Susceptibility Of Soils Research Articles

Soil erodibility in European mountain beech forests

Forests in Europe are currently not endangered by soil erosion. However, this can change with climate change or with intensified forest management practices. Using a newly established network of plots in beech forests across Europe, the aims of this study were to (i) distinguish soil properties and erodibility indices in relation to bedrock, (ii) determine geochemical properties and organic carbon (Corg) influencing erodibility, and (iii) assess the effect of soil depth on erodibility indices. Seventy-six soil samples from 20 beech forests were collected in 11 countries to quantify soil properties influencing erodibility indices: clay ratio, modified clay ratio, sodium adsorption ratio, and oxides ratio. The results indicate that the dominant soil properties, determined by bedrock, that correlate with forest soil erodibility indices are Corg, pH, electrical conductivity, calcium and sodium ions concentrations, total water-soluble cations, and the percentage of sand. According to the tested indices, soil susceptibility to erosion follows the order granite > andesite > sandstone > quartzite > limestone. Deeper soil horizons on granite are more susceptible to erosion than surface horizons are, but this is not the case for soils on limestones. In conclusion, forest management should consider the predisposition of different soil types to erosion.

Frost susceptibility of Nordic metal mine tailings

The mining industry produces significant amounts of waste materials, with the greatest volumes generated during enrichment. These waste materials or by-products, tailings, may be used as alternative civil engineering materials, reducing the need for natural resources. In cold climates, the frost behaviour of materials is one critical functional requirement in civil engineering applications. The frost behaviour of tailings classified as sand, silty sand, or sandy clayey silt (EN ISO), from four metal mines located in northern Finland and Sweden, was evaluated in this study using basic laboratory characterisation and one-dimensional freezing tests. The laboratory results were compared with existing guidelines on estimating the frost susceptibility of natural soils. Based on grain size distribution, the tailings samples were characterised as non-susceptible or frost-susceptible. Capillary rise values indicated that the frost susceptibility of the samples ranged from negligible to strong. In the one-dimensional frost heave test, measured frost heave after 96 h was 0.1–23.1 mm and calculated segregation potential (SP) was 0–9.7 mm2/Kh. Based on the frost heave test, the frost susceptibility of the samples ranged from low to strong. The results indicated that the finest samples classified as sandy clayey silt (L1−L3) generated the majority measured amount of frost heave and were classified as frost-susceptible material. The coarser tailings samples (K1-K3 and AK1) classified as sand or silty sand were classified non-susceptible, and measured frost heave amounts were low <1.0 mm (after 96 h). Thus, the tailings samples behaved like natural soils, indicating that classification methods developed for natural soils are valid for evaluation of the frost susceptibility of mine tailings. However, the influence of added reagents should be considered, and standardised frost behaviour methods should be developed.

The Underlying Factors of Soil Susceptibility to Erosion in Central Parts of Southeastern Nigeria

Soil erosion in southeastern Nigeria has a high devastating tendency which created a natural geologic hazard is causing loss of arable farm lands, destroying properties and other social infrastructures like pipelines, roads, bridges, over head and underground cables that are being exposed and or washed away by deep gully erosions. Investigations into the underlying factors of soil susceptibility to soil erosion in southeastern Nigeria led to this work. The study areas are the twenty six Local Government Areas within the centre of the zone which are Anaocha, Orumba North, Aguata, Nnewi South and Orumba South in Anambra State; Umunneochi, Bende, Ohafia, Arochukwu and Isuikwuato in Abia State; Afikpo North, Afikpo South, Ivo, Ohaozara and Onicha in Ebonyi State; Aninri, Oji River, Ezeagu, Udi and Awgu in Enugu State, and Idea to North, Idea to South, Okigwe, Orlu, and Orsu in Imo State. The dataset for this research work are from secondary and primary sources. Secondary Data were extracted from other journal publications among others, while primary data were in the form of measurement during field visit, photographs and geophysical soil survey and verification. Descriptive Statistics, Student t-test and Chi-square test analysis were used. The result shows that the soils across the study area generally are predominantly sandy with a mean of fine sand at 28.22% and coarse sand at 43.40%, while the mean of clay and silt are very low, 17.82% and 10.56% respectively. The study concludes that high sand content in the composition of soil in the study area is responsible for high rate of soil erosion in the area and therefore recommends a policy framework from the government of Nigeria that will encourage a paradigm shift from roots and tubers crop production that exposes the soil, to orchard plantation.

Estimation of clay content by magnetic susceptibility in tropical soils using linear and nonlinear models

The application of pedotransfer functions for soil attribute estimation has economic and environmental advantages. However, the appropriate choice of models is essential to obtain high accuracy. The aim was of this study was to evaluate the magnetic susceptibility (χ) potential to estimate soil clay content and to compare the estimation accuracy using linear (simple linear regression, SLR) and nonlinear models (power model, PM, and artificial neural networks, ANNs). An area of approximately 870 ha, cultivated with sugarcane in southeastern Brazil, was delimited and georeferenced for the collection of soil samples. Soil samples were collected every 2.5 ha (0.00–0.25 m), resulting in 372 points. A transect was directed in the area, and another 132 soil samples were collected at regular intervals of 30 m in the same layer. The samples were sent to the laboratory, and χ values were obtained for all points. Pedotransfer functions were developed to estimate the soil clay content using the χ values. The models were calibrated with the 372 points collected from the regular mesh of the 870-ha area, using the 132 points of the transect for validation. Regardless of the type of model applied to the pedotransfer functions, χ proved highly accurate for estimating soil clay content. However, the ANNs and PM increased the estimation accuracy, attenuated the error, and increased the estimation precision for soil samples with clay content below 200 g kg−1.

Магнетизм корінних порід та магнітна сприйнятливість ґрунту

Information support of modern agriculture and ecology forms a demand for ever higher requirements for efficiency and density of the sampling network. This fact determines the spread of high-performance methods of soil research, among which are magnetometric ones. However, these methods have a number of limitations associated with the existence in soils of ferromagnets of non-pedogenic nature. The purpose of the study is to show the patterns of spatial and profile distribution of soils with high values of magnetic characteristics, inherited from parent rocks as a result of pedogenesis. The research used: determination of specific magnetic susceptibility using kappabridge KLY-2, determination of volumetric magnetic susceptibility with kappameter KT-5 and induction of magnetic field by proton magnetometer MP 203. The study was conducted at two objects located in the central part of the Ukrainian shield region. Studies have shown that soils developed on the weathering crust are characterized by certain features of their magnetic properties. First of all, it depends on the petromagnetic parameters of the source rocks. On magnetic rocks, the MS of soils is determined primarily by inherited magnetic minerals. The magnetic susceptibility of such soils has two maxima. The first is in the upper part of the profile, where it is determined by the sum of pedogenic and terrigenous magnets. The second is located in the lower part of the profile, which consists almost entirely of weathering products.

Simulating wildfires with lab-heating experiments: Drivers and mechanisms of water repellency in alpine soils

Wildfires induce deep modifications in soils. Water Repellency (WR) is one of the prime edaphic properties experiencing alterations upon heating. Despite occurrence, extent and persistence of burning-induced soil WR has been extensively discussed, the dynamics at the basis of its formation (and loss) are still widely unclear. The vast majority of research on this topic has been conducted in the Mediterranean area, even if alpine environments are far from being untouched by fires. Alpine soils are less developed than Mediterranean ones, and differ in mineralogy and composition of organic matter (and thereby present different interactions). We thus wanted to clarify some key mechanisms regulating WR thermal alterations in an understudied environment.Our sampling design aimed at collecting soils representative of the Western Alps. Sample heating was performed in the lab at fixed temperatures (up to 300 °C), on a set of A horizons developed under pine and beech forest covers. Water Drop Penetration Time (WDPT) and Sessile Drop Contact Angle (CA) were used to test WR. Soils were analyzed in terms of organic matter (OM), pH, serpentine relative abundance, texture and DCB-extractable iron (Fe).WR was found to be extremely variable. Soils rich in OM, especially if containing abundant aromatic compounds, were found to be the most hydrophobic at room temperature. In samples exhibiting an increase in WR upon burning, repellency was maximized in correspondence of 200 °C. WR was drastically lost when samples were heated at temperatures greater than 200 °C. Above this threshold, pH systematically increased and the percentage of organic carbon (OC) sharply decreased. The change in pH is likely to have triggered an increase in the negative charge of mineral surfaces, resulting in a significant OM desorption and OC oxidation, eventually leading to a super-hydrophilic behavior in soil. The present investigation evidenced the susceptibility of Alpine soils towards thermal alteration, addressing the factors (organic matter composition and mineralogy) that mostly influence the hydrophobic behavior of these soils.

Тяжёлые металлы в почвах и мхах-эпифитах Ленинского района г. Ижевск

The article presents the results of studies on the assessment of heavy metal pollution of soils and epiphytes in of the city of Izhevsk. Objects of research: soils of near-trunk circles of black poplar (Populus nigra L.) and epiphytic moss of Schreber's pleurotium (Pleurozium schreberi (Willd. Ex Brid.) Mitt.). To assess the pollution, the magnetic susceptibility of soils and mosses was determined, as well as the average total content of heavy metals in the samples under study. The relationship between the content of heavy metals and the magnetic susceptibility of soils and epiphytes has been determined. A correlation was revealed between the total content of Zn, Cr, Fe, V in soils and in mosses, which indicates air pollution of soils. Keywords: MAGNETIC SENSITIVITY, HEAVY METALS, MOSSES-EPIPHYTES, AIR POLLUTION

Predicting Probability of Liquefaction Susceptibility Based on a Wide Range of CPT Data

In the present study, three efficient soft computing techniques (namely, genetic programming (GP), relevance vector machine (RVM), and multivariate regression splines (MARS)) are utilized to predict the probabilistic liquefaction susceptibility of soils based on reliability analysis. For this, a sum of 253 cone penetration test (CPT) data of 19 major earthquakes occurring between 1964 and 2011 have been collected from the literature. Six liquefaction parameters such as corrected cone penetration resistance, total vertical stress, total effective stress, maximum horizontal acceleration, magnitude moment, and depth of penetration are explored. To evaluate the overall performance of the proposed models, rank analysis has been carried out. Based on the values of performance indices, the GP model outperforms the other two models in terms of RMSE=0.15, R2 =0.77, and VAF=76.86 in the training stage while the same has been found 0.14, 0.81, and 80.46 in the testing phase. Also, the rank analysis confirms the superiority of the GP model in predicting the probability of liquefaction susceptibility of soils at all stages.

Seasonal variations in threshold wind speed for saltation depending on soil temperature and vegetation: A case study in the Gobi Desert

The threshold wind speed for saltation (Ut), an index of soil susceptibility to wind erosion, is affected by dynamics of various land surface conditions. Little information is available on the primary factors that affect Ut in the Gobi Desert. This study explored seasonal variations of Ut and its relations with land surface conditions at Tsogt-Ovoo, which is a dust source hotspot in East Asian drylands, based on a 6-year (2012–2017) measurement. The land surface parameters (soil moisture and temperature, and vegetation components of live, standing dead, and litter) were simulated by an ecosystem model. Results show that saltation tended to occur during February–June under strong western winds (>10 m s−1), with the highest frequencies in 2012 and 2015. The saltation season was divided into two periods: spring (February–early May) with an increase in saltation (i.e., a decrease in Ut); and early summer (late May–July) with a decrease in saltation (i.e., an increase in Ut). For 2012 and 2015, multi-regression analysis reveals that Ut negatively correlated with soil temperature in spring (R2adjusted = 0.39) and positively with vegetation components of live and standing dead in early summer (R2adjusted = 0.70). We assume that wind erosion was possibly enhanced through soil freeze–thaw processes and then was suppressed through plant growth in addition to dead leaves that were residues from the preceding summer. We establish a statistical model of Ut for this hotspot to analyze the relative contributions of erosivity and erodibility to wind erosion during 2012–2017.

Evaluation of flow liquefaction and liquefied strength using the cone penetration test: an update

A method to evaluate the susceptibility of soils to undrained strength loss that could result in flow liquefaction as well as a method to estimate the resulting liquefied undrained shear strength of predominately sand-like soils using the cone penetration test (CPT) were outlined by Robertson in 2010. Based on published data and recent case histories, this technical note describes a recommended update to these methods to estimate the large-strain liquefied or remolded undrained shear strength for both sand-like and clay-like soils as well as soils that transition from sand-like to clay-like. The proposed update acknowledges that soil behavior can vary from sand-like to clay-like and that CPT interpretation to estimate large-strain undrained shear strength changes due to the changing drainage conditions during the CPT. The updated method builds upon previously published data combined with recent experience and case histories.

Assessing anthropogenic contribution in highly magnetic forest soils developed on basalts using magnetic susceptibility and concentration of elements

Mineral magnetic properties are sensitive indicators for evaluating environmental changes, including environmental pressure caused by atmospherically deposited anthropogenic magnetic particles. The most commonly and easily measured magnetic parameter of soils is magnetic susceptibility, which reflects the combined ferromagnetic minerals of lithogenic, pedogenic, and anthropogenic origins. In volcanic soils rich in ferrimagnetic minerals, unfortunately, contributions of pedogenic and anthropogenic origins are masked by the lithogenic contribution. More study is therefore needed of soils developed on highly magnetic lithologies. This work aimed to determine links between magnetic susceptibility and concentration of potentially toxic elements derived from anthropogenic activities in soil (Aluandic Andosols) developed from highly magnetic parent material in a locality where contamination is not expected. The approach is based on relationships between magnetic properties and geochemical signatures of the investigated soils. Magnetic properties are represented by mass-specific magnetic susceptibility (χ) and frequency-dependent magnetic susceptibility (χFD%). Geochemical signatures are represented by concentrations of the elements Fe, Si, Ti, Zr, Sr, Al, Nb, Mn, Ca, Rb, K, P, Zn, S, Pb, Cr, V, Ni, Cu, and As; pH in H2O; soil organic carbon content; and granulometry. Soil contamination was evaluated using two indexes: enrichment factor and geo-accumulation index. Our findings show that χFD% correlates with presence of the toxic elements S and Pb, derived from human activities, while χ exhibits strong correlation with elements Al, Ti, V, and Fe, reflecting natural origin of parent material. In case of soils with well-developed humus horizon, χFD% can be used as a proxy parameter for identifying anthropogenic influence. Our findings are beneficial also for archaeologists using magnetic susceptibility of soils as a link to chemical signatures of past settlement activities.

Monitoring magnetic susceptibility and spatial distribution of soil attributes in different land uses: a case study in an arid and semi-arid region, southern Iran

The magnetic susceptibility (MS) technique could be used as an efficient tool for management, monitoring, and analysis of soil properties. This study was conducted to investigate the relationship among the magnetic parameters and soil surface properties as well as their spatial variation in different land uses in Fars Province, southern Iran. Three dominant land uses in the study area including cropland, barren, and pasture were selected, and a total of 72 samples were collected from the soil surface (0–15 cm). Physicochemical properties, total free (Fed) and amorphous (Feo) iron forms, and MS in both high (xhf) and low (xlf) frequencies were determined. The results showed a significant difference (p˂0.05) for xlf average values among different land uses which were decreased in the order of cropland (45.31× 10−8 m3 kg−1), barren (31.68 × 10−8 m3 kg−1), and pasture (17.84 × 10−8 m3 kg−1), respectively. There was a positive significant correlation (p <0.01) between the MS values and Fed and Fed-Feo, while a negative significant correlation was observed among xlf and EC, gypsum, and Feo/Fed. The spherical model suitably described the spatial behavior of magnetic parameters and soil properties. The spatial distribution maps represented an almost parallel pattern in the spatial variations of MS, Fed, Fed-Feo, and evolution index, but an inconsistent pattern for Feo, CaCO3, gypsum, and EC in the study area. This indicates the role of diamagnetic materials in decreasing the soil magnetic properties. Results of this study clearly revealed that the MS technique is of great potential in monitoring the spatial variations of soil properties.

Magnetic susceptibility of soils as affected by lithology, geomorphology and climate in Jazmoorian Watershed, central Iran

Magnetic susceptibility (MS) as a fast, non-destructive, and reasonable technique is very useful in soil genesis and evolution studies. The MS of soils along a climolithotoposequence in Jazmoorian Watershed was studied in the present research and the vertical distribution of MS in the representative pedons affected by soil forming factors (parent material, climate and relief) was also investigated. Rock pediment, mantled pediment, piedmont plain, alluvial fan, and playa geomorphic positions with two igneous (gabbro, diorite, granite, and andesite) and sedimentary (limestone, conglomerate and playa deposits) parent materials were selected. Thirteen representative pedons which best reflected the variations of soil forming factors were studied. Results of the study showed that the maximum (877.8 × 10−8 m3 kg−1) and the minimum (5.2 × 10−8 m3 kg−1) low frequency (χlf) MS were respectively determined in the soils formed on igneous and sedimentary parent materials. The χlf values were increased with depth in soils affected by igneous parent material, but the opposite trend was found in soils with a sedimentary origin. The activity ratio of Feo/Fed in xeric and aridic moisture regimes were 0.03 and 0.09, respectively. Meanwhile, MS value in surface soil of pedon 2 (with xeric moisture regime) is lower than its parent material which is a support for the higher weathering of this soil due to higher moisture compared to pedon 5 with an aridic moisture regime. Decreasing evolution trend of soils on igneous parent material was in the order of alluvial fan < piedmont plain < mantled pediment, but in the soils on sedimentary parent material was in the order of playa < rock pediment < mantled pediment < alluvial fan. Results of the study clearly showed that the soil χlf values changed with variations in climate, parent material, and topography.

Investigation of Internal Erosion Susceptibility of Core Soil from Three Dams

Laboratory tests on internal erosion of cohesionless soils are often performed on cells submitted to a controlled seepage. The cell dimension depends on the grain size of tested soil and must meet the geometric and hydraulic scale requirements as regards to the modeled process. Three specimens collected from different zoned dams in Morocco were characterized for their geotechnical properties and dispersion sensitivity, and then submitted in two different cells to internal erosion (Hole Erosion Test) under controlled seepage. The erosion kinetics was measured, and soil classification was assessed as regards to the useful engineering guidelines. The results showed that specimen dimensions can affect the erosion parameters which are quite different from a cell to another. Even though the derived erosion coefficient values are different from the two testing cells, the classification of the three soils regarding the susceptibility to erosion, using engineering guidelines, indicated that the tested soils fall overall in neighboring erosion classifications. However, the soil involving the lower clay content provided the greatest resistance against internal erosion.

Frost susceptibility of soils―A confusing concept that can misguide geotechnical design in cold regions

Frost susceptibility of soils―A confusing concept that can misguide geotechnical design in cold regions

Common-Origin Approach to Assess Level-Ground Liquefaction Susceptibility and Triggering in CPT-Compatible Soils Using ΔQ

AbstractCurrent engineering practice employs clean sand–based procedures to evaluate liquefaction triggering in nonplastic, coarse-grained soils and low-plasticity, fine-grained soils below level o...

Using the equation for computing the wind erodible fraction of soils in the conditions of the Czech republic

Abstract The erodible fraction (EF) of soil (soil aggregates and particles &lt;0.84 mm) is one of the basic factors according to which the susceptibility of soil to wind erosion can be assessed. The standard method for determining the EF content is the use of a rotary sieve. Nevertheless, its availability is limited by its price and the fact that it is not mass-produced and is necessary to build the sieve to order. An alternative method of determining the EF content is to use an equation based on knowledge of the content of sand, silt, clay, organic carbon, and calcium carbonate. However, this equation has only been tested for US conditions. Therefore, the research focuses on the validation of the equation for the conditions of the Czech Republic, specifically in the territory of Southern Moravia. The results show that the equation validated for the USA cannot be used to determine the EF content in soils of the Czech Republic. Using the statistical program Unistat©, a new equation was proposed with correlation coefficient R = 0.8238 which means good applicability of the equation for the local soils at least in the area of Southern Moravia.

Sources of Magnetic Particles from Air Pollution in Mountainous Area

Measurement of magnetic susceptibility of topsoil represents a very useful tool for the detection of atmospherically depositedmagnetic particles. The samples of forest soils from the Moravian-Silesian Beskydy Mountains (the Czech Republic) were used foridentification of emissions sources of particles with magnetic ordering. Magnetic susceptibility was measured at bulk samples ofgrain size class under 2 mm. Microanalysis using electron microscope with an energy dispersive X-ray spectrometer was used forthe determination of particles in the magnetic fraction. The samples of dust from the sintering plant of the Iron Works in the townof Třinec were analysed. The values of magnetic susceptibility of forest soils in the Třinec region are increased. In the relatively nearvicinity of the industrial area, the average value for Javorový Mount was 7.90×10-6 m3/kg, for Ostrý Mount it was 6.69×10-6 m3/kg. It was proved that they were higher than the average values from the Beskydy Mountains (4.64×10-6 m3/kg). The concentrationsof lead and magnetic susceptibility in soils showed significant correlation dependence (rs = 0.85). The iron and steel industryrepresent the primary source of the pollution load in forest soils of the studied area. Statistically, significant dependences betweenthe organic matter content and the lead and zinc concentrations as well as between the magnetic susceptibility values and the ironconcentrations in forest soils were found. It was confirmed that the airborne particles are deposited on vegetation and accumulatedin the organic horizon of forest soils.

High-resolution soil erodibility map of Brazil

Large-scale soil erosion modeling has a crucial role in the understanding and planning of soil and water conservation strategies. The lack of spatial data on soil characteristics required to compute the soil erodibility (K-factor) has been one of the greatest obstacles in Brazil. The K-factor is a complex property that expresses the susceptibility of soil to erode according to its inherent characteristics. This factor is a key input parameter for the most widely applied soil erosion models: the Universal Soil Loss Equation (USLE) and the Revised USLE (RUSLE). Here, we computed a high-resolution (250 m cell size) spatially explicit soil erodibility map across Brazil. To compute the K-factor, we applied the equations originally proposed in the USLE nomograph and EPIC, using the following soil properties, organic matter content, soil texture, soil structure, and permeability. To qualitatively evaluate our new K-factor map, its values were compared against standard K-factor values obtained from experimental plots across Brazil. We found that the USLE nomograph leads to a more precise estimation of the K-factor in Brazil than EPIC. The K-factor estimates by the USLE nomograph range from 0.0002 to 0.0636 t ha h ha−1 MJ−1 mm−1, with a mean value of 0.0181 t ha h ha−1 MJ−1 mm−1. Our findings pave the way for a better understanding of soil erosion across multiple scales and thereby contributing to better land-use planning and management in Brazil. The dataset is freely available at doi:https://doi.org/10.5281/zenodo.4279869

Spatial distribution of urea induced ammonia loss potentials of German cropland soils

Urea is currently the most distributed nitrogen fertilizer in the world. Its application to soil is accompanied by loss of ammonia (NH3), which contributes to eutrophication, soil acidification, formation of particulate matter and results in economic losses for farmers. Predicting susceptibility of cropland soils to release NH3 after urea fertilization is therefore of high interest for both society and farmers.The present study aimed at (i) developing a process-driven model that estimates susceptibility of cropland soils to release NH3 after urea application based on the most relevant processes occurring within the soil and (ii) to use this model to derive the spatial distribution of urea induced NH3 loss potentials of German cropland soils. Therefore, urea induced NH3 loss potential was studied in the lab for 26 German cropland soils and CEC, initial soil pH (pHi), texture and SOC were determined. For a subset of these soils (n = 12) soil buffer capacity and pH dynamic after urea application were also analysed.Ammonia loss potential of cropland soils was found to be primarily dependent on CEC, but is superimposed by pHi as well as SOC as they directly affect maximum soil pH during urea hydrolysis. Two process-driven models for estimation of Potential Ammonia Loss (PAL) were developed using either CEC and pHi (PAL 1; r2 = 0.82) or CEC, pHi and SOC (PAL 2; r2 = 0.88) as input variables. Due to limited availability of suitable spatial SOC data only PAL 1 could be applied for evaluating NH3 loss potentials of German cropland soils. The spatial distribution revealed a strong heterogeneity. Cropland soils susceptible to NH3 release due to urea fertilization are primarily located in northern and eastern Germany. Therefore, future large-scale estimations of NH3 loss due to urea fertilization need to consider regional soil characteristics identified here as most relevant for soil NH3 loss.