Abstract: Clear-cut areas formed after forest decline due to acid deposition, pest attacks, or wind-breaks in temperate mountainous regions are often populated by grass (mainly Calamagrostis villosa). This study focused on the changes of soil chemical characteristics under the grass cover replacing the forest, focusing mainly on aluminium (Al) speciation. Clear-cut area due to strong acid deposition in the Jizera Mountains (Northern Bohemia) was studied. The soils under grass cover exhibit higher pH values and lower exchangeable Al content compared to adjacent surviving forest. Mobile Al species under the grass have larger proportion of non-toxic organic complexes. The content of exchangeable base cations is slightly higher under the grass. The positive effect of grass on soil chemistry was enhanced by liming. The temporary grass cover can therefore improve soil chemical quality for following reforestation. However, the differences are generally limited to surface organic horizons. Similar results were found also on a bark-beetle clear-cut area in the Bohemian Forest (Southern Bohemia) with smaller acid deposition; nevertheless, most differences were not significant there.
Abstract: Soil acidification and consequent Al release is a problem particularly under forests in mountainous areas of the Czech Republic. It is controlled by a number of factors, like acid deposition, forest type, parent rock, altitude, etc. The Jizera Mountains region presents an area heavily influenced by acidification and forest decline. This paper focused on the effect of stand factors on spatial distribution of soil characteristics of the surface organic (0) and sub-surface (B) horizons from 98 sites using a combination of principal component analysis (PCA) and geostatistics. In the PCA, five principal components (PC) describing more than 70% of total variation were selected. The properties of the O and B horizons (pH, C, N, and S content, potentially dangerous Al forms) were in most cases separated, suggesting different processes and effects in each horizon. Spatial variation of PC scores was analysed using variograms, maps of their distribution were created using kriging. Spatial correlation with stand factors (altitude, slope aspect, forest type and age, soil unit, liming, and grass cover) was analysed using cross-variograms. The surface horizons are more sensitive to external influence (acid deposition, liming, grass expansion) and their spatial variation is stronger. The B horizons are more influenced by forest type (beech vs. spruce) and age, and by soil units (cambic vs. spodic horizons). The effect of stand factors is complex and often indirect. Nevertheless, used combination of pedometrical methods provided concise information about spatial variation and relationships between soil characteristics and the effect of stand factors.
Abstract: Anthropogenic soils are formed by human activities. The contents of potentially risk elements are one of the most important criteria of the exploitability of such soils for the agricultural production. The aim of this paper is to assess the contents of the selected potentially risk elements in 16 areas of the Sokolov region, including 5 reclaimed areas and 11 natural soils. 116 sampling locations were analysed in total. Another aim is to analyse the relationships between the elements, using multivariate statistical methods. The contents of the risk elements studied were in most cases under the limit values. In some cases, as with Pb, they were very low compared to the limit values. In the principal component analysis, four components explaining 74% of total variability were selected. The first component (30.2% of variability) showed strong correlations with Mn, V, Ni, and Cu contents. The second component (15.8% of variability) correlated with As and Be. The third component (14.3%) correlated with Pb and Cd. The fourth component (13.7%) correlated with Zn and Cr. The mean scores of each area were projected into the component plots, which enables the assessment of the relative importance of each group of elements in each particular area. The reclaimed and the natural soils are clearly distinguished. It can be concluded that the contents of the risk elements studied do not currently present any important problem in the reclaimed areas. Nevertheless, the situation should be further monitored.
Abstract: The objective of this study was to investigate the benefits of methods that incorporate terrain attributes as covariates into the prediction of soil depth. Three primary terrain attributes – elevation, slope and aspect – were tested to improve the depth prediction from conventional soil survey dataset. Different methods were compared: 1) ordinary kriging (OK), 2) co-kriging (COK), 3) regression-kriging (REK), and 4) linear regression (RE). The evaluation of predicted results was based on comparison with real validation data. With respect to means, OK and COK provided the best prediction (both 110 cm), RE and REK gave the worst results, their means were significantly lower (79 and 108 cm, respectively) than the mean of real data (111 cm). F-test showed that COK with slope as covariate gave the best result with respect to variances. COK also reproduced best the range of values. The use of auxiliary terrain data improved the prediction of soil depth. However, the improvement was relatively small due to the low correlation of the primary variable with used terrain attributes.
Abstract: This paper is focused on soil organic matter quality assessment in acid forest soils. Soil samples were collected in the Jizera Mountains region. Vegetation cover of sampling sites was formed by spruce or beech monocultures. Humus quality was assessed by the ratio of absorbances of pyrophosphate soil extract at the wavelengths of 400 and 600 nm (A400/A600). Humus fractionation was performed on selected soil samples. DRIFT spectra of individual fractions were measured. Higher pH and lower C and N contents were found in beech forest than in spruce forest. A400/A600 well correlates with C and N contents (r = 0.510*** and 0.615***, respectively). C and N content increases as to humus quality decreases. DRIFT spectra of fulvic acids turned out to be unsuitable for describing differences in humus quality. DRIFT spectra of humic acids and humin were hence more suitable. The difference between spruce and beech forest was found in 1514.cm–1 (C=C bounds of benzene rings) and 1550 cm–1 (N-H bounds in monosubstituted amides) bands intensities. Humic acids and humin coming from the O horizons of beech forest are relatively enriched by nitrogen functional groups. Values of humic acids aromaticity index did not differ between beech and spruce forests. DRIFT spectroscopy was shown as a possible method for detailed humus quality studying.
Abstract: Soils of reclaimed dumpsites after coal mining are considered as typical anthropogenic soils. These soils are at the beginning of their development and have certain specific characteristics. The aim of this study was to describe a soil survey performed on anthropogenic soils of a reclaimed dumpsite, to analyse spatial variability of selected properties using geostatistical methods, and to evaluate the development of reclaimed dumpsite soils. It has been shown that geostatistical methods are suitable for a description of anthropogenic soil properties and their variability. However, characterization of soil properties on the border between areas with different types of reclamation can be difficult due to sharp discontinual transitions caused by human activity. Properties of these soils vary profoundly greatly dependent on the properties of the soil substrate and the type of reclamation. The average content of organic carbon in the topsoil (0–20 cm) was 1.92% on the area covered with a layer of natural topsoil and 0.92% on the area covered by a layer of loess. An initial A horizon can develop even in 10 years under favourable conditions.
Abstract: Remote sensing data have an important advantage; the data provide spatially exhaustive sampling of the area of interest instead of having samples of tiny fractions. Vegetation cover is, however, one of the application constraints in soil science. Areas of bare soil can be mapped. These spatially dense data require proper techniques to map identified patterns. The objective of this study was mapping of spatial patterns of bare soil colour brightness in a Landsat 7 satellite image in the study area of Central Bohemia using object-oriented fuzzy analysis. A soil map (1:200 000) was used to associate soil types with the soil brightness in the image. Several approaches to determine membership functions (MF) of the fuzzy rule base were tested. These included a simple manual approach, k-means clustering, a method based on the sample histogram, and one using the probability density function. The method that generally provided the best results for mapping the soil brightness was based on the probability density function with KIA = 0.813. The resulting classification map was finally compared with an existing soil map showing 72.0% agreement of the mapped area. The disagreement of 28.0% was mainly in the areas of Chernozems (69.3%).
Abstract: Soil acidification promotes Al release from minerals and parent bedrocks; it also affects Al mobilization and speciation. Speciation of KCl extractable and water-extractable Al in forest soils was done by means of HPLC/IC method. Species Al3+ were the most abundant Al forms in the KCl extracts (around 93%). Prevailing Al forms (more than 70%) in aqueous extracts were AI(X)(1+), {i.e., Al(OH)(2)(+), Al(SO4)(+), AIF(2)(+), Al(oxalate)(+), Al(H-citrate)(+), etc.} species. It is assumed that most of KCl and water-2 extractable Al is bound in soil sorption complex (i.e., highly dispersed colloidal fraction of the soil solid phase creating negative charge) where majority of Al exists in the form of Al3+ species. The ECEC values, total carbon content and parameters related to soil organic matter composition (N and S content) have apparent effect on Al speciation. The most toxic Al3+ species are more concentrated in the B horizons compared to the A and E horizons. Aqueous extracts simulate Al release to soil solution under normal conditions; it can thus exhibit the actual Al toxicity. On the other hand, KCl extraction describes a potential threat for case of strong disturbance of natural soil conditions.
Abstract: Massive forest damage has been observed in certain mountainous regions affected by acidification. Declining of trees is ascribed to direct effect of SO2 and also increasing concentration of mobile forms of Al in soils. The aim of this paper is to describe the influence of stand factors to distribution of Al forms in the Jizera Mountains region, Czech Republic. A set of 251 samples from 98 sites was collected. Basic soil characteristics and the content of different Al forms were determined. The amount and relative share of these Al forms under different types of vegetation was evaluated, with emphasis on the surface organic horizons. The results showed that phytotoxic mobile Al forms are, the most influenced by altitude and organically bound Al forms by forest type. Non-toxic forms of Al are more abundant in broadleaved forest. Soils under coniferous forest are-more affected by acidification.
Abstract: Soil acidification in mountainous regions of the Czech Republic presents a serious problem. This paper summarizes several projects dealing with this problem exploiting different methods and having different objectives: 1) Long-term soil and forest development in the Krkonose Mountains. 2) Soil and forest development along an elevation transect in the Sumava Mountains. 3) Long-term effects of liming. 4) Comparison of soil acidification between three mountainous regions, with emphasis on labile Al content. 5) Spatial distribution and factors of soil acidification and Al release in the Jizera Mountains. The results of these projects showed that acidification in forest soils in the mountainous areas is caused by a combination of different factors, especially by the type of vegetation, atmospheric deposition, parent rock, altitude, and others. A slight improvement of soil properties is apparent after the decrease of immissions in the 1990's.
Abstract: Distinguishing between different sources of potentially toxic elements in soils can be difficult. This paper describes an application of principal component analysis (PCA) to distinguish between geogenic enrichment and anthropogenic pollution with Be, Cd, Co, Cr, Cu, Hg, Ni, Pb, and Zn at 14 localities in Northern and North-eastern Czech Republic. Element speciation, profile distribution, and local geology were used to facilitate interpretation of the PCA results. Of the total element contents in the topsoil and subsoil, a group of non-polluting elements, comprising Co, Cr, Cu, Ni, and Zn, was identified by PCA. There were more non-polluting elements in the subsoil than in the topsoil. The silicate-bound fraction was the most abundant in their speciation. They are likely to be mainly of geogenic origin, therefore. Beryllium also probably originated mainly from parent rocks. However, it had a closer relationship with geogenic Hg and Pb. Cadmium, Pb, and Hg showed strong topsoil enrichment. In speciation, there were larger proportions of their mobile and mobilizable fractions. This implies a significant contribution of anthropogenic pollution to their soil content. In addition, sites with some geochemical anomaly and polluted sites were indicated by the PCA. The analysis provided a concise summary of the complex information on both the generally prevailing origin of potentially toxic elements and the origin of elements at individual sampling localities.
Abstract: In order to determine the mobility of Pb, Zn and Cd in soils from the PÅ™Ãbram region (Czech Republic) heavily contaminated by metallurgy, two profiles of alluvial soils were closely studied. Total contents of heavy metals were determined after digestion with a mixture of HF and HClO4. Heavy metal mobility was assessed using the mobility factor (MF) that represents the proportion of heavy metals present in the exchangeable and carbonate bound fraction based on the Tessier’s sequential extraction procedure. The MF ranged from 2 to 46% for lead, 19 to 62% for zinc and 61 to 94% for cadmium. The profile distribution of zinc and cadmium showed a variable development with depth, which is caused by high amounts of these metals present in labile forms. The profile distribution of lead (the least mobile metal) is characterized by a gradual decrease with depth. The results indicate a higher contamination of the soil profile situated 2.5 km away from the smelter in comparison with the profile in its close vicinity. This fact confirms the existence of extreme fluvial contamination.
Abstract: Soil acidification and Al release in forest soils is controlled by a number of factors, like acid deposition, forest type, parent rock, altitude, etc. This paper studies the principal stand factors affecting spatial distribution of the content of KCl-extractable Al (Al-KCl, mainly exchangeable), Na4P2O7-extractable Al (AI(Na4P2O7)) mainly organically bound), and other soil characteristics related to acidification in surface organic (O) and subsurface mineral (B) horizons in the Jizera Mountains region. Geostatistical methods were exploited. The highest Al-KCl contents in the O horizons were related to high S and N content, low pH and low Ca and Mg content in soil. Liming decreased Al-KCl contents in the O horizons. Al-NaP2O7 in the O horizons was more abundant under spruce than under beech; in both horizons it was increased on the immission clear-cut areas populated by grass. Surface horizons are more sensitive to external influence (acid deposition, liming) and their spatial variation is stronger. In the mineral horizons, the effect of pedogenetic processes is more important. The effect of stand factors on Al behaviour is complex and often indirect, mediated for example by organic matter or soil reaction. It is difficult to clearly distinguish the effects of the particular factors.
Abstract: The aim of this study is to find a suitable treatment of conventional soil survey data for geostatistical exploitation. Different aims and methods of a conventional soil survey and the geostatistics can cause some problems. The spatial variability of clay content and pH for an area of 543 km(2) was described by variograms. First the original untreated data were used. Then the original data were treated to overcome the problems that arise from different aims of conventional soil survey and geostatistical approaches. Variograms calculated from the original data, both for clay content and pH, showed a big portion of nugget variability caused by a few extreme values. Simple exclusion of data representing some specific soil units (local extremes, non-zonal soils) did not bring almost any improvement. Exclusion of outlying values from the first three lag classes that were the most influenced due to a relatively big portion of these extreme values provided much better results. The nugget decreased from pure nugget to 50% of the sill variability for clay content and from 81 to 23% for pH.
Abstract: This study examined consistency of spatial variation of plant-available soil nutrients P, K, Mg and soil pH in two fields of an area of 54 and 67.5 ha (haplic Luvisol and luvic Chernozem) in the region of Cesky Brod (Central Bohemia). Computed variograms showed a spatial dependence extending to 150 m on an average with small fluctuations for most analysed data sets. These results of two different fields indicate that soil spatial variation is rather a general feature than specific to every field. However, soil available Mg in one field showed a shorter-range (89 m) and soil pH in the other showed considerably longer-range (375 m). Consistency of spatial variation features makes it possible to construct regional average and proportional variograms with great precision. This can bring further practical opportunities.
Abstract: Soil organic matter is important in controlling heavy metal behaviour in soils. This study aims to determine the distribution of organically bound Cd, Pb, and Zn between humic and fulvic acids in 20 samples of heavily polluted Fluvisols. Traditional procedure of alkaline sodium hydroxide/pyrophosphate extraction of humic substances with consequent humic acids precipitation by acidification was used. All of the three metals were bound predominantly on fulvic acids (mean share was 98.4, 82.0, and 95.7% of total organically bound Cd, Pb, and Zn content respectively). Mainly the level of pollution controlled the amount of metals bound on fulvic acids. On humic acids, a limited amount of specific sorption sites for the metals is expected. Lead content bound on humic acids was negatively correlated with soil pH. The results suggest relatively high potential mobility of organic fractions of heavy metals in soils under this study. The selectivity of alkaline extracting agent is briefly discussed.
Abstract: Labile Al forms can be dangerous in acid soils due to their potential toxicity to plants. This paper deals with the distribution of exchangeable, weakly organically bound, and total organically bound Al forms in soils on 98 sites of the Jizera Mountains region. For the extraction of these Al forms, 0.5M KCI (Al-KCl), 0.3M CuCl2 (Al-CuCl2), and 0.05M Na4P2O7 (Al-Na4P2O7) solutions were used, respectively. Aluminium concentrations in all extracts were determined by means of ICP-OES. Following mean concentrations of Al forms were found in the O and B horizons (mg/kg): Al-KCl - 1236 and 832, Al-CuCl2 - 4268 and 1945, and AlNa4P2O7 - 5043 and 8420. Basic soil characteristics were determined by commonly used methods. Their influence on Al forms distribution was assessed. Factor analysis showed that the most important soil factors controlling Al forms distribution were soil reaction and the total content of Ca (or Ca and Mg in the B horizon).
Abstract: Labile Al forms and species can be a threat in acid soils due to their potential toxicity to plants. However, there is no universally accepted extraction method. Several extraction reagents for Al release from soil have been tested. KCl (0.5 or 1 M) is recommended for extraction of exchangeable Al, while 0.5 or 0.3 M CuCl2 is suggested for extraction of 'weakly organically bound Al'. Both 0.1 and 0.05 M Na4P2O7 are shown to be suitable for the extraction of 'total organically bound Al'. These extractions are relatively simple, robust, and applicable to different soils and soil horizons. In the second part of the paper, detailed speciation of exchangeable soil Al by means of an HPLC instrument equipped with an ion column (IQ is presented. An experimental set-up is described and tested on a set of samples. Interpretation of the speciation results is proposed, based on the separation of Al ions and Al complexes according to their charge. Speciation is shown to be dependent mainly on soil pH and organic matter quality. A general scheme of Al fractionation and speciation in soil is proposed.
Abstract: The low capacity of acid sandy soils to bind P is one reason for the leaching and runoff of P from these soils. Various soil amendments have been used to reduce P leaching. This study was conducted to show the effect of CaCO3, dolomite, gypsum, and CaCl2 on P retention by the Ap horizon of a Spodosol. Phosphorus sorption was studied in a batch experiment at an initial P concentration range of 0 to 10 mg L-1. The amendment rate used was 0.05 mmol of either Ca or Ca + Mg (and also 0.1 mmol in the case of CaCO3 and gypsum) per g of soil. The influence on P retention of time after soil amendment (1 h to 1 week) was assessed. P adsorption was described by Langmuir and Freundlich equations. All amendments, except for CaCl2, increased soil pH and P retention by soil. CaCO3 was more effective then dolomite, the carbonates (CaCO3 and dolomite) were more effective in their interaction with the soil, and gypsum increased P retention by itself, its effect was weakened upon interaction with soil. Sorption of P in soil amended with gypsum was faster than sorption in soil amended with CaCO3. The effect of the amendments under study was mainly to provide Ca ions, which must be accompanied by an increase in pH to increase P retention.
Abstract: The distribution of cadmium, lead and zinc in exchangeable, organic, and 2M HNO3-extractable fractions as well as the effect of heavy metal concentrations on soil microflora was investigated. Six sampling transects were chosen in the Litavka River alluvium in 1999-2001. Concentrations or all metals increased with decreasing distance from the Source of contamination. The concentrations of Cd and Zn in exchangeable fraction were higher than in organically bound fraction, a reverse trend was found in Pb speciation. All measured parameters of soil microbial activity were affected by heavy metal concentrations. The decrease in CFU was most significant in the case of oligotrophic bacteria and spore-forming bacteria. Significant inhibition of C-biomass occurred in soils highly contaminated by heavy metals. The C-biomass:C-ox ratio decreased with increasing soil pollution. Generally, the values of enzymatic activities were highest in the soil above the source of contamination and they were decreased as approaching the Source of contamination. Our results demonstrate that several parameters of microbial activity could be used as good indicators of increasing concentrations of Cd, Pb, and Zn in soil.
Abstract: Analysis of spatial distribution and correlation of soil properties represents an important outset for precision agriculture. This paper presents an analysis of spatial distribution and mutual correlations, both classical and spatial, of soil properties in an agricultural field in Klucov. Clay and fine silt content, pH, organic carbon content (C-org), moisture (Theta), total porosity (P-t), capillary porosity (P-c), and coefficients of aggregate vulnerability to fast wetting (K-v1), to slow wetting and drying (K-v2), and to mechanical impacts (K-v3) were determined. Semivariogram ranges from 206 m (clay content) to 1120 in (K-v3) were detected. Many relationships between soil properties were spatially based. Fine silt content and C-org proved to be the most important soil properties controlling all the three aggregate vulnerability coefficients, which was not clear for K-v2 from classical correlation only. Determined spatial correlations and similarities in spatial distribution may serve as groundwork in delineation of different zones for site-specific management.
Abstract: Stability of soil structure represents an indicator of soil quality. The aim of this paper was to assess the effect of soil properties on structure vulnerability in an Orthic Luvisol. The aggregates were most vulnerable to fast wetting (mean K-v1 = 9.99, i.e. this effect can decrease the aggregate size 9.99 times). Lower destruction was caused by slow wetting and drying (K-v2 = 3.70) and mechanical forces (K-v3 = 1.67). Fine silt (particles of 0.002-0.01 mm) was the most important soil characteristic decreasing aggregate vulnerability (r = -0.334, -0.248, and -0.393 for K-v1, K-v2, and K-v3, respectively). Silt (0.01-0.05 mm) increased vulnerability to fast wetting (r = 0.318). Very fine sand (0.05-0.1 mm) increased vulnerability to mechanical impacts (r = 0.307). Organic carbon decreased vulnerability only slightly. Humus quality was rather related to porosity. Higher moisture of samples in time of collection increased aggregate vulnerability. Multiple regression, used for description of the effect of basic soil properties, provided the best model for K-v1 (R-2 = 27.45%), the poorest for K-v2 (R-2 = 7.23%).
Abstract: Spatial heterogeneity of dumpsite soils differs from that of natural soils due to their anthropogenic origin, which makes description of their properties more complicated. In anthropogenic soil of a reclaimed dumpsite in Northern Bohemia, the spatial distribution and interrelations among basic soil properties and two aluminum forms were studied by a combination of factor analysis and geostatistics. Similar distribution patterns were found for soil pH, exchangeable acidity, oxidizable carbon content, pyrophosphate-extractable organic carbon and labile Al. Humus quality parameter (A(400)/A(600) ratio) and Al extractable with sodium pyrophosphate showed different spatial distributions. Ranges of variogram models (spherical with nugget) for most of these variables were between 280 and 290 m; their distribution patterns were related to topsoil reclamation management. In factor analysis, three factors explaining 83.8% of total variation were selected and their interpretation was facilitated by kriging. The first factor accounted for positive effects of soil reclamation, including decreasing soil acidity and labile aluminum content, whereas the influence of afforestation, especially on humus quality and content, was well pronounced in the second factor. The effect of depositing, indicated by elevation. was probably expressed in the third factor influencing aluminum content extractable with sodium pyrophosphate. Geostatistics proved to be useful for anthropogenic soils on reclaimed areas where spatial distribution of soil properties is determined more by human activity than by natural evolution.
Abstract: Several proxy methods have been used recently to outline increased levels of pollution, One of them is based on measurements of the concentration of (ferri)magnetic minerals of anthropogenic origin. This method has been used recently in the mapping of both polluted and unpolluted areas. In order to validate this method, a more detailed study of links between magnetic parameters characterising the physical shape of magnetic minerals and concentrations of heavy metals is needed. In this study, we analysed the magnetic characteristics of alluvial soils, formed as a result of several breakdowns of wet deposit sink of ashes from a lead ore smelter. The soils were previously analysed for concentration of lead, zinc and cadmium. Our results show that in this case of a shared source of heavy metals and magnetic minerals, simple measurements of magnetic susceptibility discriminate well between polluted and clean areas. In addition, the concentration pattern agrees with the concentrations of the heavy metals studied in deeper soil layers that were not affected by post-depositional changes due to climate and remediation efforts. (C) 2001 Elsevier Science B.V. All rights reserved.
Abstract: Forest decline in North-Bohemian mountains have been attributed to soil acidification caused by acid deposition and consequent release of toxic Al forms in soil. This study was aimed at the comparison of soil acidification indices among mountainous regions of Krusne hory and Jizerske hory in Northern Bohemia and Sumava region in Southern Bohemia. Soil pH, exchangeable acidity, organic carbon content, humus quality, labile and organically bound Al content, potential cation exchange capacity, base saturation and content of major base cations (Ca, Mg, and K) were determined in both forest and grassland soil samples from the three areas. it was shown that the acidification rate generally followed the order Jizerske hory > Sumava > Krusne hory. Principal cause of soil acidification was forest vegetation. Acidification and Al release were intensified by high precipitation and leaching. Differences among the areas caused by anthropogenic soil acidification were not proved.
Abstract: In 110 soil samples taken from the surface layer of the dumpsite Litov, content of labile Al in 1 M KCl extract and of Al extractable with 0.05 M Na4P2O7 was determined in order to assess the influence of basic soil properties and management measures on Al forms. All determined properties showed very high variability. Mean labile Al content was 70.1 mg.kg(-1), mean content of Al in pyrophosphate extract was 1487 mg.kg(-1). On sites where no improving measures took effect, there was higher acidity and carbon and labile Al content than on areas covered with natural topsoil or planted with high-grown tries, On the latter areas, on the contrary, there was a higher amount of Al in pyrophosphate extract, probably due to higher content of complexing organic compounds. The relationships were complicated by carbon derived from brown coal remains, However, as a result of management measures, the processes developed towards processes common in natural soils. soil pH and organic matter being the most important factors affecting Al speciation.
Abstract: In soil samples collected from 49 soil profiles situated in the mountainous region of Krusne hory and Jizerske hory in Northern Bohemia on both forest and adjacent grassland sites, content of labile forms of Al and total content of Al in 1 M KCl extract, and Al extractable with 0.05 M Na4P2O7 were determined as well as basic soil characteristics. The contents of determined Al forms were relatively high, especially in the forest soils. As it was revealed by means of multiple regression analysis, in the surface horizons, these contents were controlled mainly by soil reaction. In the subsurface horizons they were controlled also by the content of organic carbon extractable with 0.05 M Na4P2O7 (EOC). EOC is a limiting factor for organically bound Al forms if it is not abundant as it was the case of surface horizons of forest soils. Al determined in the Na4P2O7 extract contained probably also a considerable amount of inorganic Al forms, especially in the soils where sorption sites of soil organic matter were limited.
Abstract: In soil samples taken from 18 soil profiles situated in the Sumava region on both forest and adjacent meadow stands, total content of Al in 1M KCl extract and labile forms of Al were determined. Al bound in organic complexes was determined in 0.05M Na4P2O7 extract. Basic soil characteristics were also determined. Multiple analysis of variation of particular Al forms showed that the greatest differences resulted from the differences in soil cover. The content of exchangeable Al, both total and labile, was significantly higher in forest soils than in grassland soils. The content of labile Al in 1M KCI extract was in close correlation with the total exchangeable Al, the content of Al extracted by 0.05M Na4P2O7 was not significantly correlated to exchangeable forms. In factor analysis, two common factors were selected explaining more than 75% of the total variation. According to weights distribution among all variables it was possible to describe the first factor as a factor of soil reaction showing significant influence on the content of exchangeable forms of Al in soil. The second factor was described as a factor of soil organic matter.
Abstract: Heavy metal speciation in soil by means of sequential extraction provides more detailed information for assessment of metal mobility and bioavailability than the determination of total metal content in soils or extraction with 2 mol.l(-1) HNO3. The most often used reagents for extraction of different metal forms were used in the study. Two-step sequential extraction with 0.1 mol.l(-1) Ca(NO3)(2) (exchangeable metal forms) and 0.05 mol.l(-1) Na4P2O7 at pH 12 (organically bound forms) was applied to soil samples from heavily polluted alluvium of the Litavka river in the district of Pribram. Proportion of exchangable and organically bound metals in relation to metals extractable with 2 mol.l(-1) HNO3 followed the order Cd > Zn > Pb. This proportion was relatively lower at a high level of contamination. Zn manifested the highest mobility through the soil profile. Pb and Cd can be accumulated by the organic matter in topsoil.
Abstract: Speciation of Cd, Pb, and Zn in soils of two areas with different source and level of contamination in the alluvium of the Litavka river was studied in order to assess mobility and availability of metals. Two-step sequential extraction with 0.1M Ca(NO3)(2) for exchangeable metals and with 0.05M Na4P2O7 for organically bound metals was used. Proportion of fracions was calculated in relation to concentrations extracted with 2M HNO3. Exchangeable form accounted in average for 33.7-58.7% of Cd, 0.32-9.8% of Pb, and 15.5-23.1% of Zn, respectively. Organic fraction accounted for 1.7-35.4% of Cd, 1.3-22.3% of Pb, and 3.5-22.3% of Zn, respectively. Lower proportion was found in the heavily polluted area. Exchangeable metals were rather homogeneously distributed through the soil profile, organic lead and to a lower extent also cadmium were accumulated in the topsoil. Mobility of studied forms followed order Zn > Cd > Pb. In case of lead, specific sorption was suggested. Proportion of mobile forms in the area moderately polluted was negatively correlated with 2M HNO3-extractable metal content (r = -0.749, -0.707, and -0.704 for Cd, Pb, and Zn, respectively).
Abstract: Content of cadmium, lead and zinc in plant roots and shoots (grasses of genera Festuca and Pea) from areas with different level and origin of contamination in the alluvium of the Litavka river was analyzed. In the area slightly polluted by atmospheric deposition, mean metal content in shoots was 0.312, 4.42 and 43.4 mg.kg(-1) dry weight of Cd, Pb and Zn, respectively. In the area heavily polluted by floods of contaminated water, corresponding values were found 2.38, 58.4 and 104.4 mg.kg(-1). Metal content in roots was significantly higher. Metal content decreased with the distance from the source of pollution. A part of concentration of Pb and Cd in plants originated from foliar uptake. Mobility in plants followed order Zn > Cd > Pb; correlation coefficients between shoot and root concentration were 0.644, 0.476 and 0.893 for Cd, Pb and Zn, respectively. Metal accumulation in roots was relatively more important at higher concentration levels. Evaluation by means of factor analysis showed that it was possible to select three factors for each area accounting for more than 85% of total variability.
Abstract: In a polluted area, samples of soils and plants were collected and analyzed in order to assess the mobility and accumulation of Cd, Pb and Zn in plants as influenced by the of different metal forms in soil. Metals were accumulated in roots. Metal mobility in plants decreased in the order Zn > Cd > Pb; it was generally lower in heavily polluted areas. The content of all the three metals in plant roots correlated with topsoil concentration of their 2 mol/L HNO3-extractable forms. Besides, Cd and Zn correlated with exchangeable and Zn also with the organic form content. The concentration factor as a measure of metal mobility from soil to plants decreased with increasing level of contamination.
Abstract: Soils of the alluvium of the Litavka river, an area of heavy point contamination with heavy metals, were studied. Contents of Cd, Pb, and Zn were determined in extracts with cold 2M HNO3. Metal distribution is very heterogeneous. Area influenced by atmospheric deposition from lead-smelting plants as the main source of contamination and area polluted with floods of contaminated water were distinguished. In the former, mean contents of Cd, Pb, and Zn in topsoil were 1.71, 376.4, and 74.5 mg.kg(-1), respectively. They decreased with distance from the source of pollution and with soil depth, with exception of Pb due to parent rock. In the area under floods, the mean contents of Cd, Pb, and Zn in topsoil were 33.6, 2979, and 3363 mg.kg(-1), respectively. They decreased with the distance from the source and from the river; metal mobility through the soil profile was higher here. Very close correlation was found between Cd and Zn. In factor analysis, three factors for each area accounting for more than 90% of total variability were selected.
