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Serpentinite is a fairly common parent material for soils of the Alps and Apennines in Italy. In the Apennines these soils may show very different degrees of development even over small areas. This work was undertaken to study the pedogenesis on a soil catena occurring on a very small hill, with a particular attention to the clay mineral transformations. The catena is only 100 m long, but four...
The rare earth elements (REE) content, particle-size distribution, and clay mineralogical composition were analyzed for the paddy soils collected from the central region of the Mekong River, Laos, to study the origin and inherent potentiality of soils. REE as the chondrite-normalized curve or the plot of Ce/Eu against Eu/Sm were found to be useful for grouping soils according to their origins. The...
The 18 O/ 16 O and D/H ratios of the structural oxygen and hydrogen of naturally occurring clay minerals carry information about the conditions under which the minerals formed. Clays generally form in isotopic equilibrium with the environment, and hence have isotopic compositions that reflect the temperature of formation and the 18 O/ 16 O and D/H...
Mosses can influence soil formation because of its role in the transfer of energy, water and chemical compounds. This study was conducted (1) to compare the morphological, chemical and mineralogical properties of soils under two species of mosses (Pleurozium schreberi (Brid.) Mitt. and Ptilium crista-castrensis (Hedw.)), and (2) to determine the chemical composition of the moss carpets associated...
The purpose of this research was to: (1) characterize the clay mineralogy of soils in and adjacent to Karkevagge, a recently deglaciated valley in Arctic Sweden, (2) document chemical weathering in a periglacial environment and (3) use the mineralogy to help explain landscape evolution. Soil samples were analyzed from 11 sites that differ in elevation, parent material, drainage, slope and vegetation...
The determination of the types and relative amounts of the minerals present in soil forms an essential component of most soil characterization efforts. This paper reviews protocols for XRD-based quantitative clay mineral analysis in soils, with emphasis on methods using mineral intensity factors in combination with the so-called 100% approach. We summarize methodological differences and characteristic...
Little has been published on the diversity and importance of microaggregates in tropical latosols and their chemistry and fertility. This study presents a detailed analytical and submicroscopical characterization of microaggregates in selected Brazilian Latosols, representing all latosols orders, by means of electron microprobe and scanning electron microscopy (SEM) at high magnification. Chemical...
Genetically modified crops, which produce Bacillus thuringiensis toxins, release the toxins into soils through root exudates and upon decomposition of residues. Several studies showed that Bacillus thuringiensis toxins adsorbed on pure clay minerals and model clay-OM or oxides associations as well as on soils. We determined the adsorption of the toxin from Bacillus thuringiensis subsp. tenebrionis...
Given appropriate management, soils may serve as a sink for carbon, and thereby play a potentially important role in helping countries meet CO 2 emission reductions as agreed to under the Kyoto Protocol. To fully judge the capacity of soils to store carbon, however, gaps regarding the mechanisms of organic carbon (OC) stabilization need to be filled. A number of studies have demonstrated the...
This study examined pedogenesis, as well as the clay mineralogy of soil and rock samples obtained from a transect of gypsiferous and calcareous materials. The main objectives of this research were to study the relationship between clay minerals and physiographic units as well as the relative importance of key pedogenic processes in controlling clay mineralogy. Palygorskite, chlorite, illite, smectite,...
We have investigated the clay mineralogy of 3 pedons along a toposequence of perhumid forest soils facing a subalpine lake in northeastern Taiwan to gain insight into the individual factors that affect weathering rates. Toposequence of the transect was investigated from summit to footslope and at the lakeshore. The natural drainage of soils varies from well drained to poorly drained. The major minerals...
Field and laboratory observations based on X-ray diffraction techniques suggest that 2:1 clay minerals behave as a K reservoir. However, 2:1 soil clay assemblages are most often composed of a mixture of different 2:1 clay mineral populations and the role of these different clay mineral populations in K absorption or K release are not fully understood. This present work addressed this question, through...
A soil chronosequence consisting of six profiles formed on quartz tholeiite basalt ranging in age from 10,000 years to 1. 8 Million years (My) was studied here. Soil clays were identified using XRD diffractogram decomposition methods for samples obtained from the A and C horizons of profiles. The results showed that kaolinite minerals dominated in all the clay fractions. Gibbsite was prominent in...
It has been described several times that plant activity enriches the upper part of soil profiles in the inorganic elements they use for their growth (Si, K, Ca, Mg…). This phenomenon called “nutrient uplift” or “element translocation” can counteract element loss via leaching in surface soils and may therefore impact clay mineral stability in upper soil horizons. However, apart from some studies in...
We investigated to what extent soil K balances, resulting from plant off-take and K fertilizer application rates, had changed the content of illitic (10 Å) materials (as discrete illite and as illitic layers in mixed-layer minerals) in soil clay fractions. We also assessed to what extent different particle size fractions were involved in the processes. The study was performed on soil samples from...
Changes in the clay mineralogy of soil samples collected from the Rothamsted Classical Experiments over the past ~150years were examined. Comparisons were undertaken to assess the impact of (i) different fertiliser practices on the top soil and sub soil of the Park Grass Experiment and (ii) the effects of changing land use from agriculture to woodland where soil pH either remained close to pH 7 or...
A nitrogen budget study of a highly fertilized coffee plantation growing on an Acrisol (Ultisol: Ustic Paleohumult) in Southern Costa Rica provided clear evidence of low nitrate (NO 3− ) leaching to groundwater, in spite of a large annual rainfall and fairly high soil permeability. In this study, conducted at the same site, we measured soil properties in relation to nitrate adsorption...
As a consequence of global warming, additional areas will become ice-free and subject to weathering and soil formation. The most evident soil changes in the Alps will occur in proglacial areas where young soils will continuously develop due to glacier retreat. Little is known about the initial stages of weathering and soil formation, i.e. during the first decades of soil genesis. In this study, we...
Clay mineralogy of the Jiujiang soils, classified as red earth (on summit and slope), were investigated using X–ray diffraction (XRD), cation exchange capacity (CEC) determination, and high-resolution transmission electron microscopy (HRTEM). The XRD results show that the soils included kaolinite, illite, vermiculite, and mixed-layer I/S and K/S as clay minerals. In XRD patterns of clay separates...
Catenary relationships of surface soils in the vicinity of kibbutz Shomrat in the Galilee coastal plain of Israel were studied including optically stimulated luminescence (OSL). The research provides new insights into the local pedogeomorphic history and confirms that the study area is of different age than the central coastal plain of Israel. The soil toposequence is composed of polygenic red Hamra...
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