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1
Ping, W. Virgil, Ching-Chin Ling und Robert K. H. Ho. „Influence of Soil Suction and Environmental Factors on Drying Characteristics of Granular Subgrade Soils“. Transportation Research Record: Journal of the Transportation Research Board 1714, Nr. 1 (Januar 2000): 98–106. http://dx.doi.org/10.3141/1714-13.
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According to contractors in Florida, construction problems have emerged because pavement soils hold excessive water and are difficult to dry and compact. Recent research on the effects of soil suction and environmental conditions on drying rate characteristics of six types of troublesome granular soils is presented. Two types of tests were conducted for the study: soil suction tests using the thermocouple psy-chrometer method and drying rate tests using an environmental chamber. The experimental results showed that both the soil suction and relative humidity had direct effects on the soil-drying rate. The drying rate decreased with an increase in soil suction for each soil type and also decreased with an increase in the percentage of fines. The influence of relative humidity on the soil-drying rate was much more significant than the effect of the temperature. The rate of water evaporation was extremely low for the soils with a higher percentage of fines when the relative humidity was high. The A-2-4 soils with greater than 20 percent of fines may have such a low drying rate in an environment with high relative humidity that they are difficult to handle during construction.
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Aust, W. Michael, Masato Miwa, James A. Burger, Steve C. Patterson und Emily A. Carter. „Wet-Weather Timber Harvesting and Site Preparation Effects on Coastal Plain Sites: A Review“. Southern Journal of Applied Forestry 28, Nr. 3 (01.08.2004): 137–51. http://dx.doi.org/10.1093/sjaf/28.3.137.
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Abstract Increased interest in sustainable forestry has intensified the need for information on the interactions of forest soils, harvesting methods, site disturbances, and the efficacy of methods for ameliorating disturbances. On wet pine flats, such as those commonly found in the Atlantic and Gulf Coastal Plains, conditions such as frequent rainfall, low relief, and poor internal soil drainage often predispose forest soils to harvest disturbances and potential damage. Typical forest operations use heavy logging equipment, such as rubber-tired feller-bunchers and skidders. During dry soil conditions, these machines cause little soil disturbance, but under moist to saturated conditions, such operations may compact soils and interfere with normal soil drainage. Many studies have been conducted to characterize soil disturbance and site preparation effects on tree seedling survival and growth and to evaluate the amelioration effect of site preparation on disturbed soils. However, results are sometimes contradictory due to site specificity, and results have not been summarized in the context of pine plantation management. This article summarizes previous research results of the wet-weather harvesting and bedding effects on soil properties as related to loblolly pine (Pinus taeda) productivity for a variety of Coastal Plain region sites types. South. J. Appl. For. 28(3):137–151.
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Holmstrom, D. A., und M. R. Carter. „Effect of subsoil tillage in the previous crop year on soil loosening and potato yield performance“. Canadian Journal of Plant Science 80, Nr. 1 (01.01.2000): 161–64. http://dx.doi.org/10.4141/p99-001.
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Soil compaction under potato rotations can be a common problem in Prince Edward Island. This can be further aggravated by naturally occurring compact subsoils. A study was conducted at eight sites on sandy loam soils in three regions of Prince Edward Island to determine whether the recommended practice of subsoiling the fall prior to the potato crop would improve the physical condition of the soil and result in improved yields. The study found that subsoiling provided only a marginal improvement in soil physical conditions. Soil loosening did not increase potato yield or quality. Key words: Potato, subsoiling, yield response, potato quality
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Ho, Soo Ying, Mohd Effendi Bin Wasli und Mugunthan Perumal. „Evaluation of Physicochemical Properties of Sandy-Textured Soils under Smallholder Agricultural Land Use Practices in Sarawak, East Malaysia“. Applied and Environmental Soil Science 2019 (06.02.2019): 1–14. http://dx.doi.org/10.1155/2019/7685451.
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A study was conducted in the Sabal area, Sarawak, to evaluate the physicochemical properties of sandy-textured soils under smallholder agricultural land uses. Study sites were established under rubber, oil palm, and pepper land uses, in comparison to the adjacent secondary forests. The sandy-textured soils underlain in all agricultural land uses are of Spodosols, based on USDA Soil Taxonomy. The soil properties under secondary forests were strongly acidic with poor nutrient contents. Despite higher bulk density in oil palm farmlands, soil properties in rubber and oil palm land uses showed little variation to those in secondary forests. Conversely, soils under pepper land uses were less acidic with higher nutrient contents at the surface layer, especially P. In addition, soils in the pepper land uses were more compact due to human trampling effects from regular farm works at a localized area. Positive correlations were observed between soil total C and soil total N, soil exchangeable K, soil sum of bases, and soil effective CEC, suggesting that soil total C is the determinant of soil fertility under the agricultural land uses. Meanwhile, insufficient K input in oil palm land uses was observed from the partial nutrient balances estimation. In contrast, P and K did not remain in the soils under pepper land use, although the fertilizers application by the farmers was beyond the crop uptake and removal (harvesting). Because of the siliceous sandy nature (low clay contents) of Spodosols, they are poor in nutrient retention capacity. Hence, maintaining ample supply of organic C is crucial to sustain the productivity and fertility of sandy-textured soils, especially when the litterfall layers covering the E horizon were removed for oil palm and pepper cultivation.
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Papatheodorou, Effimia M., Spiros Papakostas und George P. Stamou. „Fire and Rhizosphere Effects on Bacterial Co-Occurrence Patterns“. Microorganisms 11, Nr. 3 (19.03.2023): 790. http://dx.doi.org/10.3390/microorganisms11030790.
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Fires are common in Mediterranean soils and constitute an important driver of their evolution. Although fire effects on vegetation dynamics are widely studied, their influence on the assembly rules of soil prokaryotes in a small-scale environment has attracted limited attention. In the present study, we reanalyzed the data from Aponte et al. (2022) to test whether the direct and/or indirect effects of fire are reflected in the network of relationships among soil prokaryotes in a Chilean sclerophyllous ecosystem. We focused on bacterial (genus and species level) co-occurrence patterns in the rhizospheres and bulk soils in burned and unburned plots. Four soils were considered: bulk-burnt (BB), bulk-unburnt (BU), rhizosphere-burnt (RB), and rhizosphere-unburnt (RU). The largest differences in network parameters were recorded between RU and BB soils, while RB and BU networks exhibited similar values. The network in the BB soil was the most compact and centralized, while the RU network was the least connected, with no central nodes. The robustness of bacterial communities was enhanced in burnt soils, but this was more pronounced in BB soil. The mechanisms mainly responsible for bacterial community structure were stochastic in all soils, whether burnt or unburnt; however, communities in RB were much more stochastic than in RU.
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Cucci, Giovanna, Giovanni Lacolla, Marcello Pagliai und Nadia Vignozzi. „Effect of reclamation on the structure of silty-clay soils irrigated with saline-sodic waters“. International Agrophysics 29, Nr. 1 (01.01.2015): 23–30. http://dx.doi.org/10.1515/intag-2015-0005.
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Abstract The objective of the work was to evaluate, by using the micromorphometric method, the effects of reclamation on porosity of two different clay loam soils irrigated with saline-sodic waters. Soil samples of the Ap horizon were put in cylindrical containers and irrigated with 9 types of saline-sodic waters (3 levels of salinity combined with 3 levels of sodicity). After a 4-year period, correction treatments were initiated by addition of calcium sulphate and leaching until electrical conductivity and sodium absorption ratio values of the drainage water matched 3 dS m-1 and 9, respectively. After 2 years of correction treatments, undisturbed soil samples were taken from the surface layer and soil thin sections for porosity measurements. Both soils did not show critical macroporosity values (> 10%, below this threshold a soil is classified as compact). Nevertheless, the soils exhibited a different behaviour: total porosity of the Pachic Haploxeroll soil was not affected by difference in water salinity and alkalinity; on the contrary, the Udertic Ustochrept soil showed a lower porosity associated with higher salt concentration in the irrigation waters. This may be due to the different iron and aluminium sesquioxides content and, as a consequence, a different effect on soil aggregate stability.
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Vis, Benjamin N., Daniel L. Evans und Elizabeth Graham. „Engagement with Urban Soils Part II: Starting Points for Sustainable Urban Planning Guidelines Derived from Maya Soil Connectivity“. Land 12, Nr. 4 (15.04.2023): 891. http://dx.doi.org/10.3390/land12040891.
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Using the Precolumbian lowland Maya model of urban soil connectivity discussed in Part I, we review how soil connectivity can transition into urban planning policy and, by extension, could ultimately become codified as vantages and guidelines for urban design. In Maya agro-urban landscapes, the interspersion of open and green space with construction and paving provides edges (or interfaces) between sealed and unsealed soils at which the potential for soil connectivity manifests. These edges create an undeniable opportunity for urban planning to determine methods, guidelines, and conditions that can enhance soil connectivity. We argue that adequate attention to soils in urban sustainability goals would counteract misconceptions about the compact city paradigm and compensation for soil sealing in urban practice. Through preserving and increasing urban soil availability, proximity, and accessibility, advisory policies can stimulate shared values and everyday behaviours that reinforce the responsible and productive use of urban soils. Such urban planning can enable and encourage widespread participation in urban soil management. To promote policymaking on urban soils, we assess the importance and challenges of using urban green space as a proxy for the presence of urban soils. Our review suggests that urban green space offers high potential for use in urban planning to develop habit architectures that nurture soil-oriented pro-environmental behaviour. However, we also acknowledge the need for consistent and systematic data on urban soils that match sustainable urban development concepts to assist the effective transition of soil connectivity into urban planning codifications. Formulating adequate soil-oriented planning guidelines will require translating empirical insights into policy applications. To this end, we propose methods for enhancing our understanding and ability to monitor urban soil connectivity, including onsite surveys of land-use and bottom-up experience of soils, the mapping of the edges between sealed and unsealed soils, and using landscape ecological scales of analysis. In conclusion, we position soil care and connectivity as a primary task for urban planning and design and digest our findings and empirical vantages into concrete starting points devised as instruments to support urban planning in achieving soil codification.
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Nickayin, Samaneh Sadat, Francesca Perrone, Barbara Ermini, Giovanni Quaranta, Rosanna Salvia, Filippo Gambella und Gianluca Egidi. „Soil Quality and Peri-Urban Expansion of Cities: A Mediterranean Experience (Athens, Greece)“. Sustainability 13, Nr. 4 (14.02.2021): 2042. http://dx.doi.org/10.3390/su13042042.
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Soil loss and peri-urban settlement expansion are key issues in urban sustainability, with multi-disciplinary implications that go beyond individual ecological and socioeconomic dimensions. Our study illustrates an assessment framework diachronically evaluating urbanization-driven soil quality loss in a Southern European metropolitan region (Athens, Greece). We tested the assumption that urban growth is a process consuming high-quality soils in a selective way analyzing two spatial layers, a map illustrating the diachronic expansion of settlements at five time points (1948, 1975, 1990, 2000, and 2018), and a geo-database reporting basic soil properties. The empirical results showed that the urban expansion in the Athens region took place by consuming higher- quality soil in fertile, mostly flat, districts. It entailed a persistent soil quality decrease over time. This trend globally accelerated in recent years, but in a heterogeneous way. Actually, newly built, more compact areas expanded on soils with lower erosion risk than in the past. Besides, low-density land take is likely to be observed in soils with moderate-high or very-high qualities. These evidences reflect the need for a comprehensive evaluation of complex processes of land take informing spatial planning for metropolitan sustainability.
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Lavkulich, L. M., und J. M. Arocena. „Luvisolic soils of Canada: Genesis, distribution, and classification“. Canadian Journal of Soil Science 91, Nr. 5 (Oktober 2011): 781–806. http://dx.doi.org/10.4141/cjss2011-014.
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Lavkulich, L. M. and Arocena, J. M. 2011. Luvisols of Canada: Genesis, distribution, and classification. Can. J. Soil Sci. 91: 781–806. Luvisols link the soil continuum on the Quaternary landscapes. These soils are developed from parent materials rich in Ca and Mg in a relatively humid climate. An acidic eluvial horizon overlying a phyllosilicate-enriched illuvial Bt horizon is the common horizon sequence in Luvisolic soils. Lessivage or the translocation of clays with minimal chemical alteration is the characteristic soil-forming process and results to the diagnostic Bt horizon with well-developed, oriented clay skins or cutans. These soils commonly form intergrades with Chernozems, Podzols and Vertisols. With time, the eluvial horizons experience increased chemical weathering and further release of sequioxides to form Brunisolic and Podzolic sequences within the eluvial Ae in biseqeual soils. Lessivage significantly influences several ecosystem functions of soils. The high amounts of phyllosilicates in the Bt horizon serve as one of the most active sorption sites in soils for metals and organic materials including soil carbon. Sorption of cations takes place through cation exchange reactions and determines the availability of cations to plant roots as well as in the “colloid facilitated transport” of strongly sorbing metals and organic pollutants. Clays in Bt can be restrictive to water and air movement as well as to root growth and distribution. Agricultural and forestry practices such as tillage can compact the structure of Luvisols and may decrease soil productivity.
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Akyıldız, Mehmet Hayrullah, und Ergün Akbaş. „BASİT VE ÇOKLU REGRESYON ANALİZLERİ İLE KOMPAKSİYON PARAMETRELERİNİN TAHMİN EDİLMESİ VE F TESTİ İLE ANLAMLILIĞININ İNCELENMESİ“. e-Journal of New World Sciences Academy 15, Nr. 4 (31.10.2020): 186–95. http://dx.doi.org/10.12739/nwsa.2020.15.4.1a0461.
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Compaction is the compaction of the moist soil by laying it in layers, rolling it by applying vibration. Compaction is widely used both for the frequency control of road embankments and embankment dams and in other important engineering projects. Therefore, it is important to determine the compaction parameters correctly. The lack of sufficient laboratory equipment at the construction sites and the limited deadline of work increased the importance of correlation equations. If there are sufficient data and results are obtained within tolerable safety limits, it is considered appropriate to use statistics in estimation of compaction parameters. This situation provides a gain both in terms of economy and time. In the study, the compaction parameters were tried to be estimated by subjecting the soil index properties of Adıyaman Balkar, Çelik and Pınaryayla Ponds to simple and multiple regression analyzes. First, the data of the soils belonging to the ponds were used, then, as a result of the sieve analysis, the index properties of fine-grained soils containing only clay and silt were evaluated and compaction parameters were tried to be determined. Simple and multiple regression analyzes were made with the help of the Eview program, where the statistical analysis of the existing data was made, and the statistical significance of the obtained models was examined by performing the F test. It was determined that higher correlations were obtained compared to other sample data, especially by using the data of samples that do not contain sand and gravel material.
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Gorban, V. A. „To the method of studying the permittivity of soils (on an example of soils of ravine forests of the northern variant of the steppe zone of Ukraine)“. Fundamental and Applied Soil Science 17, Nr. 3-4 (08.11.2016): 90–97. http://dx.doi.org/10.15421/041616.
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The article is devoted to the establishment of the peculiarities of the method for studying the dielectric permittivity of soils, which is its important electrophysical characteristic. The dielectric permittivity of the soil, which is a complex multiphase medium, depends on the dielectric properties of the mineral composition of its solid phase, the chemical composition, structure and composition of soil particles, their shape and size, and also the dielectric features of inter-porous air and moisture. Now it is possible to greatly simplify the technique of measuring the dielectric permittivity of soils due to the wide dissemination of compact digital instruments that provide high accuracy in measuring the capacitive characteristics of various media. For the approbation of the method, samples of soils of ravine forests of the northern variant of the steppe zone of Ukraine were used, as well as individual soil fractions of 2–3, 1–2 and 0.5–1 mm. All samples were studied in an air-dry state to level out the effect of moisture on the dielectric permittivity of soils, as described in many scientific papers. For measurements, a cylindrical condenser made of organic glass was manufactured, which does not conduct an electric current. The diameter of the capacitor plates was 20 mm, the distance between them was 0.7 mm. After placing the sample in the condenser, it was sealed by pressure from above the weight of about 0.3 kg to create a better contact with the covers of the capacitor. The measurements were carried out using a digital capacitance meter CM-9601A in the range of 0.1–200 picofarads at a test frequency of 800 Hz. At the end of the measurement, the soil sample was weighed to calculate its density. All measurements were performed three times. As a result of using this technique, it was found that the permittivity of a general soil sample is generally higher than that of individual soil fractions. This is explained by the more compact placement of soil particles in the soil sample and its greater density, while in studies of individual fractions, due to their shape, there remain pores between the aggregates that are not filled with soil material, which cause a decrease in sample density. As a result, the maximum density is typical for the soil fraction 0.5–1 mm, and the minimum for the fraction 2–3 mm. This is due to the fact that the maximum permittivity, as a rule, is characteristic for the fraction 0.5–1 mm, and the minimum for the fraction 2–3 mm. This assertion was proved by the measurements carried out. It was also found that the value of dielectric permittivity is significantly affected by soil enrichment of the clay fraction, the increased content of which causes an increase in the dielectric permittivity. Thus, as a result of the research, a method for measuring the dielectric permittivity of soils was tested using a modern digital capacitive meter. An increase in the dielectric permittivity of soils with an increase in their density and an increase in the content of the clay fraction was established. Soils, in general, have an increased permittivity in comparison with soil fractions of 2–3, 1–2 and 0.5–1 mm. There was a need to develop and approbate a technique for measuring the dielectric permittivity of soils in the field using undisturbed addition samples. In the future, in complex studies of soils, it is also desirable to perform a measurement of their dielectric permeability.
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Watson, Gary W., Gary Kupkowski und Kerstin G. von der Heide-Spravka. „Influence of Backfill Soil Amendments on Establishment of Container-grown Shrubs“. HortTechnology 3, Nr. 2 (April 1993): 188–89. http://dx.doi.org/10.21273/horttech.3.2.188.
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Cotoneaster apiculata and Juniperus chinensis `Pfitzeriana Compacta' were planted on a site with compacted clay soil. Plants were placed in holes the same size as the root ball (no backfill), or in holes three times the diameter of the root ball with sloping sides. The three backfill soils used were composed of site-soil (50%) amended with sand (40%) and leaf compost (10%), site-soil (75%) amended with mushroom compost (25%), and unamended site-soil. After 14 months, root density was not different in any of the treatments, and root densities were not different in the compacted clay soil outside of the planting hole, indicating that root growth was not inhibited at the interface between the backfill soil and the compacted site clay soil. Shoot growth of C. apiculata grown in backfill amended with sand and leaf compost was larger than shoot growth of plants grown in other backfills.
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Zhai, Zhanghui, Yaguo Zhang, Shuxiong Xiao und Tonglu Li. „Undrained Elastoplastic Solution for Cylindrical Cavity Expansion in Structured Cam Clay Soil Considering the Destructuration Effects“. Applied Sciences 12, Nr. 1 (03.01.2022): 440. http://dx.doi.org/10.3390/app12010440.
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Soil structure has significant influences on the mechanical behaviors of natural soils, although it is rarely considered in previous cavity expansion analyses. This paper presents an undrained elastoplastic solution for cylindrical cavity expansion in structured soils, considering the destructuration effects. Firstly, a structural ratio was defined to denote the degree of the initial structure, and the Structured Cam Clay (SCC) model was employed to describe the subsequent stress-induced destructuration, including the structure degradation and crushing. Secondly, combined with the large strain theory, the considered problem was formulated as a system of first-order differential equations, which can be solved in a simplified procedure with the introduced auxiliary variable. Finally, the significance and efficiency of the present solution was demonstrated by comparing with the previous solutions, and parametric studies were also conducted to investigate the effects of soil structure and destructuration on the cavity expansion process. The results show that the soil structure has pronounced effects on the mechanical behavior of structured soils around the cavity. For structured soils, a cavity pressure that is larger than the corresponding reconstituted soils when the cavity expands to the same radius is required, and the effective stresses first increase to a peak value before decreasing rapidly with soil structure degradation and crushing. The same final critical state is reached for soils with different degrees of the initial structure, which indicates that the soil structure is completely destroyed during the cavity expansion. With the increase of the destructuring index, the soil structure was destroyed more rapidly, and the stress release during the plastic deformation became more significant. Moreover, the present solution was applied in the jacking of a casing during the sand compact pile installation and in situ self-boring pressuremeter (SBPM) tests, which indicates that the present solution provides an effective theoretical tool for predicting the behavior of natural structured soils around the cavity.
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Stoppe, Nina, und Rainer Horn. „Microstructural strength of tidal soils – a rheometric approach to develop pedotransfer functions“. Journal of Hydrology and Hydromechanics 66, Nr. 1 (01.03.2018): 87–96. http://dx.doi.org/10.1515/johh-2017-0031.
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Abstract Differences in soil stability, especially in visually comparable soils can occur due to microstructural processes and interactions. By investigating these microstructural processes with rheological investigations, it is possible to achieve a better understanding of soil behaviour from the mesoscale (soil aggregates) to macroscale (bulk soil). In this paper, a rheological investigation of the factors influencing microstructural stability of riparian soils was conducted. Homogenized samples of Marshland soils from the riparian zone of the Elbe River (North Germany) were analyzed with amplitude sweeps (AS) under controlled shear deformation in a modular compact rheometer MCR 300 (Anton Paar, Germany) at different matric potentials. A range physicochemical parameters were determined (texture, pH, organic matter, CaCO3 etc.) and these factors were used to parameterize pedotransfer functions. The results indicate a clear dependence of microstructural elasticity on texture and water content. Although the influence of individual physicochemical factors varies depending on texture, the relevant features were identified taking combined effects into account. Thus, stabilizing factors are: organic matter, calcium ions, CaCO3 and pedogenic iron oxides; whereas sodium ions and water content represent structurally unfavorable factors. Based on the determined statistical relationships between rheological and physicochemical parameters, pedotransfer functions (PTF) have been developed.
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Rai, S. N. „EARTHWORM BIODIVERSITY IN DIFFERENT LAND USE SYSTEM“. International Journal of Research -GRANTHAALAYAH 5, Nr. 6 (30.06.2017): 347–52. http://dx.doi.org/10.29121/granthaalayah.v5.i6.2017.2041.
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Researches have proved that the occurrence of different species of earthworms in good numbers is a positive sign of healthy soil. Establishment of earthworm population makes the soil more compact and the poor structure of deep soil changes in to friable top soil. Twenty two species of earthworms are identified from different land use systems. The potential soil reclaiming species are Eutyphoeus incommodus, Eutyphoeus nicholsoni, Eutyphoeus waltoni, Octochaetona surensis, Amynthas morrisi, Metaphire posthuma and Lampito mauritii. Metaphire posthuma is very abundant in garden soils. Eutyphoeus nicholsoni is mostly confined to garden litter soil with medium and low population as deep burrowing species. Octochaetona surensis is very common in dense bamboo plantations. Amynthas morrisi is mostly confined to decomposing paddy straw and composting litter. The cultivated soils of sugarcane and jowar, the species association index of Eutyphoeus incommodus and Ramiella naniana is very high though Ramiella naniana is purely a geophagous species.
Seeds of earthworms can easily be transported if they are properly packed in vials with water soaked filter paper. The seeds will not hatch out within 10 days from the date of their laying.
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Abramova, Tamara. „SILICATIZATION OF CULTURAL LAYER SOILS IN ARCHAEOLOGICAL EXCAVATIONS“. LIFE OF THE EARTH 45, Nr. 2 (14.06.2023): 193–208. http://dx.doi.org/10.29003/m3448.0514-7468.2023_45_2/193-208.
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The preservation and in situ museumification of archaeological objects of stratigraphic sections of cultural layer soils, whose value depends on the integrity and intactness, is a complex and underdeveloped problem. This is due to some specific properties of these soils, such as the heterogeneity of soil composition both vertically and horizontally; the diversity of inclusions, the uneven compressibility of the strata, the ability to self-compact from their weight, changes in hydrogeological conditions, soil soaking and the decomposition of organic inclusions. As a result, these soils are the most unfavorable in artificial stabilization. In the study, a wide range of soils of the cultural layer from various places with stabilization plans were examined. Our analysis of the deposits made it possible to separate these soils by geochemical features which have the highest impact on the intensity of the chemical solution’s interaction processes with the mineral component of the soil. This chemical solution is in a family of silicate compositions with surfactants of the amide class. These organic liquid glass hardeners activate the skeletal part of the soil and provide the complete mobilization of the main cementing substance (silica gel). Pilot tests of various modifications of organo-silicate solutions were carried out at the sites of Chersonesos (Sevastopol), Tanais (Rostov region), Moscow, etc. The soils ranged from sandy to loamy with various inclusions (building stone, ceramics, bones, fish scales, shells, ash, soot, plant roots, etc.). Soil stabilization was carried out by injecting chemical solutions of various densities with the use of vertical and horizontal injections. An important finding of the work was that forming a new soil mass with improved properties was determined by the composition, properties of the soil and injection solutions, the distance from the injector and the depth of the stabilized area. For the first time in Russia, at the center of Moscow, it was possible to preserve the soil mass in situ of the cultural layer of the 16-17th centuries and exhibit it for 32 years to visitors in the underground archaeological museum.
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Chude, V. O., E. E. Oku, G. I. C. Nwaka und M. S. Adiaha. „Soil compaction assessment as a manipulative strategy to improve soil biodiversity: an approach for meeting SDG two and six“. Міжвідомчий тематичний науковий збірник "Меліорація і водне господарство", Nr. 1 (25.06.2020): 131–43. http://dx.doi.org/10.31073/mivg202001-224.
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The rapid increase in soil deterioration has been a drawback to global development, acting like a barrier to sustainability of Agriculture and the environment. Biodiversity in soil plays a crucial role in ecosystem sustainability, but yet there exist a rapid deterioration in soil biodiversity especially due to increase soil toxins, chemical spills, wind erosion including the rapid down-pour by rainfall which destroys soil structure and degrade soil biota. Soil compaction reduction manipulation through tillage and application of fertilizer plays a major role for food production, apart from being a part of environmental sustainability strategy. Field studies was conducted, where the status of soil compaction was examined, a replicate of four (4) soil sample were collected at a twenty (20) points sampling station using the proportionate stratified random sampling technique. Laboratory analysis output indicated high soil compaction. Laboratory analysis output was ranked with FAO standardize rate for compaction effect on soil biodiversity. Result of the finding indicated high soil compaction with bulk density value range of 1,56 gcm-3 – 2,71 gcm-3 which was found to be too compact for sustainable soil biota development. And porosity value range of 1% - 41% was obtained, which indicated tight soil spore that can imped soil biodiversity. Correlation analysis (R2) revealed a positive correlation between topography and soil compacting, with a ranking output of the soil been poor in biodiversity (biota load). Outcome of this investigation concluded that proper tillage, application of fertilizer including organic matter be carried out for the study area soils and soils of its environs.
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Sochacki, Stanley, Peter Ritson und Bruce Brand. „A specialised soil corer for sampling tree roots“. Soil Research 45, Nr. 2 (2007): 111. http://dx.doi.org/10.1071/sr06014.
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Sampling and measurement of tree root systems is arduous, expensive, and time-consuming. The lack of adequate and efficient equipment has resulted in the development of a new soil-root sampling apparatus which is able to sample tree roots of any diameter and soils of any hardness. This apparatus is inexpensive, compact, manoeuvrable, and very versatile in application.
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Abdul-Baki, Aref A., S. Aslan, S. Cobb, E. Beardsley und T. Burke. „448 Soil Problems Affecting Date Palm Growth, Yield, and Fruit Quality in Coachella Valley“. HortScience 34, Nr. 3 (Juni 1999): 521E—522. http://dx.doi.org/10.21273/hortsci.34.3.521e.
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A 3-year experiment was conducted to identify problems in Coachella Valley date palm (Phoenix dactylifera) orchards that limit vegetative growth, yield, and fruit quality. Major problems that were identified included soil compaction and stratification that restrict water permeation into the root zone, and low fertility as reflected by the low organic -matter content of the sandy soils. To eliminate the impact of these stresses on plant growth, yield, and fruit quality, a no-tillage alternative management system was introduced to replace the conventional practice of tillage that compacts the soil. No-till was coupled with the use of cover crops to enrich the soil with organic matter, fix N, recycle nutrients, and improve water holding capacity of the sandy soil. In already established orchards, an additional treatment—slip plowing—was also implemented to loosen the soil at lower depths to facilitate water permeation. The positive effects of the alternative system on the soil, tree growth, yield, and fruit quality will be presented.
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Rees, H. W., T. L. Chow, Z. Xing, S. Li, J. O. Monteith und L. Stevens. „Depth to compact subsoil effects on soil properties and barley–potato yields on a loamy soil in New Brunswick“. Canadian Journal of Soil Science 95, Nr. 3 (August 2015): 203–18. http://dx.doi.org/10.4141/cjss-2014-038.
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Rees, H. W., Chow, T. L., Xing, Z., Li, S., Monteith, J. O. and Stevens, L. 2015. Depth to compact subsoil effects on soil properties and barley–potato yields on a loamy soil in New Brunswick. Can. J. Soil Sci. 95: 203–218. An experiment was established to investigate the implications of thickness of soil over compact subsoil on plow layer soil thermal and water regimes and ultimately the yield of potato (Solanum tuberosum L.) and barley (Hordeum vulgare L.). Three depths were considered, 24 cm (shallow), 36 cm (medium) and 60 cm (deep). Results on soil temperature impacts were inconclusive. The shallow treatment water content was most greatly affected by precipitation and had the greatest potential to become saturated then drying out more than the other treatments. The deep treatment did not improve soil temperature and water regimes enough to increase crop yield. The medium depth, which most closely approximated existing local solum development, proved superior to the shallow treatment in terms of crop yield and reduced soil moisture variation, while the deep treatment did not warrant the effort required to create under field conditions. Barley and potato yields from the medium depth were greatest with 20% (significant) and 8% (not significant) more yield, respectively, than from the shallow treatment. The eroded soil profiles common to the New Brunswick potato belt exacerbate soil erosion since an eroded soil has less volume to accept water from a rainfall event, making the soil more prone to erosion, especially if it is true that our weather is changing, with the amplitude of weather shifts becoming greater. Incorporation of subsoil materials into the plow layer of eroded soils due to soil loss may result in further reduction in crop yield.
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Ciarkowska, Krystyna, und Anna Miechówka. „Gypsic rendzinas of Nida Basin (southern Poland): a review“. Soil Science Annual 69, Nr. 2 (01.06.2018): 101–8. http://dx.doi.org/10.2478/ssa-2018-0010.
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Abstract The article presents the overview of the gypsic rendzinas that occur in the Nida Basin (Niecka Nidziańska) as based on authors’ results and observations and also literature data. The influence of gypsum forms (selenite, shale and compact gypsum) and allogenic admixtures on the properties of rendzinas was described. Furthermore, attention was paid to the specific climate conditions of the Nida Basin reflected in the native vegetation cover on the gypsum-derived soils. Finally, there is a proposal for classification of this area’s gypsic rendzinas and the soil properties were described for the specified soil units.
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Poonam, Rajan Bawa, D. Nayak, H. Sankhyan und S. S. Sharma. „Soil Nutrient Storage Under Major Ecosystems of Cold Deserts of Himachal Pradesh“. Indian Journal of Forestry 40, Nr. 2 (01.06.2017): 127–32. http://dx.doi.org/10.54207/bsmps1000-2017-8z33wr.
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The present investigation was carried out at village Goshal of Lahaul and Spiti cold desert district of Himachal Pradesh during the year 2010 to 2013 to compare soil physical and chemical properties by demarcating the study area into three main ecosystems viz; forest ecosystem, alpine pasture ecosystem and agro ecosystem. The soil physical properties of all the three ecosystems revealed that the soils were found nearly neutral in reaction, having no salt problem and were medium in physical status. Bulk density was more in alpine and forest ecosystem due to grazing and soil was more compact as compared to agro ecosystem. The average soil moisture was maximum in agro ecosystem. Average soil nutrient status for all the three ecosystems depicted that the fields where peas and pulses were planted were found to be possessing higher nitrogen contents than other areas due to the fixation of atmospheric nitrogen.
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Valdes, María. „Aspectos ecofisiológicos de las micorrizas“. Botanical Sciences, Nr. 49 (10.04.2017): 19. http://dx.doi.org/10.17129/botsci.1363.
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Mycorrhiza is the part of the roots infected with particular soil fungi. This type of association is formed by most of the plants. There are several types of mycorrhizae; this short review is concerned only with Ectomycorrhiza (EM) and the Vesicular-Arbuscular Mycorrhiza (VAM). These two types are the most common in nature. EM has a compact fungus mantle over the root surface and intercellular hypha in the cortex; the V AM has a loose network of hyphae in the soil surrounding the root and hyphal growth within the cortical cells. Mycorrhizas increase nutrient uptake and hence plant growth. Since mycorrhizas are surrounded by an extensive hyphal network than may extcnd into the soil, this network represents a greater surface area, in other words, mycorrhizas shorten the distance that nutrients must diffuse through the soil to the root and their hyphae increase the volume of soil available to the plant for nutrient uptake. Physiological responses to root colonization with mycorrhizal fungi by most of the plants are dependent on the level of soil fertility and on the degree of mycorrhizal dependency of the plant. Soils having a high fertility have mostly a poor colonization, hence, for plant growth to respond to inoculation, soils must have a low fertility. Mycorrhizal dependency can be very different among plant species; plants with short root hairs are more dependent on mycorrhizal fungi. Most soils contain mycorrhizal fungi and their distribution varies with climatic, edaphic environment and land use. There are differences in effectiveness in colonization and in enhanced nutrient uptake among the fungi.
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Samec, M., A. Santiago, J. P. Cárdenas, R. M. Benito, A. M. Tarquis, S. J. Mooney und D. Korošak. „Quantifying soil complexity using network models of soil porous structure“. Nonlinear Processes in Geophysics 20, Nr. 1 (15.01.2013): 41–45. http://dx.doi.org/10.5194/npg-20-41-2013.
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Abstract. This paper describes an investigation into the properties of spatially embedded complex networks representing the porous architecture of soil systems. We suggest an approach to quantify the complexity of soil pore structure based on the node-node link correlation properties of the networks. We show that the complexity depends on the strength of spatial embedding of the network and that this is related to the transition from a non-compact to compact phase of the network.
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Dai, Chen-Xiang, Qiong-Fang Zhang, Shao-Heng He, An Zhang, Hua-Feng Shan und Tang-Dai Xia. „Variation in Micro-Pores during Dynamic Consolidation and Compression of Soft Marine Soil“. Journal of Marine Science and Engineering 9, Nr. 7 (06.07.2021): 750. http://dx.doi.org/10.3390/jmse9070750.
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In this study, to explore the microstructure deformation mechanism of marine soft marine soil under cyclic loading, we analyzed the dynamic properties of soft marine soil under cyclic loading via dynamic consolidation compression testing. Then, using Image-Pro Plus (IPP) 6.0 image analysis software, and according to the dynamic consolidation compression test results and the images from a scanning electron microscope (SEM), we determined the weakening effect of soft soils under different consolidation confining pressures, different cyclic stress ratios, and different over-consolidation ratios. After dynamic consolidation and compression, the pore structure of undisturbed soft marine soil tends to compact, the degree of soil particle fragmentation intensifies, small pores increase, large pores decrease, the pores become more regular, and the distribution of pores is directional. Subsequently, for undisturbed soft marine soil, the higher the consolidated confining pressure, cyclic dynamic stress ratio, and over-consolidation ratio, the greater the damage to the pore structure, and the more obvious the structural weakening effect exhibited under cyclic loading.
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Zakrevskaya, L. V., K. A. Nikolaeva, A. I. Gandelsman und P. A. Orekhov. „Soil bases modified with lime waste and polycarboxylates“. Journal of Physics: Conference Series 2124, Nr. 1 (01.11.2021): 012023. http://dx.doi.org/10.1088/1742-6596/2124/1/012023.
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Abstract Increasing the volume of road construction is one of the priority areas of infrastructure development in any country. When building roads, it is preferable to use local materials to reduce the cost of their transportation, therefore, it is advisable to build the roadbed on local soils. It is worth noting that clay water-saturated soils are the most common, which complicates the construction of the road due to some features of this type of soil. The object of the study is a water-saturated clay with the following characteristics: natural humidity from 25.3 % to 28.1% by weight, optimal humidity from 11.8 % to 16.7% by weight, the number of plasticity from 0.118 to 0.153. Clay soils have a number of features: waterlogged soils are difficult to compact and develop, it is quite problematic to dry them, and thixotropy is also characteristic of clay soils. In this regard, it is most advisable to use the method of complex mineral binders to optimize their physical and mechanical properties. In the course of laboratory studies, compositions of soil compositions with the addition of lime waste and superplasticizer P-17 were developed. The dependence of the strength on the consumption of mineral binders and surfactants is established: the maximum compressive strength of the soil being fixed is achieved at a lime content of 25 wt.% and at a P-17 content in the range of 0.10-0.5 wt.%.
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Secco, Deonir, Doglas Bassegio, Araceli Ciotti de Marins, Bruna de Villa, Luiz Antônio Zanão Junior, Tiago Roque Benetoli da Silva und Affonso Celso Gonçalves Junior. „Long-term effects of cover crops on physical-hydric properties of compacted soil“. Acta Scientiarum. Agronomy 45 (23.08.2023): e62390. http://dx.doi.org/10.4025/actasciagron.v45i1.62390.
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The screening of cover crops is essential for improving the physical-hydric properties of compacted soils. This study aimed to evaluate the effects of mixed or single cover crops on improving the physical-hydric properties of compacted Oxisol. Species with tap-rooted and fibrous-rooted rooting patterns were evaluated. The species included pearl millet (Pennisetum americanum), pigeon pea (Cajanus cajan), sunn hemp (Crotalaria spectabilis), velvet bean (Mucuna pruriens), white oat (Avena sativa), black oat (Avena strigosa), rye (Secale cereale), black oat + forage turnip (Raphanus sativus), black oat + white lupin (Lupinus albus L.), and black oat + group pea (Pisum arvense L.). Mixing cover crops did not improve the physical properties of the soil. The tap-rooted pigeon pea effectively reduces bulk density and increases porosity and saturated hydraulic conductivity (Ksat) in compact soils. The selection of cover crops with characteristics that improve soil physical-hydric properties is crucial for compacted areas.
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Ivanova, I. L., L. V. Kislitsina und A. A. Vazhenina. „Chemical pollution of soils of the Primorsky Region as a risk factor for population health“. Sanitarnyj vrač (Sanitary Doctor), Nr. 9 (12.09.2022): 680–88. http://dx.doi.org/10.33920/med-08-2209-07.
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The article presents the results of a hygienic study to assess the chemical contamination of soils in residential areas of Primorsky Krai based on the results of social and hygienic monitoring from 2018 to 2020. The analysis of the actual concentrations of heavy metals in the soil was carried out for 7 chemical elements: lead, zinc, copper, nickel, cadmium, manganese, mercury in 12 administrative territories of the region. Soil safety control points are certified using a system of geoinformation technologies. It has been established that a feature of the administrative territories of the northern part of the region is a sharp predominance of natural sources of chemical pollution over all others. Contamination with toxic elements of soils in the southern part of the region, especially in places of compact residence of the population, is of a pronounced technogenic character. The leading mechanism for the accumulation of microelements in the soils of the cities of Primorsky Krai is their intake from the atmospheric air, heavily polluted by man-made emissions, the leading sources of which are motor vehicles, railroad and sea transport.
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Parker, Robert T., Douglas A. Maguire, David D. Marshall und Pat Cochran. „Ponderosa Pine Growth Response to Soil Strength in the Volcanic Ash Soils of Central Oregon“. Western Journal of Applied Forestry 22, Nr. 2 (01.04.2007): 134–41. http://dx.doi.org/10.1093/wjaf/22.2.134.
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Abstract Mechanical harvesting and associated logging activities have the capacity to compact soil across large portions of harvest units, but the influences of compaction on long-term site productivity are not well understood. Previous research in central Oregon has shown that volcanic ash soils compact readily under both compression and vibration loads, resulting in long-term alteration in soil density and a decline in tree growth. In this study, soil strength (SS) and tree growth were assessed in areas subject to repeated timber harvesting with the objective of quantifying the relationship between ponderosa pine (Pinus ponderosa Laws.) growth and SS. Two thinning treatments (felled only versus felled and skidded) in 70- to 80-year-old ponderosa pine stands were replicated at three sites in 1991. Subsequent 5-year growth in diameter, height, and volume of residual trees were assessed with respect to SS measured by a recording penetrometer. Felled and skidded plots had 44% higher SS values than felled-only plots (P = 0.05). Although no treatment effect on growth was detected at the plot level, diameter, height, and volume growth of individual trees within plots declined significantly as average SS within a 30-ft zone of influence increased from approximately 800 to 2,500 kPa. Results show the potential use of SS measurements for monitoring impacts of harvesting operations on tree growth.
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Scharenbroch, Bryant C. „Impacts of Aerated Compost Tea on Containerized Acer saccharum and Quercus macrocarpa Saplings and Soil Properties in Sand, Uncompacted Loam, and Compacted Loam Soils“. HortScience 48, Nr. 5 (Mai 2013): 625–32. http://dx.doi.org/10.21273/hortsci.48.5.625.
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Aerated compost teas (ACTs) are applied to soils with the intent of improving microbial properties and nutrient availability and stimulating plant growth. Anecdotal accounts of ACT for these purposes far outnumber controlled, replicated, and peer-viewed experiments that have examined the impacts of ACT on soil properties and plant growth responses. This research assessed the impacts of four rates of ACT compared with water on containerized Acer saccharum and Quercus macrocarpa saplings growing in loam, compacted loam, and sandy soils. No significant differences were found comparing water with ACT applied at rates of 2, 4, and 40 kL ACT/ha for any of the six tree responses and 21 soil responses. Microbial biomass nitrogen (N) and potassium (K) increased, and available N decreased, in soils treated with ACT at 400 kL·ha−1 compared with water. Shoot, root, total biomass, and the root/shoot ratio were significantly greater for Quercus macrocarpa trees growing in compact loam with the 400 kL ACT/ha treatment compared with water, but significant differences were not detected for this application rate compared with water in the other soil types and in no instances with Acer saccharum saplings. These results provide some support for claims of ACT being able to increase soil microbial biomass and K, but provide minimal support for ACT being able to increase tree growth across multiple species in a variety of soil types. An application rate of 400 kL ACT/ha may be attainable for trees in containers with limited soil volumes, but this application rate is likely cost-prohibitive, and not practical, in the landscape. At this application rate, ≈1000 L of ACT would be required to treat a typical, and relatively small, critical root zone of 25 m2.
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Harper, RJ, und RJ Gilkes. „Hardsetting in the surface horizons of sandy soils and Its implications for soil classification and management“. Soil Research 32, Nr. 3 (1994): 603. http://dx.doi.org/10.1071/sr9940603.
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Marked variations in hardsetting occur in the sandy surface horizons of duplex deep sandy soils in a semi-arid area of Western Australia. Hardsetting by definition only occurs in dry soils and increases with field texture. Soil strength measured on remoulded samples in the laboratory conformed with field assessments of strength (consistence). Most (79%) of the variation in strength between Ap horizon samples was explained by clay content, with small differences in clay content resulting in large differences in strength. Half of the maximum measured strength in the Ap horizons was achieved at a clay content of only 8%. The A2 horizons were markedly stronger than corresponding Ap horizons, despite similar clay contents, and this difference in strength is related to the larger organic matter content of the Ap horizons. Hardsetting of these sandy soils may be explained in terms of the cementing action provided by clay which forms bridges between particles. Organic material weakens these bridges. Hardsetting may affect the wind erodibility of sandy soils, through differences in surface conditions (i.e. loose v. compact) and by increasing the resistance to abrasion by saltating sand. It is not clear what effect it will have on plant performance. Hardsetting is a continuous, rather than discrete soil attribute, and if it is to be described in the field, and used in soil classification schemes, objectives class limits should be defined, perhaps using dry consistence ratings.
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Shvets, Ludmila, und Maksym Kucherenko. „DEVELOPMENT OF AN INSTALLATION FOR THE PRODUCTION OF ELECTRICITY AND WATER SUPPLY WITH WIND DRIVE“. ENGINEERING, ENERGY, TRANSPORT AIC, Nr. 4(119) (23.12.2022): 120–26. http://dx.doi.org/10.37128/2520-6168-2022-4-15.
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To supply water to the fields, an irrigation system is built, which includes a source of water supply, a water intake structure with a pumping unit, transport, distribution and working channels or pipes. Closed or open irrigation networks are built on the fields. In a closed network, water under pressure is supplied through pipes and hydrants to irrigation machines or installations. The open network is laid in the form of temporary pipelines, channels or trays, from which water is supplied by pumps to sprinklers and watering machines. Near cities and large livestock complexes, fields are irrigated with wastewater, which is also used with fertilizers. Water is supplied to the soil by sprinkling, surface, and subsoil and drip irrigation. Water is broken into drops and distributed over the irrigated area in the form of rain. The size of the drops should not exceed 1...2 mm. Rain intensity should be no more than 0.1...0.2 mm/min for heavy soils, 0.2...0.3 mm/min for medium loams, 0.5...0.8 mm/min for light soils. Under such conditions, raindrops do not damage plants, compact the soil less and do not destroy soil clods, water has time to soak into the soil, and puddles do not form on the surface of the soil. It is important to evenly distribute water over the irrigated field and ensure the specified irrigation rate. Fertilizers are applied at the same time as watering. Water is also supplied in furrows, in strips or by flooding the entire irrigated area. When irrigating the subsoil, water is fed into the soil through pipes with holes, through mole holes located at a depth of 40...50 cm. Through soil capillaries, water rises into the upper layers of the soil. This method is not recommended for use on sandy and loamy soils. Proposed design of a wind-driven power generation and water supply installation.
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Leeuwen Cornelis, van, de Rességuier Laure, Mary Séverine, Laveau Coralie, Mousset-Libeau Etienne, Marguerit Elisa, Roby Jean-Philippe und Quiquerez Amélie. „Soil type and soil preparation influence vine development and grape composition through its impact on vine water and nitrogen status“. E3S Web of Conferences 50 (2018): 01015. http://dx.doi.org/10.1051/e3sconf/20185001015.
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The influence of soil type and preparation on vine development and grape composition was investigated in a 50 ha estate located in Saint-Emilion (Bordeaux, France) and planted predominantly with Merlot. Part of the vineyard was planted down the slopes and another part of the vineyard was planted on terraces, where soils were profoundly modified through soil preparation. Grape composition (berry weight, sugar, total acidity, malic acid and pH), vigor (pruning weight), vine nitrogen status (Yeast Available Nitrogen (YAN) in grapes) and vine water status (δ13C) was measured at a very high density grid of 10 data points per hectare. Water deficit was globally weak over the estate because of high soil water holding capacity whereas vine nitrogen status was highly variable. Vine vigor and grape composition were predominantly driven by vine nitrogen status. On terraces, where soils were deep, due to invasive soil preparation, water deficits were particularly small or non-existent and vine nitrogen status was highly variable. Grape quality potential was medium to low, except in places with low nitrogen status, but at the expense of low yields. On parcels planted down the slopes water deficits were recorded because vine rooting was limited by compact subsoils. Vine nitrogen status was homogeneous. Grape quality and yield were medium to high and relatively homogeneous. When possible, downhill plantations are to be preferred over terraces because in the latter vine yield and quality parameters are highly variable because of massive soil movements prior to plantation.
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Matviishyna, Zh M., und 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, Nr. 2 (06.07.2019): 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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Ávila-Dávila, Laura, Manuel Soler-Méndez, Carlos Francisco Bautista-Capetillo, Julián González-Trinidad, Hugo Enrique Júnez-Ferreira, Cruz Octavio Robles Rovelo und José Miguel Molina-Martínez. „A Compact Weighing Lysimeter to Estimate the Water Infiltration Rate in Agricultural Soils“. Agronomy 11, Nr. 1 (18.01.2021): 180. http://dx.doi.org/10.3390/agronomy11010180.
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Infiltration estimation is made by tests such as concentric cylinders, which are prone to errors, such as the lateral movement under the ring. Several possibilities have been developed over the last decades to compensate these errors, which are based on physical, electronic, and mathematical principles. In this research, two approaches are proposed to measure the water infiltration rate in a silty loam soil by means of the mass values of a lysimeter weighing under rainfall conditions and different moisture contents. Based on the fact that with the lysimeter it is possible to determine acting soil flows very precisely, then with the help of mass conservation and assuming a downward vertical movement, 12 rain events were analyzed. In addition, it was possible to monitor the behavior of soil moisture and to establish the content at field capacity from the values of the weighing lysimeter, from which both approach are based. The infiltration rate of these events showed a variable rate at the beginning of the rainfall until reaching a maximum, to descend to a stable or basic rate. This basic infiltration rate was 1.49 ± 0.36 mm/h, and this is because soils with fine textures have reported low infiltration capacity. Four empirical or semi-empirical models of infiltration were calibrated with the values obtained with our approaches, showing a better fit with the Horton’s model.
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Denis, TIKI, BITOM Mamdem Lionelle, IBRAHIM Achille, SOUNYA Jean Boris, LEUMBE LEUMBE Olivier und BITOM Dieudonné. „Study of Digital Surface Data for Soils and Flood Risk Areas Mapping in Sudano-Sahelian Zone (Mayo-Danay Division, Far North Cameroon)“. International Journal of Advanced Remote Sensing and GIS 10, Nr. 1 (17.06.2021): 3473–91. http://dx.doi.org/10.23953/cloud.ijarsg.501.
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In general, living close to a river is advantage, but there is always of flooding risk, that recurrence in recent decades provokes serious material damage and loss of life. Thus, in order to protect environmental health, economic viability and human activity zones of Mayo-Danay, a careful study of components of natural environment, mainly soil, has proved essential. Clearly, use of GIS in management of natural disasters is most relevant method, designed on integration, Multicriteria Analysis (MCA) and spatial data. Thus, Digital Elevation Model is obtained by manual digitization of contour lines, in order to define the large pedological sets on which wells have been opened, profiles described, soil samples taken and analyzed in laboratory. Main results reveal that soils are sandy to clayey, with neutral and basic pH (7 to 8), high CEC and low organic matter. While, quartz is predominant, associated with smectites, illites, feldspars and iron oxyhydroxides. Updated soil map shows five soil units (1) vertisols with hydromorphic characters (26%), (2) tropical ferruginous soils (32%), (3) less evolved hydromorphic soils (15%), (4) halomorphic vertic soils (9%), and (5) hydromorphic vertic soils (18%). It is an excellent tool for work and research, that responds to agronomic and development problems. It is therefore an excellent tool for work and research, which responds to agronomic and development problems. The multi-criteria spatial analysis establishes hazard and vulnerability, crossing of which gives of flood risk areas map, according to hazard level, very high (12%), high (16%), moderate (14%), low (30%) and very low (28%) risks. For this purpose, it emerges that rainfall is relatively low (700 mm/year), but falls very abruptly during short periods, at high intensity with flows exceeding the infiltration capacities. Morphology of low-slope "yayrés" (280 m) (2‰) is bordered by high landscape (500 to 1400 m) that prevent flow of many rivers that converge into plain. Sandy soils dominated by quartz favor fast rising in water table, while very clayey soils governed by 2/1 clayey (smectites) whose behavior induce waterproofing and intense surface runoff that generate flooding. Evidently, land use change leads to transformation of natural spaces into agricultural and urban environments, which makes soils more compact and impermeable, favorable to flooding. Keywords Soil; Flood risks; Mapping; Mayo-Danay Division; Spatial data DOI: https://doi.org/10.23953/cloud.ijarsg.501
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Mahadi, Muhammad R., Ying Chen und Pieter Botha. „Instrumented Soil Bin for Testing Soil-Engaging Tools“. Applied Engineering in Agriculture 33, Nr. 3 (2017): 357–66. http://dx.doi.org/10.13031/aea.11874.
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Abstract. An indoor soil bin was developed in this study for testing soil-engaging tools. The design criteria included that the soil bin had to be compact, well controlled in its operational parameters, instrumented to measure soil cutting forces, and be safe to operate. The test tool could travel at any specific speed, up to 8 km h-1. A compact dynamometer was designed for the soil bin for measuring soil cutting forces in three directions. The calibration results of the dynamometer showed a linear relationship between the loads and the output voltages, with coefficients of determination of 0.99. The cross sensitivity between the directions was from 0.31% to 4.7%. The soil bin and the dynamometer were tested using a disc operated at three values of tilt angle of 0°, 10°, and 20°. The test results showed that the soil bin allowed precise control of the tool travel speed and working depth in the designed ranges. Forces of the disc had an increase in vertical and lateral forces, and decrease in draft force, with the increase in tilt angle. These trends are in line with other studies in the literature. The results proved the full-functioning status of the soil bin and the dynamometer. Keywords: Calibration, Design, Disc, Dynamometer, Soil bin, Test, Tilt angle.
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Kucharski, J., und J. Wyszkowska. „Inter-relationship between number of microorganisms and spring barley yield and degree of soil contamination with copper“. Plant, Soil and Environment 50, No. 6 (10.12.2011): 243–49. http://dx.doi.org/10.17221/4028-pse.
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The purpose of the study has been to determine the effect of soil contamination with copper on the modification of microbial number and spring barley yield and to assess whether spores of actinomycete Streptomyces odorifer and Streptomyces viridis were used for detoxification of copper polluted soils. The tests were performed in a pot experiment, which was conducted on two types of soil: Eutric Cambisol soil derived from light loamy sand and Eutric Cambisol soil derived from light loam. The results showed that number of all analysed microorganisms was significantly negatively correlated with a degree of soil contamination by copper, but positively correlated with the yield of spring barley. In general, the adverse impact of copper on the development of oligotrophic bacteria and their spores, eutrophic bacteria and their spores as well as actinomycetes and fungi was much weaker in more compact (light loam) than lighter (light loamy sand) soil. Copper had a strong toxic effect on spring barley and significantly inhibits the growth and development of the plants. An inoculum containing spores of Streptomyces viridis and Streptomyces odorifer did not alleviate the negative response of spring barley to copper contamination of soil, although it had positive influence on the growth of some microorganisms.
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Parker, Robert T. „Monitoring Soil Strength Conditions Resulting from Mechanical Harvesting in Volcanic Ash Soils of Central Oregon“. Western Journal of Applied Forestry 22, Nr. 4 (01.10.2007): 261–68. http://dx.doi.org/10.1093/wjaf/22.4.261.
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Abstract The volcanic ash-derived soils in central Oregon have been shown to compact readily and remain compacted for long periods of time, leading to significant reductions in ponderosa pine (Pinus ponderosa, Laws) tree growth. Concerns over the potential for long-term reduction in forest site productivity on private forestlands in the region led to the development of a soil monitoring process for precisely quantifying changes to the soil environment caused by mechanical harvesting in second-growth ponderosa pine stands. For this study, soil strength was used as an indicator for soil compaction. A recording penetrometer was used to measure soil strength to a depth of 2 ft at intervals of 5 ft along transects established across harvest units. At each sampling point, the number of machine passes was estimated as no disturbance, 1–2 machine passes, 3–5 machine passes, or main skid trails. The penetrometer data were then summarized for each of the four categories. The results show a rapid rise in soil strength with increasing machine activity and 40–70% of the harvest units compacted in a single harvest cycle. The process proved to be an unbiased and practical system for quantifying the extent and intensity of soil strength conditions resulting from mechanical harvesting.
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LIU, XING, ZHENMING YANG, LINGLING GAO, WUYAN XIANG, BO ZHANG, ZHONGLEI XIE und JIANGFENG YOU. „COMPARISON OF THE CHARACTERISTICS OF ARTIFICIAL GINSENG BED SOILS IN RELATION TO THE INCIDENCE OF GINSENG RED SKIN DISEASE“. Experimental Agriculture 50, Nr. 1 (27.06.2013): 59–71. http://dx.doi.org/10.1017/s0014479713000367.
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SUMMARYRed skin disease seriously limits the production and quality of Panax ginseng (ginseng) in the Changbai Mountains of Northeast China, which is the main origin of ginseng. To cultivate ginseng, the albic and humus horizons of albic luvisols are artificially mixed to produce ginseng bed soils. To clarify the relationship between red skin disease and soil characteristics, red skin disease indices were calculated from six plots located on a ginseng farm. Ginseng roots were analysed for aluminium (Al) content. Soils from the ginseng beds were sampled at three depths for the evaluation of physico-chemical parameters. Al fractionation from the soil solid fraction was analysed using atomic absorption spectrophotometry. Ginseng plants exhibiting larger red skin areas accumulated higher concentrations of Al in the epidermis and in the fibrous roots. Ginseng bed soils in the six plots were acidic with pHH2O values ranging from 4.0 to 5.0. Plots exhibiting higher red skin disease indices also had higher bulk densities, moisture contents and nitrate concentrations. They also contained higher concentrations of exchangeable Al, NaOH-extracted Al and ammonium oxalate-oxalic-extracted Al in the bed soils. The Al saturation and molar ratio of base cations to Al were above 20% and below 10, respectively, in the two plots with the highest disease indices. Compact soils with higher moisture, nitrate concentrations and active Al species may increase the incidence of ginseng red skin disease.
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Silva, Dilma Daniela, und Richard C. Beeson. „A Large-volume Rhizotron for Evaluating Root Growth Under Natural-like Soil Moisture Conditions“. HortScience 46, Nr. 12 (Dezember 2011): 1677–82. http://dx.doi.org/10.21273/hortsci.46.12.1677.
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An experimental system that allows imposition of precise irrigation treatments with easy and quick observations of unrestricted root growth of woody plants was developed. The system mimics natural deep soil percolation and facilitates rapid assessment of large root populations. It was designed to be relatively inexpensive to build so that treatments could be efficiently replicated. Designs for this star-shaped rhizotron were developed and evaluated with the goals of: 1) optimizing volume and shape for minimal physical restriction and use with mature woody plants; 2) developing a drainage system comparable to natural deep soils; and 3) facilitating ease, accuracy, and duration of data acquisition. The final design allows efficient root observation, uses a wick-type drainage system to provide a near-uniform profile of soil moisture, and is easily manageable for precise long-term data acquisition. This rhizotron has eight independent viewing/sampling windows and holds 0.16 m3 of soil. An associated lightweight and compact camera positioning frame was developed that facilitates acquisition of digital photographs of soil profiles for time-series assessment of morphological and architectural parameters.
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Lakshmikantha, M. R., Pere C. Prat und Alberto Ledesma. „Experimental evidence of size effect in soil cracking“. Canadian Geotechnical Journal 49, Nr. 3 (März 2012): 264–84. http://dx.doi.org/10.1139/t11-102.
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Results of an experimental study on the formation of crack patterns during drying of a soil paste are presented. The objective is to ascertain whether fracture mechanics plays a significant role in explaining the process of formation and propagation of cracks during drying of soils due to changes in environmental conditions such as temperature and humidity. The experiments consist of five geometrically similar rectangular specimens in two series of different thicknesses, subjected to drying conditions in an environment-controlled laboratory. Cracking initiates shortly before the soil reaches a near-solid quasi-brittle consistency. Although crack initiation can be explained by classical soil mechanics effective stress theory, crack development and propagation appear to be energy-driven. The results prove that cracking stress does depend on the size of the specimen and suggest that fracture mechanics might be applicable to soil cracking, at least in the context of the present research. Fracture toughness of the soil used was determined using compact tension tests at different water contents. Its tensile strength was also determined by a direct method for two natural specific weights (bulk density) and two dry specific weights with different water contents.
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Navidi, Mehdi, Abbas Banj Shafiei, Ahmad Alijanpour, Sajad Pirsa, Hesam Ahmady-Birgani, Manuel Esteban Lucas-Borja und Demetrio Antonio Zema. „Effects of Post-Fire Mulching with Loranthus europaeus Jacq. on Surface Runoff and Rainsplash Erosion in a Semi-Arid Pine Forest“. Resources 12, Nr. 3 (21.02.2023): 31. http://dx.doi.org/10.3390/resources12030031.
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To avoid flooding and erosion hazards, post-fire management actions are essential in Mediterranean forests after severe wildfires. In this regard, mulching is the most common action but some mulch materials, such as straw, may lead to adverse impacts in burned forests. The use of yellow mistletoe fruits (Loranthus europaeus Jacq., hereafter “LE”) for the production of biodegradable mulch and its effectiveness in post-fire hydrology have never been studied. To fill this gap, this study has evaluated surface runoff and rainsplash erosion in a pine forest in Central Eastern Spain burned by a wildfire and mulched by a mixture of LE fruits and straw (with or without adding clay particles) using a portable rainfall simulator. Compared to untreated sites, runoff increased in burned and mulched soils (by 13.6% for the mixture without clay and by 17.2% when clay was added, in the latter case significantly). This increase was mainly due to the compact layer created by mulch application on the soil surface. However, the peak flow and the time to peak were lower in mulched soils (on average by 32.7% and 60.5%, significantly only for the mulch mixture without clay), thus indicating that, in these soils, peak runoff takes longer and its maximum value is lower compared to untreated sites. Soil erosion noticeably and significantly decreased (up to 97%) in mulched areas in comparison to untreated sites without significant differences between the two mixtures. Overall, this study indicates to land managers that soil mulching with a mixture of Loranthus europaeus Jacq. and straw is an effective post-fire management action to reduce the soil erosion risk after a wildfire.
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Guo, Yongfa, Jing Cao, Huafeng Sun, Wenyun Ding, Guofeng Hua, Wei Wei und Siyang Huang. „Effect of Ultrafine Cement (UFC) on the Corrosion Resistance of Cement Soil in Peat Soil Environment“. Materials 16, Nr. 16 (08.08.2023): 5520. http://dx.doi.org/10.3390/ma16165520.
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Many peat soils are distributed around plateau lakes, and the reinforcement of peat soils with high organic matter content by ordinary cement cannot meet the actual engineering requirements. In order to obtain better mechanical properties and durability of the reinforcement, this experiment prepared peat soil by mixing humic acid reagent into the alluvial clay soil with low organic matter content. The cement soil samples were prepared by adding cement and ultrafine cement (UFC) by stirring method; the samples were then soaked in fulvic acid solution to simulate the cement soil in the peat soil environment. Using the unconfined compressive strength (UCS) test, scanning electron microscope (SEM) test, and pores and cracks analysis system (PCAS) test, the effect of UFC content change on cement soil’s humic acid erosion resistance was explored, and the optimal UFC content range was sought. The results of the UCS test show that with an increase in immersion time, the strength curves of cement soil samples gradually increase to the peak strength and then decrease. Significant differences in the time correspond to the peak strength, and the overall presentation is two processes: the strength enhancement stage and the corrosion stage of the sample. The incorporation of UFC makes the cement soil in the peat soil environment exhibit excellent corrosion resistance, and the optimal UFC content is 10%. The results of the SEM and PCAS tests show that the microstructure of cement soil after immersion time exceeds 90 days, increases with an increase in immersion time, and its structural connectivity gradually weakens. The excellent characteristics of UFC particles, such as small particle size, narrow particle size distribution, fast hydration reaction rate, high hydration degree, and many hydration products, weakened the adverse effects of humic acid on the cement soil structure to a certain extent. Therefore, although the number of macropores increases, they are not connected. It still presents a relatively compact honeycomb overall structure, which correlates well with the UCS results.
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Venkatarama Reddy, B. V., und M. S. Latha. „Retrieving clay minerals from stabilised soil compacts“. Applied Clay Science 101 (November 2014): 362–68. http://dx.doi.org/10.1016/j.clay.2014.08.027.
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Bloch, Jonathan, Bernadette Johnson, Nathan Newbury, Jack Germaine, Harry Hemond und Joe Sinfield. „Field Test of a Novel Microlaser-Based Probe for in situ Fluorescence Sensing of Soil Contamination“. Applied Spectroscopy 52, Nr. 10 (Oktober 1998): 1299–304. http://dx.doi.org/10.1366/0003702981942807.
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The use of lasers to induce fluorescence in environmental contaminants such as fuels offers the potential for real-time, in situ chemical characterization in a variety of environmental media. This paper describes the first reported use of a passively Q-switched, fiber-coupled microlaser in situ for fuel-contamination characterization in subsurface soil. A 266 nm microlaser-based probe mounted in a cone penetrometer was tested at an area contaminated by both aviation and heating fuels. By examining the spectral and temporal fluorescence characteristics as the probe was pushed into soil, we identified BTEX compounds, as well as moderate-weight and heavy aromatic hydrocarbons, and were able to map an underground contamination plume in real time. Specifically, BTEX compounds were identified by their unique fluorescence signatures (wavelengths less than approximately 315 nm and lifetimes less than 7 to 10 ns) and by comparison with extensive laboratory studies of BTEX and fuel-contaminated soils. These tests demonstrate that the microlaser-based probe offers the potential for in situ, real-time characterization of soils and groundwater in a compact, inexpensive package.
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Ambrušec, Ljubica, Ranko Gantner, Goran Herman, Vesna Gantner, Krešimir Bošnjak und Gordana Bukvić. „Green manuring with crimson clover as an alternative to mineral fertilization in maize production“. Holistic approach to environment 11, Nr. 4 (07.09.2021): 102–8. http://dx.doi.org/10.33765/thate.11.4.1.
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Role of mineral fertilizers is to complement the soils’ indigenous supply of minerals for crop plants nutrition. Among the mineral nutrients, nitrogen is generally considered as the most yield-contributing. Obtaining nitrogen from legumes is potentially more sustainable than from industrial sources. Crimson clover (Trifolium incarnatum L.) has long been appreciated as cover crop grown for green manuring due to its capability for binding the atmospheric nitrogen into plant-available form. Green manuring effects of crimson clover for succeeding maize crop were tested in 2019 year on two locations of Northeastern Croatia differing in soil texture: 1) on the site A where the soil was compact and dominated by clay and 2) on the site B where the soil was loose and dominated by loam. The research was conducted in a year with favourable rainfall during maize vegetation. Results have shown that green manuring with crimson clover for maize as the main crop delivered somewhat lower maize grain and aboveground mass yields than the conventional full-dose mineral fertilization on deep fertile soils around Osijek (Northeastern Croatia). When compared to conventional agronomy, green manuring was associated with additional agrotechnical operations required for crimson clover cover crop establishment and its herbage incorporation into soil prior to seeding main maize crop. Research should be continued in more different environments (year × location combinations) in order to produce reliable evaluation of crimson clover’s green manuring services.
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Venkatarama Reddy, B. V., und M. S. Latha. „Influence of soil grading on the characteristics of cement stabilised soil compacts“. Materials and Structures 47, Nr. 10 (19.07.2013): 1633–45. http://dx.doi.org/10.1617/s11527-013-0142-1.
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Broersma, K., J. A. Robertson und D. S. Chanasyk. „The effects of diverse cropping systems on aggregation of a Luvisolic soil in the Peace River region“. Canadian Journal of Soil Science 77, Nr. 2 (01.05.1997): 323–29. http://dx.doi.org/10.4141/s96-013.
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Aggregate distribution and stability of surface soil were determined for different cropping systems of a Luvisolic soil in the Peace River region of Alberta. Gray Luvisolic soils have inherent problems that include weak platy structured surface horizons which are underlain by compact sub-soils. The cropping systems consisted of (i) continuous barley (CB) (Hordeum vulgare L.); (ii) barley/forage (BF), 3 yr of barley followed by 3 yr of forage (mixture of bromegrass [Bromus inermis Leyss] and red clover [Trifolium pratense L.]); (iii) continuous grass (CG) (bromegrass); and (iv) continuous legume (CL) (red clover). The barley/forage rotation consisted of two phases, the barley phase (BF) and forage phase (BF). Each phase was present every year. Aggregate separation by dry-sieving with a rotary sieve indicated that the CL cropping system had fewer large aggregates and more small aggregates than the other cropping systems. The CG, BF and CB cropping systems had more larger aggregates and were similar to each other. Wet-sieving, by contrast, resulted in the CG cropping system having greater amounts of large aggregates while the CL, BF phases, and CB cropping systems were similar with more smaller aggregates. Wet-sieving of the different aggregate size fractions from the rotary dry-sieve indicated that the cropping system aggregate stability was in the order of: CG > CL > BF ≥ BF ≥ CB. The stability of the BF cropping system was greater than that of the BF as it had recently come out of the BF phase (3 yr of forage production). Aggregate stability for the cropping system soils was consistent among the evaluation method of wet-sieving and the McCalla water-drop method. Inclusion of forage crops are important in maintaining or improving soil structure of Luvisolic surface horizons. Key words: Luvisolic soil, cropping systems, aggregation, aggregate stability, Peace River region
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Liu, Shuai, Jinsheng Zhan und Xiaoli Wang. „Influence of composition of curing agent and sand ratio of engineering excavated soil on mechanical properties of fluidized solidified soil“. Materials Science-Poland 41, Nr. 1 (01.03.2023): 57–67. http://dx.doi.org/10.2478/msp-2023-0007.
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Abstract With the continuous expansion of the urban scale, the development of engineering construction has been accelerated. In this process, excavated engineered soils produced in the construction process are facing the problem of difficult treatment. In this work, the influence of the composition ratio of different curing agents on the strength of fluidized solidified soil was studied. It was found that when the proportion of fly ash and quicklime in the curing agent was 1:1, and the percentage of the curing agent in the soil was 15%, the 28 days unconfined compressive strength of fluidized solidified soil reached the maximum value. When the composition and content of the curing agent and the slump of the fluidized solidified soil remained unchanged, the strength and water stability of the fluidized solidified soil increased with the increase of the sand ratio of the excavated engineered soil. X-ray powder diffraction (XRD) and scanning electron microscopy (SEM) showed that with the increase of sand in the soil ratio, more needle-like ettringite crystals were produced in the fluidized solidified soil, which were more compact, had fewer voids, and had higher overall compactness. The carbon emissions of the prepared fluidized solidified soil and the common backfill materials were calculated, and it proved that the carbon emissions of the fluidized solidified soil were the lowest. Therefore, this work offers a new method for resource utilization of excavated soil and provides a carbon emission reference for green low-carbon building materials. Finally, it was recommended to choose engineered excavation soil with high sand content to obtain higher performance from fluidized solidified soil.