The stability of soil structure is crucial for providing most of the essential functions of soil. In our previous research in a region of Chernozem soil, multiple linear regression analysis showed that soil aggregate stability within this morphologically diverse study area could be predicted using the soil organic matter content and one of the terrain attributes. Therefore, this present study aims to determine if a similar procedure can be applied to areas of different soil types, namely a Haplic Luvisol, two Haplic Cambisols, and a Calcaric Leptosol. Basic soil properties such as the organic carbon (Cox) content, Fe content, Mn content, CaCO3 content, pH, magnetic susceptibility, bulk density (ρz), electrical conductivity, and water-stable aggregate (WSA) index were measured, and terrain attributes were derived using a system for automated geoscientific analyses and a digital elevation model. It was found that it was not possible to propose similar predictive models for all locations. The models included different combinations of the Cox content, CaCO3 content, Fe content, ρz, and various terrain attributes. The Cox content was the main parameter that positively affected the WSA index values in the areas of Luvisol and Leptosol soils. Magnetic susceptibility was the main parameter that positively correlated with the WSA index in the two areas of Cambisols, and in one Cambisol area, the WSA index was also positively correlated with the ratio between amorphous and crystalline Fe forms. Negative impacts were observed for ρz (Luvisol and one Cambisol) and the CaCO3 content (Leptosol). From the terrain attributes, slope was mostly included in the predictive models. The other attributes were the catchment slope and profile curvature. The best model prediction assessed based on the coefficient of determination was found for the Leptosol area (R2 =0.69), followed by the Luvisol are (R2 =0.60) and both Cambisol areas (R2 =0.52, respectively 0.33).

Background: Environmental magnetism, focusing on ferrimagnetic iron oxides, provides useful additional information on pollution of different environments. Magnetic methods have been applied to studies of atmospheric dust, namely PM10 (particulate matter smaller than 10 micrometers) in, e.g., industrial or urban areas. Until now, positive correlation was reported between concentration of iron oxides (expressed in terms of either magnetic susceptibility, saturation remanent or saturation induced magnetization) and concentration of PM10 or smaller. Purpose of this study was to verify the relationship between iron oxides and PM at monitoring site close to source of emissions rich in iron oxides during period of smoggy conditions. Results: We examined 24-hours PM10 and PM1 samples, collected during 10 days of smoggy winter period at a site close to steel plant, which represents a significant source of atmospheric emissions in industrial region of Northern Moravia (Czech Republic), known for generally high degree of air pollution. Magnetic hysteresis loops were measured in order to obtain parameters reflecting the concentration and grain-size distribution of iron oxides. Our data show unexpected negative correlation between saturation magnetization (concentration of ferrimagnetic iron oxides) and both PM1 and PM10 concentrations, to the best of our knowledge the trend not being reported yet. Conclusions: Our finding may seemingly disqualify magnetic methods as useful proxy in air pollution studies. However, we suggest that this is an exceptional case, specific to this region and monitoring site, as well as to synoptic conditions during the smoggy period. Although the significant dust emissions are presumably rich in iron oxides, the overall air quality at the monitoring site is determined by the general environment, controlled by many other sources of different character in the region, and by the specific climatic conditions. Thus, the nearby steel plant, presumably emitting dust rich in ferrimagnetic iron oxides, dominates the deposited dust at the nearby monitoring site only during very few days of suitable weather (namely wind speed and direction).

The effect of wood-ash fertilization on forest soils has been assessed mainly through geochemical methods (e.g., content of soil organic matter or nutrients). However, a simple and fast method of determining the distribution of the ash and the extent of affected soil is missing. In this study we present the use of magnetic susceptibility, which is controlled by Fe-oxides, in comparing the fertilized soil in the forest plantation of pine and oak with intact forest soil. Spatial and vertical distribution of magnetic susceptibility was measured in an oak and pine plantation next to stems of young plants, where wood ash was applied as fertilizer. Pattern of the susceptibility distribution was compared with that in non-fertilized part of the plantation as well as with a spot of intact natural forest soil nearby. Our results show that the wood-ash samples contain significant amount of ferrimagnetic magnetite with susceptibility higher than that of typical forest soil. Clear differences were observed between magnetic susceptibility of furrows and ridges. Moreover, the dispersed ash remains practically on the surface, does not penetrate to deeper layers. Finally, our data suggest significant differences in surface values between the pine and oak plants. Based on this study we may conclude that magnetic susceptibility may represent a simple and approximate method of assessing the extent of soil affected by wood-ash.

Copper ore mining and processing are among the most harmful anthropogenic influences for the environment and they are a subject of international and national law regulations. Recultivation of areas influenced by mining and processing industry is commonly applied and monitored in order to restore as much as possible the natural environment. In this study, environmental magnetic methods are applied in order to assess the degree of soil restoration in terms of soil development, after remediation of waste dump from Cu-processing plant. Soils developed under birch forest stands of different age (5, 15, and 25 years) as well as raw waste material were sampled along depth down to 20–30 cm. Variations in magnetic parameters and ratios obtained (magnetic susceptibility, frequency-dependent magnetic susceptibility, anhysteretic remanence (ARM), isothermal remanence (IRM), ARM/IRM100mT) suggest the presence of magnetic enhancement in the upper 0–15 cm, the thickness of this layer varying depending on the age of the forest stand. Magnetic mineral responsible for this enhancement is of magnetite type, while waste material contains a large amount of hematite, as evidenced by coercivity analysis of IRM acquisition curves and thermal demagnetization of composite IRM. Magnetic grain-sized proxy parameters suggest that magnetite particles are coarser, magnetically stable, while no or minor amount of superparamagnetic grains were detected at room temperature. A well-defined linear regression between the topsoil magnetic susceptibility and the approximate age of the forest stand provides an indication that the magnetic enhancement is of pedogenic origin. It is concluded that the observed magnetic enhancement of recultivated soils studied is linked to a combined effect of pedogenic contribution and possible additions of industrial ashes as a liming agent for soil restoration.

In studies of the magnetic properties of soils, the frequency-dependent magnetic susceptibility percentage (X-FD%) is often used for the identification of ultrafine magnetically superpara-magnetic/stable single-domain (SP/SSD) particles. This parameter is commonly used as an indicator for increased pedogenesis. In strongly magnetic soils, the SP/SSD magnetic signal ( mostly bio-pedogenic) may be masked by lithological signals; making pedogenesis hard to detect. In this study, we compare results for the detection of ultrafine SP/SSD magnetic particles in andic soils using two instruments: a Bartington MS2B dual-frequency meter and an AGICO Kappabridge MFK1-FA. In particular, the study focuses on the effect of pedogenesis by investigating the relationship between specific soil magnetic and chemical properties ( soil organic carbon and pH(H2O)). The values of X-FD% obtained with the MS2B varied from 2.4 to 5.9 per cent, and mass-specific magnetic susceptibility (X-LF) from 283 to 1688x10(-8) m(3) kg(-1), while values of X-FD% and X-LF obtained with the MFK1-FA varied from 2.7 to 8.2 per cent and from 299 to 1859 x 10(-8) m(3) kg(-1), respectively. Our results suggest that the detection of the SP/SSD magnetic fraction can be accomplished by comparing relative trends of X-FD% along the soil profile. Moreover, the discrimination between bio-pedogenic and lithogenic magnetic contributions in the SP/SSD fraction is possible by comparing the X-FD% and X-LF data determined in the fine earth (<2 mm) and the coarse fraction (4-10 mm) samples down the soil profile.

In the case of andic soils − developed on volcanic rocks − permanently humid conditions are essential for andosolisation processes. Although volcanic rocks are usually rich in highly magnetic iron oxides, knowledge about these minerals in andic soils with respect to the soil development is missing. The aim of this contribution is to investigate the relationship between magnetic and basic chemical properties of soils developed on volcanic basement and parameters related to the pedogenesis factors. The studied sites are located on basaltic lava flows in the eastern part of the French Massif Central. Investigated pedons with alu-andic, sil-andic, and vitric properties were pedologically described and analysed by a set of magnetic and soil-chemical methods. Magnetic parameters include low-field volume-specific and mass-specific magnetic susceptibility, frequency-dependent magnetic susceptibility, remanent properties (including S-ratio) and coercivities. Chemical parameters included the pHH2O, soil organic matter, total cation exchange capacity, base saturation, and content of Fe and Al extracted in dithionite-citrate, acid-ammonium oxalate, and pyrophosphate solutions. Micro-morphology of Andosols and parent material was observed by scanning electron microscopy, completed with energy dispersive spectrometry. The pedogenesis factors are represented by parent-rock age, annual precipitation, and soil thickness. Our findings suggest that (1) precipitation is the most important pedogenesis factor with a strong relationship to the relative magnetic grain-size, concentration of ferrimagnetic minerals, aluminium dissolved in pyrophosphate and acid-ammonium oxalate, and content of organic matter; (2) parent-material age shows a well-pronounced relationship with magnetic grain-size parameters represented by the frequency-dependent susceptibility and ratio of saturation remanent to saturation induced magnetisation (Mrs/Ms), selective dissolution parameters, and pHH2O; (3) thickness of soil profile shows a link to Mrs/Ms, pHH2O, and content of organic matter.

This study focused on developing a method for estimating topsoil organic carbon content from measured mass-specific magnetic susceptibility in Chernozems heavily affected by water erosion. The study was performed on a 100 ha area, whereby 202 soil samples were taken. A set of soil samples was divided into 3 subsets: A (32 samples), B (67 samples), and C (103 samples). The mass-specific magnetic susceptibility using low (χlf) and high (χhf) frequency, and organic carbon content were measured at all soil samples. The contents of iron and manganese, extracted with a dithionite-citrate solution (Fed, Mnd) and ammonium oxalate (Feo, Mno), were quantified in A and B samples. Models for predicting organic carbon content from magnetic susceptibilities were designed as follows: (1) subset A was used as the training set for calibration, and subsets B and C were used as the test sets for model validation, either separately (subset B only), or together (merged subsets B and C); (2) merged subsets A and B were used as the training set and subset C was used as the test set. Results showed very close correlations between organic carbon content and all measured soil properties. Obtained models relating organic carbon content to mass-specific magnetic susceptibility successfully predicted soil organic carbon contents.

Knowledge of spatial distribution of soil aggregate stability as an indicator of soil degradation vulnerability and its possible prediction are required for many scientific and practical environmental studies. The goal of our study was to provide a model for predicting soil aggregate stability within morphologically diverse areas, where soil properties have been affected by soil material redistribution due to erosion. The study was performed on a study site (6 ha area) in the loess region of Southern Moravia, Czech Republic. Haplic Chernozem, which is an original dominant soil unit, has been transformed into different soil units (eroded phases of Chernozem, Regosol, colluvial Chernozem and Colluvial soil). 36 sampling spots were selected in order to represent diverse soils. The following soil properties were measured: oxidable organic carbon content (C-ox), CaCO3 content, pH(H2O), PHKCl, soil particle density (rho(s)), bulk density (rho(d)), porosity (P), actual field soil-water content (theta(field)), content of iron and manganese (in ammonium oxalate extract, Fe-o and Mn-o, and dithionite-citrate extract, Fe-d and Mn-d) and mass specific magnetic susceptibility (chi(lf) and chi(hf)). The aggregate stability was assessed using various tests to study different disruption mechanisms. Terrain attributes were derived from a digital elevation model.In general, the lowest soil aggregate stability was observed on steep slopes, which were highly impacted by soil erosion. The highest aggregate stability was measured on soils sampled at relatively flat upper parts, which were less influenced by erosion processes. Higher stability was also obtained on toe slopes, where the sedimentation of previously eroded soil material occurred. The simple correlations revealed that characteristics resulting from the tests studying aggregate slaking due to the compression of the entrapped air (Water Stable Aggregate index and coefficient of vulnerability from fast wetting test) were positively impacted by the C-ox, P, Fe-o, Mn-o, Fe-d, Mn-d, chi(lf) and chi(hf) values, and negatively by the rho(d) value. The soil aggregate stability was also negatively influenced by the plan and total terrain curvatures, i.e. larger aggregate stability was measured at concave parts in comparison with that at convex parts. Almost no statistically significant relationships were found in the case of the tests evaluating either aggregate disintegration caused by the micro-cracking due to the different swelling, or by the physico-chemical dispersion due to the osmotic stress or the mechanical aggregate breakdown. The multiple linear regressions resulted in the model for estimating the WSA index using the C-ox content, total terrain curvature and actual field soil-water content (theta(field)). In this model the C-ox content positively and the total terrain curvature and theta(field) value negatively influenced the value of the WSA index. Since C-ox was positively related with iron content and thus also with the magnetic susceptibility, the alternative model was proposed for less costly and time consuming WSA estimation. The WSA index may be predicted by combining the mass specific magnetic susceptibility (chi(lf) and chi(hf)), total terrain curvature and actual field soil-water content (theta(field)). (C) 2015 Elsevier B.V. All rights reserved.

Identification of Andosols is primarily based upon the content of their colloidal constituents—clay and metal‐humus complexes—and on the determining of andic properties. This needs time and cost‐consuming geochemical analyses. Our primary aim of this study is to describe the magnetic and geochemical properties of soils rich in iron oxides derived from strongly magnetic volcanic basement (in this case Andosols). Secondary aim is to explore links between magnetic and chemical parameters of andic soils with respect to genesis factors: parent material age, precipitation, and thickness of the soil profile. Six pedons of andic properties, developed on basaltic lavas, were analyzed down to parent rock by a set of magnetic and geochemical methods. Magnetic data of soil and rock samples reflect the type, concentration, and particle‐size distribution of ferrimagnetic minerals. Geochemical data include soil reaction (pH in H2O), cation exchange capacity, organic carbon, and different forms of extractable iron and aluminum content. Our results suggest the following: (1) magnetic measurements of low‐field mass‐specific magnetic susceptibility can be a reliable indicator for estimating andic properties, and in combination with thermomagnetic curves may be suitable for discriminating between alu‐andic and sil‐andic subtypes. (2) In the studied Andosols, strong relationships were found between (a) magnetic grain‐size parameters, precipitation, and exchangeable bases; (b) concentration of ferrimagnetic particles and degree of crystallization of free iron; and (c) parameters reflecting changes in magneto‐mineralogy and soil genesis (parent material age + soil depth).

Evaluation of soil erosion using common direct methods is costly and time-consuming. Therefore there is a need to develop suitable indirect methods for this purpose. One of the alternative methods that can be used is measurement of soil magnetic properties. The aim of this study is to evaluate the suitability of measuring magnetic susceptibility in assessing soil degradation due to erosion at two locations with different soil types. After the application of an empirical model to predict the values of magnetic parameter after erosion of soil material from the surface, the amount of soil loss is estimated. The first site is located in Southern Moravia. Dominant soil unit was Chernozem that was gradually degraded on steep slopes to Regosols. Second study site is in Central Bohemia, where dominant soil unit is Luvisol, gradually transformed to Regosols due to soil erosion.

Dust emission and deposition in topsoil have negative effect on individual components of the ecosystem. In addition to routine geochemical analyses, magnetic measurements may provide useful complementary information related to the type, concentration and grain-size distribution of the technogenic magnetic particles (TMPs) and thus the degree of contamination of the environment. The aim of this contribution is to use magnetic parameters in distinguishing dust from a wide range of sources of air pollution (power industry, cement, coke, ceramic industries and biomass combustion). We measured magnetic susceptibility, hysteresis parameters and thermomagnetic curves. Our results suggest that predominant component in tested samples is magnetite, only dust from coking plant and the combustion of lignite contained also maghemite and/or hematite. Mixture of sizes, ranging from fine single-domain to coarse multi-domain grains, was detected. Our results indicate that industrial dusts from various sources of emissions have different specific magnetic properties and magnetic measurements may provide very helpful information.