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1
Ivanyuk, Halyna. "Analysis of “Systematics of Polish Soils”." Visnyk of the Lviv University. Series Geography, no. 44 (November 28, 2013): 122–32. http://dx.doi.org/10.30970/vgg.2013.44.1210.
Анотація:
The “Systematics of Polish Soils” (SgP, 2011) is very close to WRB and “Soil Taxonomy”. The morphological characteristics of the soils, investigated in the field, rather than soil genesis are diagnostic criteria. The main provisions of the new “Systematics”, properties of soils of higher taxonomic levels have been reviewed. Some diagnostic horizons, which were not borrowed from other classifications, have been described. We tried to find equivalents in the Ukrainian classification for some soils names. The correlation of Poland soils and WRB has been analyzed. Key words: Systematics of Polish Soils, classification, order, soil type, diagnostic horizon, WRB.
2
Baldrian, P. "Microbial enzyme-catalyzed processes in soils and their analysis." Plant, Soil and Environment 55, No. 9 (October 14, 2009): 370–78. http://dx.doi.org/10.17221/134/2009-pse.
Анотація:
Currently, measuring enzyme activities in soils or other lignocellulose-based materials is technically feasible; this measurement is particularly suitable for evaluating soil processes of biopolymer (cellulose, hemicelluloses, lignin, chitin and others) degradation by microbes and for assessing cycling and mobilization of principal nutrients including nitrogen, phosphorus and sulfur. With some considerations, assay methods can provide reliable information on the concentration of enzymes in soil or the rates of enzyme-catalyzed processes. Enzyme analyses in recent studies demonstrated a high level of spatial variability of soil enzyme activity both in depth and in space. The vertical gradients of enzyme activities are most developed in forest soils. Furthermore, enzyme activity in soils is regulated by seasonally-dependent variables such as temperature, moisture and the input of fresh litter. While several enzymes are widely produced by different groups of soil microorganisms, some of them can be used as indicators of the presence or activity of specific microbial taxa.
3
Chakravarthy, Thokala, and K. Shyam Chamberlin. "Fly ash and bagasse ash embankment in flexible pavements for the analysis and strengthening of black cotton soil’s strength stabilized properties." E3S Web of Conferences 391 (2023): 01005. http://dx.doi.org/10.1051/e3sconf/202339101005.
Анотація:
Soil stabilization is necessary to increase the soil’s durability, volume stability, and engineering expansion strength. Expansive soils (also known as black cotton soil), a problem that affects the entire world and poses various challenges for civil engineers, are extremely hard while dry but completely lose their strength when wet. In this study, fly ash has been employed to stabilize the soil. Five, ten, twenty, and twenty-five percent of fly ash was used in the experiments. Bagasse ash is an easily accessible byproduct of the sugar cane refining process that has negative environmental effects. In this study, any potential pozzolanic benefits are evaluated while taking into account bagasse ash. material that stabilizes elongated soil In order to examine the soils’ geotechnical characteristics, the experimental investigation focuses on altering the fly ash content of the soils. The goal is to learn more about the characteristics of black cotton soil’s tensile strength. The primary goal of this research is to examine the effects of bagasse ash on the engineering expansive soil’s properties as revealed by various lab tests, and after improving the treated soil through embankment work at various civil engineering activities, such as roadways.
4
Edmondson, Jill L., Zoe G. Davies, Sarah A. McCormack, Kevin J. Gaston, and Jonathan R. Leake. "Are soils in urban ecosystems compacted? A citywide analysis." Biology Letters 7, no. 5 (April 20, 2011): 771–74. http://dx.doi.org/10.1098/rsbl.2011.0260.
Анотація:
Soil compaction adversely influences most terrestrial ecosystem services on which humans depend. This global problem, affecting over 68 million ha of agricultural land alone, is a major driver of soil erosion, increases flood frequency and reduces groundwater recharge. Agricultural soil compaction has been intensively studied, but there are no systematic studies investigating the extent of compaction in urban ecosystems, despite the repercussions for ecosystem function. Urban areas are the fastest growing land-use type globally, and are often assumed to have highly compacted soils with compromised functionality. Here, we use bulk density (BD) measurements, taken to 14 cm depth at a citywide scale, to compare the extent of surface soil compaction between different urban greenspace classes and agricultural soils. Urban soils had a wider BD range than agricultural soils, but were significantly less compacted, with 12 per cent lower mean BD to 7 cm depth. Urban soil BD was lowest under trees and shrubs and highest under herbaceous vegetation (e.g. lawns). BD values were similar to many semi-natural habitats, particularly those underlying woody vegetation. These results establish that, across a typical UK city, urban soils were in better physical condition than agricultural soils and can contribute to ecosystem service provision.
5
Rubio, Eduardo, María del Socorro Rubio-Alfaro, and Martín Hernández-Marín. "Wetting Front Velocity Determination in Soil Infiltration Processes: An Experimental Sensitivity Analysis." Agronomy 12, no. 5 (May 10, 2022): 1155. http://dx.doi.org/10.3390/agronomy12051155.
Анотація:
An experimental approach for measuring the wetting front velocity in soils during water infiltration processes is presented. This experimental research is developed to test the sensitivity of the measurement technique in the detection of differences in the dynamics of the wetting front advancement in different soil testing scenarios. Experimental scenarios include undisturbed and artificially compacted soils, square and circular cross-sections of soil samples, water flowing in both directions downward and horizontal, and water infiltration in a block soil sample. The measurement technique is based on wetting front detection employing moisture sensors that measure the soil’s electrical conductivity. The technique was able to detect differences in wetting front in contrasting scenarios. Two-dimensional wetting front advancement experiments carried out on a block sample confirmed the results obtained for the one-dimensional case.
6
Švec, O., L. Bílek, J. Remeš, and Z. Vacek. "Analysis of operational approach during forest transformation in Klokočná Range, Central Bohemia." Journal of Forest Science 61, No. 4 (June 3, 2016): 148–55. http://dx.doi.org/10.17221/102/2014-jfs.
Анотація:
Afforestation of agricultural lands may be in many cases a positive step. Especially, it is a beneficial with waterlogged soils, stony soils or for soils which are for any other reason less fertile and unsuitable for farming. Even too in the agricultural landscape, afforestation can be very important by the breaking of large farm blocks by windbreakers and bio-corridors. The value, quality and fertility of soil can be assessed in different ways. The aim of this study is to determine the criteria for the identification of agricultural land suitable for afforestation. This evaluation process is based on Evaluated Soil Ecological Units (BPEJ) that are publicly available and already processed for all agricultural land. The results are represented by complete list of Evaluated Soil Ecological Units that are suitable for afforestation with stating the reason why they were chosen.
7
Kaminski, P., M. Urlaub, J. Grabe, and C. Berndt. "Geomechanical behaviour of gassy soils and implications for submarine slope stability: a literature analysis." Geological Society, London, Special Publications 500, no. 1 (December 19, 2019): 277–88. http://dx.doi.org/10.1144/sp500-2019-149.
Анотація:
AbstractSubmarine slope failures pose a direct threat to seafloor installations and coastal communities. Here, we evaluate the influence of free gas on the soil's shear strength and submarine slope failures in areas with gassy soils based on an extensive literature review. We identify two potential destabilization mechanisms: gas bubbles in the pore space lead to a reduced shear strength of the soil and/or gas induces excess pore pressures that consequently reduce the effective stress in the soil. Our evaluation of the reported mechanical and hydraulic behaviour of gassy sediments indicates that the unfavourable impact of entrapped gas on a soil's shearing resistance is not sufficient to trigger large-scale slope failures. Liquefaction failure due to high gas pressures is, however, a viable scenario in coarse-grained soils. Transferring the gas influence on the soil mechanical behaviour to constitutive models is identified as the most important prerequisite for a successful future analysis of slope stability.
8
Šarapatka, B., M. Bednář, and P. Novák. "Analysis of soil degradation in the Czech Republic: GIS approach." Soil and Water Research 5, No. 3 (September 16, 2010): 108–12. http://dx.doi.org/10.17221/487-swr.
Анотація:
In our work, we have evaluated the available data on the individual types of soil damage, which has been processed in the Czech Republic in recent decades. The individual types of degradation (water erosion, wind erosion, soil compaction, extreme soils (clay soils), loss of organic matter, acidification, dryness impact, and intoxication) were classified in one of three groups: physical degradation, desertification and chemical degradation. Each type of degradation was assigned a specific weight reflecting the importance of this kind of soil degradation. The maps of individual areas of degradation were processed by overlay and assigning weighting techniques in ArcView Spatial Analyst GIS environment to create the final maps for each class of the degradation threat. The same technique was used to create the final map showing the most troubled areas in the Czech Republic, threatened by soil damage.
9
Widden, Paul. "Microfungal community structure from forest soils in southern Quebec, using discriminant function and factor analysis." Canadian Journal of Botany 64, no. 7 (July 1, 1986): 1402–12. http://dx.doi.org/10.1139/b86-192.
Анотація:
Fungal isolation data, from four forest soils, were analyzed using both discriminant analysis and factor analysis, to investigate the structure of fungal communities. The analyses indicated that the forest of origin was a major factor determining fungal community structure in these soils. Discriminant analysis separated the fungal communities of coniferous-forest soil samples from those of deciduous-forest soil samples. The pine-forest soil, which was in an early stage of invasion by hardwoods, had a fungal community intermediate in structure between the extremes. Of the microfungi isolated, Botryotrichum piluliferum, Farrowia seminuda, Geomyces pannorus, Mucor hiemalis, Penicillium janthinellum, Trichoderma polysporum, and Zygorrhynchus moelleri were associated with the coniferous sites, whereas an Acremonium species, Gliomastix murorum, Paecilomyces carneus, Pae. fumosoroseus, Penicillium spinulosum, and Pen. thomii characterized the deciduous-forest soils. Many pine-forest soil fungi were species abundant in the other soils, a possible reflection of the successional stage of the forest. Both factor analysis and discriminant analysis yielded similar interpretations of the data and indicated the importance of fungal interactions in determining community structure. The discriminant analyses also showed that fungal isolation data gave a better separation between the soils of the four forests than did abiotic data.
10
Miltenyi, Gregory P. L., Malte C. Ebach, and John Triantafilis. "Assessing the Australian Soil Classification using cladistic analysis." Soil Research 53, no. 7 (2015): 772. http://dx.doi.org/10.1071/sr14323.
Анотація:
The Australian Soil Classification (ASC) has its roots in both the Handbook of Australian Soils and the Factual Key. The scheme’s use of mutually exclusive characteristics has led to Soil Orders containing a diverse range of soils, such as the Dermosols. The extent of these groupings has resulted in classes of soils sharing greater relationships with soils from other classes than they do with soils in the same class. Situations such as this arise from artificial classifications and highlight the need for natural classifications. Natural classifications accurately represent what is occurring in nature and are desirable because they represent evidence of a common history, process or mechanism. This study uses cladistics, a robust biological method that uncovers natural classifications, to assess the naturalness of the ASC. The analysis has the secondary aims of identifying natural soil orders and establishing which characters and tiers require revision. Two measures commonly used in cladistics, consistency index (CI) and retention index (RI), are used along with confidence levels generated by bootstrapping. The cladistic analysis undertaken consisted of coding 113 morphological and non-morphological characters used to identify 13 of the 14 Soil Orders in ASC into binary and multi-state matrices and analysis using a parsimony cladistic algorithm. The results suggest that, because of its low CI (0.196), the ASC is not a natural classification. However, certain Soil Orders of Organosols, Podosls and Vertosols, which all registered high CI, are natural. The analysis also indicated which soil morphological characters and Soil Orders require revision in order to make the ASC more natural, namely, soil colour and characters located in the Great Groups as well as Soil Orders such as Chromosols, Ferrosols and Dermosols. We conclude that cladistics offers a new avenue in discerning relationships between soils and in assessing the accuracy of, and identifying where improvements can be made in, the classifications used to identify them.
11
Crisan, Vlad Emil, Lucian Constantin Dinca, and Sorin Stefan Deca. "Analysis of Chemical Properties of Forest Soils from Bacau County." Revista de Chimie 71, no. 4 (May 5, 2020): 81–86. http://dx.doi.org/10.37358/rc.20.4.8045.
Анотація:
State forests are analyzed periodically, once every 10 years. This includes an analysis of forest soils. The present paperdescribes and interprets the chemical properties of forest soils from Bacau County focusing on the period 1983-2015. As such, 823 soil profiles and 2435 pedogenetic horizons were analysed taking into consideration the soil type, pH, humus content, nitrogen content, base saturation degree and the total cation exchange capacity. The most widespread types of soils are: eutriccambisol, luvisol, preluvisoland dystriccambisol. The dystriccambisols from Bacau County are strongly acid soils, while eutriccambisols and preluvisols are moderately acid. All forest soils from this area have a high cationic exchange capacity and are very well (dystriccambisol, eutriccambisol,luvisol) or well supplied (preluvisol, rendzina) with nitrogen. Knowing the chemical properties of soils is important for the analysis of stand variability and for adopting silvicultural methods adequate for the management of long-lasting forests.
12
Hofmann, E., T. Németh, and A. Bidló. "Thermal analysis of soils formed on limestone in the Bükk Mountains, North Hungary." Agrokémia és Talajtan 67, no. 1 (June 2018): 5–22. http://dx.doi.org/10.1556/0088.2018.67.1.1.
Анотація:
The present article discusses the applicability of thermoanalytical methods in the analysis of Hungarian soils formed on carbonate rocks. Up to now only limited mineralogical and soil chemical research has been done on these soils. Soils from the Bükk Mountains, the most varied limestone region in Hungary, were used for the investigations. The aim was to extend our incomplete knowledge on the mineral composition and formation processes of these soils and to demonstrate the possibilities and evaluation potential of thermoanalytical techniques. All the soils investigated were formed on limestone and had different surface soil thickness, influenced by the accumulation of silicate debris and the microterrain. The results of soil mineralogical analysis revealed an extraordinarily high proportion of quartz compared to that of other minerals (especially calcite), indicating that these soils could not have originated solely from the weathering of the limestone bedrock. The results also showed that thermoanalytical methods could complement classical chemical and instrumental (XRPD) methods in research on the genesis of soils formed on limestone.
13
Aubeny, Charles, Robert Lytton, and Dina Tang. "Simplified Analysis of Unsteady Moisture Flow Through Unsaturated Soil." Transportation Research Record: Journal of the Transportation Research Board 1821, no. 1 (January 2003): 75–82. http://dx.doi.org/10.3141/1821-09.
Анотація:
The moisture diffusion properties of unsaturated soils control the rate of infiltration of surface moisture into the soil mass and hence are critical to a wide variety of civil structures, including pavements, structures, retaining walls, and slopes. Because of the dependence of permeability on suction and the nonlinearity of the suction–moisture relationship, the analytical formulation for flow through unsaturated soils is highly nonlinear. An approximate linear analysis of this problem, which was originally proposed by Peter Mitchell, was investigated. One advantage of this approximate analysis is that it can provide the practical basis for measuring soil moisture diffusion characteristics in laboratory tests. A second advantage is that the linear formulation provides an analytical tool accessible to practitioners. Mitchell originally based his formulation on a relatively restrictive assumption on the permeability-versus-suction relationship. An approach to circumventing that restriction is proposed. The findings of a laboratory test program that uses Mitchell’s formulation to estimate a soil’s moisture diffusion characteristics are presented. Finally, some simple analytical predictions demonstrate the practical significance of the soil moisture diffusion properties.
14
Prasanna, Shwetha. "Analysis of Hydraulic Properties of Indian Forest Soil." Journal of Civil Engineering and Construction 7, no. 1 (February 24, 2018): 12. http://dx.doi.org/10.32732/jcec.2018.7.1.12.
Анотація:
Soils are a product of the factors of formation and continuously change over the earth’s surface. The analysis of the spatial variability of soil properties is important for land management and construction of an ecological environment. Soils are characterized by high degree of spatial variability due to the combined effect of physical, chemical or biological processes that operate with different intensities and at different scales. The spatial variability of soil hydraulic properties helps us to find the subsurface flux of water. The most frequently used hydraulic properties are soil water retention curve and saturated hydraulic conductivity. Both these hydraulic properties exhibit a high degree of spatial and temporal variability. The primary objective of this study was to analyze the spatial variability of hydraulic properties of forest soils of Pavanje river basin. Correlation analysis technique has been used to analyze various soil properties. Spatial variability of the forested hillslope soils at different depths varied considerably among the soil hydraulic properties. The spatial variability of water retention at all the different pressure head is low at the top layers, and increases towards the bottom layers. The saturated hydraulic conductivity is almost same in the top layers, but more in the bottom layers of forest soil.
15
Dmytruk, Y. M. "Ecological-evolutionary analysis of lithium content in soils." Fundamental and Applied Soil Science 17, no. 1-2 (January 9, 2018): 31–39. http://dx.doi.org/10.15421/041603.
Анотація:
The point is that investigation of geochemistry and behavior of Lithium in Ukraine’s soils is been rather exceptional. We have analyzed the content of Lithium in soils: modern and buried under the ramparts of various ages. The research territory includes Prut-Dniester and Prut-Siret interfluvial. Most often there are Phaeozems (Luvic Phaeozem, or Mollic Gleysol or Eutric Gleysol) and Chernozems (Luvic Chernozem or Chernic Chernozem). Buried soils are located directly near the modern background soils, so the differences between them are the result of evolution of the background soils during burial (the screening) after the construction of ramparts. On the Podvirna site current landscapes are wood and meadow-steppe; in the past, subboreal stage, were probably closer to the steppe; buried soil – Chernozem typical with a little profile, in the modern of soil structure prevails Luvic Phaeozem. The sites Ridkivtsi and Grushivka are characterized forest landscapes and in the past on those areas dominated wood-meadow landscapes. At present prevailing types of soils are Phaeozems or Gleysol. Soil samples have taken for the genetic horizons. After drying and preparing of soils in them had performed analytical determination of total content (Nitrate extract, followed by evaporation of hydrogen peroxide) of Lithium and its mobile forms (ammonium acetate-extract with pH = 4,8). The results of analyzes had processed by using statistical and mathematical testing based on the program «Statistica 6.0». Our obtained results are indicating background of total Lithium content, which ranges from 8,70 to 33,5 mg∙kg-1 and its average amount was 22,3±6,01 mg∙kg-1; amplitude quantity of Lithium mobile forms is between 0,20 to 2,60 mg∙kg-1, with an average content of 0,60±0,57 mg∙kg-1. The mean of total Lithium content of all soils with buried soils in particular are decreased from Podvirna site (27,4 mg∙kg-1) to the site Ridkivtsi (22,8 and 26,3 mg∙kg-1, accordingly) and site Grushivka (20,0 and 19,1 mg∙kg-1, accordingly), while the number of mobile forms changed significantly from substantial Podvirne hospital (1,43 mg∙kg-1) to the hospital Grushivka (0,83 and 0,91 mg∙kg-1, respectively) and hospital Ridkivtsi (0,44 and 0,79 mg∙kg-1, appropriately). In the majority of background soils we had discovered humus-eluvial-illuvial redistribution, sometimes - eluvial-illuvial redistribution. It is important to know that we had not observed high Lithium content in the parent rock of soils (except for two sections of the site Ridkivtsi with discussion rather recognition of the parent rock of the profile). This is demonstrating the determining influence of pedogenesis on the redistribution of chemical elements in the of soils. Actually, Lithium has often accumulated in the upper humus horizons (as a result of the impact of organic matter and of soil biota as a whole) or in the horizons of clay accumulation. To crown it all pedogenesis fundamentally has changing features of the vertical distribution of Lithium content. Concerning future research is necessity of application of isotopic analysis to identify the characteristics of different ages soils.
16
Sheppard, Petra J., Eric M. Adetutu, Tanvi H. Makadia, and Andrew S. Ball. "Microbial community and ecotoxicity analysis of bioremediated, weathered hydrocarbon-contaminated soil." Soil Research 49, no. 3 (2011): 261. http://dx.doi.org/10.1071/sr10159.
Анотація:
Bioremediated soils are usually disposed of after meeting legislated guidelines defined by chemical and ecotoxicity tests. In many countries including Australia, ecotoxicity tests are not yet mandatory safety requirements. This study investigated the biotreatment of weathered hydrocarbon-contaminated soils in 12-week laboratory-based microcosms. Monitored natural attenuation resulted in ~43% reduction of total petroleum hydrocarbon contaminant to 5503 mg/kg (C16–C35), making the soil suitable for disposal as waste under current guidelines (pesticide and metal contents within safe limits). 16S rDNA (universal and AlkB) and ITS-based DGGE fingerprints showed stable and adapted microbial communities throughout the experimental period. However, ecotoxicology assays showed 100% mortality of earthworms (Eisena fetida) in potting soils containing ≥50% (≥2751 mg/kg, legally safe in situ concentrations) contaminated soil over 14 days. Up to 70% reduction in radish (Raphanus sativus) seed germination was observed in potting soils containing ≥10% contaminated soil (≥550 mg/kg, legally safe ex situ concentrations for soil disposal into residential areas). The results indicate the toxicity of these soils to soil biota despite meeting legislated Australian safe levels and guidelines for disposal or use in residential areas.
17
Nemadodzi, Lufuno Ethel, Jacques Vervoort, and Gerhard Prinsloo. "NMR-Based Metabolomic Analysis and Microbial Composition of Soil Supporting Burkea africana Growth." Metabolites 10, no. 10 (October 10, 2020): 402. http://dx.doi.org/10.3390/metabo10100402.
Анотація:
Burkea africana is a leguminous tree used for medicinal purposes, growing in clusters, on soils impoverished from most nutrients. The study aimed to determine the factors responsible for successful reproduction and establishment of the B. africana trees in nature, as all efforts for commercial production has been proven unsuccessful. An investigation was carried out to determine the metabolomic profile, chemical composition, and microbial composition of the soils where B. africana grows (Burkea soil) versus the soil where it does not grow (non-Burkea soil). 1H-NMR metabolomic analysis showed different metabolites in the respective soils. Trehalose and betaine, as well as a choline-like and carnitine-like compound, were found to be in higher concentration in Burkea soils, whereas, acetate, lactate, and formate were concentrated in non-Burkea soils. Liquid Chromatography-Mass Spectrometry analysis revealed the presence of numerous amino acids such as aspartic acid and glutamine to be higher in Burkea soils. Since it was previously suggested that the soil microbial diversity is the major driver for establishment and survival of seedlings in nature, Deoxyribonucleic acid (DNA) was extracted and a BLAST analysis conducted for species identification. Penicillium species was found to be highly prevalent and discriminant between the two soils, associated with the Burkea soils. No differences in the bacterial composition of Burkea and non-Burkea soils were observed. The variances in fungal composition suggests that species supremacy play a role in development of B. africana trees and is responsible for creating a supporting environment for natural establishment and survival of seedlings.
18
Whitley, A. E., J. L. Moir, and P. C. Almond. "A meta-analysis of exchangeable aluminium in New Zealand soils using the National Soils Database." Soil Research 57, no. 2 (2019): 113. http://dx.doi.org/10.1071/sr18246.
Анотація:
Soil acidification and associated aluminium toxicity are critical issues in New Zealand, particularly in high and hill country areas. However, there have been few studies that have examined the key drivers of exchangeable Al concentrations in New Zealand soils. The National Soils Database was used to investigate the relationship between soil chemical, physical and environmental variables and KCl-extractable Al (AlKCl) for New Zealand soils. Soil AlKCl concentrations were strongly associated with base saturation, soil pH, cation exchange capacity, total N, total C and soil order. However, the relationships differed among the three depth zones (0–20cm, 20–50cm and 50–120cm). Soil acidity and high cation exchange capacity contributed to high concentrations of AlKCl in the soil, whereas high base saturation and total C had the opposite effect. Total N decreased with increasing AlKCl in the topsoil (0–20cm), which is likely a response to the effects of Al toxicity on biological N fixation by pasture legumes. Across a pHH2O range of 3.8–6.4, AlKCl was measured at concentrations that can be toxic to sensitive plants (>1.0 cmolc kg−1). Brown Soils and Podzols are likely more susceptible to Al toxicity, with the highest mean concentrations of AlKCl measured across all depth zones.
19
Lee, C. Y., and H. G. Poulos. "Cyclic analysis of axially loaded piles in calcareous soils." Canadian Geotechnical Journal 30, no. 1 (February 1, 1993): 82–95. http://dx.doi.org/10.1139/t93-008.
Анотація:
This paper describes a simple nonlinear pile-soil interface model incorporated into a modified boundary element analysis to simulate the behaviour of piles in calcareous soils subjected to both static and cyclic loading. A shaft resistance degradation model and a cyclic secant soil modulus degradation model are proposed, and implemented in the nonlinear analysis. Parametric solutions are presented which examine the overall characteristics of axial pile response determined from the nonlinear analysis. Comparisons are made between the theoretical predictions and the measured results of laboratory model tests and published field tests of grouted piles in calcareous soils. These comparisons enable some conclusions to be drawn regarding the suitability of alternative nonlinear analyses. Key words : grouted piles, cyclic loading, calcareous soils, nonlinear analysis.
20
Neagu, Anisoara-Arleziana, Alina Soceanu, and Semaghiul Birghila. "Analysis of Soils Parameters in Correlation with Vegetation Period." Revista de Chimie 71, no. 9 (September 5, 2020): 210–20. http://dx.doi.org/10.37358/rc.20.9.8331.
Анотація:
Soil is a complex ecosystem whose functionality is related to the links that exist between chemical, physical, biological parameters and microbial communities. Our purpose was to carry out an analysis of variance of chemical properties of the soil in relation to the vegetation period. The analysis of the soil gives us knowledge about the fertility status of the soil, which is closely related to the nutritional status of plants. The analysis involved urban soil, agricultural soil and greenhouse soil from Dobrogea area. Soil samples come from the urban area: Constanta, agricultural area: Ciocarlia de Sus and greenhouse:Cumpana. To estimate the seasonal changes in the soil, three periods were studied: before vegetation (sowing), after the vegetation period (harvesting), relative rest period (winter). The chemical parameters evaluated were: soil reaction pH (acidity degree), conductivity - as an indicator of the nutrients available in the soil (soluble salts), ion exchange capacity (cations and anions), organic matter (humus), nitrogen content (total nitrogen and nitrites), the amount of extractable iron. The pH values were in the range corresponding to the weak acid-neutral soil for all three types of sample soils, with slight variations from one period to another while the recorded conductivity values indicate that the analyzed soils belong to the category of non-saline soils. The analyzed soil samples presented low concentrations of nitrites and the assimilable iron content was in the range 48.81 - 259.12 ppm.
21
Zhou, Yu-feng, Nan Zhang, Weizheng Han, Qing-qing Li, Cheng-ya, and Na Li. "Analysis of Onshore and Offshore Soils in the Lower Xiangjiang River." Journal of Physics: Conference Series 2224, no. 1 (April 1, 2022): 012072. http://dx.doi.org/10.1088/1742-6596/2224/1/012072.
Анотація:
Abstract The soil on the west bank of the Xiangjiang River in the main urban area of Changsha, Hunan Province is referred to as shore soil, and the soil on the mid-levels of the Yuelu Mountains in Changsha is referred to as offshore soil. To stabilise the heavy metals in the soils, which do not readily migrate by pyrolysis, these soil samples were heated at 450°C for 3 hours in a muffle furnace and removed after natural cooling. These heated and stabilised soils were analysed by inductively coupled plasma emission spectrometry (ICP-OES), scanning electron microscopy (EMS) and XRD diffractometry respectively. It can be found that: (1) There is a difference in the heavy metal content between the shoreline soil and the offshore soil of the Xiangjiang River. (2) The scanning electron microscope shows that the microstructure of the soil is altered by prolonged river water infiltration and washing. (3) Both onshore and offshore soils are a mixture of crystalline and non-crystalline materials, with less non-crystalline material in the onshore soil compared to the offshore soil. (4) The main crystalline material in both onshore and offshore soils is SiO2.(5) Soil samples containing metallic elements are mostly in non-crystalline form.
22
Schnitzer, Morris. "The in situ analysis of organic matter in soils." Canadian Journal of Soil Science 81, no. 3 (August 1, 2001): 249–54. http://dx.doi.org/10.4141/s00-064.
Анотація:
Traditionally, studies on soil organic matter (SOM) begin with the extraction of SOM from soils, its fractionation into humic acid, fulvic acid, and humin, followed by de-ashing of each fraction. These are tedious, laborious and inefficient procedures that do not provide any chemical information on these materials. Instead, recently developed methods such as solid-state 13C NMR and pyrolysis – field ionization mass spectrometry (Py-FIMS) can now be used for the in situ analysis of SOM in soils. These methods identify the major chemical components of SOM without extractions and fractionations, and yield valuable information on the main chemical structures in these materials. A better knowledge of the structural chemistry of SOM will help SOM chemists and other soil scientists to better understand the complex chemical and biochemical reactions that occur in soils, and will enable them to develop practices that will improve soil management and soil productivity. Key words: Extraction, fractionation, solid state 13C NMR, pyrolysis-field ionization mass spectrometry, chemical composition
23
Cao, Wei Ping, Min Zhao, and Qi Chao Shi. "A Numerical Analysis on the Behavior of End-Bearing Pile for Supporting Embankment over Soft Soils." Advanced Materials Research 378-379 (October 2011): 502–6. http://dx.doi.org/10.4028/www.scientific.net/amr.378-379.502.
Анотація:
Piled embankments are increasingly used to construct highways on soft soils. End-bearing piles for supporting embankment exhibit different characteristics for the soil arch developed within the embankments. A numerical analysis was conducted to evaluate the soil stress concentration ratio, pile and soil settlements, pile axial force, negative skin friction (NSF) and location of the neutral plane (NP) during embankment filling and consolidation of soft soils. The results indicate that the stress concentration ratio varies with time and most of the embankment load is born by the pile. The soil pressure on the soft soils increase and reach a maximum value during the filling, then decrease gradually and maintain nearly a constant value at the end of the consolidation. The settlement of shallow soft soils differs significantly from that of the deep soft soils. The location of the NP shows a complicated variation.
24
Fenu, Luigi, Eleonora Congiu, Mariangela Deligia, Gian Felice Giaccu, Alireza Hosseini, and Mauro Serra. "Buckling Analysis of Piles in Multi-Layered Soils." Applied Sciences 11, no. 22 (November 11, 2021): 10624. http://dx.doi.org/10.3390/app112210624.
Анотація:
Pile buckling is infrequent, but sometimes it can occur in slender piles (i.e., micropiles) driven into soils with soft layers and/or voids. Buckling analysis of piles becomes more complex if the pile is surrounded by multi-layered soil. In this case, the well-known Timoshenko’s solution for pile buckling is of no use because it refers to single-layered soils. A variational approach for buckling analysis of piles in multi-layered soils is herein proposed. The proposed method allows for the estimation of the critical buckling load of piles in any multi-layered soil and for any boundary condition, provided that the distribution of the soil coefficient of the subgrade reaction is available. An eigenvalue-eigenvector problem is defined, where each eigenvector is the set of coefficients of a Fourier series describing the second-order displaced shape of the pile, and the related buckling load is the eigenvalue, thus obtaining the effective buckling load as the minimum eigenvalue. Besides the pile deformed shape, the stiffness distribution in the multi-layered soil is also described through a Fourier series. The Rayleigh–Ritz direct method is used to identify the Fourier development coefficients describing the pile deformation. For validation, buckling analysis results were compared with those obtained from an experimental test and a finite element analysis available in the literature, which confirmed this method’s reliability.
25
Kocaman, Kadir, Askin Ozocak, Tuncer B. Edil, Ertan Bol, Sedat Sert, Kurban Onturk, and Mustafa Ozsagir. "Evaluation of Soil-Water Characteristic Curve and Pore-Size Distribution of Fine-Grained Soils." Water 14, no. 21 (October 29, 2022): 3445. http://dx.doi.org/10.3390/w14213445.
Анотація:
A soil’s physical properties, mineral types, and pore structure significantly influence the shape and properties of the soil-water characteristic curve (SWCC). This study investigated the effects of the soil’s physical properties and mineral types on the SWCC and pore-size distribution (PSD). Eight different soils from an alluvial deposit in Istanbul and Adapazarı/Türkiye were used in the study. The test samples were prepared by compaction at optimum water content (OWC) and wet side of optimum water content (wet of OWC). The samples were prepared by consolidation from the slurry. The PSDs of the samples were calculated using the SWCCs and evaluated with scanning electron microscope (SEM) analysis. In addition, the mineral types of all soils were determined by X-ray diffraction analysis. The soil which contains illite-type minerals has higher matric suction than containing kaolin-type. The effect of the clay percentage is more pronounced in silty soils than in plasticity and activity. Soil suction increased with decreasing compaction water content in clayey soils. The air entry water contents rose as the void ratio, liquid limit, clay content, and plasticity increased. The compaction conditions affected the macropore structure more than the micropore structure. In addition, the ratio of macro-micro pore sizes increased with the rise of the compaction water content.
26
Maduka,, C. M., and Udensi, Chukwuma Great. "Comparative analysis of the effect of some organic manure on soil microorganisms." Bionatura 4, no. 3 (August 15, 2019): 922–25. http://dx.doi.org/10.21931/rb/2019.04.03.8.
Анотація:
This study showed that the abundance of different microbial groups was general in soil with amendments in comparison to soils without amendments. It was discovered that soils with organic manures were rich in bacteria and fungi diversity when compared with soil without organic manure, which recorded low microbial counts. Escherichia coli and Staphylococcus aureus were widely distributed in this study. The soil treatment which had Cow dung showed highest microbial count and heights for growth of maize seeds, and the compost manure soil treatment followed this, and the poultry manure soil treatment was next. This suggests that the higher the fertility in amended soils is revealed in the heights of the maize plant grown and colony counts. Plant height recorded under various amendments showed significant differences (p<0.05).
27
Silveira, Felipe Gomes Frederico da, Luciano da Silva Souza, Laércio Duarte Souza, João de Mendonça Naime, and Carlos Manoel Pedro Vaz. "Estimation of Water Retention Curve for Soils of Bahia, Brazil, Based on Soil Particle-Size Analysis." Journal of Agricultural Science 10, no. 12 (November 15, 2018): 126. http://dx.doi.org/10.5539/jas.v10n12p126.
Анотація:
Soil water retention curve (SWRC) is an important soil attribute because it is a soil quality indicator and is fundamental to study water dynamics in the soil-plant-atmosphere system. Since the conventional SWRC determination is laborious and time-consuming, making it difficult to process a large volume of samples, pedotransfer functions have been used to estimate it by using other soil physical attributes easily determined. Thus, this study aimed to apply Arya-Paris model to SWRC estimation for soils of Bahia state, Brazil, based on soil particle-size analysis, and to compare estimated and determined data of SWRC. Samples were collected from horizons A and AB and/or B and/or C, for a total of 15 soils and 62 horizons. Particle-size was determined by automatic soil particle-size analyzer (PSA) based on g-ray attenuation and traditional Bouyoucos’ hydrometer (BH) method. Arya-Paris model showed better SWRC predictions for sandy soils, followed by clayey, loamy, and very clayey soils. Good model performance was observed for all soils together. The α 1 scaling factor provided better predictions, followed by α 3, and α 2 showed unsatisfactory behavior. BH method, using only 7 soil particle-size fractions, gave slightly higher predictions than PSA using 30 soil particle-size fractions.
28
Najafi-Ghiri, M., and A. Abtahi. "Potassium fixation in soil size fractions of arid soils." Soil and Water Research 8, No. 2 (May 15, 2013): 49–55. http://dx.doi.org/10.17221/52/2012-swr.
Анотація:
Amounts of potassium (K) fixed in soil fractions of 10 calcareous soils of southern Iran were measured to evaluate the contributions of different soil size fractions to K fixation. Soil particles were fractionated after dispersion of the soils with an ultrasonic probe. Potassium fixation analysis was done by addition of 1000 mg K/kg samples. Mineralogy of the size fractions was determined by X-ray diffraction. The clay fractions were dominated by smectite, chlorite, mica, and palygorskite. Potassium fixation capacities ranged from 104 to 148 mg/kg for clay, from 102 to 155 mg/kg for silt, and from 96 to 187 mg/kg for sand fractions. A positive and significant relationship (P < 0.05) was obtained between K fixation capacity and smectite content for the clay fractions. High amounts of K fixed in the sand fraction may be explained by a larger diffusion path of fixed K out of the frayed edges of micaceous and smectitic minerals into the extracting solution, low cation exchange capacity (CEC) of the coarse fraction and thereby the high concentration gradient along solution and interlayers, physical entrapment of K ions in coarse aggregates cemented by carbonates, and by the presence of clay particles in coarse fractions due to incomplete dispersion of coarse aggregates.
29
Wei, Hui, Jiayue Yang, Ziqiang Liu, and Jiaen Zhang. "Data Integration Analysis Indicates That Soil Texture and pH Greatly Influence the Acid Buffering Capacity of Global Surface Soils." Sustainability 14, no. 5 (March 4, 2022): 3017. http://dx.doi.org/10.3390/su14053017.
Анотація:
Soil acidification is a global environmental issue that decreases soil functions, and it has been significantly accelerated by anthropogenic activities in recent decades. Soils can resist acidification upon receiving acid inputs due to the resistance or/and resilience capacity of soils, which is termed the acid buffering capacity of soils, and it is often indicated by the soil pH buffering capacity (pHBC). An increasing number of studies have been conducted to quantify soil pHBC at various sites, but to date, integration of global data is lacking; therefore, the variations in large-scale soil pHBC and the factors that influence these variations are still unclear. In this study, we collected previously published data on soil pHBC to analyze its variations on a large scale, as well as investigate the underlying factors influencing these variations. The results showed that soil pHBC varied substantially from site to site, with a mean of 51.07 ± 50.11 mmol kg−1 pH−1. Soil texture and pH, separately or collectively, explained a considerable proportion of the total variation of global soil pHBC. It is well-established that a series of processes contribute to the soil acid buffering capacity in different pH ranges, and the global data analyses showed that pH 5.5 could be a key threshold value; different buffering systems may be active at pH > 5.5 and pH < 5.5. Moreover, tropical soils were more acid-sensitive than temperate and subtropical soils, and forest soils had significantly lower soil pHBCs than grassland and cropland soils. This could be attributed in part to the different soil properties, such as soil texture or pH, among the different climatic zones and ecosystems.
30
Karaulov, A. M., K. V. Korolev, L. A. Bartolomey, and E. P. Bragar. "TO THE STATISTICAL ANALYSIS OF SOIL SHEAR TESTS RESULTS." Construction and Geotechnics 11, no. 3 (December 15, 2020): 8–17. http://dx.doi.org/10.15593/2224-9826/2020.3.01.
Анотація:
The result of any shear tests, which are the most popular laboratory methods for determination the strength characteristics of soils, is a set of values of the ultimate shear resistance and the corresponding normal pressure along the shear section. The theoretical background for the analysis of the soil shear tests results is the theory of probability and mathematical statistics. At the same time, we have questions about the determination of the calculation values of soil strength parameters. So, during the processing of shear tests results according to a consolidated-drained scheme for sandy soils the calculation values of soil specific cohesion are often negative, which is incorrect. The article considers an example of processing of shear tests data of sandy loam for various normal pressures, and analyzes the results of statistical processing of soil tests. The normative methods for probabilistic assessment of soil strength characteristics are based on using of normal distribution law of a random variable. It is assumed that the valuesof a random variable can vary from -¥ to +¥, while the soil strength parameters can vary in a limited range, i.e. accept only positive valuesfrom 0 to +¥. This circumstance does not matter for the majority of clayed soils, which strength parameters are far enough from zero. However, it has a significant effect on the result for small sought-for values, particularly, in assessing of specific cohesion for sandy soils. Therefore, for such cases, the article presents a variant of the statistical processing of the shear tests results with using the reduced normal distribution law of a random variable.
31
Mir, Shakeel Ahmad, Nasir Bashir Naikoo, Fehim Jeelani Wani, M. H. Chesti, Inayat Khan, Eajaz Ahmad Dar, Bodiga Divya, et al. "Comparative Analysis of Soil Quality Assessment and Its Perception by Rice Farmers." Land 11, no. 9 (August 26, 2022): 1401. http://dx.doi.org/10.3390/land11091401.
Анотація:
The present study was conducted in three villages of district Budgam in the union territory of Jammu and Kashmir, to find out how farmers differentiate the quality of soils and to determine the level of concurrence between farmers perception and scientific assessment of soil quality. Five fields in each village were selected and ranked on the basis of soil quality indices computed from the minimum data set of indicators, including plant available nutrients N, P, K, Ca, Mg, S, OC, BD, WHC (water holding capacity), CEC (cation exchange capacity) as well as microbial count. The respondents ranked the same 5 selected fields on the bases of their experience and perceptions of soil quality. The study reveals that 58% of farmers ranked the best soils correctly whereas, the percentage of farmers who ranked 2nd, 3rd, 4th and 5th soils correctly was 40, 30, 40, and 45%, respectively. The study found that a greater number of farmers from the remotest village Dalwash were able to judge the soils properly, thereby indicating more profound knowledge and better cognitive abilities to understand soils in the local context. The results divulged by the current study highlight the remarkable local soil knowledge of the farmers and therefore, linking this knowledge system with scientific concepts would prove valuable for sustained land-use management.
32
Saeed, Iftikhar Ahmed, Minjuan Wang, Yanzhao Ren, Qinglan Shi, Muhammad Hammad Malik, Sha Tao, Qiang Cai, and Wanlin Gao. "Performance analysis of dielectric soil moisture sensor." Soil and Water Research 14, No. 4 (October 9, 2019): 195–99. http://dx.doi.org/10.17221/74/2018-swr.
Анотація:
Soil moisture (SM) varies greatly in the soil profile. We developed a low-cost sensor for SM monitoring at three vertical depths. The sensor function was based on dielectric theory to monitor SM. Three linear calibration models were established using different soils. The sensor for each depth showed acceptable statistics of validations. The linear fit coefficient of determination (R<sup>2</sup>) ranged from 0.95 to 0.99. Root mean square error (RMSE) ranged from 1.35 to 4.30. The sensor performed consistently for at least 4 months, and is suitable for continuous monitoring of in situ SM and irrigation scheduling.
33
Johnsen, Anders R., Anne Winding, Ulrich Karlson, and Peter Roslev. "Linking of Microorganisms to Phenanthrene Metabolism in Soil by Analysis of 13C-Labeled Cell Lipids." Applied and Environmental Microbiology 68, no. 12 (December 2002): 6106–13. http://dx.doi.org/10.1128/aem.68.12.6106-6113.2002.
Анотація:
ABSTRACT Phenanthrene-metabolizing soil microbial communities were characterized by examining mineralization of [14C]phenanthrene, by most-probable-number (MPN) counting, by 16S-23S spacer DNA analysis of the numerically dominant, culturable phenanthrene-degrading isolates, and by examining incorporation of [13C]phenanthrene-derived carbon into sterols and polar lipid fatty acids (PLFAs). An unpolluted agricultural soil, a roadside soil diffusely polluted with polycyclic aromatic hydrocarbons (PAHs), and two highly PAH-polluted soils from industrial sites were analyzed. Microbial phenanthrene degraders were not detected by MPN counting in the agricultural soil and the roadside soil. In the industrial soils, phenanthrene degraders constituted 0.04 and 3.6% of the total number of CFU. 16S-23S spacer DNA analysis followed by partial 16S DNA sequencing of representative isolates from one of the industrial soils showed that one-half of the isolates belonged to the genus Sphingomonas and the other half were closely related to an unclassified beta-proteobacterium. The 13C-PLFA profiles of the two industrial soils were relatively similar and resembled the profiles of phenanthrene-degrading Sphingomonas reference strains and unclassified beta-proteobacterium isolates but did not match the profiles of Pseudomonas, Mycobacterium, or Nocardia reference strains. The 13C-PLFA profiles of phenanthrene degraders in the agricultural soil and the roadside soil were different from each other and different from the profiles of the highly polluted industrial soils. Only in the roadside soil were 10me/12me18:0 PLFAs enriched in 13C, suggesting that actinomycetes metabolized phenanthrene in this soil. The 13C-PLFA profiles of the unpolluted agricultural soil did not resemble the profiles of any of the reference strains. In all of the soils investigated, no excess 13C was recovered in the 18:2ω6,9 PLFA, suggesting that fungi did not contribute significantly to assimilation of [13C]phenanthrene.
34
Jiang, Xinmei, Jiaye Lyu, and Hao Tang. "Differential Analysis of Biochar Effects on Soil Physicochemical Properties." Highlights in Science, Engineering and Technology 26 (December 30, 2022): 21–28. http://dx.doi.org/10.54097/hset.v26i.3635.
Анотація:
For a long time, because of China’s large population and small per capita resource occupancy, the use of natural resources is unreasonable. Soil degradation problem due to the long-term irrational utilization of land resources is becoming more and more serious, which seriously damaging the ecological environment and hindering China’s modernization process. Facing the problem of soil remediation, biochar technology has become a research hotspot because of its advantages of green environmental protection, low cost, high efficiency, and wide application. And black soil in northeast China and southern region of red soil as important soil types of agroforestry in China, over the years have experienced serious soil degradation crisis. In this paper, black soil and red soil are selected as research objects to explore the impact of biochar on the physical and chemical properties of the two soils. This paper intends to use the methods of investigation and analysis, and comparison in many aspects. Through the study, it was found that the application of biochar had the same trend of influence on the organic carbon content and C/N ratio of the two soils, but the index of black soil increased more significantly. The change trend of soil bulk density and pH was also consistent with the application of biochar, and the difference was not significant. The effects of biochar applied to the two soils on greenhouse gas emissions were quite different. The soil health of black soil and red soil is of great significance in China’s agricultural production and life. This paper expects to bring reference value to the improvement of the overall soil function and the promotion of ecological restoration process of China’s biochar modification work for different soil types in the north and south, by comparing the impact of biochar on the physical and chemical properties of the two soils. A better soil improvement program can be obtained after comparative analysis, so as to provide suggestions on sustainable development and comprehensively promote ecological construction.
35
Hu, Yafei, and Hung Q. Vu. "Analysis of soil conditions and pipe behaviour at a field site." Canadian Geotechnical Journal 48, no. 6 (June 2011): 847–66. http://dx.doi.org/10.1139/t11-010.
Анотація:
Water main pipes buried in expansive soils are often subjected to severe distress subsequent to installation. Excessive stresses may be induced due to either differential movement of the soils or swelling pressures from the soils along the pipes, impairing their performance or even breaking them. Field monitoring is an important means for understanding soil behaviour and its interaction with water mains. For this purpose, field instrumentation was successfully installed to monitor the performance of a section of water main placed in a well-developed area of a city neighbourhood where more frequent pipe breakage had occurred in recent years. The instrumentation included sensors to measure pipe wall strains, pipe displacement, in situ soil water content, soil pressure, and temperature. The instruments were installed in both the soil backfill and native soil around the backfill. This paper presents the analyses of monitoring data collected during the first 3 years after instrument installation. It was observed that the soil and pipe behaviour was affected significantly by soil properties and seasonal changes and correlated closely with the change pattern of the local meteorological conditions.
36
Meshram, Veena, Deepa Biswas, and Vasu Choudhary. "Physico-chemical and Carbon Stock Analysis of Soil under Forest Ecosystem." Ecology, Environment and Conservation 28, no. 04 (2022): 2087–94. http://dx.doi.org/10.53550/eec.2022.v28i04.067.
Анотація:
Temperature and moisture levels in the soil are two of the most important factors that determine the rate of soil respiration. Changes in the microclimate of the soil throughout the year play an essential part in determining seasonal fluctuations in the amount of carbon dioxide that is emitted from the soil at individual locations, and climatic variances because varying rates of soil respiration at distant sites. In forest ecosystems, one essential step in the cycling of carbon is the transfer of carbon dioxide from the soil to the atmosphere. The in-situ measurement of the increase in CO2 concentration at the soil’s surface is often what is meant when people talk about “soil respiration.” At the level of soils, CO2 emission is induced by both plant and microbial activities, including root respiration and the breakdown of organic matter in soil and litter. According to some reports, soils are responsible for between 60 and 80 percent of the overall respiration of an ecosystem. Microorganisms that live in the soil and the litter are responsible for the vast majority of heterotrophic respiration that occurs in forest ecosystems. A measurement of soil respiration in a substrate that is deteriorating has been recognised as a helpful indication of the rate of decomposition and mineralization of organic matter, as well as the cycling of carbon in an ecosystem, and as an index of relative soil biological activity. In order to investigate the physicochemical properties, bacterial and fungal populations, and soil respiration of various land use zones in Indian forest, the present study was carried out.
37
Janaki Rama Suresh, G., K. Sreenivas, and R. Sivasamy. "Hyperspectral analysis of clay minerals." ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XL-8 (November 28, 2014): 443–46. http://dx.doi.org/10.5194/isprsarchives-xl-8-443-2014.
Анотація:
A study was carried out by collecting soil samples from parts of Gwalior and Shivpuri district, Madhya Pradesh in order to assess the dominant clay mineral of these soils using hyperspectral data, as 0.4 to 2.5 μm spectral range provides abundant and unique information about many important earth-surface minerals. Understanding the spectral response along with the soil chemical properties can provide important clues for retrieval of mineralogical soil properties. The soil samples were collected based on stratified random sampling approach and dominant clay minerals were identified through XRD analysis. The absorption feature parameters like depth, width, area and asymmetry of the absorption peaks were derived from spectral profile of soil samples through DISPEC tool. The derived absorption feature parameters were used as inputs for modelling the dominant soil clay mineral present in the unknown samples using Random forest approach which resulted in kappa accuracy of 0.795. Besides, an attempt was made to classify the Hyperion data using Spectral Angle Mapper (SAM) algorithm with an overall accuracy of 68.43 %. Results showed that kaolinite was the dominant mineral present in the soils followed by montmorillonite in the study area.
38
Katyal, J. C., S. P. Doshi, and P. K. Malhotra. "Use of cluster analysis for classification of Benchmark soil samples from India in different micronutrient availability groups." Journal of Agricultural Science 104, no. 2 (April 1985): 421–24. http://dx.doi.org/10.1017/s0021859600044117.
Анотація:
SummaryIn view of the increase in micronutrient deficiencies in crop plants, ans attempt is made to group 57 Benchmark Indian soils into different micronutrient availability classes (clusters) vis-à-vis some soil characteristics. Since most of the soil characters are expressed in proportions or percentages (a usual practice in soil studies), the data matrix was transformed into log10 values to bring it nearer to normality. The transformed data matrix was used for cluster analysis and subsequently also for discriminant analysis. By following the method of Euclidean cluster analysis, the 57 Benchmark soils could be subdivided into three clusters. The distinctness of clusters was proven by distance-matrix as well as discriminant analysis. All the soils of cluster I and II originated from arid and semi-arid climates and these were alkaline in reaction, low in organic carbon (OC) and high in total lime. On the contrary, cluster III comprised all but a few soils from humid-subhumid regions. These soils were acidic in reaction and relatively high in OC and total lime. The soils of cluster I and II were poorer in diethylene triamine penta-acetic acid (DTPA) extractable micronutrient cations than those of cluster III. This study thus reveals that it is possible to classify diverse soils by statistical means into distinct clusters based upon micronutrient availability and associated soil properties. Furthermore, it suggests that soils of arid and semi-arid climates as a group, because of their low micronutrient availability, are expected to be more prone to deficiencies than those of humid and subhumid zones.
39
V., Giridhar, G. Jagadeesh, and P. Rajendra Kumar. "Regression Analysis on Compaction Characteristics of Sand Clay Soils." ECS Transactions 107, no. 1 (April 24, 2022): 19265–77. http://dx.doi.org/10.1149/10701.19265ecst.
Анотація:
Soil compaction is one of the major geo technical engineering applications in infrastructure development of the nation. Large volumes of soil are used in the construction of flyovers, earth dams, and railways. There is a need to understand comprehensively in a unified and coherent manner. Thus the knowledge of compaction behavior and its characteristics of fine grained soils at different compaction energies assume great importance from they viewpoint of practical significant. In the present work, compaction parameters such as (MDD) (max) and optimum moisture content (OMC) care determined at various compaction energies by conducting the laboratory compaction tests. In the field, the compaction of soils usually involves using different compaction energies. A limited experimental investigation has been taken up in the present study. The cardinal aim of the present study is to focus on effect of compaction energy on the behavior and compaction characteristics and unconfined compressive strength (qu) of soils.
40
Menon, Shashank, and Xiaoyu Song. "Coupled Analysis of Desiccation Cracking in Unsaturated Soils through a Non-Local Mathematical Formulation." Geosciences 9, no. 10 (October 2, 2019): 428. http://dx.doi.org/10.3390/geosciences9100428.
Анотація:
The formation of desiccation cracks in unsaturated soils as a discontinuity phenomenon can compromise the integrity of civil infrastructure on unsaturated soils. Because of the singularity at such discontinuities, the mathematical modeling of desiccation cracking is challenging. In this study, we apply a coupled nonlocal peridynamic poroelastic framework to model desiccation cracking in unsaturated soils. The soil skeleton is modeled by a nonlocal peridynamic elastic solid. A peridynamic equivalence of the generalized Darcy’s law is utilized to model unsaturated fluid flow. Cracking is determined by a critical stretch criterion between material points as well as an energy criterion. We present numerical simulations of desiccation cracking in soil bars and thin soil discs for one-dimensional cracking and two-dimensional cracking networks, respectively. The numerical results have demonstrated that the proposed nonlocal mathematical framework is a promising and robust method for modeling desiccation cracking in unsaturated soils.
41
Nizamutdinov, T. I., A. R. Suleymanov, E. N. Morgun, An V. Gusev, O. S. Tupakhina, Al V. Gusev, A. V. Plekhanov, D. S. Tupakhin, and E. V. Abakumov. "Soils of the polar archaeological site “Settlement Labytnangi 1 (Komy village)”: morphological analysis and chemical composition." Dokuchaev Soil Bulletin, no. 114 (March 25, 2023): 66–108. http://dx.doi.org/10.19047/0136-1694-2023-114-66-108.
Анотація:
Soils of archaeological sites are highly interesting objects for multidisciplinary research in various fields of soil science, ecology, archaeology, anthropology and other sciences. Currently, the soils of archaeological sites in the Arctic regions have not been studied sufficiently, although many ancient monuments beyond the polar circle have been found. This work is devoted to the study of morphological and chemical properties of soils of the archaeological site “Settlement Labytnangi 1”, which is located beyond the northern polar circle, near the cities of Labytnangi and Salekhard (Yamal-Nenets Autonomous Okrug). Development of these territories (according to archaeological research) began in the Eneolithic (Late IV – III millennia BC) and continues to the present day. Soil types on the territory of the monument are represented by soil-like bodies (urbikvazizems), podzols, turbozems, urbo-agrozems and peat soils with inclusions of archaeological and anthropogenic artifacts dating back to the XX century. Most of the studied soils were previously subjected to the processes of cryoturbation, although at present the lower boundary of the active layer of permafrost lies at a depth of 120–130 cm, according to the conducted electrophysical sounding. Significant changes occurred in the acid-base properties of the studied soils. In addition, anthropogenic activity entailed the introduction of biophilic elements and organic matter into the soil profile, in particular phosphorus, which is concentrated in the urbanized soil horizons (phosphorus concentrations above 2 800 mg/kg were recorded). The concentrations of heavy metals in the soils are at/below the conventional background (vicinity of Salekhard and Labytnangi). However, some excess concentrations of copper (up to 87.5 mg/kg), zinc (up to 303.3 mg/kg), lead (up to 76.1 mg/kg), and cadmium (up to 2.1 mg/kg) in the urbanized soil horizons have been detected. According to the results of the work, we can conclude that the soils of the archaeological site were formed under the strong influence of modern and past anthropogenic activity, which determined their morphological structure and chemical characteristics at present.
42
Czarny, Jakub, Justyna Staninska-Pięta, Jolanta Powierska-Czarny, Jacek Nowak, Łukasz Wolko, and Agnieszka Piotrowska-Cyplik. "Metagenomic Analysis of Soil Bacterial Community and Level of Genes Responsible for Biodegradation of Aromatic Hydrocarbons." Polish Journal of Microbiology 66, no. 3 (September 27, 2017): 345–52. http://dx.doi.org/10.5604/01.3001.0010.4865.
Анотація:
The aim of the studies was to compare the composition of soil bacterial metabiomes originating from urbanized areas and areas con¬taminated with hydrocarbons with those from agricultural soil and forest soil obtained from a protected wild-life park area. It should be noted that hydrocarbons are everywhere therefore bacteria capable of their utilization are present in every soil type. In the hydrocarbon-contaminated soil and in the soil of anthropogenic origin, the bacteria belonging to Gammaproteobacteria were dominant (28.4–36.6%), whereas in the case of agricultural soil and protected wild-life park soil their ratios decreased (22.8–23.0%) and were similar to that of Alphaproteobacteria. No statistically significant changes were observed in terms of the Operational Taxonomic Unit identified in the studies soils, however, based on the determined alpha-diversity it can be established that contaminated soils were characterized by lower biodiversity indices compared to agricultural and forest soils. Furthermore, the dioxygenase level was also evaluated in the studied soils, which are genes encoding crucial enzymes for the decomposition of mono- and polycyclic aromatic hydrocarbons during the biodegradation of diesel oil (PAHRHDαGN, PAHRHDαGP, xylE, Cat 2,3, ndoB). It was concluded that both the population structure of the soil metabiome and the number of genes crucial for biodegradation processes differed significantly between the soils. The level of analysed genes showed a similar trend, as their highest number in relations to genes encoding 16S RNA was determined in urban and hydrocarbon-contaminated soil.
43
Silveira, Érico Leandro da, Rodrigo Matheus Pereira, Denilson César Scaquitto, Eliamar Aparecida Nascimbém Pedrinho, Silvana Pómpeia Val-Moraes, Ester Wickert, Lúcia Maria Carareto-Alves, and Eliana Gertrudes de Macedo Lemos. "Bacterial diversity of soil under eucalyptus assessed by 16S rDNA sequencing analysis." Pesquisa Agropecuária Brasileira 41, no. 10 (October 2006): 1507–16. http://dx.doi.org/10.1590/s0100-204x2006001000008.
Анотація:
Studies on the impact of Eucalyptus spp. on Brazilian soils have focused on soil chemical properties and isolating interesting microbial organisms. Few studies have focused on microbial diversity and ecology in Brazil due to limited coverage of traditional cultivation and isolation methods. Molecular microbial ecology methods based on PCR amplified 16S rDNA have enriched the knowledge of soils microbial biodiversity. The objective of this work was to compare and estimate the bacterial diversity of sympatric communities within soils from two areas, a native forest (NFA) and an eucalyptus arboretum (EAA). PCR primers, whose target soil metagenomic 16S rDNA were used to amplify soil DNA, were cloned using pGEM-T and sequenced to determine bacterial diversity. From the NFA soil 134 clones were analyzed, while 116 clones were analyzed from the EAA soil samples. The sequences were compared with those online at the GenBank. Phylogenetic analyses revealed differences between the soil types and high diversity in both communities. Soil from the Eucalyptus spp. arboretum was found to have a greater bacterial diversity than the soil investigated from the native forest area.
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Li, Yanlin, Chunmei Zeng, and Meijun Long. "Variation of soil nutrients and bacterial community diversity of different land utilization types in Yangtze River Basin, Chongqing Municipality." PeerJ 8 (July 17, 2020): e9386. http://dx.doi.org/10.7717/peerj.9386.
Анотація:
The diversity and community distribution of soil bacteria in different land use types in Yangtze River Basin, Chongqing Municipality were studied by using Illumina MiSeq analysis methods. Soil physical and chemical properties were determined, and correlation analyses were performed to identify the key factors affecting bacterial numbers and α-diversity in these soils. The results showed that the soil physical and chemical properties of different land use types decrease in the order: mixed forest (M2) > pure forest (P1) > grassland (G3) > bare land (B4). There were significant differences in bacterial diversity and communities of different land use types. The diversity of different land use types showed the same sequence with the soil physical and chemical properties. The abundance and diversity of bacterial in M2 and P1 soils was significantly higher than that in G3 and B4 soils. At phylum level, G3 and B4 soils were rich in only Proteobacteria and Actinobacteria, whereas M2 and P1 soils were rich in Proteobacteria, Actinobacteria and Firmicutes. At genus level, Faecalibacterium and Agathobacter were the most abundant populations in M2 soil and were not found in other soils. Pearson correlation analysis showed that soil moisture content, pH, AN, AP, AK and soil enzyme activity were significantly related to bacterial numbers, diversity and community distribution.
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Enagbonma, Ben Jesuorsemwen, and Olubukola Oluranti Babalola. "Metagenomics Shows That Termite Activities Influence the Diversity and Composition of Soil Invertebrates in Termite Mound Soils." Applied and Environmental Soil Science 2022 (May 30, 2022): 1–9. http://dx.doi.org/10.1155/2022/7111775.
Анотація:
Background. Soil invertebrates are a significant part of the functioning and biodiversity of engineered soil. Nevertheless, it remains unclear how termite bioturbation that promotes soil nutrients affects the diversity and composition of invertebrates that dwell in soils from termite mounds. Therefore, we tested the premise that the rich nutrients accrued in soils from termite mounds encourage a complex variety of soil invertebrates. Methods. Whole DNA was extracted from soils from termite mounds and adjacent soils that were 10 m away from the mound. The soil samples were then sequenced using metagenomics. Results. Disparity in the composition of the soil invertebrate communities between the termite mound and their adjacent soils was clear from the results. Also, principal coordinate analysis showed that the structure of the soil invertebrate communities in termite mound soils was distinctive from that of the adjacent soils. The canonical correspondence analysis showed that phosphorus, soil pH, and soil organic carbon were the environmental factors that significantly explained the variation in the composition and diversity of the soil invertebrate communities between the two habitats. Conclusion. Metagenomics and chemical analysis jointly offered a route to examine the compositional and diversity variations in soil invertebrate communities in relation to termite bioturbation.
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Pacheco-Londoño, Leonardo C., Eric Warren, Nataly J. Galán-Freyle, Reynaldo Villarreal-González, Joaquín A. Aparicio-Bolaño, María L. Ospina-Castro, Wei-Chuan Shih, and Samuel P. Hernández-Rivera. "Mid-Infrared Laser Spectroscopy Detection and Quantification of Explosives in Soils Using Multivariate Analysis and Artificial Intelligence." Applied Sciences 10, no. 12 (June 18, 2020): 4178. http://dx.doi.org/10.3390/app10124178.
Анотація:
A tunable quantum cascade laser (QCL) spectrometer was used to develop methods for detecting and quantifying high explosives (HE) in soil based on multivariate analysis (MVA) and artificial intelligence (AI). For quantification, mixes of 2,4-dinitrotoluene (DNT) of concentrations from 0% to 20% w/w with soil samples were investigated. Three types of soils, bentonite, synthetic soil, and natural soil, were used. A partial least squares (PLS) regression model was generated for predicting DNT concentrations. To increase the selectivity, the model was trained and evaluated using additional analytes as interferences, including other HEs such as pentaerythritol tetranitrate (PETN), trinitrotoluene (TNT), cyclotrimethylenetrinitramine (RDX), and non-explosives such as benzoic acid and ibuprofen. For the detection experiments, mixes of different explosives with soils were used to implement two AI strategies. In the first strategy, the spectra of the samples were compared with spectra of soils stored in a database to identify the most similar soils based on QCL spectroscopy. Next, a preprocessing based on classical least squares (Pre-CLS) was applied to the spectra of soils selected from the database. The parameter obtained based on the sum of the weights of Pre-CLS was used to generate a simple binary discrimination model for distinguishing between contaminated and uncontaminated soils, achieving an accuracy of 0.877. In the second AI strategy, the same parameter was added to a principal component matrix obtained from spectral data of samples and used to generate multi-classification models based on different machine learning algorithms. A random forest model worked best with 0.996 accuracy and allowing to distinguish between soils contaminated with DNT, TNT, or RDX and uncontaminated soils.
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Abdalla, Khatab, Pauline Chivenge, Philippe Ciais, and Vincent Chaplot. "No-tillage lessens soil CO<sub>2</sub> emissions the most under arid and sandy soil conditions: results from a meta-analysis." Biogeosciences 13, no. 12 (June 21, 2016): 3619–33. http://dx.doi.org/10.5194/bg-13-3619-2016.
Анотація:
Abstract. The management of agroecosystems plays a crucial role in the global carbon cycle with soil tillage leading to known organic carbon redistributions within soils and changes in soil CO2 emissions. Yet, discrepancies exist on the impact of tillage on soil CO2 emissions and on the main soil and environmental controls. A meta-analysis was conducted using 46 peer-reviewed publications totaling 174 paired observations comparing CO2 emissions over entire seasons or years from tilled and untilled soils across different climates, crop types and soil conditions with the objective of quantifying tillage impact on CO2 emissions and assessing the main controls. On average, tilled soils emitted 21 % more CO2 than untilled soils, which corresponded to a significant difference at P<0.05. The difference increased to 29 % in sandy soils from arid climates with low soil organic carbon content (SOCC < 1 %) and low soil moisture, but tillage had no impact on CO2 fluxes in clayey soils with high background SOCC (> 3 %). Finally, nitrogen fertilization and crop residue management had little effect on the CO2 responses of soils to no-tillage. These results suggest no-tillage is an effective mitigation measure of carbon dioxide losses from dry land soils. They emphasize the importance of including information on soil factors such as texture, aggregate stability and organic carbon content in global models of the carbon cycle.
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Abdalla, K., P. Chivenge, P. Ciais, and V. Chaplot. "No-tillage lessens soil CO<sub>2</sub> emissions the most under arid and sandy soil conditions: results from a meta-analysis." Biogeosciences Discussions 12, no. 18 (September 18, 2015): 15495–535. http://dx.doi.org/10.5194/bgd-12-15495-2015.
Анотація:
Abstract. The management of agroecosystems plays a crucial role in the global carbon cycle with soil tillage leading to known organic carbon redistributions within soils and changes in soil CO2 emissions. Yet, discrepancies exist on the impact of tillage on soil CO2 emissions and on the main soil and environmental controls. A meta-analysis was conducted using 46 peer-reviewed publications totaling 174 paired observations comparing CO2 emissions over entire seasons or years from tilled and untilled soils across different climates, crop types and soil conditions with the objective of quantifying tillage impact on CO2 emissions and assessing the main controls. On average, tilled soils emitted 21 % more CO2 than untilled soils, which corresponded to a significant difference at P < 0.05. The difference increased to 29 % in sandy soils from arid climates with low soil organic carbon content (SOCC < 1 %) and low soil moisture, but tillage had no impact on CO2 fluxes in clayey soils with high background SOCC (> 3 %). Finally, nitrogen fertilization and crop residue management had little effect on the CO2 responses of soils to no-tillage. These results suggest no-tillage is an effective mitigation measure of carbon dioxide losses from dry land soils. They emphasize the importance of including information on soil factors such as texture, aggregate stability and organic carbon content in global models of the carbon cycle.
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Nizamutdinov, Timur, Azamat Suleymanov, Evgenia Morgun, Natalia Dinkelaker, and Evgeny Abakumov. "Ecotoxicological Analysis of Fallow Soils at the Yamal Experimental Agricultural Station." Food Processing: Techniques and Technology 52, no. 2 (July 6, 2022): 350–60. http://dx.doi.org/10.21603/2074-9414-2022-2-2369.
Анотація:
The agricultural use of soils is limited by their contamination with various compounds and low contents of nutrients. We aimed to study the unique soils of the Yamal Experimental Station to determine their contamination with heavy metals and assess their potential fertility.
Established in 1932, the Yamal Experimental Station (Salekhard, Russia) has bred new varieties of vegetable crops in open and protected ground. In August 2021, we made a soil section and 40 pits in a 0–10 cm layer. X-ray fluorescence was used to determine 11 metals and oxides. The qualitative assessment was based on the total soil pollution, soil pollution, and geoaccumulation indexes. Finally, we determined the contents of nutrients.
The metals and metal oxides showed regressive-accumulative distribution along the soil profile. The concentrations of all ecotoxicants (except for arsenic) were within the maximum/approximate permissible values. Since arsenic has a high regional background content, its elevated concentrations make the soil suitable for agricultural use if proper quality control is in place. The total soil pollution index classified the level of pollution as “acceptable”. The geoaccumulation index showed the soils as mostly “unpolluted” with metals. The soil pollution index had values below 1, which indicated the absence of pollution.
The fallow soils of the Yamal Experimental Station have a high level of potential fertility and are suitable for agricultural reuse according to the soil quality indexes applied. They can also serve as a local geochemical standard that has a long history of agrogenic transformation in cryogenic ecosystems. Taking into account increased concentrations of arsenic, we recommend primary quality control of agricultural products to identify its possible migration in the soil-plant system.
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Miller, R., S. Jones, and M. Lindaman. "Pulverizing Soils for Laboratory Analysis." Communications in Soil Science and Plant Analysis 43, no. 1-2 (January 2012): 445–50. http://dx.doi.org/10.1080/00103624.2012.641831.