Effect Of Soil Particle Size Research Articles

Effect of soil particle size on soil-subsoiler interactions using the discrete element method simulations

The discrete element method (DEM) has been widely used as a modelling tool to investigate soil-tool interactions. Soil particle size has an important effect on soil disturbance behaviours and cutting forces in discrete element models. In this study, discrete element models were developed using the EDEM software and evaluated using laboratory tests to investigate the effect of varying modelled particle radii (ranging from 3 to 19 mm) on soil-subsoiler interactions in the models. Soil disturbance characteristics (soil rupture distance ratio, height of accumulated soil, soil disturbance area, soil density change rate, and fragmentation index), solution time of the computer, and soil cutting forces (draft and vertical) were measured. Based on the ANOVA outputs, all these variables were significantly affected by the treatments at p

Prediction of soil macro- and micro-elements in sieved and ground air-dried soils using laboratory-based hyperspectral imaging technique

Hyperspectral image analysis in laboratory-based settings has the potential to estimate soil elements. This study aimed to explore the effects of soil particle size on element estimation using visible-near infrared (400–1000 nm) hyperspectral imaging. Images were captured from 116 sieved and ground soil samples. Data acquired from hyperspectral images (HSI) were used to develop partial least square regression (PLSR) models to predict soil available aluminum (Al), boron (B), calcium (Ca), copper (Cu), iron (Fe), potassium (K), magnesium (Mg), manganese (Mn), sodium (Na), phosphorus (P) and zinc (Zn). The soil available Al, Fe, K, Mn, Na and P were not predicted with high precision. However, the developed PLSR models predicted B (R2CV = 0.62 and RMSECV = 0.15), Ca (R2CV = 0.81 and RMSECV = 260.97), Cu (R2CV = 0.74 and RMSECV = 0.27), Mg (R2CV = 0.80 and RMSECV = 43.71) and Zn (R2CV = 0.76 and RMSECV = 0.97) in sieved soils. The PLSR models using reflectance of ground soil were also developed for B (R2CV = 0.53 and RMSECV = 0.16), Ca (R2CV = 0.81 and RMSECV = 260.79), Cu (R2CV = 0.73 and RMSECV = 0.29), Mg (R2CV = 0.79 and RMSECV = 45.45) and Zn (R2CV = 0.76 and RMSECV = 0.97). RMSE of different PLSR models, developed from sieved and ground soils for the corresponding elements did not significantly differ based on the Levene's test. Therefore, this study indicated that it was not necessary to grind soil samples to predict elements using HSI.

荒漠草原区土壤粒径组成对柠条根际土壤微生物数量及酶活性的影响

PDF HTML阅读 XML下载 导出引用 引用提醒 荒漠草原区土壤粒径组成对柠条根际土壤微生物数量及酶活性的影响 DOI: 10.5846/stxb201810252309 作者: 作者单位: 作者简介: 通讯作者: 中图分类号: 基金项目: 宁夏自然科学基金项目（NZ15001）；国家自然科学基金项目（31860158） Effects of soil particle size on enzyme activities and the amount of soil microorganism in rhizosphere of Caragana korshinskii in desert steppe Author: Affiliation: Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:柠条（Caragana korshinskii）是荒漠草原区主要的造林绿化树种，研究其根际土壤微生物和酶活性与不同土壤类型土壤粒径组成的关系有重要意义，然而土壤粒径对荒漠草原柠条根际土壤微生物数量和酶活性的影响知之甚少，探讨土壤颗粒组分与微生物数量、土壤酶活性之间的关系，以及土壤颗粒组成对荒漠草原区固沙灌木植物柠条根际土壤微生物数量及酶活性的影响，可为揭示荒漠草原土壤退化及生态修复提供参考。以宁夏荒漠草原区土壤粒径组成差异显著的灰钙土、红黏土、风沙土环境下栽植的柠条为研究对象，研究不同土壤颗粒组成对根际土壤微生物数量及酶活性的相互关系与影响。结果表明：土壤微生物的数量表现为细菌 > 放线菌 > 真菌。根际土壤中的细菌、真菌数量显著高于非根际，且在3种不同类型的土壤中随着细砂粒的增多，真菌和放线菌数量逐渐降低，而细菌数量呈先增大后减小的趋势；根际与非根际土壤的蔗糖酶、碱性磷酸酶及过氧化氢酶活性均呈现出灰钙土 > 红黏土 > 风沙土的趋势，红黏土根际土壤中的脲酶活性显著高于灰钙土与风沙土；除过氧化氢酶外，土壤酶活性表现为根际高于非根际，在3种不同类型的土壤中随着细砂含量的增加，土壤酶活性均呈递减趋势。土壤颗粒组成与微生物数量之间没有明显的相关性，而与土壤酶活性之间显著相关，土壤酶活性与黏粒、粉粒呈正相关，与细砂、中砂呈负相关关系，根际土壤中酶活性更高，能够为植物及微生物提供更多的营养。 Abstract:Caragana korshinskii is the main afforestation tree species in desert steppe, it is important to study the relationship between microorganisms and enzymes in rhizosphere soil and soil particle size composition. Soil types affect enzyme activities and the amount of microorganism in rhizosphere soil, soil particle size in different soil types is different, however, little is known about how soil particle size affect on enzyme activities and the amount of soil microorganism in rhizosphere of Caragana korshinskii planted in desert steppe. In this study, soil enzyme activities and the amount of soil microorganism in rhizosphere and non-rhizosphere soil in three soil types were analyzed, as well as soil particle size of sierozem, red clay soils, and aeolian sandy soils in Yanchi country of Ningxia. The results showed that the amount of bacteria in rhizosphere soil was significantly higher than that in non-rhizosphere soil, and the amount of fungi increased with the increase of fine sand grains in three soil types. The activities of sucrase, alkaline phosphatase, and catalase in rhizosphere and non-rhizosphere soil presented the tendency of sierozem > red clay soils > aeolian sand soils. The urease activity in red clay soils of rhizosphere was significantly higher than that in sierozem and aeolian sand soils. The amount of fungi and actinomycetes decreased gradually, while the amount of bacteria increased firstly and then decreased. The amount of bacteria and fungi were more abundant than bulk soil. With the increasing of fine sand content, the amount of fungi and actinomycetes gradually decreased while the amount of bacteria increased and then decreased. Soil enzyme activity in rhizosphere exceeded bulk except catalase. With the increasing of fine sand content, soil enzyme activity gradually decreased. There was no significant correlation between soil particle size and the amount of soil microorganism and soil enzyme activity presented a positive correlation with clay and silt sand but it negatively correlated with fine sand and medium sand, rhizosphere soil has higher enzyme activity and could provide more nutrients for plants and microorganisms. 参考文献 相似文献 引证文献

埋設鋼材の腐食速度に及ぼす土壌粒子径と土壌含水率の影響

埋設鋼材の腐食速度に及ぼす土壌粒子径と土壌含水率の影響

Understanding the effect of soil particle size on corrosion behavior of natural gas pipeline via modelling and corrosion micromorphology

Abstract The effect of particle size on the electrochemical corrosion behavior of natural gas pipeline steel in a 1.5 wt% NaCl sandy soil corrosive environment was investigated by standard quartz sand. A mathematical model of gas/liquid/solid three-phase boundary (TPB) zone and the soil particle size was developed, and then the theoretical calculation indicated that a critical particle size corresponded to 1.2 mm radius. The laboratory experiments indicated that the corrosion rate of natural gas pipeline steel increased with decreasing soil particle size to

Particle size effects on coarse soil-geogrid interface response in cyclic and post-cyclic direct shear tests

The interface shear behavior of soil against geosynthetic is important in the design of geosynthetic-reinforced soil structures. This study involves the use of a series of Monotonic Direct Shear (MDS) tests, Cyclic Direct Shear (CDS) tests and Post-cyclic Direct Shear (PCDS) tests to investigate the coarse silica soil-geogrid interface monotonic and cyclic shear behavior. In particular, the influence of cyclic shear on the interface monotonic behavior is analyzed in detail. The effect of soil particle size on interface cyclic and post-cyclic shear behavior is examined and discussed. The results indicate that in cyclic direct shear, the interfaces exhibit cyclic hardening, the interface damping ratio decreased with increasing cycle number and soil relative density, and an interface with a larger particle size has a higher contraction value. In the monotonic condition, the shear stress–displacement curves exhibit post-peak strain softening behavior, and the apparent adhesion and friction angle at the interface both increased with increasing soil particle size. Cyclic shear increased the apparent adhesion at the interface and intensified the soil dilatancy.

Particle size effects on bioaccessible amounts of ingestible soil-borne toxic elements

The unified BARGE method was used to examine the effects of soil particle size on the bioaccessible amounts of potentially toxic elements in multi-contaminated soils from a closed landfill site. The results show that bioaccessible As, Al, Cd, Cr, Cu, Mn, Ni, Pb and Zn increased with decreasing soil particle size and the <0.002 mm soil fraction contained much greater amounts of the bioaccessible elements, as compared to other soil fractions (0.002–0.063 mm, 0.063–0.125 mm, and 0.125–0.250 mm). As, Al and Cr had much lower bioaccessibility, as compared to the six cationic heavy metals. In contrast with other elements, As bioaccessibility tended to be higher in the gastrointestinal phase than in the gastric phase. There was a significant soil particle size effect on bioaccessibility of As and Al in the gastrointestinal phase: As bioaccessibility decreased with decreasing particle size, and the finer soil fractions tended to have a higher Al bioaccessibility, as compared to the coarser soil fractions. The research findings prompt the need for further division of soil particle size fractions in order to more accurately assess the bioaccessible amounts of soil-borne potentially toxic elements in contaminated lands.

土壤粒径大小对蒽荧光特性的影响及校正

土壤粒径大小对蒽荧光特性的影响及校正

Effect of particle size on the electrochemical corrosion behavior of X70 pipeline steel

In this study, by using a standard quartz replace of sandy soil particles, the effect of soil particle size (0.1–0.25 mm, 0.6–1.0 mm) on the electrochemical corrosion behavior of X70 pipeline steel in sandy soil corrosive environment simulated by 3.5 wt% sodium chloride (NaCl) was investigated through polarization curve and electrochemical impedance spectroscopy (EIS) technology. The results indicated that the polarization resistance of X70 steel decreased with decreasing particle size. For all polarization curves, the right shift of cathodic branch with decreasing particle size, suggesting that the cathode oxygen reduction process is accelerated. The corrosion of X70 steel is controlled by the process of cathode diffusion and oxygen reduction. This can be attributed to the effect of gas/liquid/solid three-phase boundary (TPB) zone on cathodic process of X70 steel, and the corrosion rate is mainly determined by the cathodic reaction. EIS of X70 steel consisted of two capacitive loops with 7, 60 and 90 days buried corrosion, and the charge transfer resistance of X70 steel increased with increasing particle size.

Soil signature simulation of complex mixtures and particle size distributions

Soil reflectance signatures were modeled using the digital imaging and remote sensing image gen- eration model and Blender three-dimensional (3-D) graphic design software. Using these tools, the geometry, radiometry, and chemistry of quartz and magnetite were exploited to model the presence of particle size and porosity effects in the visible and the shortwave infrared spectrum. Using the physics engines within the Blender 3-D graphic design software, physical representations of granular soil scenes were created. Each scene char- acterized a specific particle distribution and density. Chemical and optical properties of pure quartz and mag- netite were assigned to particles in the scene based on particle size. This work presents a model to describe an observed phase-angle dependence of beach sand density. Bidirectional reflectance signatures were simulated for targets of varying size distribution and density. This model provides validation for a phenomenological trade space between density and particle size distribution in complex, heterogeneous soil mixtures. It also confirms the suggestion that directional reflectance signatures can be defined by intimate mixtures that depend on pore spac- ing. The study demonstrated that by combining realistic target geometry and spectral measurements of pure quartz and magnetite, effects of soil particle size and density could be modeled without functional data fitting or rigorous analysis of material dynamics. This research does not use traditional function-based models for sim- ulation. The combination of realistic geometry, physically viable particle structure, and first-principles ray-tracing enables the ability to represent signature changes that have been observed in experimental observations. © The Authors. Published by SPIE under a Creative Commons Attribution 3.0 Unported License. Distribution or reproduction of this work in whole or in part requires full attribution of the original publication, including its DOI. (DOI: 10.1117/1.OE.54.9.094103)

Effect of soil particle size on the corrosion behavior of natural gas pipeline

In this study, the effect of soil particle size (0.1–0.25mm, 0.6–1.0mm) on the corrosion behavior of natural gas pipeline was investigated by electrochemical technology. The results indicated that the polarization resistance of pipeline steel decreased with decreasing particle size. For all polarization curves, the right shift of cathodic branch with decreasing particle size, suggests that the cathode oxygen reduction process is accelerated. The corrosion of steel is controlled by the process of cathode diffusion and oxygen reduction. This can be attributed to the effect of gas/liquid/solid three-phase boundary (TPB) zone on cathodic process of pipeline steel, and the corrosion rate is mainly determined by the cathodic reaction. The corrosion rate of pipeline steel increased with decreasing particle size.

Evaluation of Field Portable X-Ray Fluorescence Performance for the Analysis of Ni in Soil.

As a rapid, in-situ analysis method, Field portable X-ray fluorescence spectrometry (FP-XRF) can be widely applied in soil heavy metals analysis field. Whereas, some factors may affect FP-XRF performance and restrict the application. Studies have proved that FP-XRF has poorer performance when the concentration of target element is low, and soil moisture and particle size will affect FP-XRF performance. But few studies have been conducted in depth. This study took an example of Ni, demonstrated the relationship between Ni concentration and FP-XRF performance on accuracy and precision, and gave a critical value. Effects of soil moisture and particle size on accuracy and precision also had been compared. Results show that, FP-XRF performance is related to Ni concentration and the critical value is 400 mg x kg(-1). Relative standard deviation (RSD) and relative uncertainty decrease while the Ni concentration is below 400 mg x kg(-1), hence FP-XRF performance improves with increasing Ni concentration in this range; RSD and relative uncertainty change little while the Ni concentration is above 400 mg x kg(-1), hence FP-XRF performance does not have correlation with Ni concentration any more. For in-situ analysis, the relative uncertainty contributed by soil moisture is 3.77%, and the relative certainty contributed by particle size is 0.56%. Effect of soil moisture is evidently more serious than particle size both on accuracy and precision.

Testosterone sorption and desorption: Effects of soil particle size

Soils contain a wide range of particles of different diameters with different mobility during rainfall events. Effects of soil particles on sorption and desorption behaviors of steroid hormones have not been investigated. In this study, wet sieve washing and repeated sedimentation methods were used to fractionate the soils into five ranges. The sorption and desorption properties and related mechanisms of testosterone in batch reactors filled with fractionated soil particles were evaluated. Results of sorption and desorption kinetics indicate that small soil particles have higher sorption and lower desorption rates than that of big ones. Thermodynamic results show the sorption processes are spontaneous and exothermal. The sorption capacity ranks as clay>silt>sand, depending mainly on specific surface area and surface functional groups. The urea control test shows that hydrogen bonding contributes to testosterone sorption onto clay and silt but not on sand. Desorption tests indicate sorption is 36–65% irreversible from clay to sand. Clays have highest desorption hysteresis among these five soil fractions, indicating small particles like clays have less potential for desorption. The results provide indirect evidence on the colloid (clay)-facilitated transport of hormones (micro-pollutants) in soil environments.

토양 세척법에 의한 유류오염 사질토양의 TPH 추출 효율 평가

The influences of various operating parameters on physico-chemical techniques were evaluated to remediate petroleum-contaminated sandy soil including S/L ratio, kinetic, and effect of soil particle size. The simple extraction using tap water removed only 20.6% of total petroleum hydrocarbon (TPH), and addition of NaOH enhanced the removal of TPH to approximately 30%. To meet the regulation levels, a surfactant, sodium dodecyl sulfate, was added, and the removal of TPH increased to 4 times. Probably, the carbonate minerals affected chemical aging and soprtion of petroleum, which inhibited the extraction of TPH. The soil with smaller particle size contained more TPH, and the removal of TPH was obstructed with smaller particle size. However, NaOH addition increased the removal of TPH in the smaller particles. The physico-chemical properties of soil influenced greatly the removal of petroleum even in sandy soil.

Remediation of soils contaminated with chromium using citric and hydrochloric acids: the role of chromium fractionation in chromium leaching

Acid washing is a common method for soil remediation, but is not always efficient for chromium‐contaminated soil. Both soil particle size and the forms of chromium existing in the soil affect the efficiency of soil washing. Laboratory batch and column dissolution experiments were conducted to determine the efficiencies of citric and hydrochloric acids as agents to extract chromium from soils contaminated with chromium. The effects of soil particle size and chromium fractionation on Cr leaching were also investigated. About 90% of chromium in the studied soil existed either in residual form or bound to iron and manganese oxides, and Cr fraction distributions were similar for all soil particle sizes. Almost all exchangeable and carbonate‐bound chromium was removed by washing once with 0.5 M HCl, whereas organic chromium was more effectively removed by washing with citric acid rather than with HCl solution of the same concentration. For chromium fractions that were either bound to Fe‐Mn oxides or existed as residual forms, the efficiencies of acid washing were usually 20% or less, except for 0.5 M HCl solution, which had much higher efficiencies. Separation of the soil sample by particle size before the separate washing of the soil fractions had little improvement on the chromium removal.

Selection of Preprocessing Parameters for PCA of Soil Classification Affected by Particle Sizes Based on Vis/NIR Spectroscopy

. Instrumental measurement of soil properties are affected by several factors including soil texture. The classification of soil texture can help improve the accuracy of calibration models for soil measurement. In the study, the effect of soil particle size on the selection of preprocessing methods for principle component analysis (PCA) of soil classification was examined. Total 178 soil samples with five textures were collected from Silsoe Farm, Cranfield, England. After dried and ground, soil samples sieved by a 2mm sieve were named by Mixed Group. A Vis/NIR spectrophotometer (LabSpec2500, spectral range 350-2200nm, ASD) was used for spectral scanning of soil samples. After that, all samples were sieved by a 1mm sieve and divided into two groups: one with particle size less than 1mm named by Thin Group and another with particle size between 1mm and 2mm named by Thick Group. Preprocessing methods of moving average with segment size of 5(MA5), standard normal variation (SNV) and 1st Savitzky-Golay derivatives with smoothing points of 3(Der1(3)) were examined. PCA was applied to evaluate the discriminative capacity of MA5, MA5+SNV and MA5+Der1(3). The score plots of 1st~2nd and 2nd~3rd PCs show that MA5+Der1(3) is the best preprocessing method not only for Thick Group and Thin Group, but also for Mixed Group. MA5+SNV is suitable for Thick Group and Thin Group but does not perform well for Mixed Group. Only MA5 does not perform well in any of three groups. The study suggests that pre-processing with 1st derivative is an essential step for soil classification with various particle sizes using Vis/NIR spectroscopy.

Influence of Soil Particle Size on the Measurement of Sodium by Near-Infrared Reflectance Spectroscopy

This study evaluates the effect of soil particle size (SPS) on the measurement of exchangeable sodium (Na) (EXC-Na) by near-infrared reflectance (NIR) spectroscopy. Three hundred thirty-two (n = 332) top soil samples (0–10 cm) were taken from different locations across Uruguay, analyzed by EXC-Na using emission spectrometry, and scanned in reflectance using a NIR spectrophotometer (1100–2500 nm). Partial least squares (PLS) and principal component regression (PCR) models between reference chemical data and NIR data were developed using cross validation (leaving one out). The coefficient of determination in calibration (R2) and the root mean square of the standard error of cross validation (RMSECV) for EXC-Na concentration were 0.44 (RMSECV: 0.12 mg kg–1) for soil with small particle size (SPS-0.053) and 0.77 (RMSECV: 0.09 mg kg–1) for soils with particle sizes greater than 0.212 mm (SPS-0.212), using the NIR region after second derivative as mathematical transformation. The R2 and RMSECV for EXC-Na concentration using PCR were 0.54 (RMSECV: 0.07 mg kg–1) and 0.80 (RMSECV: 0.03 mg kg–1) for SPS-0.053 and SPS-0.212 samples, respectively.

IMPROVING PHOSPHORUS SENSING BY ELIMINATING SOIL PARTICLE SIZE EFFECT IN SPECTRAL MEASUREMENT

This study investigated the effects of soil particle size on the reflectance spectra of sandy soils using ultraviolet,visible, and near-infrared spectroscopy in sensing phosphorus (P) concentration. Pure sandy soil was graded into threeparticle sizes. Sieve sizes were 125, 250, and 600 .m for fine, medium, and coarse, respectively. Phosphorus application ratesfor the soil samples were 0.0, 12.5, 62.5, 175.0, 375.0, 750.0, and 1000.0 mg kg-1. Concentrations of P in the soil sampleswere analyzed. The reflectance of the samples was measured between 225 and 2525 nm at 1 nm intervals. Overall, soils withcoarse particles absorbed light more than those with medium and fine particles. Detection analysis for soil particle sizes wasconducted using ratio and discriminant analysis methods. Prediction analyses for P concentration were performed usingmultiple linear regression (MLR; stepwise and maximum R2 methods) and linear partial least squares (PLS). Results showedthat detection of the particle size in a spectrum and then the prediction of P using individual calibration models for each soilparticle size produced lower prediction errors. For the maximum R2 MLR, stepwise MLR, and linear PLS analyses,respectively, the standard errors of prediction (SEPs) for determining P concentration without removing the particle size effectwere 105.8, 106.2, and 69.8 mg kg-1 and after removing the particle size effect were 52.8, 73.4, and 64.4 mg kg-1.

Relationship between temperature sensitivity of capillary pressure and soil particle size

In a review of data in the published literature, we found that the effect of temperature on capillary pressure in natural soils increased with decreasing geometric mean soil particle diameter. This observation had implications both for hydrologic modeling and for elucidating the mechanisms that controlled the temperature sensitivity of capillary pressure. Two mechanisms were suggested to explain this observation. The first mechanism proposed that changes in soil mineral particle size resulted in changes in the proportion of hydrophyllic and hydrophobic surfaces, yielding changes in their wettabilities, and temperature effects on capillary pressure. The second mechanism proposed that the observation was due to the effect of soil particle size on disjoining pressure. A model derived from the second mechanism could be fitted to the available data and yielded parameter estimates consistent with current models of disjoining pressure profiles above surfaces.

Microhabitat Selection by Antlion Larvae, Myrmeleon Crudelis: Effect of Soil Particle Size on Pit-Trap Design and Prey Capture

Selective pressure for choosing an adequate habitat should be strong in semisedentary animals because they have limited mobility once established. I examined microhabitat preferences and the adaptive value of these preferences in the antlion larva Myrmeloen crudelis, a semisedentary insect that digs pit traps in soils to capture small arthropods. I tested the habitat preferences of M. crudelis between two soil types in a tropical dry forest of Costa Rica. Specifically, I compared the soil particle composition size within and outside antlion aggregations and manipulated the availability of fine- and coarse-grained soil to assess how differences in soil grain size affect the design and performance of larval traps. Adjacent to antlion pits the soil was composed of a greater proportion of fine-grained particles (≤2 mm) than soil 1 m away from the pits. A set of experiments demonstrated that (1) in the presence of equal availability of fine- and coarse-grained soils, all larvae built their pits in fine-grained soil; (2) the larvae required less time to start and finish traps in fine-grained soil; (3) the larvae constructed larger and deeper pits in fine-grained soil; and (4) prey capture increased greatly in fine-grained traps compared with coarse-grained traps. Antlion larvae respond to variations in the proportion of fine particles in the soil, suggesting that antlion aggregations result from an active microhabitat selection. The preference for fine-grained soils is adaptive since pits constructed in such substrate are functional for longer periods and much more successful in trapping prey than pits in coarse-grained soil. Sit-and-wait predators that use sessile traps are spatially constrained to track prey abundance. Therefore, the ability to detect and select microhabitats with better conditions that enhance capture success may be under strong selection for this type of organism.