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Bruno Delvaux - One of the best experts on this subject based on the ideXlab platform.
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soil microbial populations shift as processes protecting organic matter change during Podzolization
Frontiers in Environmental Science, 2018Co-Authors: Marieliesse Vermeire, Jeanthomas Cornelis, Eric Van Ranst, Steeve Bonneville, Sebastian Doetterl, Bruno DelvauxAbstract:In the upper part of the solum of mineral soils, soil organic and mineral constituents co-evolve through pedogenesis, that in turn impacts the transformation and stabilization of soil organic matter (SOM). Here, we assess the reciprocal interactions between soil minerals, SOM and the broad composition of microbial populations in a 530-year chronosequence of podzolic soils. Five pedons, derived from beach sand, are studied. From young to old soils, net acidification parallels mineral dissolution and the formation of eluvial and illuvial horizons. Organo-mineral associations (OMA) accumulate in the illuvial B horizon of the older soils (330-530 yrs). Apart from contributing to SOM stabilization and protection, organo-mineral compounds progressively fill up interparticle voids. The subsequent loss of porosity leads to horizon induration, decrease of hydraulic conductivity, which promote redoximorphic processes. While recalcitrant SOM is preserved in the topsoil of the old soils, the largest quantity of protected SOM occurs in the indurated, temporalily waterlogged B horizons, through both the OMA accumulation and inhibition of microbial decomposition. SOM protection is thus both time- and horizon-specific. The microbiota also evolve along the chronosequence. Fungi dominate in all horizons of the younger soils and in the topsoil of the older soils, while bacteria prevail in the cemented B horizons of older soils. This shift in microbial community composition is due to the interdependent co-evolution of SOM and minerals during pedogenesis. Our results call for considering the microenvironment and parameters inherent to decomposer microorganisms to understand SOM protection processes in soils.
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Rare earth elements dynamics along pedogenesis in a chronosequence of podzolic soils
Chemical Geology, 2016Co-Authors: Marie Vermeire, Sophie Cornu, Zuzana Fekiacova, Marie Detienne, Bruno Delvaux, Jeanthomas CornelisAbstract:Rare earth elements (REE) total concentration and signature in soils are known to be impacted by successive soil-forming processes. So it can be used as probe of soil processes. However, few studies focus on their behavior in Podzols. Podzols result from the combination of two main pedogenic processes: (1) the strong weathering in the surface eluvial horizon; (2) the downward transfer of dissolved organic matter (OM) and mobile Al and Fe, and their accumulation in the illuvial horizon beneath. Iron oxides and OM are known to have strong affinities with REE, and to play an important role in transfer and immobilization of REE. In order to decipher the relative importance of Fe oxide and OM in REE fate during Podzolization, and to investigate whether REE can trace Podzol formation, we study here the evolution of REE signatures along five pedons, aged from 120 to 530 years, in a Cambisol-Podzol chronosequence located in the Cox Bay of Vancouver Island. Our results show that the REE content is strongly correlated to the general loss of elements and mineral weathering. Furthermore, the accumulation of secondary OM, Al and Fe-bearing phases does not impact the REE signature of the bulk soil. Both our results and the ones available in the literature indicate that the release of REE induced by weathering and subsequent leaching in percolating water are the main pathways determining the REE fate in Podzols. Furthermore, we show that REE can be released and mobilized in very short periods of time during Podzolization (330 years).
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Metal complexing properties of forest floor leachates might promote incipient Podzolization in a Cambisol under deciduous forest
Geoderma, 2001Co-Authors: Hugues Titeux, Vincent Brahy, Bruno DelvauxAbstract:The characteristics of both the mineral substrate and the humus layer are of key importance in podzol formation. However, the properties of the forest floor leachates are seldom considered. We measured the complexation capacity by Cu2+ titration (CuCC), the optical density (E-4/E-6), as well as the concentrations of dissolved organic carbon (DOC) and of major and trace ions in the liquid extracts of forest floors of two Cambisols and two Luvisols on loess under deciduous forest. The vegetation consists of a mixture of beech, oak and maple. The humus type is a fibrimor in one Cambisol and a moder in the three other soils. Both in the solid phase and in the liquid extracts of the forest floors, the Si/(Al + Fe) and C/(Al + Fe) atomic ratios are much larger in the fibrimor than in the moders. In the liquid extracts, the complexation capacity (CuCC) and the density of metal binding sites (CuCC/DOC are larger in the fibrimor than in the moders. These large CuCC and CuCC/DOC in the fibrimor leachate are linked with relatively small stability constant of the humus-Cu complex and relatively large E-4/E-6 ratio, i.e. with reactive organic ligands with low molecular weight and weak aromatic character. These characteristics are associated with current incipient Podzolization in the Cambisol with a fibrimor, and might be considered as an indicator of a substantial podzolizing potential of the forest floor. (C) 2002 Elsevier Science B.V. All rights reserved.
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Surface Podzolization in Cambisols under deciduous forest in the Belgian loess belt
European Journal of Soil Science, 2000Co-Authors: Vincent Brahy, Hugues Titeux, Anne Iserentant, Bruno DelvauxAbstract:Surface Podzolization involves the migration of metal-humus complexes to a depth of a few centimetres. In acid soils derived from loess, this process has been diagnosed mainly by morphological observation. We investigated this process in a toposequence of Luvisols and Cambisols on loess using selective extraction and mineralogical data as well as characteristics of the leaf litter. The humus type (O and OAh horizons) is a moder in the three Luvisols and one of the Cambisols, whereas it is a fibrimor in the two other Cambisols. The contents in total alkaline and alkaline-earth cations range from 35 to 60 cmol(c) kg(-1) in the fibrimor and from 40 to 90 cmol(c) kg(-1) in the moder humus. In the two Cambisols with fibrimor smectite occurs in the clay fraction of the Ah horizon; Fe-humus complexes seem to have moved, but no more than 9 cm, from the Ah to the AB horizon beneath. Relative to the Ah horizon, the upper part of the AB has larger tetraborate-extractable Fe/Al ratio and optical density of the oxalate extract. Such features converge to diagnose surface Podzolization in the Cambisols with fibrimor. However, they were not detected in the Cambisol and Luvisols with moder. In the two Cambisols with fibrimor, surface Podzolization is consistent with (i) their smaller iron content, (ii) their more advanced weathering stage and (iii) their lower acid neutralizing capacity.
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Incipient Podzolization and weathering caused by complexation in a forest Cambisol on loess as revealed by a soil solution study
European Journal of Soil Science, 2000Co-Authors: Vincent Brahy, Hugues Titeux, Bruno DelvauxAbstract:Surface Podzolization has so far been diagnosed from morphological observations, selective extraction and mineralogical investigations. We studied this process in two Cambisol profiles developed in loess, one with a fibrimor humus and the other with a dysmoder humus, by characterizing the chemical composition and the complexing properties of the soil solution. The solutions were sampled bimonthly for 3 years at four depths (4, 8, 13, 25 cm) using both zero-tension and low-tension capillary-wick lysimeters. The leachates from the Ah horizon of the soil with fibrimor contained less nitrate, sulphate and calcium than those from the one with a dysmoder because there was less bioturbation and mineralization in it. Both the complexation capacity and the density of ligand binding sites were larger in the soil solutions of the Ah (4 cm) and AB (8 cm) horizons of the soil with the fibrimor. In this soil, the complexing properties of the liquid phase induced a depletion of inorganic monomeric aluminium. In this environment, the hydroxy interlayered 2:1 clay minerals lose their Al-interlayers and transform into vermiculite and smectite, which in turn weather, producing large amounts of magnesium in the soil solution. This was found to be a major characteristic of weathering by complexation and incipient Podzolization in the Cambisol with the fibrimor. In this process, nitric acid probably contributes to mineral dissolution.
Emmanuel Fritsch - One of the best experts on this subject based on the ideXlab platform.
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Evolution of lipid abundance and molecular composition during the podzolisation of laterites in the upper Amazon basin
Biogeochemistry, 2008Co-Authors: Marion Bardy, Sylvie Derenne, Emmanuel FritschAbstract:In the upper Amazon basin, podzolisation involves the remobilization of large amounts of organic matter and chemical elements (Fe, Al, Si) previously accumulated in lateritic formations. In order to better understand the fate of organic matter in podzolic environments in this area, the evolution of lipid abundance and molecular composition were studied along a representative soil sequence showing the transition between a latosol and a well-developed podzol. Total solvent extracts were obtained from eight key soil samples from three profiles and their overlying litters, and enable us to follow both lateral and vertical evolutions. Lipid composition was determined by gas chromatography-mass spectrometry (GC-MS). Major compound classes include alkanes, alkanones, alkanols, alkanoic acids, ω-hydroxyacids, as well as aromatics, steroids and triterpenoids. Free lipids do not accumulate in the early stages of podzolisation but are abundant in well-developed podzolic horizons, possibly due to (i) combined acidity and waterlogging, (ii) limited amounts of complexing elements, (iii) a decreased microbial activity. The evolution of lipid composition is consistent with podzolisation mechanisms previously highlighted in the sequence. This paper provides further evidence for the occurrence of anoxic conditions in deep waterlogged podzolic horizons. It also shows that aromatic, phytotoxic compounds are stabilized in the well-developed podzol. This may play a role in the vegetation changes associated with podzolisation in the area.
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Podzolization as a deferralitization process a study of an acrisol podzol sequence derived from palaeozoic sandstones in the northern upper amazon basin
European Journal of Soil Science, 2004Co-Authors: Emmanuel Fritsch, N Do R Nascimento, Guilherme Taitson Bueno, A J Herbillon, Th Allard, Adolpho Jose Melfi, R Astolfo, H BoucherAbstract:Morphological, geochemical and mineralogical studies were carried out in a representative soil catena of the low-elevation plateaux of the upper Amazon Basin to interpret the steps and mechanisms involved in the Podzolization of low-activity clay soils. The soils are derived from Palaeozoic sandstones. They consist of Hydromorphic Podzols under tree savannah in the depressions of the plateaux and predominantly of Acrisols covered by evergreen forest elsewhere. Incipient Podzolization in the uppermost Acrisols is related to the formation of organic-rich A and Bhs horizons slightly depleted in fine-size particles by both mechanical particle transfer and weathering. Weathering of secondary minerals by organic acids and formation of organo-metallic complexes act simultaneously over short distances. Their vertical transfer is limited. Selective dissolution of aluminous goethite, then gibbsite and finally kaolinite favour the preferential cheluviation of first Fe and secondly Al. The relatively small amount of organo-metallic complexes produced is related to the quartzitic parent materials, and the predominance of Al over Fe in the spodic horizons is due to the importance of gibbsite in these low-activity clay soils. Morphologically well-expressed podzols occur in strongly iron-depleted topsoils of the depression. Mechanical transfer and weathering of gibbsite and kaolinite by organic acids is enhanced and leads to residual accumulation of sands. Organo-metallic complexes are translocated in strongly permeable sandy horizons and impregnate at depth the macro-voids of embedded soil and saprolite materials to form the spodic Bs and 2BCs horizons. Mechanical transfer of black particulate organic compounds devoid of metals has occurred later within the sandy horizons of the podzols. Their vertical transfer has formed well-differentiated A and Bh horizons. Their lateral removal by groundwater favours the development of an albic E horizon. In an open and waterlogged environment, the general trend is therefore towards the removal of all the metals that have initially accumulated as a response to the ferralitization process and have temporarily been sequestrated in organic complexes in previous stages of soil Podzolization.
Jeanthomas Cornelis - One of the best experts on this subject based on the ideXlab platform.
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soil microbial populations shift as processes protecting organic matter change during Podzolization
Frontiers in Environmental Science, 2018Co-Authors: Marieliesse Vermeire, Jeanthomas Cornelis, Eric Van Ranst, Steeve Bonneville, Sebastian Doetterl, Bruno DelvauxAbstract:In the upper part of the solum of mineral soils, soil organic and mineral constituents co-evolve through pedogenesis, that in turn impacts the transformation and stabilization of soil organic matter (SOM). Here, we assess the reciprocal interactions between soil minerals, SOM and the broad composition of microbial populations in a 530-year chronosequence of podzolic soils. Five pedons, derived from beach sand, are studied. From young to old soils, net acidification parallels mineral dissolution and the formation of eluvial and illuvial horizons. Organo-mineral associations (OMA) accumulate in the illuvial B horizon of the older soils (330-530 yrs). Apart from contributing to SOM stabilization and protection, organo-mineral compounds progressively fill up interparticle voids. The subsequent loss of porosity leads to horizon induration, decrease of hydraulic conductivity, which promote redoximorphic processes. While recalcitrant SOM is preserved in the topsoil of the old soils, the largest quantity of protected SOM occurs in the indurated, temporalily waterlogged B horizons, through both the OMA accumulation and inhibition of microbial decomposition. SOM protection is thus both time- and horizon-specific. The microbiota also evolve along the chronosequence. Fungi dominate in all horizons of the younger soils and in the topsoil of the older soils, while bacteria prevail in the cemented B horizons of older soils. This shift in microbial community composition is due to the interdependent co-evolution of SOM and minerals during pedogenesis. Our results call for considering the microenvironment and parameters inherent to decomposer microorganisms to understand SOM protection processes in soils.
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Rare earth elements dynamics along pedogenesis in a chronosequence of podzolic soils
Chemical Geology, 2016Co-Authors: Marie Vermeire, Sophie Cornu, Zuzana Fekiacova, Marie Detienne, Bruno Delvaux, Jeanthomas CornelisAbstract:Rare earth elements (REE) total concentration and signature in soils are known to be impacted by successive soil-forming processes. So it can be used as probe of soil processes. However, few studies focus on their behavior in Podzols. Podzols result from the combination of two main pedogenic processes: (1) the strong weathering in the surface eluvial horizon; (2) the downward transfer of dissolved organic matter (OM) and mobile Al and Fe, and their accumulation in the illuvial horizon beneath. Iron oxides and OM are known to have strong affinities with REE, and to play an important role in transfer and immobilization of REE. In order to decipher the relative importance of Fe oxide and OM in REE fate during Podzolization, and to investigate whether REE can trace Podzol formation, we study here the evolution of REE signatures along five pedons, aged from 120 to 530 years, in a Cambisol-Podzol chronosequence located in the Cox Bay of Vancouver Island. Our results show that the REE content is strongly correlated to the general loss of elements and mineral weathering. Furthermore, the accumulation of secondary OM, Al and Fe-bearing phases does not impact the REE signature of the bulk soil. Both our results and the ones available in the literature indicate that the release of REE induced by weathering and subsequent leaching in percolating water are the main pathways determining the REE fate in Podzols. Furthermore, we show that REE can be released and mobilized in very short periods of time during Podzolization (330 years).
A.g. Jongmans - One of the best experts on this subject based on the ideXlab platform.
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Podzolization an additional paradigm
Edafologia, 2002Co-Authors: Peter Buurman, A.g. JongmansAbstract:Present models of podsolization emphasize the mobilization and precipitation of dissol- ved organic matter, together with Al(-silicates) and Fe. Such models cannot explain the dominance of pellet-like organic matter in most zonal podzols, and the discrepancy between the chemistry of percola- ting organic matter (DOC) and the organic matter accumulated in podzol-B horizons. The present paper offers an explanation in which dynamics of the rooting system of the vegetation, and the decay of its litter is combined with leaching by organic acids. Such a model can explain the domi- nance of root-derived organic matter podzol-B horizons. It is suggested that organic matter derived from roots is dominant in zonal podzols while illuvial organic matter may dominate in (nutrient-poor of hydro- morphic) intrazonal podzols.
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chemical mineralogical and morphological characterization of three podzols developed on glacial deposits in northern europe
Geoderma, 2000Co-Authors: P A Melkerud, A.g. Jongmans, D. C. Bain, T TarvainenAbstract:The chemistry, mineralogy and micromorphology of three soil profiles formed on genetically different Quaternary deposits have been studied in relation to the Podzolization process. The soil materials showed quite uniform geochemical composition both within and between the study sites independent of great geographical distance and there is accumulation of sesquioxides in the Bs horizons at all three sites. Mineralogical distributions derived from calculated normative compositions, X-ray diffraction analysis and thin section point counting show similar depth-related trends. The clay fractions at all three sites are dominated by a vermiculitic phase which contains variable degrees of polymeric hydroxy-Al in the interlayer space in most B horizons.
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do plants drive Podzolization via rock eating mycorrhizal fungi
Geoderma, 2000Co-Authors: Nico Van Breemen, Ulla S Lundstrom, A.g. JongmansAbstract:Weathering and supply of nutrients derived from minerals to plants is known to be stimulated by plant symbiotic mycorrhizal fungi. Nutrients are generally thought to pass the bulk soil solution bef ...
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evidence for microbial decomposition of organic acids during Podzolization
European Journal of Soil Science, 1995Co-Authors: U S Lundstrom, N Van Breemen, A.g. JongmansAbstract:Summary Microbial aspects of Podzolization were studied by percolating organic acids through sterile and non-sterile soil in columns. Six columns containing sand from a fluvioglacial sediment were percolated (90 mm d−1) with mor extract and an oxalate-citrate solution. In three of these, sterilized soil solutions were used. Weathering was enhanced by organic acids which formed complexes with aluminium and iron. In the non-sterile soil columns weathering by organic acids was inhibited at 7–8 cm because the acids were degraded by microorganisms. Weathering was evident from colour change, contents of extractable aluminium and iron, and the micromorphology. Enhanced weathering in the sterile columns was also suggested by larger amounts of aluminium, iron, silica and base cations leached from the columns. Comparison of the output of aluminium, iron and silica from the sterile soil with that from the non-sterile soil, suggests that probably an aluminium-iron-silicate phase was formed in the deeper parts of the non-sterile columns.
Jon Petter Gustafsson - One of the best experts on this subject based on the ideXlab platform.
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phosphorus in 2d spatially resolved p speciation in two swedish forest soils as influenced by apatite weathering and Podzolization
Geoderma, 2020Co-Authors: Gbotemi A Adediran, Jon Petter Gustafsson, J Marius R Tuyishime, Delphine Vantelon, Wantana KlysubunAbstract:Abstract The cycling and long-term supply of phosphorus (P) in soils are of global environmental and agricultural concern. To advance the knowledge, a detailed understanding of both the vertical and lateral variation of P chemical speciation and retention mechanism(s) is required, a knowledge that is limited in postglacial forest soils. We combined the use of synchrotron X-ray fluorescence microscopy with multi-elemental co-localisation analysis and P K-edge XANES spectroscopy to reveal critical chemical and structural soil properties. We established a two-dimensional (2D) imagery of P retention and speciation at a microscale spatial resolution in two forest soil profiles formed in glaciofluvial and wave-washed sand. The abundance and speciation of P in the upper 40 cm was found to be influenced by soil weathering and Podzolization, leading to spatial variability in P speciation on the microscale ( 600 μm) hot spots of inclusions in aluminosilicates or as discrete micro-sized apatite grains. The subsoil apatite represents a pool of P that trees can potentially acquire and thus add to the biogeochemically active P pool in temperate forest soils.
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advances in understanding the Podzolization process resulting from a multidisciplinary study of three coniferous forest soils in the nordic countries
Geoderma, 2000Co-Authors: Ulla S Lundstrom, D. C. Bain, Jon Petter Gustafsson, N Van Breemen, P A W Van Hees, Reiner Giesler, Hannu Ilvesniemi, Erik Karltun, P A Melkerud, Mats OlssonAbstract:Advances in understanding the podzolisation process resulting from a multidisciplinary study at three coniferous forest soils in the Nordic countries
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podzolisation mechanisms and the synthesis of imogolite in northern scandinavia
Geoderma, 1995Co-Authors: Jon Petter Gustafsson, A R Fraser, D. C. Bain, Prosun Bhattacharya, W J MchardyAbstract:Abstract The nature of the short-range ordered Al and Fe minerals of the spodic B horizons of northern Scandinavia was studied by selective dissolution, transmission electron microscopy, infrared absorption and sulphate adsorption experiments. Imogolite-type materials (proto-imogolite allophane and well-developed imogolite) were the predominant oxalate-extractable Al minerals. Minor amounts of gibbsite and kaolinite were also found. The Fe oxides were less abundant and relatively well crystallized. Imogolite-type materials were the predominant source of positive charge, as evidenced by the amount of sulphate adsorbed. The Fe:AI ratio of the pyrophosphate extracts was positively correlated with the ratio of pyrophosphate-C to oxalate-extractable Al—this observation provides field evidence that imogolite-type materials were particularly unstable in the presence of organic substances. It is hypothesized that most accumulated Al and Fe originated from the congruent dissolution of primary minerals followed by the downward migration and degradation of metal-organic complexes, but incongruent weathering within the B horizon might have made additional contributions to the precipitation of the short-range ordered minerals. Historical climatic change might, to some extent, explain why metal-organic complexes were almost absent in many B horizons.