dissertations relevant to the proposed theme. The soil is a multiphase system, and its morphological and constitutional aspects act to facilitate or hinder water permeability, so each pedological horizon works as a mechanism in the same soil profile. The physical / chemical factors of the water will also act contributing to the classification of soil hydrological groups. In Brazil, Embrapa carried out classifications of diagnostic horizons, hydrological groups and soil types, based on international authors, adapted to tropical conditions. However, karst areas, which represent a percentage of 20% of the earth's surface, may present particular conditions for soil formation and hydrological behavior, and may include local areas of high permeability, groundwater leakage and unsatisfactory waste disposal. Soils in karst environments are poorly developed, with reddish clays of low activity normally. In Brazil, studies of this type of environment are scarce, but some studies carried out in karst areas bring some basic information about the soils. The researchers found that brought information on soils in carstes, were plotted on the Brazilian map. Research has shown that there is an information gap for pedological development in karst areas, but it is possible to make associations between these soil classes and other environments, including hydrological behavior.Keywords: Soil Hydrological Groups; Tropical Soil; Karst.
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Kummer, Larissa, Vander de Freitas Melo, Yara Jurema Barros y Julio César Rodrigues de Azevedo. "Extrações sequenciais de chumbo e zinco em solos de área de mineração e metalurgia de metais pesados". Revista Brasileira de Ciência do Solo 35, n.º 6 (diciembre de 2011): 2005–18. http://dx.doi.org/10.1590/s0100-06832011000600017.
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A extração sequencial permite obter informações mais detalhadas sobre origem, modo de ocorrência, disponibilidade biológica e físico-química, mobilização e transporte dos metais pesados em ambientes naturais. Com o objetivo de estudar as formas de Pb e Zn foram selecionados oito perfis de solos de diferentes locais dentro de área de mineração e metalurgia de Pb, no município de Adrianópolis (PR), Vale do Rio Ribeira. As amostras foram coletadas nas profundidades de 0 a 10, 10 a 20 e 20 a 40 cm. Foram determinados os teores totais de Pb e Zn e sua especiação nas formas: solúvel; trocável; ligada a carbonatos; ligada à matéria orgânica; ligada aos óxidos de Fe de Al de baixa cristalinidade; ligada aos óxidos de Al cristalinos e filossilicatos 1:1 e 2:1; e residual. Com base nos valores percentuais de participação de cada fração nos teores totais, procedeu-se ao agrupamento das amostras similares por meio da análise de componentes principais (PCA). Houve basicamente duas formas de contaminação dos perfis de solo, sendo uma em decorrência das partículas das chaminés e a outra em função do acúmulo de rejeitos sólidos sobre os solos. A primeira foi mais prejudicial ao ambiente em razão dos maiores teores totais e de formas mais disponíveis no solo (solução mais trocável). De modo geral, houve maior associação de Pb aos carbonatos, seguida das frações residual e óxidos de Fe e Al de baixa cristalinidade. O Zn apresentou-se em formas mais insolúveis, aumentando a participação da fração residual nos teores totais. A PCA foi sensível às diferentes formas de Pb nos solos, pois promoveu o agrupamento das amostras, principalmente, em função da participação das formas trocáveis, ligadas aos óxidos de Fe e Al e ligadas aos carbonatos, em relação aos teores totais.
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Sheldon, Nathan D. "Using Carbon Isotope Equilibrium to Screen Pedogenic Carbonate Oxygen Isotopes: Implications for Paleoaltimetry and Paleotectonic Studies". Geofluids 2018 (10 de diciembre de 2018): 1–11. http://dx.doi.org/10.1155/2018/5975801.
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Stable isotope compositions of pedogenic carbonates (δ13Ccarb, δ18Ocarb) are widely used in paleoenvironmental and paleoaltimetry studies. At the same time, both in vertical stratigraphic sections and in horizontal transects of single paleosols, significant variability in δ18Ocarb values is observed well in excess of what could reasonably be attributed to elevation changes. Herein, a new screening tool is proposed to establish which pedogenic carbonate δ18Ocarb compositions reflect formation in isotopic equilibrium with environmental conditions through the use of the co-occurring δ13Corg composition of carbonate-occluded or in profile organic matter, where Δ13C = δ13Ccarb – δ13Corg. Based upon 51 modern soils from monsoonal, continental, and Mediterranean moisture regimes, Δ13C = +15.6 ± 1.1‰ (1σ), which closely matches theoretical predictions for carbonates formed at carbon isotope equilibrium through Fickian diffusion. Examples from both disequilibrium and equilibrium cases in the geologic record are examined, and it is shown that previous δ18Ocarb records used to infer Cenozoic uplift in southwestern Montana do not provide any constraint on paleoelevation because >90% of the pedogenic carbonate isotopic compositions are out of equilibrium. Guidelines for future paleoaltimetry studies include collection of both vertical stratigraphic sections and lateral transects, of at least three nodules per horizon, petrographic screening of nodules for diagenesis, collection of at least one independent proxy for paleoclimate or paleovegetation, and screening δ18Ocarb values using Δ13C measured for each paleosol.
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Gordienko, O. A. y R. N. Balkushkin. "Spatial heterogeneity of soil properties of recreational areas of Volgograd". Dokuchaev Soil Bulletin, n.º 114 (25 de marzo de 2023): 109–34. http://dx.doi.org/10.19047/0136-1694-2023-114-109-134.
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The article presents the developed soil maps and maps of spatial variability of soil properties (pH, total salt and carbonate content, organic carbon, density) in some recreational areas of Volgograd. The anthropogenic soils in the studied recreational areas include various urbostratozems (Urbic Technosols (Transportic)), Ekranic Technosols (Transportic), as well as quasizems (Phaeozems (Tehnic)), among the agrogenic ones – accumulation-carbonate agrozems (Cambisols (Aric, Protocalcic). Natural soils are represented by light and dark humus soils, chestnut soils, solonetz, as well as stratozems and psammozems. According to the data of isolinear mapping, it was found that acid-alkaline properties of soils of green zones vary from slightly alkaline to alkaline depending on the soil horizon and anthropogenic load. The mapping did not reveal salinization of the upper 0–30 cm layer. Values of organic carbon vary greatly (1–10%) and are conditioned by the presence or absence of meliorative artificial layers, as well as by the character of territory use. The content of calcium carbonates in the upper 30 cm is small and varies from 0.7 to 5%. It is established that the physical properties (density) directly depend on the level of anthropogenic load, increasing in footpaths and lawns. Spatial assessment of the properties of urban soils is important for identifying areas with an excess or on the contrary – low content of certain chemical and physical indicators for the planning of landscaping and gardening of urban areas.
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Zhang, Li, Wei Han, Min Peng, Fei Liu, Yuntao Song, Xiujin Liu, Qiaolin Wang et al. "Geochemical characteristics of rare earth elements (REEs) in soils developed on different parent materials, in the Baoshan area, Yunnan Province, SW China". Geochemistry: Exploration, Environment, Analysis 21, n.º 2 (16 de febrero de 2021): geochem2019–082. http://dx.doi.org/10.1144/geochem2019-082.
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The geochemistry of rare earth elements (REEs) was studied in rock samples from host formations, ore samples from two mineral deposits (the Hetaoping Cu-Pb-Zn mine: HTP and the Heiyanao Fe-Cu-Pb-Zn mine: HYA) and the overlying or nearby soils to better understand REE concentrations, distributions and behaviour during weathering from different parent materials at the regional scale, Baoshan area, Yunnan Province, SW China. The mudstone and sandstone formations have the highest total REE (ΣREE) contents. Chondrite-normalized diagrams for rocks and ores show significant light REEs (LREEs) enrichments and Eu depletion (except for ores in HYA). Cerium displays an obvious negative anomaly in carbonate rocks (Є-3-R, C-R, D-R, T-1-R and T-2-R). Soils overlying carbonate rock formations (T-1-S, C-S and Є-3-S) have the highest ΣREE contents, while soils overlying basalts have the lowest ΣREE contents. Soils show enrichments in LREEs with negative Eu anomalies and slight Ce anomalies in the studied soils. Soils with high ∑LREE/∑heavy REE (HREE) values may result from the preferential absorption of LREEs by organic matter. Negative Eu anomalies in soils occur for parent materials in the study area lacking feldspar, especially soils developed from carbonates. Compared to the parent materials, most soils show REE enrichment because alkali metals are removed and REEs are concentrated by low mobility in surficial processes and positive Ce anomalies because of weathering dissolution of other trivalent REEs with ionic radii similar to that of Ca2+.Supplementary material: Additional data (Tables S1 and S2) and sample locations (Fig. S1) are available at https://doi.org/10.6084/m9.figshare.c.5303140
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Matviishyna, Zh M. y S. P. Doroshkevych. "Micromorphological peculiarities of the Pleistocene soils in the Middle Pobuzhzhya (Ukraine) and their significance for paleogeographic reconstructions". Journal of Geology, Geography and Geoecology 28, n.º 2 (6 de julio de 2019): 327–47. http://dx.doi.org/10.15421/111932.
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The basic micromorphological features of fossil Pleistocene soils of the Middle Pobuzhzhya region are revealed. The early Neopleistocene (Shyrokyne, Martonosha, Lubny) and Middle Pleistocene Zavadivka soils are characterized by bright brownish, reddish and brownish colors of plasma, compact composing structural separations in the form of cleave blocks with densely packed nodular formations of ferruginous matter, cracksman ship of the mass, a significantamount of ferruginous, manganese and carbonate new formations. In the soils of the early optimum of the Kaydaky stage, signs of the eluvial-illuvial processes were observed (impoverished on the thin clays and humus fields with the «washed» grains of the mineral skeleton, the destroyed microaggregates in the eluvial and the impregnation of the plasma by calomorphic clays in the form of streaks, films, streams in the illuvial horizons). In the Pryluky soils there is a well-expressed microagregation of the mass, a branched net of twisted pores, humus coagulation in the humus and humus transition horizons, various forms of carbonate new formations as the impregnation and plasma cementation by microcrystalline calcite, presence of isolated crystals of crypto-, micro- and small crystalline calcite. The specific individual features of the Vytachiv soils are cleave block microstructure, the presence of the nodular concentric organo-iron-clay formations, and microorsteins. Dofinivka soils are characterized by a loose microstructure, fuzzy rounded microaggregates, a developed system of twisted pores, and enrichment of mass on carbonates. In order to clarify the genetic types of fossil Pleistocene soils of the Middle Pobuzhzhya, identification of the signs of elementary soil formation processes was carried out on the basis of micromorphological analysis data. The significance of the results of micromorphological researches for paleogeographical reconstruction is outlined. It has been established that certain groups of soil formation processes are characteristic for fossil soils of separate paleogeographical stages. In the soils formed up to the Dnieper glaciation (Shyrokyne, Martonosha, Lubny and Zavadivka), signs of processes of claying, rubbification, ferralization, cleaving were displayed, but weakly expressed humus formation, thoughcarbonization were diagnosed. In the soils formed after the maximum glaciation (Kaydaky, Pryluky, Vytachiv, Dofinivka), signs of the such processes as humus formation, podzolization, lessive, leaching, damp-meadow soil formation on floodplain, migration of carbonates, etc., are established. It is processes which are predominating in the modern soils of the territory of Ukraine. Assertaintment of elementary soil-forming processes, diagnosed in multi-annual fossil soils, have made it possible to identify their genetic types and as a result, to reconstruct the soil cover in separate stages of the Neopleistocene, to establish regional patterns of evolutional stadial changes and the natural environment in the Pleistocene on the territory of the Middle Pobuzhzhya.
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Samer Hadi, Zahraa y Khitam Abdulhussein Saeed. "MICROBIAL-INDUCED CALCITE PRECIPITATION" AS A POTENTIAL SUSTAINABLE TECHNIQUE FOR POLLUTED SOIL BIOREMEDIATION: A REVIEW". Journal of Engineering and Sustainable Development 26, n.º 4 (1 de julio de 2022): 18–29. http://dx.doi.org/10.31272/jeasd.26.4.2.
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Industrialization and population growth have increased the emission and buildup of environmental heavy metals. These components' bioaccumulation as exposure have been related to a range of illnesses and cancer, and the mechanical and physical properties of soil are altered. The "Microbial Induced Calcite Precipitation" is an environmentally green, friend, and sustainable method. This review focused on the metal remediation technology's effects and how to make them sustainable and more environmentally friendly. Many bacteria produce urease, the bacillus is a more common type. Bacteria, with sizes ranging from 0.5 to 3.0µm, are the most common microbes found in soils. It is critical to examine the type of soil, Bacterial size, and size of pore throat. The calcium carbonate majority tends to coat the surface of soils with coarse particles in the state of the contact points in soils with particles smaller than bacterial size (heterogeneous and limited precipitation). The bacterial concentration appears to affect crystal shape, calcium carbonate formation, and the cementation effect of geomaterials. Calcite precipitation takes place most when the pH is between 7.5 and 9.5. Calcite is formed three times at 50°C, while the unconfined compressive strength is only 60% of that at 25°C. Calcium carbonate can be immobilized or formed into undissolved compounds by binding free ions to the calcium carbonate's surfaces, resulting in a form of non-toxic and chemically stable.
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Froitzheim, Nikolaus, Jaroslaw Majka y Dmitry Zastrozhnov. "Methane release from carbonate rock formations in the Siberian permafrost area during and after the 2020 heat wave". Proceedings of the National Academy of Sciences 118, n.º 32 (2 de agosto de 2021): e2107632118. http://dx.doi.org/10.1073/pnas.2107632118.
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Anthropogenic global warming may be accelerated by a positive feedback from the mobilization of methane from thawing Arctic permafrost. There are large uncertainties about the size of carbon stocks and the magnitude of possible methane emissions. Methane cannot only be produced from the microbial decay of organic matter within the thawing permafrost soils (microbial methane) but can also come from natural gas (thermogenic methane) trapped under or within the permafrost layer and released when it thaws. In the Taymyr Peninsula and surroundings in North Siberia, the area of the worldwide largest positive surface temperature anomaly for 2020, atmospheric methane concentrations have increased considerably during and after the 2020 heat wave. Two elongated areas of increased atmospheric methane concentration that appeared during summer coincide with two stripes of Paleozoic carbonates exposed at the southern and northern borders of the Yenisey-Khatanga Basin, a hydrocarbon-bearing sedimentary basin between the Siberian Craton to the south and the Taymyr Fold Belt to the north. Over the carbonates, soils are thin to nonexistent and wetlands are scarce. The maxima are thus unlikely to be caused by microbial methane from soils or wetlands. We suggest that gas hydrates in fractures and pockets of the carbonate rocks in the permafrost zone became unstable due to warming from the surface. This process may add unknown quantities of methane to the atmosphere in the near future.
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Mandžukovski, Dejan, Aco Teofilovski, Marjan Andreevski, Renata Ćušterevska, Rossen Tzonev y Marius Dimitrov. "Relationships between vegetation of Macedonian pine (Pinus peuce Griseb.) and different types of soils on which it develops". Hacquetia 21, n.º 1 (12 de febrero de 2022): 89–106. http://dx.doi.org/10.2478/hacq-2021-0030.
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Abstract This paper deals with relationships between vegetation of Macedonian pine (Pinus peuce) and soils developed on different parent materials on the territory of North Macedonia. We analysed the floristic composition at localities on limestone, on scree of dolomite marble and on scree of silicate. On limestone and scree of dolomite marble, rendzinas on hard limestone and dolomite have developed, and on silicate parent material brown forest soils. The vegetation was sampled according to the Braun-Blanquet approach. DCA and indicator values were used for ecological interpretation of the vegetation patterns. The mechanical and chemical properties of soil and textural classes were also processed. An evident increased presence of carbonates in the soil of scree of dolomite marble on Nidže Mountain was observed, unlike that on Shar Mountain which has formed on typical limestone. Although it is a forest community dominated by the same species, differences between the massifs, the precipitation regime, geology, differences in soil properties in relation to the appearance of carbonates and pH values, and other factors, result in differences in their floristic composition and are the reason for the distinction between the two groups. On silicate on Nidže Mountain, Macedonian pine forests have also developed on brown forest soils, with a different floristic composition to that of the other group on carbonate (dolomite and limestone).
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Kodirova, Dilrabo, Nilufar Safarova, Bunyod Safarov y Jamolbek Turdaliev. "Chemical and agrochemical properties of typical rainfed sierozem soils of Uzbekistan". BIO Web of Conferences 65 (2023): 04006. http://dx.doi.org/10.1051/bioconf/20236504006.
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The agrochemical properties of soil are important for its fertility, plant growth and development, and harvesting. In this case, humus is one of the main indicators of the total amount of nutrients. These indicators vary by soil layer. The reduction of the amount of humus in the lower layers of the soil has a negative effect on the agrophysical and agrochemical properties of the soil. Soil humus is a complex of high molecular complex chemicals consisting of protein, amino acid, wax, tar, low molecular organic acids, cellulose, lignin, chitin and other substances. Its amount is closely related to a number of factors and conditions - the amount and quality of biomass falling into the soil, the chemical composition of the soil, the environment, water-air, thermal properties, and physical-mechanical properties. This article presents information on the chemical and agrochemical status of typical rainfed sierozems. According to the results of the study, rainfed sierozems are very low in humus, low to moderate in mineral nitrogen and mobile phosphorus, moderate to high in exchangeable potassium. Carbonates are not evenly distributed along the profile of rainfed silozems, that is, some sections differ from the surface layers in their carbonate content, while in other sections, some accumulation of carbonates is observed in the middle and lower layers.
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Biondi, Caroline Miranda, Clístenes Williams Araújo do Nascimento y Adelazil de Brito Fabricio Neta. "Teores naturais de bário em solos de referência do estado de Pernambuco". Revista Brasileira de Ciência do Solo 35, n.º 5 (octubre de 2011): 1819–26. http://dx.doi.org/10.1590/s0100-06832011000500036.
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O bário (Ba) é um metal alcalino terroso de ocorrência natural no solo. É constituinte de carbonatos, sulfatos e silicatos e ocorre como substituto isomórfico de elementos como Ca e K nos minerais. Quando disponível em elevados teores no solo, o Ba pode causar toxidez a diversos organismos vivos. Para considerar que determinado solo está livre de contaminação por esse elemento, faz-se necessário conhecer os teores de Ba nesse solo em condição natural. Portanto, a determinação de teores naturais de Ba em solos é essencial para a construção de uma legislação que sirva de base ao monitoramento e remediação de áreas contaminadas por esse elemento e que seja adequada à realidade pedológica local. Nesse contexto, o objetivo desta pesquisa foi determinar os teores naturais de Ba como base de referência de qualidade para os Solos de Referência do Estado de Pernambuco. Foram coletadas amostras dos dois primeiros horizontes dos 35 perfis de referência, as quais foram submetidas à digestão ácida em micro-ondas (método 3051A). Nos extratos obtidos foi efetuada a determinação dos teores de Ba por ICP-OES. Observaram-se teores de Ba superiores aos valores de prevenção e de investigação estabelecidos pela legislação brasileira (CONAMA, 2009), corroborando a necessidade de maior conhecimento das diversidades regionais para a elaboração de normas nacionais. Os teores naturais de Ba determinados nos solos podem ser utilizados como base para a definição dos valores de referência de qualidade para Ba nos solos de Pernambuco, de acordo com o preconizado pela legislação nacional.
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Smirnova, M. A., A. N. Gennadiev y Yu G. Chendev. "Short–Range Variation of Humus and Carbonate Profiles of Arable Chernozems (Key Site in Belgorod Region)". Почвоведение, n.º 3 (1 de marzo de 2023): 300–311. http://dx.doi.org/10.31857/s0032180x22601086.
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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.
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Silveira, Maria Lucia, Luís Reynaldo Ferracciú Alleoni y Andrew Chang. "Condicionadores químicos de solo e retenção e distribuição de cádmio, zinco e cobre em latossolos tratados com biossólido". Revista Brasileira de Ciência do Solo 32, n.º 3 (junio de 2008): 1087–98. http://dx.doi.org/10.1590/s0100-06832008000300017.
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O uso agrícola é uma das alternativas eficientes para o manejo de biossólidos. Dependendo, porém, da origem (urbana e, ou, industrial) e do sistema de tratamento, biossólidos podem conter concentrações elevadas de metais pesados, que, por sua vez, podem acumular-se nos solos. O uso de condicionadores químicos pode reduzir a biodisponibilidade e a mobilidade de metais no solo e, conseqüentemente, os riscos ao meio ambiente. Neste estudo, avaliaram-se os efeitos da adição de quatro condicionadores [carbonato de cálcio (CaCO3), sulfato de Ca (CaSO4), fosfato de potássio monobásico (KH2PO4) e hidroxiapatita sintética (HA)] na retenção e distribuição de Zn, Cu e Cd em Latossolos tratados com biossólido. Considerando a baixa solubilidade, a HA foi equilibrada nos valores de pH 4, 5 e 6. Utilizaram-se amostras superficiais (0-0,2 m) de um Latossolo Vermelho acriférrico (LVwf) e de um Latossolo Amarelo distrófico (LAd). Dois gramas de terra foram colocados para reagir em câmaras-duplas de difusão com 2 g de biossólidos com teores elevados de metais. Após atingir o equilíbrio (aproximadamente sete dias), a solução foi centrifugada, filtrada e acidificada, e as concentrações de Zn, Cu e Cd foram determinadas. As fases sólidas (solo e biossólido) foram secas por congelamento e, a seguir, procedeu-se à extração seqüencial de Zn, Cu e Cd. Os condicionadores foram eficientes na remoção de Zn, Cd e, em menor proporção, de Cu da solução. Em geral, o CaCO3 foi o mais eficiente na imobilização dos metais seguido da HA (pH 6). A HA equilibrada nos valores de pH 4 e 5 não promoveu imobilização dos metais. Após a introdução dos condicionadores, a quantidade de metais no solo ligados à fração trocável foi reduzida e os teores dos metais ligados à superfície dos óxidos/carbonatos foram aumentados, sobretudo nos tratamentos em que se utilizaram CaCO3 e HA (pH 6).
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Gaultier, Jeanette, Annemieke Farenhorst y 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.º 1 (1 de febrero de 2006): 89–95. http://dx.doi.org/10.4141/s04-074.
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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
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Thaler, Caroline, Guillaume Paris, Marc Dellinger, Delphine Dissard, Sophie Berland, Arul Marie, Amandine Labat y Annachiara Bartolini. "Impact of seawater sulfate concentration on sulfur concentration and isotopic composition in calcite of two cultured benthic foraminifera". Biogeosciences 20, n.º 24 (21 de diciembre de 2023): 5177–98. http://dx.doi.org/10.5194/bg-20-5177-2023.
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Abstract. Marine sediments can be used to reconstruct the evolution of seawater [SO42-] and δ34S over time, two key parameters that contribute to refine our understanding of the sulfur cycle and thus of Earth's redox state. δ34S evolution can be measured from carbonates, barites and sulfate evaporites. [SO42-] variations can be reconstructed using fluid inclusions in halites, a method that only allows a low-resolution record. Reconstruction of the past sulfur cycle could be improved if carbonates allowed the tracking of both seawater δ34S and [SO42-] variations in a sole, continuous sedimentary repository. However, most primary carbonates formed in the ocean are biogenic, and organisms tend to overprint the geochemical signatures of their carbonates through a combination of processes often collectively referred to as vital effects. Hence, calibrations are needed to allow seawater δ34S and [SO42-] reconstructions based on biogenic carbonates. Because foraminifera are important marine calcifiers, we opted to focus on calcite synthesized by individuals of rosalinid benthic foraminifera cultured in the laboratory under controlled conditions, with varying seawater [SO42-] (ranging from 0 to 180 mM). Our experimental design allowed us to obtain foraminiferal asexual reproduction over several generations. We measured bulk carbonate-associated sulfate (CAS) content and sulfur isotopic composition (δ34SCAS) on samples of tens to hundreds of specimens from a selection of culture media, where [SO42-] varied from 5 to 60 mM. Increasing or decreasing [SO42-] with respect to modern-day seawater concentration (28 mM) impacted foraminiferal population size dynamics and the total amount of bioprecipitated carbonate. Foraminiferal CAS concentration increased proportionally with [SO42-] concentration from 5 mM up to 28 mM and then showed a plateau from 28 to 60 mM. The existence of a threshold at 28 mM is interpreted as the result of a control on the precipitation fluid chemistry that foraminifera exert on the carbonate precipitation loci. However, at high seawater sulfate concentrations (> 40 mM) the formation of sulfate complexes with other cations may partially contribute to the non-linearity of the CAS concentration in foraminiferal tests at high increases in [SO42-]. Yet, despite the significant effect of seawater [SO42-] on foraminiferal reproduction and on CAS incorporation, the isotopic fractionation between CAS and seawater remains stable through varying seawater [SO42-]. Altogether, these results illustrate that CAS in biogenic calcite could constitute a good proxy for both seawater [SO42-] and δ34S and suggests that sulfate likely plays a role in foraminiferal biomineralization and biological activity.
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Damiano, Caterina, Paolo Sonzini, Daniela Intrieri y Emma Gallo. "Synthesis of cyclic carbonates by ruthenium(VI) bis-imido porphyrin/TBACl-catalyzed reaction of epoxide with CO2". Journal of Porphyrins and Phthalocyanines 24, n.º 05n07 (mayo de 2020): 809–16. http://dx.doi.org/10.1142/s1088424619501888.
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The catalytic activity of the ruthenium(VI) bis-imido porphyrin complex/TBACl binary system in promoting the CO[Formula: see text] cycloaddition to epoxides forming cyclic carbonates is here reported. The system was very efficient in catalyzing the conversion of differently substituted epoxides under mild experimental conditions (100 [Formula: see text]C and 0.6 MPa of CO[Formula: see text]. Even if the sole TBACl resulted active under the optimized experimental conditions, the addition of ruthenium species was fundamental to maximizing the reaction productivity both in terms of epoxide conversions and cyclic carbonate selectivities. A preliminary mechanistic study indicated a positive role of ruthenium imido nitrogen atom in activating carbon dioxide.