Properties Of Sandy Soil Research Articles

Effect of Co-Use of Fly Ash and Granular Polyacrylamide on Infiltration, Runoff, and Sediment Yield from Sandy Soil under Simulated Rainfall

Coal fly ash (FA) and polyacrylamide (PAM) are two common amendments for improving hydraulic properties of sandy soil. However, their interaction effect on infiltration-runoff processes in sandy soil has been scarcely reported. In this study, FA and anionic PAM granules were mixed thoroughly with a 0–0.2 m sandy soil layer at FA rates of 0%, 10%, and 15% (w/w soil), and PAM rates of 0%, 0.01%, and 0.02% (w/w soil) along with each FA rate. A simulated rainfall laboratory experiment (slope gradient of 10°, rainfall intensity of 1.5 mm/min) was conducted. During the rainfall, the cumulative runoff yield increased while the average infiltration rate decreased with increasing FA and PAM rates. A higher FA rate of 15% and varying PAM rates resulted in a prominent increase in cumulative sediment yield. After the rainfall, the two-dimensional distribution of water content retained in the soil profile reflected that both FA and PAM increased the water retention capacity of sandy soil, and the effect became more obvious at higher FA and PAM rates. The possible mechanism for the effect of FA and PAM on inhibiting water infiltration during the rainfall and retaining water in the soil layer after the rainfall is attributed to the filling of pores of the coarse soil particles by fine-sized FA particles and flocculation function and binding action of PAM.

Impact of secondary succession in abandoned fields on some properties of acidic sandy soils

Abstract Abandonment of agricultural lands in recent decades is occurring mainly in Europe, North America and Oceania, and changing the fate of landscapes as the ecosystem recovers during fallow stage. The objective of this study was to find the impact of secondary succession in abandoned fields on some parameters of acidic sandy soils in the Borská nížina lowland (southwestern Slovakia). We investigated soil chemical (pH and soil organic carbon content), hydrophysical (water sorptivity, and hydraulic conductivity), and water repellency (water drop penetration time, water repellency cessation time, repellency index, and modified repellency index) parameters, as well as the ethanol sorptivity of the studied soils. Both the hydrophysical and chemical parameters decreased significantly during abandonment of the three investigated agricultural fields. On the other hand, the water repellency parameters increased significantly, but the ethanol sorptivity did not change during abandonment. As the ethanol sorptivity depends mainly on soil pore size, the last finding could mean that the pore size of acidic sandy soils did not change during succession.

Use of montmorillonite-enriched siltstone for improving water condition and plant growth in sandy soil

Revegetation in arid and semi-arid regions is restricted by soil water shortage. Improvement of sandy soil properties, especially for soil water related properties, is therefore vital for successful revegetation. In this study, montmorillonite-enriched siltstone (MS), a type of fine particle soil material, was used to improve sandy soil in a field experiment with four volume proportions: 0% (M0%), 25% (M25%), 75% (M75%), and 100% (M100%) of MS, which was then planted with alfalfa (Medicago sativa) for 3 years. The objective was to investigate the improvement effect of MS on the physical properties of sandy soil and its support for plant growth. The results showed that the addition of MS significantly increased the soil physical quality (SPQ) indicators, such as available water capacity (AWC), which increased from 7.39% (M0%) to 10.18% (M100%), while hydraulic conductivity (Ks) decreased by 34.1% (M25%) and 57.5% (M75%), and bulk soil air capacity (ACB) decreased by 12.6% (M25%) and 39.4% (M75%). These results were mainly related to the high content of fine particles in MS, such as montmorillonite, a 2:1 clay mineral. The average profile soil water content (SWC) increased from 9.20% to 14.08% (M25%) and 24.62% (M75%). The temporal stability of SWC was also significantly increased by MS addition, while drainage was significantly decreased. Both above-ground biomass (ABG) and water use efficiency (WUE) increased by approximately two times in M25% and M75% in 2015 and five times in M25% and M75% in 2016. This result verified the positive effect of MS addition on sandy soil properties. However, more than 75% MS addition (such as M100%) in sandy soil decreased ACB to less than 15% and decreased ABG by 75.3% compared with that of M75%. This study gives a new strategy for improving sandy soil using local finer materials with a high content of montmorillonite. Considering the improvement effects and engineering cost, a 25% volume proportion of MS was recommended.

Optimization of water-physical properties of sandy soils of natural-technogenic origin

Optimization of water-physical properties of sandy soils of natural-technogenic origin

Analysis on hydraulic characteristics of improved sandy soil with soft rock.

Hydraulic properties of sandy soil from the Mu Us sandy land of Shaanxi Province were analyzed by using SEM technology. Soil porosity, the water characteristic curve, and unsaturated hydraulic conductivity of aeolian sandy soil with added soft rock were analyzed, and fractal characteristics were established. Soil hydraulic properties revealed the effect of soft rock application on soil structure and hydraulic properties. Mass ratios of soft rock to aeolian sand were 1:5, 1:2, and 1:1. Results showed that the addition of soft rock can significantly increase the bulk density of sandy soil and reduce the total porosity and macroporosity. The mass fraction of water-stable aggregates greater than 0.25mm increases significantly, increasing the fractal dimension of soil pores; reducing the soil saturated water content and saturated hydraulic conductivity. SEM technology and pore fractal theory were used to predict the soil salinity curve and unsaturated hydraulic conductivity of the improved saline soil.

Measurement and modelling of soil dielectric properties as a function of soil class and moisture content

In this study, four textural classes of soil (Clay, Clay Loam, Loam, and Loamy Sand) were used to investigate the dielectric properties of soils, using a vector network analyser with an open-ended coaxial probe kit at room temperature (25 ± 2°C) in the 700–7000 MHz microwave frequency range. Four levels of soil moisture content (oven dry, 33% field capacity, 66% field capacity and 100% field capacity) were maintained to perform the experiment with three replication and three observation each. The results showed that, with increasing soil moisture, from oven dry conditions to 100% field capacity, both the real (Dielectric Constant) and imaginary (Loss Factor) components of the dielectric properties increased; however, the responses were not linear. The dielectric properties of oven dry soils were very low compared with the soils with higher moisture content. Therefore, soil moisture was the major contributor to the dielectric behaviour of soil. The dielectric properties of sandy soil were much lower than the other soils; however, the dielectric loss factor of the Dookie clay soil was higher compare with the other soils. Models were developed to explain the dielectric properties of soils as a function of frequency and moisture content. The goodness of fit (r2) for these models varies between 0.952 for the Dookie Sandy Soil to 0.997 for the Dookie Loam Soil, suggesting that these models were adequate to describe the dielectric properties of these soils over the range of frequencies and moisture contents assessed in this study. Another model was developed to estimate the expected penetration depth of electromagnetic waves in these soils, based on the model of the dielectric properties. It was clear that penetration decreases with both frequency and moisture content. Low frequencies penetrate further into the soils than higher frequencies. Similarly, dry soils allow further penetration than moist soils.

Application of artificial neural networks in settlement prediction of shallow foundations on sandy soils

This paper presents an application of artificial neural networks (ANNs) in settlement prediction of a foundation on sandy soil. In order to train the ANN model, a wide experimental database about settlement of foundations acquired from available literatures was collected. The data used in the ANNs model were arranged using the following five-input parameters that covered both geometrical foundation and sandy soil properties: breadth of foundation B, length to width L/B, embedment ratio Df/B, foundation net applied pressure qnet, and average SPT blow count N. The backpropagation algorithm was implemented to develop an explicit predicting formulation. The settlement results are compared with the results of previous studies. The accuracy of the proposed formula proves that the ANNs method has a huge potential for predicting the settlement of foundations on sandy soils.

The effects of bottom ash in coastal sand

In the construction industry, breakage of sand particles is very common especially at the very early stage of the pile driving work. The breakage of sand particles will result in change of size spectrum and alter its engineering properties. In this research, the effectiveness of bottom ash in improving the engineering properties of crushed sandy soil was studied. The bottom ash of 5%, 10%, 15% and 20% was added into the sand and crushed with 500 and 1000 blows under the Automatic Compactor machine. The engineering properties of different proportion of bottom ash mixture before crushing and after crushing with 500 and 1000 blows were tested. The engineering properties which were measured include the coefficient of uniformity, breakage index, fouling index, permeability and bearing capacity. Results show that adding of bottom ash into the crushable sand improved the load bearing capacity. By adding 20% of bottom ash, the bearing capacity of the crushed sandy soil can be improved by 55% meanwhile the permeability of the sandy soil can be improved by 200%.

Influence of Properties of Sandy Soil on Simple Estimation Method of Essentially Saturated Zone Using Soil Moisture Sampler

Influence of Properties of Sandy Soil on Simple Estimation Method of Essentially Saturated Zone Using Soil Moisture Sampler

Utilization of the trash biochar and waste of sugarcane to improve the quality of sandy soil and growth of sugarcane

An abundance of sugarcane trash (ST) can be converted into soil amendment to improve soil quality. Pot research was carried out in Malang, East Java from October 2013 to October 2014. The research aimed to study changes in the properties of sand-textured soil due to the application of trash biochar and other sugarcane wastes, as well as its effect on sugarcane growth. The study was arranged in a randomized block design with six treatments and three replications. Treatment includes: 1) ST biochar 10 t ha−1; 2) boiler ash 10 t ha−1; 3) ST compost 10 t ha−1; 4) ST biochar 5 t ha−1 + ST compost 5 t ha−1; 5) boiler ash 5 t ha−1 + ST compost 5 t ha− 1; and 6) control (without soil amendment). The treatments improved the physical and chemical properties of sandy soil, namely bulk density, total porosity, available moisture content, aggregate stability, organic-C, total-N, available-P, exchangeable-K, and CEC. However, the improvement of this soil did not affect the growth and yield of sugarcane. Further research is needed to study the effect of residues from the application of biochar on ratoon sugarcane, and research on sugarcane development land.

Enhancement of the thermal conductivity of sands via microbially-induced calcite precipitation

Energy piles and ground source heat pump systems have been shown to provide sustainable alternatives for temperature regulation in buildings and other applications such as road de-icing. However, their efficiency can be undermined in partially-saturated and dry sandy soils due to the relatively low thermal conductivity (kt) of these materials. Microbially-Induced Calcite Precipitation (MICP) has been demonstrated to be an environmentally-conscious ground improvement technology capable of modifying the engineering properties of sandy soils including increases in shear stiffness and strength and decreases in hydraulic conductivity. These improvements result from the precipitation of calcium carbonate crystals at inter-particle contacts and on particle surfaces. This paper presents results from a soil column study aimed at investigating changes in soil kt during MICP treatments and subsequent desaturation using a poorly- graded sand. The results indicate that while bio-cementation can increase soil kt, the level of enhancement depends on the degree of saturation. For instance, increases of up to 330% were measured under dry conditions while only modest increases of about 15% were measured under saturated conditions. MICP treatment may therefore be most effective at enhancing the kt of partially-saturated and dry sands. In addition, the similarity between the evolution of kt and shear wave velocity (Vs) during MICP treatment suggests that kt may provide a new method to assess cementation level and contact quality.

Engineering and Agricultural Properties of Black Cotton and Red Sandy Soil

Engineering and Agricultural Properties of Black Cotton and Red Sandy Soil

An Experimental Study on Ground Improvement by Application of Fly Ash and Lime on Clayey and Sandy Soil

Construction on locally available clayey soil is often problematic due to its swelling and shrinkage nature. Pavements are most affected as the upthrust due to regional swelling of clayey soil during monsoon season and shrinking during dry season causes unwanted cracks in the pavement. As a consequence, the pavement gets damaged. In places having extensive deposit of clayey soil, soil replacement becomes time-consuming and uneconomical. Hence the clayey soil to be considered as subgrade needs to be pre-treated. Fly ash, an industrial waste can be used for such treatment. To improve the engineering properties of on-site available clayey soil and sandy soil with lime and fly ash was studied. Based on the results obtained from experiments the suitability of fly ash and lime to be considered as additives to improve local clayey and sandy soil properties has been analyzed. It was observed that the on the addition of fly ash within 40-60% range can be satisfactorily used to replace the local clayey soil and fly ash percentage within 20-40% can be used to replace the local sand. Lime content in the range of 4-8% can be satisfactorily used in both in situ available soil and local sand with fly ash mixtures for the improvement of strength in terms of shear strength as well as CBR value.

Impact of Organic Wastes on Physical and Chemical Properties of Sandy and Loamy Soils in Egypt

The aim of this study was to evaluate the effect of two organic wastes used as soil amendments i.e. filter mud cake (FMC) and vinasse (V) on some physical and chemical properties of sandy and loamy sandy soils. Applications of organic were incubated with the soils for a three periods of 15, 30 and 60 days at four application rates (0, 0.5, 1 and 2%). This study was carried out in a two way randomized completely block design with three replications. After incubation periods, bulk density, porosity, water retention, soil pH, electrical conductivity (EC) and organic matter were determined.
 Results showed that the values of soil bulk density and soil pH were decreased with increasing the application rates of filter cake or vinasse compared with the control in two soils. In addition, application of different filter mud cake and vinasse rates to the study soils increased soil porosity, field capacity (FC), wilting point (WP), available water (AW), electrical conductivity (EC) and organic matter contents (OM) as compared to control at different period incubation time. The data of this study concluded that, organic wastes or byproducts of sugar industries could be applied to improve some soil properties.

Glucose-stimulation of natural microbial activity changes composition, structure and engineering properties of sandy and loamy soils

High inputs of easily available organic matter to the subsurface may quickly activate the native microbial communities, thereby changing soil engineering properties. We studied the effect of glucose addition, an easily available carbon source, on stress-strain properties, mineralogy, and microstructure of several loamy and sandy soils over 30 days in laboratory experiments. During the period of high microbial activity, direct shear tests revealed a reduction of the friction angle of 15–30 % and a raise of cohesion in sands. Unconfined compression tests showed a 20–30 % decrease in the compressive strength of loamy soils. With the decline of microbial activity, the stress-strain properties recovered partially. The alterations of the stress-strain properties with increasing microbial activity were linked to changes in mineralogy and composition. X-ray diffraction showed that the proportion of smectite layers in illite-smectite mixed layer minerals increased, as well as the overall imperfection of clay minerals. Glucose addition resulted in a temporary increase in the content of microaggregates (0.1-0.05 mm). Newly formed linkages of organic matter between solid particles, biofilm formation and direct interaction of cells with mineral surfaces were observed by scanning electron microscopy. Our data show that microbial-mediated processes may adversely influence stress-strain properties of soils and endanger the safety of buildings.

Mechanism of biochar soil pore–gas–water interaction: gas properties of biochar-amended sandy soil at different degrees of compaction using KNN modeling

Soil compaction has contrasting effect on soil strength (i.e., positive) and vegetation growth (i.e., negative), respectively. Biochar has been utilized mostly in combination with soils in both agricultural fields (i.e., loose soils) and geo-structures (i.e., dense soil slopes, landfill cover) for improving water retention due to its microporous structure. Biochar is also found to be useful to reduce gas permeability in compacted soil recently. However, the efficiency of biochar in reducing gas permeability in loose and dense soils is rarely understood. The objective of this study is to analyze effects of compaction on gas permeability in soil at different degrees of compaction (i.e., 65%, 80% and 95%) and also different biochar amendment contents (0%, 5% and 10%). Another aim is to identify relative significance of parameters (soil suction, water content, biochar content and compaction) in affecting gas permeability. Experiments were conducted before applying k-nearest neighbor (KNN) modeling technique for identifying relative significance of parameters. Biochar was synthesized from a coastal invasive species (water hyacinth), which has relatively no influence on food chain (as unlike in biochar produced from biomass such as rice husk, straw, peanut shell). Based on measurements and KNN modeling, it was found that gas permeability of biochar-amended soil is relatively lower than that of soil without amendment. It was found from KNN model that for denser soils, higher amount of soil suction is mobilized for a significant increase in gas permeability as compared to loose soils. Among all parameters, soil suction is found to be most influential in affecting gas permeability followed by water content and compaction.

Characterization of two- and three-dimensional morphological properties of fragmented sand grains

The geometric shape and size of sand grains are key factors that affect the mechanical and hydraulic properties of sandy soils. These morphological properties are commonly quantified via analysis of two-dimensional microscopy photos while three-dimensional measurements, such as using X-ray micro-computed tomography, are being adopted to understand and characterize the behaviours of granular materials. This study explores the relationship between two- and three-dimensional morphological properties for fragmented sand grains. Three-dimensional morphological properties of representative grains with different combinations of elongation and flatness were measured with X-ray micro-computed tomography. A framework that integrates discrete element modelling and sand grain imaging is introduced for obtaining the two-dimensional vertical projections of these grains after freefalls onto a horizontal surface. Matlab code was developed to extract the 2D silhouette outline of each grain for measuring 2D morphological properties. The relationships between 2D and 3D morphological properties were quantified, and useful empirical equations were developed. The results show that five 3D morphological properties (length, breadth, volume, surface area, and elongation) can be estimated from the 2D morphological properties of length2D, breadth2D, projection area, and aspect ratio. Estimates of 3D morphological properties including sphericity, volume, and surface area can be improved when flatness is known. A practical approach to obtain flatness from the 2D morphological analysis results is provided. The newly developed equations were evaluated using virtual soil samples and compared with previously published data for natural grains. Use of the developed equations to estimate specific surface area and permeability of soils was demonstrated.

Evaluating the Impact of Combined Application of Biochar and Compost on Hydro-physical Properties of Loamy Sand Soil

ABSTRACTBiochar, compost and their combination are important organic amendment materials for improving the hydro-physical properties of sandy soils. Series of soil columns experiments were conducted for investigating the application effects of date palm biochar and compost on evaporation, moisture distribution, infiltration, sorptivity (Sp), saturated hydraulic conductivity (Ksat) and water holding capacity (WHC) at application rates of 1%, 2%, 3% and 4% (10, 20, 30 and 40 g kg−1). The columns were filled manually with air-dried soil with 35 cm depth and the thickness of surface amended layer was 10 cm (T10) and 20 cm (T20) from soil surface at bulk density of 1400 kg m−3. The results showed that the behavior of soil moisture distribution was influenced by application of biochar, compost and biochar-compost mixture. Moreover, in the amended layer T10, applying biochar at rate of 1%, 2%, 3% and 4% reduced significantly cumulative evaporation by 5.8%, 10.8%, 12.8% and 16.1%, respectively. Meanwhile, the reduction for the biochar-compost mixture at application rates of 1%, 2%, 3% and 4% was 10%, 12.2%, 14.5% and 20%, respectively. In layer T20, applying biochar at rate of 1%, 2%, 3% and 4% reduced cumulative evaporation by 10.24%, 13.0%, 18.3% and 21.5% but this reduction amounted to 18.2%, 21%, 23% and 24% for the biochar-compost mixture, respectively. It was generally observed that the highest application rate (4%) for applied amendments was the most effective impact on Sp, Ksat and WHC compared with other rates.

Estimation of Unsaturated Hydraulic Conductivity of Granular Soils from Particle Size Parameters

Estimation of unsaturated hydraulic conductivity could benefit many engineering or research problems such as water flow in the vadose zone, unsaturated seepage and capillary barriers for underground waste isolation. The unsaturated hydraulic conductivity of a soil is related to its saturated hydraulic conductivity value as well as its water retention behaviour. By following the first author’s previous work, the saturated hydraulic conductivity and water retention curve (WRC) of sandy soils can be estimated from their basic gradation parameters. In this paper, we further suggest the applicable range of the estimation method is for soils with d10 > 0.02mm and Cu < 20, in which d10 is the grain diameter corresponding to 10% passing and Cu is the coefficient of uniformity (Cu=d60d10). The estimation method is also modified to consider the porosity variation effect. Then the proposed method is applied to predict unsaturated hydraulic conductivity properties of different sandy soils and also compared with laboratory and field test results. The comparison shows that the newly developed estimation method, which predicts the relative permeability of unsaturated sands from basic grain size parameters and porosity, generally has a fair agreement with measured data. It also indicates that the air-entry value is mainly relative to the mean grain size and porosity value change from the intrinsic value. The rate of permeability decline with suction is mainly associated with grain size polydispersity.

Effect of Coapplication of Biochar and Nutrients on Microbiocenotic Composition, Dehydrogenase Activity Index and Chemical Properties of Sandy Soil

Biochar improves soil physical, chemical and biological properties. However, there is a very limited number of studies comparing the effect of various doses of biochar and wheat straw with nutrients on microbiocenotic composition of soil and their connection with selected biochemical and chemical parameters of soil. The aim of this study was to determine the effect of the addition to the soil of wheat straw (WS) and wheat straw biochar (WSB) (300 °C) at 0.2%, 0.5%, 1%, and 2% doses and the addition of nutrients (MF) on microbial community composition (bacteria, fungi, actinobacteria, Azotobacter spp., ammonifiers, nitrifiers, denitrifiers, C. pasteurianum), dehydrogenase activity index, carbon and nitrogen fractions contents and the content of water soluble Cu, Cd, Zn, and Pb. It was demonstrated that coapplication of WS and WSB with MF at 1% and 2% doses increased carbon and nitrogen contents in soil and, in particular, their water soluble fractions (DOC and DON). The synergistic effect of biochar and MF contributed to the increase in the population of soil microorganisms. Dehydrogenase activity index in treatments with the addition of WS, WSB and MF was 1.6–4 times higher compared to the control. The content of heavy metals significantly (p ≤ 0.05) affected dehydrogenase activity and the number of nitrifiers and ammonifiers. It was demonstrated that the content of C and N measured for soil microbial biomass in treatments amended with biochar and MF was much greater than in control treatment and MF. However, our studies suggest that the microorganisms’ response to the addition of biochar with nutrients increased the number and intensified the activity of soil microorganisms.Graphic