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Journal articles on the topic 'Soil particle density'
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1
Loch, RJ, and CJ Rosewell. "Laboratory methods for measurement of soil erodibilities (K-factors) for the universal soil loss equation." Soil Research 30, no. 2 (1992): 233. http://dx.doi.org/10.1071/sr9920233.
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This paper reports a comparison of several methods for estimating the K (erodibility) factor for the Universal Soil Loss Equation (USLE) on the basis of laboratory measurements of soil properties. All methods used the nomograph of Wischmeier et al. (J. Soil Water Cons., 1971, 26, 189-93) to calculate K on the basis of laboratory data, but the data inputs ranged from: dispersed particle sizes as originally used in the nomograph; non-dispersed particle size, measured after shaking in water; and equivalent sand size distributions, based on settling velocity distributions of particles (aggregates and sand grains) at the soil surface under rain. A further method tested with the use of aggregated particle sizes resulting from rainfall wetting was a correction of the calculated K based on average density of wet sediment >0.100 mm diameter. Estimated K factors were compared with K factors derived from field measurements of soil loss for five soils. Use of dispersed particle sizes gave poor prediction of field K values for the three clay soils, and size distributions measured after rainfall wetting gave poor predictions of field K values for the four soils that had sediment of low density. Predictions of K from the use of non-dispersed particle sizes, and from the use of particle size at the soil surface under rain combined with a correction for sediment density were good for three soils, reasonable for one, and little different to that from the nomograph for the remaining soil. These latter two methods gave similar results, and were successful in predicting field values of K. As well, both methods appear to be sensitive to effects of cropping management on soil structure and erodibility. Either method could be used, depending on laboratory resources available and possible other uses of the data obtained. Simpler methods for measuring size distributions after rainfall wetting and for estimating sediment density are suggested.
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Sufardi, S., T. Arabia, K. Khairullah, and I. Apriani. "Particle size distribution and clay minerals in dryland soils of Aceh Besar, Indonesia." IOP Conference Series: Earth and Environmental Science 922, no. 1 (2021): 012013. http://dx.doi.org/10.1088/1755-1315/922/1/012013.
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Abstract Soil particle size distribution is a fundamental physical property affecting other soil properties. This research aims to determine the distribution of soil particles and the composition of clay minerals on each layer of the horizon in four soil profiles (P1, P2, P3, and P4) with different parent materials in the dryland of Aceh Besar district which includes Entisols Jantho, Andisols Saree, Inceptisols Cucum, and Oxisols Lembah Seulawah. Particle size distribution (or texture) and bulk density (BD) were analyzed in the laboratory. Soil structure and consistency were observed directly in the field. The type of clay minerals was identified by X-ray diffraction, while Fe, Al, and Si-oxide were extracted by dithionite-citrate solution. The results shown that the particle size distribution and the physical properties of dryland soils of Aceh Besar vary between soil orders. Andisols Saree has better physical properties than the physical properties of other soils and low bulk density. The Al, Fe, and Si fractions and clay mineral composition in the soil profiles also vary considerably between soil orders. The Andisols are dominated by allophane minerals (amorphous fractions) while Entisols, Inceptisols and Oxisols consist of mixed minerals of feldspar, quartz, halloysite, goethite, and other clay minerals. These soil orders have some soil physical constraints i.e. high soil bulk density, low water holding capacity and poor soil structures. Improvements in the physical properties of the soil on Aceh Besar dryland are indispensable to improve the quality of the soil.
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Jia, Mincai, and Yiming Zheng. "A prediction model of maximum dry density of over coarse-grained soil." IOP Conference Series: Earth and Environmental Science 1330, no. 1 (2024): 012050. http://dx.doi.org/10.1088/1755-1315/1330/1/012050.
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Abstract The control of maximum dry density is an important issue for over coarse-grained soil. A theoretical formula of the maximum dry density for over coarse-grained soil was derived, which is related to the maximum dry density of the original soil, particle density, and mass fraction of giant particles in the mixed soil. Maximum dry densities of seven groups of mixed soil were calculated by the discrete element method (DEM) and theoretical formula, and the results showed that the maximum dry densities obtained from the DEM were always lower than the results calculated by theoretical formula, and the difference increased with the increase in giant particle proportion. The volume growth coefficient was proposed to describe the increase in pore volume of the mixed soil caused by the embedding of giant particles, and the maximum dry density model for over coarse-grained soil was proposed. The results showed that the model fitted well to the DEM results, validating the high rationality and reliability.
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Addison, B., M. Boyes, and P. L. Singleton. "Differences in particle density between field-moist and oven-dry samples from Allophanic Soils." Soil Research 37, no. 5 (1999): 965. http://dx.doi.org/10.1071/sr98116.
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Particle density is used to calculate total soil porosity and related measurements such as macroporosity and water storage capacity. Methods for measuring particle density often advise using dry samples. This study measured particle density by displacement of water using both field-moist and oven-dry samples from 4 New Zealand Allophanic Soils. There were significant differences in particle density between the 2 methods. Oven-dry samples under-estimated particle density by up to 0.33 Mg/m 3 and as a result, calculations of porosity were under-estimated by up to 0.05 m 3/m 3 . Under-estimation of porosity can result in incorrect interpretation of a soil's aeration and water holding status. Allophanic Soils are known to undergo irreversible physical changes on drying and it is likely that these changes caused the difference in measurements. Only field-moist samples should be used to determine particle density of Allophanic Soils to ensure accurate calculation of soil porosity.
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de Jesus Duarte, Sara, Bruno Glaser, and Carlos Pellegrino Cerri. "Effect of Biochar Particle Size on Physical, Hydrological and Chemical Properties of Loamy and Sandy Tropical Soils." Agronomy 9, no. 4 (2019): 165. http://dx.doi.org/10.3390/agronomy9040165.
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The application of biochar is promising for improving the physical, chemical and hydrological properties of soil. However, there are few studies regarding the influence of biochar particle size. This study was conducted to evaluate the effect of biochar size on the physical, chemical and hydrological properties in sandy and loamy tropical soils. For this purpose, an incubation experiment was conducted in the laboratory with eight treatments (control (only soil), two soils (loamy and sandy soil), and three biochar sizes (<0.15 mm; 0.15–2 mm and >2 mm)). Analyses of water content, bulk density, total porosity, pore size distribution, total carbon (TC) and total N (TN) were performed after 1 year of soil–biochar-interactions in the laboratory. The smaller particle size <0.15 mm increased water retention in both soils, particularly in the loamy soil. Bulk density slightly decreased, especially in the loamy soil when biochar > 2 mm and in the sandy soil with the addition of 0.15–2 mm biochar. Porosity increased in both soils with the addition of biochar in the range of 0.15–2 mm. Smaller biochar particles shifted pore size distribution to increased macro and mesoporosity in both soils. Total carbon content increased mainly in sandy soil compared to control treatment; the highest carbon amount was obtained in the biochar size 0.15–2 mm in loamy soil and <0.15 mm in sandy soil, while the TN content and C:N ratio increased slightly with a reduction of the biochar particle size in both soils. These results demonstrate that biochar particle size is crucial for water retention, water availability, pore size distribution, and C sequestration.
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Meskini-Vishkaee, F., M. H. Mohammadi, and M. Vanclooster. "Predicting the soil moisture retention curve, from soil particle size distribution and bulk density data using a packing density scaling factor." Hydrology and Earth System Sciences 18, no. 10 (2014): 4053–63. http://dx.doi.org/10.5194/hess-18-4053-2014.
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Abstract. A substantial number of models predicting the soil moisture characteristic curve (SMC) from particle size distribution (PSD) data underestimate the dry range of the SMC especially in soils with high clay and organic matter contents. In this study, we applied a continuous form of the PSD model to predict the SMC, and subsequently we developed a physically based scaling approach to reduce the model's bias at the dry range of the SMC. The soil particle packing density was considered as a metric of soil structure and used to define a soil particle packing scaling factor. This factor was subsequently integrated in the conceptual SMC prediction model. The model was tested on 82 soils, selected from the UNSODA database. The results show that the scaling approach properly estimates the SMC for all soil samples. In comparison to the original conceptual SMC model without scaling, the scaling approach improves the model estimations on average by 30%. Improvements were particularly significant for the fine- and medium-textured soils. Since the scaling approach is parsimonious and does not rely on additional empirical parameters, we conclude that this approach may be used for estimating SMC at the larger field scale from basic soil data.
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Rashmi Jain and A.K. Shrivastava. "Estimation of Soil Density, Porosity, Water Holding Capacity, and Moisture content of Arpa River Based Soil." International Research Journal on Advanced Engineering Hub (IRJAEH) 1, no. 01 (2023): 32–37. http://dx.doi.org/10.47392/irjaeh.2023.005.
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Soil physics plays a pivotal role in the present scenario. It is directly related to the economic growth of India. An attempt has been made in this paper to research as well as estimate some important physical properties of the Arpa River-based soil of Bilaspur, Chhattisgarh. For soil analysis, it is required to calculate different Chemical, Physical, and Electrical properties, and Geographical. The physical properties of soil are influenced by the size, arrangement, composition, and properties of soil particles. Six distinct soil samples are taken for the current study from different places in the Arpa River. Many physical properties of these six soil samples are examined, including bulk density, particle density, porosity, water holding capacity, soil moisture content, and so on. which can be determined by different standard methods and mathematical formulas. The bulk density in this study ranges from 1.1332 to 1.466 g/cm3. The range of particle density is 2.0449 to 2.5252 g/cm3. After the determination of Bulk density and particle density, the percentage of solid space and pore space (Porosity) was evaluated. Water holding capacity varies from 8% to 48%. The moisture content of six samples varies from 25.92% to 48.14%. Based on physico-chemical parameters it is easy to find the type and amount of fertilizers for particular crops.
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Vopravil, Jan, Pavel Formánek, and Tomáš Khel. "Comparison of the physical properties of soils belonging to different reference soil groups." Soil and Water Research 16, No. 1 (2020): 29–38. http://dx.doi.org/10.17221/31/2020-swr.
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Soil properties can be influenced by long-term agricultural management practices as described in pedological literature. In this study, selected physical properties (particle density and bulk density, total porosity, maximum capillary water capacity, minimum air capacity, field capacity, permanent wilting point and available water capacity) of topsoils from different reference soil groups (Cambisols, Luvisols, Fluvisols, Chernozems and Phaeozems, Leptosols, Stagnosols and Gleysols) were sampled and analysed in the years 2016–2017. The topsoil samples were taken from points of so-called S (specific) soil pits to be sampled from the General Soil Survey of Agricultural Soils (GSSAS) which was accomplished in the years 1961–1970. In addition, some of the properties were also compared with those measured during the GSSAS. Recognising the properties, only the particle density, the maximum capillary water capacity, the permanent wilting point and the available water capacity of the topsoil of the individual soil groups were statistically significantly (P &lt; 0.05) different. A comparison of the physical properties with those analysed after more than 40 years was performed, the bulk density increased and the total porosity decreased in the topsoil of the major part of the studied soil groups.
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N., L. Edwin-Wosu, and E. Nkang A. "Studying the Physico-edaphic and Hydraulic Conductivity of Phytoremediated Spent Oil Polluted Habitat." International Journal of Plant & Soil Science 17, no. 1 (2017): 1–13. https://doi.org/10.9734/IJPSS/2017/32948.
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Several studies have recorded effect of spent lubricant oil pollution on soil properties. This study aims at evaluating the ecology of waste oil pollution and the impact of phytoremediation on soil hydraulic conductivity vis-à-vis some edaphic properties using three leguminous plants; with the objectives of performing field and laboratory study of such contamination and impact of phytoremediation on such properties as soil texture and structure, particle density, bulk density, porosity, organic matter content and total hydrocarbon content and hydraulic conductivity. Using classical and conventional methods to assess the performance of these plant species, result showed a trajectory influence across pollution levels on the soil edaphic properties culminating to decrease in hydraulic conductivity. With the impact of phytoapplication <em>P. pterocarpum </em>had greater particle size (87.73%) of sand, particle density of 2.61 g/cm<sup>3</sup> with significant difference (<em>P=0.05</em>) than <em>C. retusa</em> and <em>L. leucocephala</em> treated soils. A significantly (<em>P=0.05</em>) lower bulk density (0.83 g/cm<sup>3</sup>), increased porosity (68%) and reduced organic matter content (2.65%) were recorded in <em>P. pterocarpum </em>treated soil. Total hydrocarbon reduction (1.8 mg/g) content and its equivalent potency of greater removal and reduction (0.43 mg/g), high efficiency of 55% and 34.40 bioaccumulation quotient and a lower crusting hazard (24.63%) of sealing with increased hydraulic conductivity (5.73 ml/s) were recorded in<em> P. pterocarpum </em>treated soil. By the foregoing potency <em>P. pterocarpum </em>could be suggested as a good biological measure in integrated environmental remediation programmes.
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Kotorová, Dana, Jana Jakubová, and Ladislav Kováč. "Dependence of Heavy Soil Transport Function on Soil Profile Depth." Agriculture (Polnohospodárstvo) 57, no. 2 (2011): 45–52. http://dx.doi.org/10.2478/v10207-011-0005-0.
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Dependence of Heavy Soil Transport Function on Soil Profile DepthThe aim of this work was to quantify the effect of soil profile depth on the transport function of heavy soils. Treatments were carried out between 2006 and 2009 in Milhostov. Two variants were examined : the (conventional soil tillage and long-time no-tilled variant). Soil samples were taken in spring and autumn from soil profile depth of 0.00-0.60 m from each 0.10 m. For further evaluation the average values were used. Particle size composition, bulk density, total porosity and maximum capillary capacity were determined. Content of clay particles in soil profile was in interval 59.64-68.53% and such soils are characterised in the range from clay-loamy soil to clayey soil. The bulk density increased with the depth of soil profile and its values reached 1 184-1 646 kg m-3. The total porosity was in range 37.68-55.17% and it decreased with the depth of soil profile. The values of maximum capillary capacity were characterised for heavy soils with high content of clay particles. The depth had statistically significant effect on all observed parameters. In average, on both variants the bulk density was higher than 1 400 kg m-3, the total porosity was lower than 47% and the content of clay was higher than 30%, pointing to the possibility of soil compaction, which will result in reduced transport function of heavy soils.
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Jing, Xiaoyuan, Liuchang Su, Yisen Wang, Miao Yu, and Xuguang Xing. "How Do Microplastics Affect Physical Properties of Silt Loam Soil under Wetting–Drying Cycles?" Agronomy 13, no. 3 (2023): 844. http://dx.doi.org/10.3390/agronomy13030844.
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Soil physical properties are the main factors that influence soil fertility and directly affect the soil structure and water storage capacity. Microplastics (MPs), which have caused growing concern with respect to soil pollution, have readily been detected in cultivated soils. However, the current data regarding the effects of MPs on soil physical properties during wetting–drying cycles remain insufficient. Therefore, we aimed to explore the effects of different MP particle sizes (25, 150, 550, and 1000 μm) and concentrations (1, 3, and 5%, w/w) on soil physical properties under indoor wetting–drying cycle conditions. The addition of MPs was found to significantly reduce the saturated hydraulic conductivity and water holding capacity of soil, while impacting the bulk density, water content, and soil particle composition. The properties of soils treated with different MP particle sizes and concentrations exhibited significant differences, while the effects of wetting–drying cycles overshadowed those of MPs. Under the wetting–drying cycles, the saturated hydraulic conductivity and initial soil water content decreased significantly, the soil water holding capacity increased, and the soil bulk density showed a trend of increasing first and then decreasing. We attribute the change to a combination of the microplastics, soil particles, and frequent wetting–drying cycles. In this type of incubation, the constant change in the soil pore proportion results in a change in water and soil porosity, and finally alters the soil physical properties. These findings demonstrate that MP accumulation, together with dynamic environmental conditions, significantly impacts the physical properties of farm land soil.
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Shi, Lina, Yuanchun Peng, Xingyu Hou, and Yun Zhang. "Distribution of Pyrogenic Carbon in the Soil of a Cold Temperate Coniferous Forest 13 Years After a Severe Wildfire." Land 14, no. 4 (2025): 851. https://doi.org/10.3390/land14040851.
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Biomass combustion produces between 50 and 270 Tg of pyrogenic carbon (PyC) annually. PyC is extremely highly stable, making it a significant component of the global carbon sink. We established four plots at different slope positions within a cold temperate coniferous forest that experienced a severe fire in 2010. We mechanically divided the soil into three depths. The PyC content and density of the collected soil samples and four particle sizes were analyzed. Thirteen years after the fire, the PyC content in the soil on the upper slope was low (13.5–14.2 g·kg−1). In terms of PyC density, the valley and the upper slopes presented lower values. The PyC content in the 0~10 cm layer (14.0–16.7 g·kg−1) is only slightly more than 20% higher than that in the two deeper layers, whereas its density is 1.5~2 times more than that in the other layers. Our findings indicate that PyC is predominantly concentrated in coarse sand and silt particles. The spatial pattern of PyC is significantly influenced by the differentiation in topography, soil layer depth, and particle size. These distribution patterns strongly show that PyC plays a key role in forest ecosystem cycles affected by fire. PyC distribution in particle sizes particularly shows connections with specific soil components. There is a synergistic effect between the topographic redistribution (slope position differences), vertical stratification (soil depth), and particle size sorting of PyC. This determines the retention effect of stable carbon in fire-disturbed forest ecosystem soils, thereby influencing the soil carbon cycle.
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Redding, T. E., and K. J. Devito. "Particle densities of wetland soils in northern Alberta, Canada." Canadian Journal of Soil Science 86, no. 1 (2006): 57–60. http://dx.doi.org/10.4141/s05-061.
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Particle density is a fundamental soil physical property, yet values of soil and organic matter particle density (ρs and ρo) vary widely in the literature. We measured particle density of organic soils from five wetland types, and from exposed sediments of drying ponds, in northern Alberta, Canada. Our measured values of organic soil and pond sediment ρs varied widely (1.43–2.39 Mg m-3); however, calculated values of ρo (1.34–1.52 Mg m-3) were relatively constant. The measured and calculated ρs and ρo values were similar to those obtained in published studies using similar methods, but were higher than the values provided in many reference texts. Given the relatively small variability in ρo, the use of mean values of ρo, combined with measurements of organic matter loss-on-ignition, shows promise as a simple method for obtaining reliable estimates of ρs across a range of wetland types. Key words: Particle density, peat, organic matter, wetland soil, loss-on-ignition
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Dahal, Bhim Kumar, and Jun Jie Zheng. "Comprehensive analysis of cement-stabilised dredged marine soil: Evaluating physical, microstructural, and mechanical characteristics." Ministry of Science and Technology, Vietnam 66, no. 2 (2024): 52–60. http://dx.doi.org/10.31276/vjste.66(2).52-60.
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This study evaluates the index, microstructural, and mechanical behaviour of cement-stabilised soft soil. The marine soil dredged from Hangzhou is taken for the study. Different percentages of ordinary Portland cement (OPC)by dry mass were added to the soils during reconstitution, i.e., 5, 10, 15, and 20%. The reconstituted samples were analysed in the laboratory to determine basic properties such as moisture content, void ratio, density, specific gravity, consistency limits, and particle size distribution. The microstructures of the reconstituted samples were also evaluated through scanning electron microscopy. Results inferred a significant impact on the physical properties of the soil. An increase in cement content increases the consistency limits. Additionally, the specific gravity, plasticity index, and density of the treated soil initially decreased but increased upon further addition of cement content. The microstructure of the soil transformed from a dispersed to a flocculated structure, with larger and denser particles. The change in microstructure was also evident in the particle size distribution, with an increase in cement content leading to larger size particles. Finally, the unconfined compression test conducted on the reconstituted soil indicates a substantial enhancement in strength with higher cement content and prolonged curing periods.
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Liu, Xiao-Yang, Chang-Ming Wang, Hai-Liang Liu, and Di Wu. "An Experimental Investigation of the Mechanical Behavior and Particle Crushing Characteristic of Volcanic Soil." Materials 15, no. 15 (2022): 5423. http://dx.doi.org/10.3390/ma15155423.
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Volcanic soil is a special soil that is well-known for its distinctive texture, vesicular nature, and particle fragility. The fragility characteristic of volcanic soil is the main factor affecting the foundation stability in road engineering. This study focuses on the mechanical properties and particle crushing characteristics of volcanic soil retrieved from Northeast China. A series of triaxial consolidation and drainage shear tests are performed on volcanic coarse-grained soil (5 mm > d > 0.075 mm) under different initial relative densities and effective confining pressures. Results show the peak friction angle of volcanic soil significantly decreases with the increase of confining pressure. The particle crushing degree of volcanic soil increases with the increase of confining pressure, particle size, and relative density. The relative breakage rate of the same particle size group has a good linear relationship with a fractal dimension. Moreover, for the same particle size, the relationship between plastic work and relative breakage rate can be fitted by a power function, which is not significantly affected by relative density or effective confining pressure. From an engineering view, in addition to increasing the compaction degree of volcanic soil, volcanic soil with fine particles used as a roadbed filler can significantly reduce the deformation of the roadbed and improve the bearing capacity of the foundation.
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Zhang, L. M., Y. Xu, R. Q. Huang, and D. S. Chang. "Particle flow and segregation in a giant landslide event triggered by the 2008 Wenchuan earthquake, Sichuan, China." Natural Hazards and Earth System Sciences 11, no. 4 (2011): 1153–62. http://dx.doi.org/10.5194/nhess-11-1153-2011.
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Abstract. During the 12 May 2008 Wenchuan earthquake, a large landslide of approximately 30 million m3 occurred at Donghekou with a particle run-out distance of over 2000 m. This paper presents fascinating particle flow and segregation characteristics in the landslide process found through field investigation of changes in the soil particle size, density, and fabric along the particle movement paths. The soil particles experienced projection, long-distance flying, sliding, and rolling. Trajectory segregation, inverse grading, and particle crushing were found in the landslide event, which contributed to the heterogeneity of the soil deposits. In the initial deposition area, particles with larger diameters appeared to have flown longer. Materials from different sources mixed, forming more uniform debris. In the run-out area, the particle flow tended to cause large particles to travel further. However, particle disintegration and crushing led to more small particles along the movement paths and the observed characteristic flow distances of very large particles did not increase with the particle diameter, which is different from observations of an idealized granular mass flow.
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Botková, Natália, Justína Vitková, Peter Šurda, et al. "Impact of biochar particle size and feedstock type on hydro-physical properties of sandy soil." Journal of Hydrology and Hydromechanics 71, no. 4 (2023): 345–55. http://dx.doi.org/10.2478/johh-2023-0030.
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Abstract Biochar, as an organic amendment, could positively change soil properties, especially soil with low organic matter and/or poor structure. Biochar application in sandy soil with low organic matter could be an effective tool for improving hydro-physical parameters of the soil economically and ecologically as well. The effect on bulk density, particle density, porosity, saturated hydraulic conductivity and available water content for plants of two biochar types applied at three different particle sizes in a sandy soil was examined. The results confirmed previous studies, showing decreased bulk density, particle density and saturated hydraulic conductivity and partially increased available water content for plants and porosity. Both biochar type and particle size affected the studied soil hydro-physical parameters. After analysis and comparison of two different types of biochar and three particle sizes, the most effective treatment for sandy soil was proved by the biochar produced from willow with the smallest particle size (<125 µm).
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Saha, Uma, Fatima Rukshana, Md. Shahabuddin, Syed Md. Anwaruzzaman, Md. Matiar Rahman Mondol, and Nayan Chandra Ghosh. "EFFECT OF PARTICLE SHAPE ON ITS OTHER GRANULAR SOIL PROPERTIES." Technical Journal - River Research Institute 13, no. 1 (2016): 53–64. https://doi.org/10.5281/zenodo.12641754.
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Particle shape is usually determined for the coarse grained soil. It is one of the most important soil-grain properties. The other important soil grain properties are angle of shearing resistance of sands, gradation, denseness i.e. density index, uniformity of gradation etc. The mentioned factors have some inter related impacts. The strength of soil is an utmost important factor among all soil engineering parameters and is determined finding out the angle of shearing resistance. In this paper, particle shapes and particle sizes are determined minutely in the laboratory and its in-situ test such as SPT values and corresponding density indices; others are collected from the report of soil mechanics division of geotechnical research directorate of River Research Institute (RRI). In order to find out the other granular properties by determining particle shapes an attempt has been made to predict the strength of grain soils through conventional means. The study finds that SPT values as well as strength of granular soils increases with depth. It is also found that particle sizes increase with depth and their SPT also increases with depth. The shapes are found sub-rounded with medium spherecity while the depths are increased. The study result will help find out the denseness and uniformity of gradation of relevant soils in any location of Bangladesh. So, it will be an opportunity for a design engineer who may expedite the construction works by determining the particle shape of granular soil. Moreover, a design engineer may predict the granular soil strength and other grain properties through determining the particle shape of coarse grained soils. The findings of the present study are expected to help predict granular soil strength and other grain properties of any location by determining particle shape.
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Carter, M. R., D. A. Angers, E. G. Gregorich, and M. A. Bolinder. "Characterizing organic matter retention for surface soils in eastern Canada using density and particle size fractions." Canadian Journal of Soil Science 83, no. 1 (2003): 11–23. http://dx.doi.org/10.4141/s01-087.
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Interest in the storage of organic matter in terrestrial ecosystems has identified a need to better understand the accumulation and retention of organic C and N in soil. The proportions of C and N associated with clay and silt particles (i.e., “capacity level”), water-stable macro-aggregates (WSA) (>250 µm), particulate (POM) (>53 µm), and light fraction (LF) organic matter, for the 0- to 10-cm soil depth, were assessed at 14 agricultural experimental sites established on Gleysolic, Podzolic, Luvisolic , and Brunisolic soils in the cool, humid region of eastern Canada. Organic C and N in the clay plus silt particles was at or near the capacity level for soils with clay plus silt content < 40%. For soils with >60% clay plus silt, the degree of saturation was 65–70% indicating a potential for further organic C and N retention. The mean proportion of C and N found in the POM was 22 and 27%, whil e the LF organic matter contained 7 and 5% C and N, respectively. Mean soil WSA content, determined by wet-sieving analysis, was 42% for air-dry soil and 54% for wetted soil, and was significantly (P < 0.05) related to both soil clay plus silt (r = 0.65) and organic C (r = 0.54). Water-stable macro-aggregate C content was proportional to soil organic C (r = 0.96, P < 0.01). At four of the sites, where soil C and N were influenced by management, an increasing level of soil organic C and N was associated with both the clay plus silt particles and the POM fraction until the former was saturated. Once the capacity level was saturated, further organic C and N accumulation was associated with the POM fraction. Although stabilized organic C and N in soil exists as a continuum, both soil particle and particulate fractions provided a practical approach to monitor, quantify and differentiate the storage and retention of C and N in soils of eastern Canada. Key words: Soil organic matter, clay plus silt associated organic C and N, size fractions, particulate organic matter, light fraction organic matter, water-stable macro-aggregates, organic amendments, Canada
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Dong, Chen, and Mahdi M. Disfani. "Impact of Gap-Graded Soil Geometrical Characteristics on Soil Response to Suffusion." Geotechnics 4, no. 1 (2024): 337–49. http://dx.doi.org/10.3390/geotechnics4010018.
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The phenomenon of fine particle migration through the voids of the granule skeleton under the seepage force is called suffusion. Relative density, original fine particle content, and gap ratio are thought to play vital roles in the suffusion process. This paper investigates the effect of geometrical characteristics (i.e., original fine particle content, gap ratio, and relative density) on soil structure and mechanical performance (i.e., small strain shear modulus) using the bender element method technique. The small strain shear modulus (G0) is used as a mechanical parameter to evaluate the shear stress transmission of the soil structure along with the erosion process. The comparison between erosion percentage and vertical strain change suggests the alteration in soil fabric after soil erosion. The G0 monitoring results show that packings with a higher original fine particle content have a lower G0 value, whereas the gap ratio and relative density present a positive relationship with G0.
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Hossain, Md Anwar, S. M. Shahinul Islam, and Md Mahmodol Hasan. "Changes in Soil Properties with Combined Use of Probiotic Cultures and Organic Farming Practices in Degraded Soils of Bangladesh." Sustainability 15, no. 5 (2023): 4430. http://dx.doi.org/10.3390/su15054430.
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A shift in agricultural management from chemical to organic practices is expected to reduce environmental hazards and improve soil health and productivity in Bangladesh. To increase knowledge of the impact of probiotic cultures and organic farming practices on the physical and chemical properties of Bangladeshi soils, an investigation was carried out during the period from July 2016 to June 2019. The study included nine treatments using combinations of probiotic cultures and organic farming practices. The experiment used a randomized complete block design with three replicates. The probiotic cultures and organic practices increased soil moisture content, porosity and silt particle and decreased bulk density, particle density and sand particles. The organic matter content (11.66%), nutrient availability and electrical conductivity (8.96%) increased with the organic practices, while pH of the soil decreased. The largest significant change in the physical properties (p ≤ 0.05) was in the compost + vermicompost + green manuring treatment, while for chemical properties this was in the poultry manure + vermicompost + green manuring. These findings suggest that the above combinations of organic treatments provide most benefit to the soils of the practices considered.
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Fahmi, Arifin, Ani Susilawati, and Ahmad Rachman. "Influence of Height Waterlogging on Soil Physical Properties of Potential and Actual Acid Sulphate Soils." JOURNAL OF TROPICAL SOILS 19, no. 2 (2015): 67. http://dx.doi.org/10.5400/jts.2014.v19i2.67-73.
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Water management is main factor that determines the successful of rice cultivation in acid sulphate soil. Soil waterlogging determines the direction and rate of chemical, geochemical and biological reaction in the soil, indirectly these reactions may influence to the changes of soil psycal properties during soil waterlogging process. The experiment was aimed to study the changes of two type of acid sulphate soils physical properties during rice straw decomposition processes. The research was conducted in the greenhouse consisting of the three treatment factors using the completely randomized design with three replications. The first factor was soil type: potential acid sulphate soil (PASS) and actual acid sulphate soil (AASS). The second factor was height of water waterlogging: 0.5-1.0 cm (muddy water–level condition) and 4.0 cm from above the soil surface (waterlogged). The third factor was organic matter type: rice straw (RS), purun tikus (Eleocharis dulcis) (PT) and mixed of RS and PT (MX). Soil physical properties such as aggregate stability, total soil porosity, soil permeability, soil particle density and bulk density were observed at the end of experiment (vegetative maximum stage). The results showed that acid sulphate soil type had large effect on soil physicl properties, soil waterlogging decreased aggregate stability, soil particle density and bulk density both of soil type.Keywords : Acid sulphate soils, soil physical properties, and waterlogging [How to Cite: Arifin F, A Susilawati and A Rachman. 2014. Influence of Height Waterlogging on Soil Physical Properties of Potential and Actual Acid Sulphate Soils. J Trop Soils 19(2): 77-83. Doi: 10.5400/jts.2014.19.2.77]
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Vera-Sabando, Cristhian Fernando, Laura Germania Mendoza-Bravo, and Saskia Valeria Guillén-Mendoza. "Evaluación de las propiedades edáficas y su relación con el manejo del suelo en cultivos de pitahaya." Horizon Nexus Journal 3, no. 2 (2025): 117–37. https://doi.org/10.70881/hnj/v3/n2/63.
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Soil management has a direct impact on its physical properties and crop productivity. In the case of pitahaya (Hylocereus spp.), mulch could be essential for conserving soil moisture and structure. This study analyzed how mulch management in pitahaya cultivation affects soil properties at different particle sizes (sand, silt, and clay). Two plots were evaluated: one with mulch and the other with traditional management, assessing soil moisture, bulk density, and particle size at different depths. Statistical analysis was performed using ANOVA and the Tukey test at 5%. The results revealed that soils managed with mulch showed higher moisture in the surface layer (0–5 cm) and lower bulk density compared to unmulched soils. This suggests that mulch reduces evaporation and helps improve soil structure. Mulch management is suggested as a strategy to optimize soil quality in pitahaya crops, thus promoting its productivity and sustainability.
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Xiao, Peng, Hanlong Liu, Armin W. Stuedlein, T. Matthew Evans, and Yang Xiao. "Effect of relative density and biocementation on cyclic response of calcareous sand." Canadian Geotechnical Journal 56, no. 12 (2019): 1849–62. http://dx.doi.org/10.1139/cgj-2018-0573.
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Microbial-induced calcium carbonate precipitation (MICP) represents a promising approach to improve the geotechnical engineering properties of soils through the precipitation of calcium carbonate (CaCO3) at soil particle contacts and soil particle surfaces. An extensive experimental study was undertaken to investigate the influence of initial relative density on the efficiency of the biocementation process, the reduction of liquefaction susceptibility, and the cyclic response in biocemented calcareous soils. For this purpose, stress-controlled undrained cyclic triaxial shear (CTS) tests were carried out on untreated and MICP-treated calcareous sand specimens for different initial relative densities and magnitudes of biocementation. Improvement in the cyclic response was quantified and compared in terms of excess pore pressure generation, evolution of axial strains, and the number of cycles to liquefaction. The cyclic experiments show that MICP treatment can change the liquefaction failure mechanism from flow failure to cyclic mobility and can significantly change the excess pore pressure generation response of initially loose specimens. Scanning electron microscope (SEM) images indicate the CaCO3 crystals alter the characteristics of the sand particles and confirm the physical change in soil fabric that impacts the dynamic behavior and liquefaction resistance of MICP-treated specimens. Furthermore, the effect of biocementation was contrasted against the effect of relative density alone, and MICP treatment was shown to exhibit greater efficiency in improving the cyclic resistance than densification.
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Johnson, Neema, Narendra Swaroop, Tarence Thomas, and Satya Ranjan Mohanta. "Assessment of Physical Properties of Soil from Different Villages of Devikulam Block of Idukki District of Kerala, India." International Journal of Environment and Climate Change 13, no. 9 (2023): 547–51. http://dx.doi.org/10.9734/ijecc/2023/v13i92269.
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Assessment of Physical properties of soil from Different villages in the Devikulam block of idukki district of Kerala was carried out in 2022-23. The study was conducted with the objective of evaluating the physical characteristics of soil, over various soil depths in the Devikulam block. Nine sampling locations were selected for the study. A total of 27 soil samples were taken at depths of 0-15 cm, 15-30 cm and 30-45 cm respectively. The result indicated that the soil of Marayoor, Kanthaloor and Keezhanthoor villages were sandy clay loam in texture. The bulk density and particle density did not vary much with increasing soil depth. The particle density remained constant because the total amount or chemical composition of the soil mineral particles remains unaltered. Water Retaining Capacity of these villages was found to be good. The pore space was found to be higher than water retaining capacity in all the villages. For sustainable soil use and agricultural Production, the physical characteristics of the soil are crucial. The movement of air and water/dissolved chemicals through soil, as well as conditions affecting germination, root growth, and erosion processes.
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Jayakrishnan, Veena, Beena K S, Unni Kartha G, and J. S. Vinod. "Effect of Hammer Impact on Wave Propagation Characteristics of Soil." International Journal of Geotechnical Earthquake Engineering 10, no. 2 (2019): 50–68. http://dx.doi.org/10.4018/ijgee.2019070104.
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Wave transmission through soil due to dynamic load causes many problems to civil engineers craving safe construction. In this article, a laboratory model study is conducted to investigate the vibration propagation characteristics of soil due to the falling masses at different depths. Different types of impact, soils, and relative densities are used to study the characteristics of vibration transmission and energy dissipation. It was found that the increase in relative density and decrease in the depth causes an increase in the Peak Particle Acceleration and wave velocity of soil. An attempt is also made to determine the dynamic properties of soil using wave velocity ratios. A simple laboratory arrangement discussed here can be used to predict the wave propagation in soil reasonably and can determine its elastic constants. From the studies, it was revealed that the wave travel in soil and the peak particle acceleration depends on many factors like density, particle gradation, impact energy, etc.
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Li, Shijin, Adrian R. Russell, and David Muir Wood. "Influence of particle-size distribution homogeneity on shearing of soils subjected to internal erosion." Canadian Geotechnical Journal 57, no. 11 (2020): 1684–94. http://dx.doi.org/10.1139/cgj-2019-0273.
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Internal erosion (suffusion) is caused by water seeping through the matrix of coarse soil and progressively transporting out fine particles. The mechanical strength and stress–strain behavior of soils within water-retaining structures may be affected by internal erosion. Some researchers have set out to conduct triaxial erosion tests to study the mechanical consequences of erosion. Prior to conducting a triaxial test they subject a soil sample, which has an initially homogeneous particle-size distribution and density throughout, to erosion by causing water to enter one end of a sample and wash fine particles out the other. The erosion and movement of particles causes heterogeneous particle-size distributions to develop along the sample length. In this paper, a new soil sample formation procedure is presented that results in homogeneous particle-size distributions along the length of an eroded sample. Triaxial tests are conducted on homogeneous samples formed using the new procedure as well as heterogeneous samples created by the more commonly used approach. Results show that samples with homogeneous post-erosion particle-size distributions exhibit slightly higher peak deviator stresses than those that were heterogeneous. The results highlight the importance of ensuring homogeneity of post-erosion particle-size distributions when assessing the mechanical consequences of erosion. Forming samples using the new procedure enables the sample’s response to triaxial loading to be interpreted against a measure of its initially homogenous state.
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Cui, Kai, and Hui Huang. "Soil-Water Characteristic Curve for Unsaturated Mixed-Soil Considering Physical Form and Dry Density Effect." Applied Mechanics and Materials 353-356 (August 2013): 785–89. http://dx.doi.org/10.4028/www.scientific.net/amm.353-356.785.
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A test is conducted to get the soil-water characteristic curve for three typical composite unsaturated soils in west Sichuan, considering its physical composition, physical form and dry density. Test data shows that the variation of physical composition, particle size and dry density can result in great change of soil-water characteristic curve. The bigger the dry density is and the more hydrophilic mineral it has, the more gently the soil-water characteristic curve is, and the higher dry density soil sample has higher residual moisture content. In addition, matrix suction decreased with less clay content and more content under the same water content. For three typical composite unsaturated soils, the change of soil-water characteristic curve resulting from variation of dry density is less in bigger water content, and is more in lower water content.
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Kang, Qinrong, Yuandi Xia, Xiaoshuang Li, Weizhong Zhang, and Chaoran Feng. "Study on the Effect of Moisture Content and Dry Density on Shear Strength of Silty Clay Based on Direct Shear Test." Advances in Civil Engineering 2022 (April 18, 2022): 1–9. http://dx.doi.org/10.1155/2022/2213363.
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Silty clay is a kind of clay with more powder group than sand group, and its shear strength is mainly influenced by moisture content, dry density, and particle gradation. In this study, the deformation characteristics of silty clay under different normal pressure conditions were investigated from the perspective of control variables through indoor direct shear experiments. The results of the study show that with the same guaranteed moisture content, it can be seen from the fitted curves that with the increase of dry density, the arrangement of soil particles becomes more compact, the cementation between soil particles is strengthened, the shear strength increases, the occlusal friction increases due to the change of arrangement between soil particles, and the angle of internal friction and cohesion are relatively larger; in addition, when the dry density is the same, with the increase of moisture content, the soil becomes softer, and the form of water in the soil particles changes. In addition, when the dry density is the same, as the moisture content increases, the soil becomes softer, the presence of water between the soil particles changes, resulting in the weakening of the occlusion between the soil particles, the shear strength decreases, and the cohesion and the angle of internal friction relatively decrease.
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Zhou, Wei Guang, Yu Long Bao, and Hong Bin Zhou. "Research on Soil-Water Characteristic Curve of Unsaturated Mixed-Soil in West Sichuan." Applied Mechanics and Materials 353-356 (August 2013): 996–1000. http://dx.doi.org/10.4028/www.scientific.net/amm.353-356.996.
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A series of tests are conducted to get the physical composition, physical form and the soil-water characteristic curve in different dry density of three typical composite unsaturated soils in west Sichuan. Test data shows that the variation of physical composition, particle size and dry density can result in great change of soil-water characteristic curve. The bigger the dry density is, the more hydrophilic mineral the soil has, the more gentle the soil-water characteristic curve is, and the higher its residual moisture content is. In addition, under the same water content, matrix suction decreases with less clay content and more content. For the three typical composite unsaturated soils, with relatively bigger water content, the change of soil-water characteristic curve resulting from variation of dry density is less, but with the water content getting smaller, the change becomes clearer.
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Sarcinelli, Tathiane Santi, Carlos Ernesto Gonçalves Reynaud Schaefer, Elpídio Inácio Fernandes Filho, Reginaldo Gonçalves Mafia, and Andreza Viana Neri. "Soil modification by termites in a sandy-soil vegetation in the Brazilian Atlantic rain forest." Journal of Tropical Ecology 29, no. 5 (2013): 439–48. http://dx.doi.org/10.1017/s0266467413000497.
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Abstract:Termites play a critical role in the regulation of soil processes, for example, water retention, nutrient cycling, and the formation and maintenance of soil structure. There is a consensus that mound-building termites modify physical and chemical soil properties in clay soils, but there is limited investigation into their influence for sandy soils in the Brazilian Atlantic rain forest. We tested the hypotheses that the termitosphere effectively improves properties of sandy soil, and that the role of termite soil particle selection is of greater importance in soils with higher sand concentration and lower nutrient status. The work was conducted in three vegetation physiognomies: woodland, savanna and grassland. In the woodland physiognomy we sampled in the border and in the interior, totalling four studied areas. We described a soil profile and collected five samples of termitaria and surface soil in each area. Also, in three 100-m2 plots allotted in each area, termite-mound density and volume were estimated, and termites were collected for taxonomic identification. Soil samples were submitted to physical and chemical analysis, and regression models were employed to analyse termite particle selection ability in different soil conditions. In most areas, the concentrations of nutrients, organic carbon and clay-size particles were significantly higher in termite mounds than in surface soils. On a weight basis, termite mounds had up to 32 times more nutrients, 12 times more organic carbon, and five times more clay than surrounding soils, however, aluminium toxicity was lower in termite mounds. Regression models demonstrated that the role of termites in soil particle selection is of greater ecological importance with decreasing soil nutrient status and increasing sand concentration. Therefore, termites greatly improve soil properties, representing truly ecosystem engineers in sandy soils, with an average soil turnover by mound-building activity reaching 10.5 m3 ha−1.
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Kou, Wen-qi, Jian-guang Bai, Hai-jun Li, and Qing-hong Liu. "Study on compaction characteristics and discrete element simulation for rubber particle-loess mixed soil." Insight - Civil Engineering 6, no. 1 (2023): 618. http://dx.doi.org/10.18282/ice.v6i1.618.
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The rapid surge in traffic volume in China has resulted in a substantial accumulation of waste tires. By harnessing the lightweight and deformable characteristics of tire rubber particles, they are combined with soil to form rubber particle-loess mixed soil, which is progressively being embraced in civil engineering as a pivotal approach towards attaining green and sustainable development. In this study, waste tire rubber particles were integrated into loess to generate rubber particle-loess mixed soil, and compaction tests were conducted to investigate its compaction characteristics. Furthermore, PFC3D (Particle Flow Code 3D) was utilized for simulating the bearing ratio test of rubber particle-loess mixed soil, thereby validating the feasibility of numerical simulation for calculating CBR (California bearing ratio) values and exploring the relationship between micromechanical characteristics and macroscopic characteristics of such mixtures. The findings indicate that the maximum dry density of rubber particle-loess mixed soil significantly decreases with an increasing content of rubber particles. The utilization of PFC3D discrete element software proves efficacious in examining the bearing capacity of this mixture. Notably, when 20 mesh rubber particles constitute 20% by volume, the CBR value reaches its pinnacle and exhibits optimal bearing capacity. From a micromechanical perspective, the variation in internal porosity of rubber particle-loess mixed soil is positively associated with changes in macroscopic optimal water content, and negatively associated with changes in macroscopic CBR value. incorporating rubber particles enhances resistance against external forces while diminishing deformation within loess. This study provides a guidance for the efficient utilization of waste tires and the improvement of loess’s characteristics.
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Kou, Wen-qi, Jian-guang Bai, Hai-jun Li, and Qing-hong Liu. "Study on compaction characteristics and discrete element simulation for rubber particle-loess mixed soil." Insight - Civil Engineering 7, no. 1 (2024): 618. http://dx.doi.org/10.18282/ice.v7i1.618.
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The rapid surge in traffic volume in China has resulted in a substantial accumulation of waste tires. By harnessing the lightweight and deformable characteristics of tire rubber particles, they are combined with soil to form rubber particle-loess mixed soil, which is progressively being embraced in civil engineering as a pivotal approach towards attaining green and sustainable development. In this study, waste tire rubber particles were integrated into loess to generate rubber particle-loess mixed soil, and compaction tests were conducted to investigate its compaction characteristics. Furthermore, PFC3D (Particle Flow Code 3D) was utilized for simulating the bearing ratio test of rubber particle-loess mixed soil, thereby validating the feasibility of numerical simulation for calculating CBR (California bearing ratio) values and exploring the relationship between micromechanical characteristics and macroscopic characteristics of such mixtures. The findings indicate that the maximum dry density of rubber particle-loess mixed soil significantly decreases with an increasing content of rubber particles. The utilization of PFC3D discrete element software proves efficacious in examining the bearing capacity of this mixture. Notably, when 20 mesh rubber particles constitute 20% by volume, the CBR value reaches its pinnacle and exhibits optimal bearing capacity. From a micromechanical perspective, the variation in internal porosity of rubber particle-loess mixed soil is positively associated with changes in macroscopic optimal water content, and negatively associated with changes in macroscopic CBR value. incorporating rubber particles enhances resistance against external forces while diminishing deformation within loess. This study provides a guidance for the efficient utilization of waste tires and the improvement of loess’s characteristics.
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Sani, Sufiyanu, Aliyu Abdulkadir, Salihu A. Hmad Pantami, Mahmud Sani, Ali Muhammad Amin, and Muhammad Yakubu Abdullahi. "Spatial Variability and Mapping of Selected Soil Physical Properties under Continuous Cultivation." Turkish Journal of Agriculture - Food Science and Technology 11, no. 4 (2023): 719–29. http://dx.doi.org/10.24925/turjaf.v11i4.719-729.5733.
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Assessments of Soil physical properties and estimation of their associated variability are essential for making site-specific decisions on soil and crop management This study examined the spatial variability of soil hydro-physical properties and variance structure at Sector F1 of the Jibia Irrigation project Katsina State, Nigeria. Grid sampling technique was used to obtain one hundred and forty-four (144) soil samples from 206 ha of land using Google earth. The grids were drawn using Google earth software at intervals of 150 m x 150 m. Surface soil samples (0 - 20 cm) were collected at grid intersection points. The collected soil samples were air-dried and passed through a 2mm sieve, and analyzed using standard laboratory procedures for physical parameters. The ArcGIS software package 10.3 was used to model the variance structure of Sand, Silt, Clay, Bulk density, Particle density, Percent total porosity and Organic Matter (OM). Results obtained revealed that the coefficient of variation (CV) ranged from 5.724% in particle density to 109% in clay. The Semivariogram showed that the range of spatial dependence varied from 0.342m for (Dry mean weight diameter) to 9.3m (Organic matter) for all measured soil properties. High Spatial dependency ratios were observed for Bulk density, Sand, Silt and clay contents. Particle density exhibited moderate spatial dependency (Nugget to sill ratio 0.25 – 0.75%). Wet Mean weight diameter and organic matter content have a weak spatial dependency. The results indicated that sandy textured soils dominated the greater part of the study area with low to moderate organic matter content. The soils being sandy-dominated has a high infiltration rate and low ability to retain moisture and nutrients were observed as the major characteristics of the soil of the study area.
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Dalal, RC, and RJ Mayer. "Long term trends in fertility of soils under continuous cultivation and cereal cropping in southern Queensland .VI. Loss of total nitrogen from different particle size and density fractions." Soil Research 25, no. 1 (1987): 83. http://dx.doi.org/10.1071/sr9870083.
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The dynamics of total N in particle-size and density fractions of six major soils which have been used for cereal cropping for 20-70 years were studied in order to identify the labile organic matter fractions in soil. For virgin soils, no single particle-size was consistently enriched in N as compared with the whole soil. The clay fraction contained the largest proportion (53% overall) of total N. Silt-size and sand-size N fractions accounted for 26% and 21% of total N, respectively. Upon cultivation, the sand-size fraction lost most of its N (as much as 89% in Langlands-Logie soil). However, N losses also occurred from silt-size and clay-size fractions in most soils. Changes in C : N ratios of different particle-size fractions upon cultivation were not consistent in all soils, possibly because of the transfer of organic C and N among these fractions. Therefore, the separation of labile organic matter fractions from the whole soil based upon particle-size may not be successful in all soils. On the other hand, the density fractionation of soil into a light fraction (<2 Mg m-3) containing relatively labile organic matter (76-96% lost upon cultivation) and a heavy fraction (>2 Mg m-3) containing less labile organic matter appears to be more successful in most soils. It is suggested that the cultural practices that enhance the amount of light fraction would increase the rate of nutrient cycling through microbial biomass and may increase the overall availability of nutrients in soil.
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Abdullah Fouad Ibrahim Al Bayaty and Amera Ismail Hussain Koshnow. "Study Some Physical Properties For Soil In Tuz khormatu North Of Iraq." Tikrit Journal of Pure Science 21, no. 7 (2023): 129–42. http://dx.doi.org/10.25130/tjps.v21i7.1120.
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In this research, a study of some physical properties for the soil of tuz khormatu have been achieved of evaluating these properties represented by physical properties for five locations with different depths. The results of Particle size analysis have showed that the soil of study area is not homogeneous and it contains a wide range of particle sizes and difference in particle sizes ratio that form the soil. The coarse soil is dominating in the study area with varying ratios with less ratios of fine soils. The coarse and fine sedimentations comes successively because of the successive flood waves. whereas most results of Atterburg limits showed that the fine soil has moderately plastic. and The specific gravity values for fine soil has ranged between (2.59-2.88) whereas The specific gravity for coarse soil (2.64-2.66).and the compaction results have showed that the maximum dry density for fine soil has ranged (1.845-2.006)g/cm3 and the optimum moisture content (10.33-12.3)% while the maximum dry density of coarse soil is (2.285-2.306) g/cm3 and the optimum moisture content (4.725-5.275)%. And the results of (C.B.R) for two samples of coarse soil (73-120)% at (95%)of compaction
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Schjønning, P., R. A. McBride, T. Keller, and P. B. Obour. "Predicting soil particle density from clay and soil organic matter contents." Geoderma 286 (January 2017): 83–87. http://dx.doi.org/10.1016/j.geoderma.2016.10.020.
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Liu, P., R. P. Chen, X. Kang, and H. Lei. "Effects of particle morphology on pore structure and soil water retention behaviors of granular soils." Géotechnique Letters 13, no. 1 (2023): 1–18. http://dx.doi.org/10.1680/jgele.22.00060.
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Given grain size distribution (GSD) and relative density, the SWRC of granular soils can be straightforwardly predicted. However, the evolution of SWRC with different particle morphologies under the same GSD is still unclear. To solve this fundamental problem, herein, four sand analogs with different particle shapes under the same GSD were produced by 3D printing. The SWRCs and the pore structure at mesoscale were synergetically measured by using nuclear magnetic resonance (NMR) technology and HYPROP water potential meter. The relationship between particle morphology and SWRC was quantitatively analyzed, and the soil pore structure evolution under different particle morphology was clearly observed. Compared with round particle shape soils, soils with the same GSD but higher degree of angularity were found to have a subtle higher air entry value at a given relative density, even though the global void ratio is larger. NMR results indicate the pore structure of specimens with different particle morphology is similar. The pore volume is increased with angularity while the maximum pore throat shows an opposite trend. The difference in maximum pore throat is the fundamental reason for the variation in air entry value, highlighting the importance of particle morphology on soil water retention behaviors.
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Gyamfi, C., J. M. Ndambuki, and R. W. Salim. "Spatial Variability Modeling of Soil Erodibility Index in Relation to Some Soil Properties at Field Scale." Environment and Natural Resources Research 6, no. 2 (2016): 16. http://dx.doi.org/10.5539/enrr.v6n2p16.
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<p class="1Body">Soil erosion is a major land degradation issue affecting various facets of human lives. To curtail soil erosion occurrence requires understanding of soil properties and how they influence soil erosion. To this end, the soil erodibility index which gives an indication of the susceptibility of soils to erosion was examined. In particular, we aimed to determine soil erodibility index at field scale and establish relationships that exist between selected soil properties and soil erodibility index. It was hypothesized that for soil erodibility index to vary spatially, then the existing soil properties should have varying spatial structure. Hundred disturbed and 100 undisturbed soil samples were collected from a 7.3 ha gridded area. The samples were analyzed for particle size distribution, bulk density, particle density, organic matter content and porosity. All soil analyses were conducted following standard procedures. Data were analyzed statistically and geostatistically on the basis of semivariograms. Sandy clay loam was the dominant soil texture in the studied field. Results indicate significant negative relationship between<strong> </strong>sand content, bulk density, particle density and organic matter with soil erodibility index. Silt correlated significantly with a positive relation with soil erodibility. Estimated erodibility for the sampled field ranged from 0.019 t.ha.hr/ha.MJ.mmto 0.055 t.ha.hr/ha.MJ.mm. The order of dominance of erodibility ranges were 0.038-0.042 t.ha.hr/ha.MJ.mm&gt; 0. 036-0.08 t.ha.hr/ha.MJ.mm&gt; 0.032-0.036 t.ha.hr/ha.MJ.mm&gt; 0.019-0.032 t.ha.hr/ha.MJ.mm&gt; 0.042-0.055 t.ha.hr/ha.MJ.mm. Regression analysis revealed silt to be the most significant variable that influences soil erodibility. The best regression of soil properties on soil erodibility index gave an R<sup>2 </sup>of 0.90. A comparison of the regression equation with other studies indicated good performance of the equation developed.</p>
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Petingco, Marvin C., Mark E. Casada, Ronaldo G. Maghirang, Oladiran O. Fasina, Zhengpu Chen, and R. P. Kingsly Ambrose. "Influence of Particle Shape and Contact Parameters on DEM-Simulated Bulk Density of Wheat." Transactions of the ASABE 63, no. 6 (2020): 1657–72. http://dx.doi.org/10.13031/trans.13718.
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HighlightsDecreasing aspect ratio and improved geometrical smoothness of particles increased DEM-predicted bulk density of wheat.Among the three particle models, the 5-sphere ellipsoidal particle was the best option to represent wheat particles, as indicated by the simulated bulk densities that best agreed with the experiments.Among the contact parameters, the wheat-to-wheat coefficient of static friction and wheat-surface coefficient of rolling friction had the greatest influence on simulated bulk density.Abstract. The discrete element method (DEM) has been shown to be an effective tool for simulating the behavior of granular material. The accuracy of simulations depends highly on the contact models, particle physical parameters, and contact parameters used. The objectives of this study were to determine the influence of particle shape and contact parameters on simulated wheat bulk density and to develop an effective wheat particle model for DEM simulation of filling a container using EDEM software. Grain characteristics, including single-kernel weight, kernel density, kernel dimensions, aspect ratio, and bulk density, were determined for three size fractions of wheat used in the experiments. Three categories of particle models (5-sphere pseudo-ellipsoidal, 7-sphere pseudo-ellipsoidal, and ASG-generated) with varying aspect ratios and geometrical smoothness were tested in the simulations. Results showed that DEM-simulated bulk density of wheat increased with lower aspect ratio and greater geometrical smoothness of pseudo-ellipsoidal particles (7-sphere versus 5-sphere). Increasing the number of spheres to approximately 30 for better representation of wheat kernel shape, using ASG-generated particles, did not reproduce the trend of greater simulated bulk density seen in the experiments. Among the six contact parameters, the wheat-wheat coefficient of static friction and wheat-surface coefficient of rolling friction had the most significant effect on the simulated bulk density. Among the different sets of particle models, the 5-sphere pseudo-ellipsoidal particles, having aspect ratios close to that of wheat kernels in each size fraction, were found to be the most practical and appropriate particle model for use in DEM simulation of wheat bulk density. This study contributes to better understanding of the influence of particle shape and contact parameters on DEM-simulated bulk density and provides a calibrated particle model for use in simulating container filling operations. Keywords: Bulk density, Contact parameters, DEM, Particle shape, Wheat.
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de Araújo, Francisca Pereira, Edson Cavalcanti Silva Filho, João Sammy Nery de Souza, Josy Anteveli Osajima, and Marcelo Barbosa Furtini. "A Study of the Chemical and Physical Characteristics of the Soils from the South of Piauí for Soil-Cement Brick Production." Materials Science Forum 869 (August 2016): 112–15. http://dx.doi.org/10.4028/www.scientific.net/msf.869.112.
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Soil-cement bricks are good examples of environmentally friendly products. This brick is the combination of soil with compacted cement with no combustion in its production. In this work the physical chemical characteristics of the soil from Piaui for producing this material were investigated. Samples of the soil were collected in three potteries from the county of Bom Jesus and pH analysis were carried out, as well as the rate of organic matter, texture, particle density, limits of liquidity and plasticity rates. The results have shown that the soils have acid tones (pH 5,49 a 6,11), which can be neutralized by adding cement, and organic matter percentages up to 1%. The samples have shown predominantly clay-rich textures with adequate plasticity limits, however, values of liquidity limits and particle density above recommended. Altogether, these soils tend to present viability concerning soil-cement brick production, provided that corrections with additives are made in order to minimize this effect.
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Owonubi, Ayodele. "Evaluation of Physical Characteristics of Soils Derived from Basement Complex Rocks of the Jos Plateau." UMYU Scientifica 1, no. 2 (2022): 39–45. http://dx.doi.org/10.56919/usci.1222.005.
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The physical characteristics of soils to a large extent influences soil productivity. The objective of this study therefore is to evaluate the physical characteristics of soils derived from basement complex rocks of the Jos Plateau. According to the methodology outlined in the Soil Survey manual, the stratification of the study region into three geologic units—granite gneiss, biotite granite, and migmatite—was the first step in the soil research process. Additionally, soil samples were collected from genetic strata and soil profile pits were dug in each of these geologic units. Following standard procedure soils were analyzed for color, particles size distribution, structure, and bulk density. Results indicated that physical soil characteristics over the geologic units studied were in most cases similar. However significant differences were observed in particle size distribution in the A-horizons. Clay content in the A horizon of these soils generally ranged from a minimum of 8% to a maximum of 28%. Clay content in the A-horizons of the magmatic soils were significantly higher (P<0.05) than soils over granite gneiss but statistically similar (P>0.05) to those of biotite granite. Particle size distribution data indicate that the soils have undergone intensive weathering. Soil structures were on the average moderately developed in the soils studied with angular and sub-angular blocky structures. Although there was evidence of soil compaction to suggest plant root development could be affected or inhibited in these soils. .
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Jozefaciuk, Grzegorz, Kamil Skic, Agnieszka Adamczuk, Patrycja Boguta, and Krzysztof Lamorski. "Structure and Strength of Artificial Soils Containing Monomineral Clay Fractions." Materials 14, no. 16 (2021): 4688. http://dx.doi.org/10.3390/ma14164688.
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Structure and strength are responsible for soil physical properties. This paper determines in a uniaxial compression test the strength of artificial soils containing different proportions of various clay-size minerals (cementing agents) and silt-size feldspar/quartz (skeletal particles). A novel empirical model relating the maximum stress and the Young’s modulus to the mineral content basing on the Langmuir-type curve was proposed. By using mercury intrusion porosimetry (MIP), bulk density (BD), and scanning electron microscopy (SEM), structural parameters influencing the strength of the soils were estimated and related to mechanical parameters. Size and shape of particles are considered as primary factors responsible for soil strength. In our experiments, the soil strength depended primarily on the location of fine particles in respect to silt grains and then, on a mineral particle size. The surface fractal dimension of mineral particles played a role of a shape parameter governing soil strength. Soils containing minerals of higher surface fractal dimensions (rougher surfaces) were more mechanically resistant. The two latter findings appear to be recognized herein for the first time.
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Hammermeister, A. M., D. S. Chanasyk, and M. A. Naeth. "Fly ash influence on near-surface temperature of a clay loam soil." Canadian Journal of Soil Science 78, no. 2 (1998): 345–50. http://dx.doi.org/10.4141/s97-058.
Full textAbstract:
It has been suggested that fly ash, when applied as a soil amendment, would increase soil temperature. However, no quantitative data have been provided to support this hypothesis. This hypothesis was tested on four fly ash treatments (0, 100, 200, and 400 t ha−1) applied to clay loam soil in a randomized block design. Bi-hourly soil temperatures were measured on 3 summer days over 2 yr, and afternoon temperatures were measured on randomly selected spring days at 5-, 10-, and 20-cm depths in the four fly ash treatments. Temperatures were measured in conjunction with surface bulk density, water content, and particle size distribution which were also used to calculate thermal heat capacity. Fly ash decreased percent clay, soil water content, and soil heat capacity. Contrary to previously expected trends, fly ash amendment did not significantly increase mean daily soil temperature under dry conditions. Generalizations in the literature regarding the influence of fly ash on soil temperature, bulk density, and water-holding capacity must be considered carefully since they generally relate only to coarse to medium textured soils. Key words: Soil amendments, bulk density, reclamation, heat capacity, thermal diffusivity, thermal conductivity, volumetric water content, particle size distribution
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Silva, Cristiane Matos da, Gustavo de Melo Bezerra Frazão, Jonathan dos Santos Viana, and Wilson Araújo da Silva. "Influence of depth on soil physical and water parameters." Concilium 24, no. 17 (2024): 395–408. http://dx.doi.org/10.53660/clm-4045-24r30b.
Full textAbstract:
Soils are made up of mineral and organic particles from the decomposition of rocks, animals and plants, distributed in surface and sub-surface layers over the years. Among the predominant classes in Brazil are the RED-YELLOW ARGISSOLS. To further understand the physical and hydric characteristics of this soil in the Tocantina Region of Maranhão and how this can affect crop development, the parameters of moisture, volumetric moisture, density, particle density, porosity and infiltration velocity were analysed at different depths (0-5; 5-10; 10-15; and 15-20 cm) at two different points. The experimental design adopted was entirely randomised, with 5 replications. The results indicated differences in most of the parameters, especially at point 2, highlighting the influence of vegetation cover and anthropogenic pressure on soil properties.
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Rai, Preeti, and Harsha Chatrath. "EFFECTS OF SOIL VISCOSITY, SOIL TEMPERATURE, AND SPECIFIC GRAVITY ON PLANTS GROWTH SOWN IN SOIL PREPARED FROM LABORATORY CHEMICAL WASTE." International Journal of Students' Research in Technology & Management 7, no. 2 (2019): 11–16. http://dx.doi.org/10.18510/ijsrtm.2019.723.
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Purpose of the study: The main purpose of this study is to find out the effect of change in soil viscosity, soil temperature and specific gravity on growth of plants sown in the soil prepared from laboratory chemical waste collected from an educational institute and with the plants sown in normal soil.
 Methodology: Three-three pots with different soil combinations mixed with solid and liquid chemical waste have been used for growing A. barbadensis Mill, Saussurea obvallata and Lilium plants. Observations were made every fifteen days for three months by checking plant height, the number of leaves, the color of leaves and soil temperature for understanding and comparison of plant growth with respect to variation in temperature. Later on density and viscosity of soils have also been checked with the help of specific gravity bottle and viscometer.
 Main Findings: Plants' growth differs with variation in soil viscosity, soil temperature, and soil density. All plants cannot grow potentially at the same temperature, viscosity, and density. A. barbadensis Mill A4 has shown better growth with least viscosity and highest particle density of soil. Saussurea obvallata BK1 has shown better growth with least viscosity and least particle density of soil. Lilium L1 has shown better growth with all the moderate values of soil.
 Applications of this study: This study helped to understand that all the plants have their own requirements of nutrients, nutrition and physical factors for their growth. This also helped to understand that although the soil has taken initially is the same, viscosity and density of the soil changes due the plants grown in it.
 Novelty/Originality of this study: The use of chemical wastes is taken into consideration instead of fertilizers to reduce pollution.
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Zhang, Xiao Ming, Qian Jin Liu, and Xing Xiu Yu. "Differences of Shear Strength between Undisturbed and Remolded Soils of Lands for Agriculture and Forestry in Menglianggu Watershed of Linyi City." Advanced Materials Research 599 (November 2012): 815–19. http://dx.doi.org/10.4028/www.scientific.net/amr.599.815.
Full textAbstract:
To find the effects of pedoturbation on soil erosion of lands for agriculture and forestry in Menglianggu watershed of Linyi city from soil mechanics, shear strengths of 3 typical land uses (6 different soils) which are undisturbed and remolded respectively were measured by direct shear apparatus. Effects of particle size and binding materials on shear strength were analyzed by comparing shear properties of undisturbed and remolded soils with the same dry density, water content and vertical loads. The results show that all the angle of internal friction ( ) and most of soil cohesion ( ) of undisturbed soils are bigger than that of remolded soils; The final shearing stress also comply with the law above; The main factors affecting shear strength are soil particle size and binding materials.
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Seitz, Steffen, Sandra Teuber, Christian Geißler, Philipp Goebes, and Thomas Scholten. "How Do Newly-Amended Biochar Particles Affect Erodibility and Soil Water Movement?—A Small-Scale Experimental Approach." Soil Systems 4, no. 4 (2020): 60. http://dx.doi.org/10.3390/soilsystems4040060.
Full textAbstract:
Biochar amendment changes chemical and physical properties of soils and influences soil biota. It is, thus, assumed that it can also affect soil erosion and erosion-related processes. In this study, we investigated how biochar particles instantly change erodibility by rain splash and the initial movement of soil water in a small-scale experiment. Hydrothermal carbonization (HTC)-char and Pyrochar were admixed to two soil substrates. Soil erodibility was determined with Tübingen splash cups under simulated rainfall, soil hydraulic conductivity was calculated from texture and bulk soil density, and soil water retention was measured using the negative and the excess pressure methods. Results showed that the addition of biochar significantly reduced initial soil erosion in coarse sand and silt loam immediately after biochar application. Furthermore, biochar particles were not preferentially removed from the substrate surface, but increasing biochar particle sizes partly showed decreasing erodibility of substrates. Moreover, biochar amendment led to improved hydraulic conductivity and soil water retention, regarding soil erosion control. In conclusion, this study provided evidence that biochar amendments reduce soil degradation by water erosion. Furthermore, this effect is detectable in a very early stage, and without long-term incorporation of biochar into soils.
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Orzechowski, Mirosław, Jacek Długosz, Sławomir Smólczyński, Barbara Kalisz, Paweł Sowiński, and Paweł Urbanowicz. "Effect of microbial UGmax enricher on soil physical and water retention properties." Soil Science Annual 69, no. 4 (2018): 243–50. http://dx.doi.org/10.2478/ssa-2018-0025.
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Abstract The paper presents the impact of UGmax enricher on soil physical and water retention properties. The experiment was established in 2005 in a 2 ha field 9 km from Lidzbark Warmiński in the village of Budniki. The studied soils were classified as Cambisols and Luvisols (IUSS Working Group WRB 2015), and they were formed from glaciolimnic deposits. Soil bulk density, soil particle density, texture, total porosity and water retention properties using low and high-pressure chambers were determined. The use of UGmax enricher on loamy soils used as arable lands in temperate climate of north-eastern Poland caused significant decrease of soil bulk density, increase of available water capacity and readily available water capacity. Statistically significant differences between examined soil properties were observed in most studied years.
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Wu, Hao, Jian Wang, Jianhua Wang, and Chencong Liao. "Asymmetric Adaptive Particle Refinement in SPH and Its Application in Soil Cutting Problems." International Journal of Computational Methods 15, no. 06 (2018): 1850052. http://dx.doi.org/10.1142/s0219876218500524.
Full textAbstract:
In this study, a novel asymmetric adaptive particle refinement algorithm in smoothed particle hydrodynamics (SPH) is developed for soil cutting problems. Each candidate particle that located at the cutting blade of the structure is split into two “children” particles to minimize the oscillation of the contact force. And thus reduce the local instability. To minimize the density refinement error, a numerical method to determine the optimal smoothing lengths for “children” particles is given. To verify the accuracy of proposed algorithm, the adaptive refinement procedure are implemented into two models: one for soil cutting test on plane strain condition and the other for sample drilling test on axisymmetric condition. The observed flow pattern of the soil and contact forces are compared with laboratory experimental data available in the literature. Results indicate that the proposed asymmetric adaptive refinement algorithm could significantly avoid severe local instability and contributes to high-accuracy simulation.