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  • 1. Bergelin, A.
    et al.
    van Hees, P. A. W.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Wahlberg, O.
    Department of Chemistry, Royal Institute of Technology, .
    Lundström, Ulla
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    The acid-base properties of high and low molecular weight organic acids in soil solutions of podzolic soils2000In: Geoderma, ISSN 0016-7061, E-ISSN 1872-6259, Vol. 94, no 2-4, p. 223-235Article in journal (Refereed)
    Abstract [en]

    The acid properties of the organic acids and identified low molecular weight (LMW) organic acids in soil solutions of podzolic soils were determined using proton affinity spectra, based on EMF titration data, and Gran titrations. The proton affinity spectra showed apparent pKa values of 2.6, 4.1, 5.4 and 6.7 for the dissolved organic material. The LMW organic acids had similar pKa values. The average specific buffer capacity as determined by Gran titrations was 8.8±0.5 μmol H+/mg DOC. The specific buffer capacity for the identified low molecular acids was 40±2 μmol H+/mg DOC.

  • 2.
    Braun, Sabina
    et al.
    Swedish University of Agricultural Sciences, Department of Soil and Environment.
    Warrinnier, Ruben
    KU Leuven, Belgium.
    Börjesson, Gunnar
    Swedish University of Agricultural Sciences, Department of Soil and Environment.
    Ulén, Barbro
    Swedish University of Agricultural Sciences, Department of Soil and Environment.
    Smolders, Erik
    KU Leuven, Belgium.
    Gustafsson, Jon Petter
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering, Water and Environmental Engineering.
    Assessing the ability of soil tests to estimate labile phosphorus in agricultural soils: Evidence from isotopic exchange2019In: Geoderma, ISSN 0016-7061, E-ISSN 1872-6259, Vol. 337, p. 350-358Article in journal (Refereed)
    Abstract [en]

    Efficient phosphorus (P) fertilization strategies are essential for intensive crop production with minimal negative environmental impacts. A key factor in sustainable P use is assessment of the plant available soil P pool using soil P tests. This study determined isotopically exchangeable P after six days of reaction with 33PO4 (P-E (6 d)) to determine how accurately two commonly used P tests, Olsen and AL (acid ammonium acetate lactate) can quantify the amount of labile P. Soil samples were taken from both highly P-amended and unamended plots at six sites within the Swedish long-term soil fertility experiments. According to P K-edge XANES spectroscopy, the P speciation was dominated by Al-bound P and organic P, with additional contributions from Fe-bound P and Ca phosphates in most soils. The results showed that the AL test overestimated P-E (6 d) by a factor of 1.70 on average. In contrast, the Olsen test underestimated P-E (6 d), with the mean ratios of P-Olsen to P-E (6 d) being 0.52 for high-P and 0.19 for low-P soils. The 33P/31P ratio in the Olsen extract of a 33PO4 spiked soil was closer to that of a 0.005 mol L−1 CaCl2 soil extract than the corresponding ratio in the AL extract, suggesting that AL extraction solubilized more non-labile P. In conclusion, the AL and Olsen methods are not suitable for direct quantification of the isotopically exchangeable soil P pool after 6 days of equilibration. However, based on the results, Olsen may be superior to AL for classification of soil P status, due to its even performance for calcareous and non-calcareous soils and lower extraction of non-labile P.

  • 3.
    Brun, Christian
    et al.
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Peltola, Pasi
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Åström, Mats E.
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Johansson, Maj-Britt
    Department of Soil and Environment, Swedish University of Agricultural Sciences.
    Spatial distribution of major, trace and ultra trace elements in three Norway spruce (Picea abies) stands in boreal forests, Forsmark, Sweden2010In: Geoderma, ISSN 0016-7061, E-ISSN 1872-6259, Vol. 159, no 3-4, p. 252-261Article in journal (Refereed)
    Abstract [en]

    The spatial distribution of 49 major, trace and ultra trace elements within a Norway spruce system was examined in three sites within the Forsmark area in central Sweden. The system included stemwood, roots, fresh green shoots, litterbags, humus, mineral soil, rhizosphere soil and moss. Based on Principal Component Analysis and manual plots the elements were grouped according to their distribution within the different compartments. One large group of elements occurring abundantly in the soil, and in much lower concentrations in the biota and litter was distinguished, containing mainly elements typically associated with soil minerals. A similar pattern was found for a second group of elements, but with higher concentrations in the biological samples and/or litter. In contrast, there was also one group of elements with high concentrations in biological samples and/or litter and low content in soil. This was mainly nutrients, but also the highly toxic Cd, Hg and Sb. This study is part of the site investigation programme, carried out by the Swedish Nuclear Fuel and Waste Management Company (SKB), in order to locate a suitable area for a deep repository for nuclear fuel waste.

  • 4. Coucheney, E.
    et al.
    Eckersten, H.
    Hoffmann, H.
    Jansson, Per Erik
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering, Land and Water Resources Engineering.
    Gaiser, T.
    Ewert, F.
    Lewan, E.
    Key functional soil types explain data aggregation effects on simulated yield, soil carbon, drainage and nitrogen leaching at a regional scale2018In: Geoderma, ISSN 0016-7061, E-ISSN 1872-6259, Vol. 318, p. 167-181Article in journal (Refereed)
    Abstract [en]

    The effects of aggregating soil data (DAE) by areal majority of soil mapping units was explored for regional simulations with the soil-vegetation model CoupModel for a region in Germany (North Rhine-Westphalia). DAE were analysed for wheat yield, drainage, soil carbon mineralisation and nitrogen leaching below the root zone. DAE were higher for soil C mineralization and N leaching than for yield and drainage and were strongly related to the presence of specific soils within the study region. These soil types were associated to extreme simulated output variables compared to the mean variable in the region. The spatial aggregation of these key functional soils within sub-regions additionally influenced the DAE. A spatial analysis of their spatial pattern (i.e. their presence/absence, coverage and aggregation) can help in defining the appropriate grid resolution that would minimize the error caused by aggregating soil input data in regional simulations.

  • 5.
    Cucarella, Victor
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Land and Water Resources Engineering.
    Renman, Gunno
    KTH, School of Architecture and the Built Environment (ABE), Land and Water Resources Engineering.
    Renman, Agnieszka
    KTH, School of Architecture and the Built Environment (ABE), Land and Water Resources Engineering.
    Phosphorus sorption properties of soils amended with recycled wastewater filter substrates2009In: Geoderma, ISSN 0016-7061, E-ISSN 1872-6259Article in journal (Other academic)
  • 6. do Nascimento, NR
    et al.
    Nicola, SMC
    Rezende, MOO
    Oliveira, TA
    Öberg, Gunilla
    Linköping University, Faculty of Arts and Sciences. Linköping University, Department of Thematic Studies, Environmental Science.
    Pollution by hexachlorobenzene and pentachlorophenol in the coastal plain of Sao Paulo state, Brazil2004In: Geoderma, ISSN 0016-7061, E-ISSN 1872-6259, Vol. 121, no 03-Apr, p. 221-232Article in journal (Refereed)
    Abstract [en]

    Organochlorine compounds were dumped by chemical industries during the 1970s in many areas of the coastal plain of Sao Paulo state in Brazil. These dumps, located on hillsides and in valleys, in both rural and urban environments, are responsible for soil and water pollution. The objective of this work was to determine how the pollutants have spread in an area occupied by a spodosol-type soil mantle. The study combines soil morphological observations with soil and water analysis of hexachlorobenzene (HCB) and pentachlorophenol (PCP) in soil toposequences. The results indicate that the highest pollutant concentrations are observed near the dump site and that the compounds contamination is increasing. A map integrating topography and chemical concentrations was created to visualize the spatial distribution of HCB levels in the landscape. Physical and chemical analyses were performed to measure HCB and PCP levels in the soil. Soil water appears to act as a vector of HCB, probably through complexation with and dispersal of dissolved organic matter. The persistence of HCB at the studied site is most likely due to the low pH values in combination with a high content of organic matter. HCB was consistently found in higher concentrations than PCP. It is plausible that the cause of this difference is that PCP is degraded more easily under sunlight than HCB and that degradation of PCP under acid conditions leads to the formation of HCB. (C) 2003 Published by Elsevier B.V.

  • 7. Eriksson, Ann Kristin
    et al.
    Gustafsson, Jon Petter
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering, Land and Water Resources Engineering. Swedish University of Agricultural Sciences, Sweden.
    Hesterberg, Dean
    Phosphorus speciation of clay fractions from long-term fertility experiments in Sweden2015In: Geoderma, ISSN 0016-7061, E-ISSN 1872-6259, Vol. 241, p. 68-74Article in journal (Refereed)
    Abstract [en]

    Phosphorus (P) losses from agricultural soils constitute a main driver for eutrophication of the Baltic Sea. There is limited knowledge about sorption and release processes of P in these soils, especially concerning the effects of fertilization. In this study, P speciation of the clay fractions from six different soils in long-term fertility experiments in Sweden was investigated by P K-edge XANES spectroscopy. As expected, unfertilized soils had lower concentrations of acid-digestible P compared with fertilized soils. Based on best-fit standards that emerged from linear combination fitting (LCF) of XANES spectra, phosphate sorbed on iron (Fe) (hydr)oxides was a dominant P species in clay fractions from unfertilized soils containing more than 35 mmol kg(-1) of oxalate-extractable Fe. In contrast, P sorbed on aluminum (Al) (hydr)oxides predominated in soils with lower concentrations of oxalate-extractable Fe. A greater proportion of organically bound P was fit for soil samples containing >2% organic carbon. The soils included one calcareous soil for which a greater proportion of P was fit as apatite. After long-term fertilization, P had accumulated mainly as P adsorbed to Al (hydr) oxides according to the XANES analysis. Our research shows that P speciation in fertilized agricultural soils depended on the level of P buildup and on the soil properties.

  • 8. Eriksson, Ann Kristin
    et al.
    Hillier, Stephen
    Hesterberg, Dean
    Klysubun, Wantana
    Ulén, Barbro
    Gustafsson, Jon Petter
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering, Land and Water Resources Engineering. Swedish University of Agricultural Sciences, Sweden.
    Evolution of phosphorus speciation with depth in an agricultural soil profile2016In: Geoderma, ISSN 0016-7061, E-ISSN 1872-6259, Vol. 280, p. 29-37Article in journal (Refereed)
    Abstract [en]

    With time, different soil-forming processes such as weathering, plant growth, accumulation of organic matter, and cultivation are likely to affect phosphorus (P) speciation. In this study, the depth distribution of P species was investigated for an agricultural clay soil, Lanna, Sweden. Small amounts of apatite-P was demonstrated in the topsoil whereas the speciation of Pat 70-100 cm depth consisted of approximately 86% apatite according to P K-edge XANES (X-ray absorption near-edge structure) spectroscopy. Because there were only minor differences in bulk mineralogy and texture, these variations in P speciation were interpreted as the result of apatite weathering of the topsoil. Speciation modeling on soil extracts supported this idea: hydroxyapatite was not thermodynamically stable in the top 50 cm of the soil. Apatite was enriched in the bulk soil relative to the clay fraction, as expected during apatite dissolution. Combined results from batch experiments, XANES spectroscopy and X-ray diffraction suggested chemical transformations of the topsoil as a result from accumulation of organic matter and airing from tillage followed by enhanced weathering of apatite, amphiboles, clay minerals, and iron oxides. This caused the formation of poorly crystalline secondary iron and aluminum (hydr)oxides in the topsoil, which retained part of the released P from apatite. Other P was incorporated into organic forms. Furthermore, the results also showed that short-term acidification below the current pH value (below 5.5 in the topsoil and 7.2 in the deeper subsoil) caused significant solubilization of P. This is attributed to two different mechanisms: the instability of Al-containing sorbents (e.g. Al hydroxides) at low pH (in the topsoil), and the acid-mediated dissolution of apatite (the subsoil).

  • 9. Ferro-Vazquez, C.
    et al.
    Novoa-Munoz, J. C.
    Costa-Casais, M.
    Klaminder, Jonatan
    Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences.
    Martinez-Cortizas, A.
    Metal and organic matter immobilization in temperate podzols: a high resolution study2014In: Geoderma, ISSN 0016-7061, E-ISSN 1872-6259, Vol. 217, p. 225-234Article in journal (Refereed)
    Abstract [en]

    Aluminium and Fe fractions were obtained in samples from two temperate podzols by selective extraction with NaOH (Al-n, Fe-n), Na-dithionite-citrate (Al-d, Fe-d), acid NH4-oxalate (Al-o, Fe-o) and Na-pyrophosphate (Al-p, Fe-p) following the traditional fractionation procedures, and also by the use of the chlorides of K (Al-K), La (Al-La) and Cu (Al-cu) as non-buffered extractants for Al. Carbon content was also determined in the Na-pyrophosphate extract (C-p). Soil sampling was done at high-resolution to allow a more detailed characterization of the vertical processes than the traditional sampling by whole soil horizons. Results showed that Al-p and Fe-p make a large proportion of the Alo and Fe-o meaning that organoaluminic complexes dominated in the "active" metal pool instead of inorganic compounds. The degree of metal saturation of soil organic matter (estimated by the (Al-p Fe-p)/C-p molar ratios) increases with depth, especially in the uppermost samples of spodic horizons (Bhs1) where it increases up to 0.1. Aluminium dominates in the adsorption positions of the organic matter in the spodic horizon (Fe-p/Al-p ratios <0.5), except in the Bhs1 horizon (ratios > 1), indicating that the immobilization of Fe containing complexes occurs 10-15 cm above that of Al The highly stable Al-OM complexes accounted on average for 60% of the organoaluminic associations (>70% in the Bhs horizons). The moderately stable complexes predominate in A horizons (57-77% in ACB1 and 37-48% in ACB2) and the largest proportions of low stability complexes were found in the uppermost samples of the spodic horizons (Bhs1) of both soils (9-21%), together with the highest Fep contents and a decrease in pH values. From a stepwise multiple regression model it is suggested that pH is the main variable accounting for the stability of Al-OM compounds together with C and organically bound Fe contents. It is suggested that the illuviation of unsaturated organic acids lower the pH in upper spodic horizons, leading to the complexation of metals from formerly precipitated organometallic complexes and/or leading to their redissolution, enabling their migration to deeper soil layers. Iron complexes would be less soluble at soil pH, resulting in a differentiation of an upper Fe-rich Bhs1 horizon and a lower Bhs2 Al-rich horizon. The depth variation in C accumulation was found to be related to the proportion of highly stable Al-OM fraction.

  • 10. Fröberg, M.
    et al.
    Grip, H.
    Tipping, E.
    Svensson, Magnus
    Swedish University of Agricultural Sciences, Department of Soil and Environment, P.O. Box 7014, SE-75007 Uppsala, Sweden.
    Strömgren, M.
    Kleja, D. B.
    Long-term effects of experimental fertilization and soil warming on dissolved organic matter leaching from a spruce forest in Northern Sweden2013In: Geoderma, ISSN 0016-7061, E-ISSN 1872-6259, Vol. 200-201, p. 172-179Article in journal (Refereed)
    Abstract [en]

    Nitrogen deposition and increasing temperature are two of the major large-scale changes projected for coming decades and the effect of this change on dissolved organic matter is largely unknown. We have utilized a long-term fertilization and soil warming experiment in Northern Sweden to study the effects of increased nutrient levels and increased temperature on DOC transport under the O horizon. The site is N limited and mean annual temperature 2. °C. Experimental fertilization with ammonium nitrate and a physiological mixture of other macro- and micro-nutrients has been going on for 22. years and soil warming, 5. °C above ambient soil temperature for 14. years, prior to the study. Experimental plots have been irrigated to avoid drying and we also studied the effect of this long-term irrigation on DOC by establishing control plots receiving no irrigation.DOC concentrations and fluxes under the O horizon were approximately 50% higher in fertilized plots than in non-fertilized control plots. We did not find any statistically significant effect of soil warming. There was a statistically significant effect of long-term irrigation on DOC with higher DOC concentration and fluxes in irrigated plots than in plots without irrigation. There were no major effects on DOC quality measured by specific UV absorbance. Fertilization approximately doubled soil organic matter stocks in the O horizon, whereas there were no such effects of warming or irrigation on soil organic matter amounts. There was no statistically significant treatment effect on DOC collected from the B horizon. We hypothesize that the positive effect of fertilization on DOC is related to increased soil C stocks.

  • 11. Giesler, R.
    et al.
    Ilvesniemi, H.
    Nyberg, L.
    van Hees, P. A. W.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Starr, M.
    Bishop, K.
    Kareinen, T.
    Lundström, Ulla
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Distribution and mobilization of Al, Fe and Si in three podzolic soil profiles in relation to the humus layer.2000In: Geoderma, ISSN 0016-7061, E-ISSN 1872-6259, Vol. 94, no 2-4, p. 249-263Article in journal (Refereed)
    Abstract [en]

    The mobilization of Al, Fe and Si in podzols is often associated with the weathering of silicate minerals in the E horizon, downward migration, and their accumulation lower in the soil profile. This study investigated Al, Fe, and Si concentrations in soil water (centrifugation samples) and estimated leaching losses from the humus layer in comparison with those in the mineral E and B horizon. Concentrations of total soluble Al and Fe in soil water were higher in the O and E horizons than in B horizon samples, but not significantly different between the two uppermost horizons. Si concentrations were higher in the E than in the O horizon. The amount of Al and Fe leaching from the E horizon (i.e. input to the B horizon) compared to amount leaching from the O horizon (i.e. the input to the E horizon) ranged from 92% to 163%. Calculated leaching losses from the lower B horizon were less than 3% of the input to the B horizon. The results suggest that a large part of the illuviated Al and Fe in the Bs horizon is derived from the O horizon. Similar values for the Si ranged from 56% to 61% (comparing E horizon output with E horizon input). Budget estimates available for one of the investigated podzols indicated that biocycling via above-ground litter explained < 12% of the estimated annual input of Al and Fe to the forest floor. Inputs of Al and Fe due to upward flow of capillary water accounted for about 26% of the Al and Fe in the O layer. The results show that there is a considerable pool of Si Al, Fe in the humus layer. This pool plays an important part in the present day biogeochemical cycling of these elements in podzolic soils. Several mechanisms possibly involved in the transfer of Al, Fe and Si from the mineral soil to the humus layer are discussed.

  • 12.
    Gustafsson, Jon Petter
    KTH, School of Architecture and the Built Environment (ABE), Land and Water Resources Engineering, Environmental Geochemistry and Ecotechnology.
    Arsenate adsorption to soils: Modelling the competition from humic substances2006In: Geoderma, ISSN 0016-7061, E-ISSN 1872-6259, Vol. 136, no 02-jan, p. 320-330Article in journal (Refereed)
    Abstract [en]

    There is currently no agreement to what extent humic substances may compete with arsenate and other anions for oxide adsorption sites in soils, and how to model this interaction. In this study, batch experiments were made in which the competition between fulvic acid and arsenate was studied in a spodic Bs horizon. Additional experiments were performed in which the pH and concentration dependence of arsenate adsorption was studied in four soils. The results showed that fulvic acid decreased the adsorption of AsO4, probably because of competition effects. The K-d value of AsO4 adsorption to the four studied soils differed by three orders of magnitude at pH 5. The introduction of an irreversibly sorbed component RO- into the Three-Plane CD-MUSIC model, and the optimisation of RO- using the K-d of AsO4 for one sample from each data set, permitted the use of the model to predict AsO4 adsorption under different conditions. On the whole, the predictions were reasonably close to measured values, but the model failed in 3 of 4 soils at high surface coverage. A strong relationship between the optimised RO- value and the observed pyrophosphate-extractable C value supported the assumption that RO- can be considered as being an adsorbed humic functional group. The large concentrations of RO- compared to those of adsorbed PO4 and SO4 suggest that humic substances may be the most important competitors for anion adsorption sites in many soils.

  • 13.
    Gustafsson, Jon Petter
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Land and Water Resources Engineering (moved 20130630).
    Mwamila, Luhuvilo B.
    KTH, School of Architecture and the Built Environment (ABE), Land and Water Resources Engineering (moved 20130630).
    Kergoat, Kevin
    KTH, School of Architecture and the Built Environment (ABE), Land and Water Resources Engineering (moved 20130630).
    The pH dependence of phosphate sorption and desorption in Swedish agricultural soils2012In: Geoderma, ISSN 0016-7061, E-ISSN 1872-6259, Vol. 189, p. 304-311Article in journal (Refereed)
    Abstract [en]

    A number of previous studies have reported the existence of a minimum in phosphate solubility between pH 5.5 and 7 in non-calcareous soils. Different hypotheses have been forwarded to explain this phenomenon. In this study, ten soil samples with varying textures and phosphorus status were subjected to batch experiments in which dissolved phosphate was measured as a function of pH and phosphate load. Soil samples with more than 20% clay all had a minimum phosphate solubility between pH 6 and 7, whereas for samples with <10% clay, no such minimum was observed. Further experiments involving additions of phosphate and arsenate showed an increasing adsorption of these anions with decreasing pH also below pH 6 in clay soils, suggesting that the pH dependence on adsorption and desorption in short-term experiments was not the same. Kinetic experiments showed that the increased phosphate desorption at lower pH values in non-calcareous clay soils was a quick process, which is consistent with adsorption/desorption being the most important mechanism governing the retention and release of inorganic P. Moreover, by comparing extraction results with batch experiment results for samples from a long-term fertility experiment, it was concluded that more than 60% of the accumulated phosphate was occluded, i.e. not reactive within 6 days. Additional evidence for an important role of occluded phosphate comes from an analysis of the Freundlich sorption isotherms for the studied soils. It is hypothesized that interlayered hydroxy-Al and hydroxy-Fe polymers in clay minerals may be important for P dynamics in clay soils by trapping some of the P in an occluded form. The results also suggest that improved knowledge on the speciation and dynamics of phosphorus in soils is required for consistent mechanistically based modeling of phosphate sorption/desorption reactions.

  • 14.
    Gustafsson, Jon Petter
    et al.
    KTH, Superseded Departments, Land and Water Resources Engineering.
    van Hees, P.
    Starr, M.
    Karltun, E.
    Lundstrom, U.
    Partitioning of base cations and sulphate between solid and dissolved phases in three podzolised forest soils2000In: Geoderma, ISSN 0016-7061, E-ISSN 1872-6259, Vol. 94, no 04-feb, p. 311-333Article in journal (Refereed)
    Abstract [en]

    The cation and SO, adsorption properties of O and B horizons of three podzolised soils in Sweden and Finland were studied through analysing the soil solution at six different sampling occasions and through a set of batch experiments. High concentrations of dissolved organic carbon and cations were found in centrifuged soil solutions from the O horizon, especially during autumn. An analysis using the WHAM-S model suggested that most of the dissolved Ca, Mg, K and Mn were counter-ions, residing in the diffuse layers of dissolved fulvic acids. Hence, the solubility of these cations depended on the solubility of organic matter. Model exercises suggested that the solubility of humics in turn was influenced by seasonal differences in hydrophobicity and by the water content. Furthermore, the model results showed that only a low proportion of the B horizon organic matter was involved in calcium binding. This is probably due to the interaction between organic matter and oxide surfaces in this horizon. In the case of sulphate adsorption in the B horizons, a surface complexation model was tested for its ability to describe batch experiment data and temporal differences in soil water chemistry. This model was based on the diffuse-layer model and it was optimised by adjusting the surface site concentration and the point of zero charge. However. the interaction between Ca2+ and SO42- could not be modelled. Comparisons between the model and the field observations proved to be difficult due to a considerable soil heterogeneity.

  • 15. Gustafsson, Jon Petter
    et al.
    van Hees, Patrick
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Starr, Michael
    Karltun, Erik
    Lundström, Ulla
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Partitioning of base cations and sulphate between solid and dissolved phases in three podzolized forest soils2000In: Geoderma, ISSN 0016-7061, E-ISSN 1872-6259, Vol. 94, no 2-4, p. 311-333Article in journal (Refereed)
    Abstract [en]

    The cation and SO4 adsorption properties of O and B horizons of three podzolised soils in Sweden and Finland were studied through analysing the soil solution at six different sampling occasions and through a set of batch experiments. High concentrations of dissolved organic carbon and cations were found in centrifuged soil solutions from the O horizon, especially during autumn. An analysis using the WHAM-S model suggested that most of the dissolved Ca, Mg, K and Mn were counter-ions, residing in the diffuse layers of dissolved fulvic acids. Hence, the solubility of these cations depended on the solubility of organic matter. Model exercises suggested that the solubility of humics in turn was influenced by seasonal differences in hydrophobicity and by the water content. Furthermore, the model results showed that only a low proportion of the B horizon organic matter was involved in calcium binding. This is probably due to the interaction between organic matter and oxide surfaces in this horizon. In the case of sulphate adsorption in the B horizons, a surface complexation model was tested for its ability to describe batch experiment data and temporal differences in soil water chemistry. This model was based on the diffuse-layer model and it was optimised by adjusting the surface site concentration and the point of zero charge. However, the interaction between Ca2+ and SO4/2- could not be modelled. Comparisons between the model and the field observations proved to be difficult due to a considerable soil heterogeneity. (C) 2000 Elsevier Science B.V.

  • 16. Harrysson Drotz, Stina
    et al.
    Tilston, Emma L
    Sparrman, Tobias
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Schleucher, Jürgen
    Umeå University, Faculty of Medicine, Department of Medical Biochemistry and Biophysics.
    Contributions of matric and osmotic potentials to the unfrozen water content of frozen soils2009In: Geoderma, ISSN 0016-7061, E-ISSN 1872-6259, Vol. 148, no 3-4, p. 392-8Article in journal (Refereed)
    Abstract [en]

    Recent reports show that biogeochemical processes continue when the soil is frozen, but are limited by water availability. However, there is little knowledge about the interactive effects of soil and environmental variables on amounts of unfrozen water in frozen soils. The aims of this study were to determine the contributions of matric and osmotic potentials to the unfrozen water content of frozen soil. We determined the effects of matric and osmotic potential on unfrozen water contents of frozen mineral soil fractions (ranging from coarse sand to fine silt) at − 7 °C, and estimated the contributions of these potentials to liquid water contents in samples from organic surface layers of boreal soils frozen at − 4 °C. In the mineral soil fractions the unfrozen water contents appeared to be governed solely by the osmotic potential, but in the humus layers of the sampled boreal soils both the osmotic and matric potentials control unfrozen water content, with osmotic potential contributing 20 to 69% of the total water potential. We also determined pore size equivalents, where unfrozen water resides at − 4 °C, and found a strong correlation between these equivalents and microbial CO2 production. The larger the pores in which the unfrozen water is found the larger the microbial activity that can be sustained. The osmotic potential may therefore be a key determinant of unfrozen water and carbon dynamics in frozen soil.

  • 17. Haslinger, E.
    et al.
    Ottner, F.
    Lundström, Ulla
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Pedogenesis in the Alno carbonatite complex, Sweden2007In: Geoderma, ISSN 0016-7061, E-ISSN 1872-6259, Vol. 142, no 1-2, p. 127-135Article in journal (Refereed)
  • 18.
    Holmström, Sara
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    van Hees, Patrick
    Lundström, Ulla
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Modelling of aluminium chemistry in soil solution of acidified and lime treated podzolic soil2004In: Geoderma, ISSN 0016-7061, E-ISSN 1872-6259, Vol. 127, no 3-4, p. 280-292Article in journal (Refereed)
    Abstract [en]

    Soil solutions were taken from untreated and lime treated Norway spruce sites in the south of Sweden. At the limed sites 3.45 t ha−1 (L) or 8.75 t ha−1 (H) dolomite were applied 15 years before sampling. The mean concentration of inorganic Al (AlQR) in the untreated control plots (C) was 37 μM and the concentration of AlQR decreased when the dosages of dolomite treatments increased. For the H plots, with high doses of dolomite treatment the mean concentration of AlQR was 17 μM. The total Al (Altot) also decreased by dolomite treatment, from 72 μM to 56 μM. Propionate (7–268 μM) and malonate (2–34 μM) were the low molecular weight organic acids (LMWOAs) found in the highest concentrations at Hasslöv. The differences in concentration of most of the determined LMWOAs were significantly increased due to treatment. The citrate average concentration for the different plots varied between 2.8 μM and 5.1 μM and the concentration of oxalate had concentrations between 1.7 μM and 2.6 μM. The experimental concentration of Al bound to LMWOAs obtained by ultrafiltration (<1000 Da) of the soil solution was in the mor layer on average 12% for the C plot and the L plots and 4% in the H plots. In the AE horizon the figures were 15% for the C plot and about 7% for the treated L and H plots, and in the Bhs horizon 9% for both the C, L and H plots. Two chemical equilibrium models were evaluated: Winderemere Humic Aqueous Model (WHAM) and a model treating the high molecular weight organic acids as monoprotic. The concentrations of inorganic Al, Al bound to identified LMWOAs and high molecular weights acids in soil solution (mor, AE and Bhs) from untreated and lime treated soil were calculated. The modelled inorganic Al values of the control plot were similar to the concentrations found in the soil solution (AlQR). For the dolomite treated plots the concentration of AlQR (0–40 μM) was higher in soil solution than that modelled by WHAM and the monoprotic model. The experimental concentration of Al bound to LMWOAs obtained by ultrafiltration (<1000 Da) of the soil solution was comparable but always higher than the modelled values. The modelling confirms that an appreciable part of the Al is strongly complexed with LMWOAs in the organic and eluvial horizons of the podzolized soil, suggesting that LMWOAs are efficient weathering agents and important for the formation of the eluvial horizon in podzols. Saturation indices (SI) for two solid Al phases were also calculated, including crystalline gibbsite and proto-imogolite (PI). The SIs for both the C and the treated plots (L and H) showed very broad ranges for the different horizons investigated, indicating undersaturation as well as oversaturation with respect to gibbsite and proto-imogolite.

  • 19. Ilvesniemi, H.
    et al.
    Giesler, R.
    van Hees, Patrick
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Magnussson, T.
    Melkerud, P. A.
    General description of the sampling techniques and the sites investigated in the Fennoscandinavian podzolization project2000In: Geoderma, ISSN 0016-7061, E-ISSN 1872-6259, Vol. 94, no 2-4, p. 109-123Article in journal (Refereed)
    Abstract [en]

    A 3-year project focusing on the fundamental processes of podzolization was carried out on three sampling sites in northern Fennoscandinavia. The soils were selected based on the previous information of the soil properties to represent typical soils in the area. In this article, the post-glacial history of the sites, site vegetation and general properties of the soils, as well as the methods used are presented. Two of the sites were classified as Typic HapLocryods and one as an Entic Haplocryod. The post-glacial age of the sites was between 9000 and 9500 years BP and the parent material was glacial till in one of the sites and glaciofluvial material in two of them. (C) 2000 Elsevier Science B.V. All rights reserved.

  • 20.
    Johansson, Emma
    et al.
    Linköping University, The Tema Institute, Department of Water and Environmental Studies. Linköping University, Faculty of Arts and Sciences.
    Ebenå, Gustav
    Linköping University, Department of Physics, Chemistry and Biology. Linköping University, The Institute of Technology.
    Sandén, Per
    Linköping University, Department of Thematic Studies, Environmental Science. Linköping University, Faculty of Arts and Sciences.
    Svensson, Teresia
    Linköping University, Department of Thematic Studies, Environmental Science. Linköping University, Faculty of Arts and Sciences.
    Öberg, Gunilla
    Linköping University, The Tema Institute, Department of Water and Environmental Studies. Linköping University, Faculty of Arts and Sciences.
    Organic and chlorine in Swedish spruce forest soil: Influence of nitrogen2001In: Geoderma, ISSN 0016-7061, E-ISSN 1872-6259, Vol. 101, no 3-4, p. 1-13Article in journal (Refereed)
    Abstract [en]

    Concentrations of organic and inorganic chlorine were estimated in samples collected in forest soils in the southern part of Sweden, and changes were observed after the addition of nitrogen in incubated samples. All of the investigated samples contained both inorganic and organic chlorine, and the concentration of organic chlorine was 2-4 times larger than that of inorganic chlorine. The results suggest that the amount of organic chlorine in mature spruce forest soils with a moderate chloride deposition in the temperate region is larger than the amount of inorganic chlorine. The results of the nitrogen incubation indicate that addition of ammonium nitrate causes a net decrease in the concentration of organic chlorine and a net increase in chloride concentration. The observed change appears to mainly be a result of a dechlorination of the organic matter present in the water leachable fraction. © 2001 Elsevier Science B.V.

  • 21.
    Karlsson, Caroline
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering, Land and Water Resources Engineering.
    Ali, Imran
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering, Land and Water Resources Engineering.
    Earon, Robert
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering, Land and Water Resources Engineering.
    Olofsson, Bo
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering, Land and Water Resources Engineering.
    Mörtberg, Ulla
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering, Land and Water Resources Engineering.
    Comparison of methods for predicting regolith thickness in previously glaciated terrain, Stockholm, Sweden2014In: Geoderma, ISSN 0016-7061, E-ISSN 1872-6259, Vol. 226, p. 116-129Article in journal (Refereed)
    Abstract [en]

    Knowledge about regolith thickness is important in several civil and environmental engineering fields. However, subsurface characteristics such as regolith thickness are difficult to determine through surface investigations and maps at regional scales. This paper presents four methods for estimating regolith thickness in a GIS environment for previously glaciated terrain with high frequency of rock outcrops: linear regression (LR) using topographical covariates; inverse distance weighting (IOW) interpolation of regolith thickness point data from well drillings: a trigonometrical approach (TA) developed for this study which uses outcrop slopes and distance between outcrops; and a simplified regolith model (SRM). The SRM is a model modified from TA which estimates the regolith thickness based on outcrops, slopes and the distance to outcrops in eight directions. The methods were compared for three study areas (Tyreso, Vallentuna and Osteraker) in Stockholm County, Sweden. Based on the results in this paper, LR proved to be the most accurate method for regolith thickness estimation, measured through root mean square error values. Whereas IDW was the most accurate method in terms of error within 2 m, which would make it a suitable model if and when large datasets of regolith point data are available. When drilling data is scarce then both the TA and SRM methods can be used for regolith estimations. However, the SRM proved to be a more accurate regolith thickness model compared to TA. SRM shows promising results and could be used at a preliminary stage in engineering projects where little or no data is available prior to detailed field investigations in previously glaciated terrain.

  • 22. Karltun, E.
    et al.
    Bain, D. C.
    Gustafsson, Jon Petter
    KTH, Superseded Departments, Land and Water Resources Engineering.
    Mannerkoski, H.
    Murad, E.
    Wagner, U.
    Fraser, A. R.
    McHardy, W. J.
    Starr, M.
    Surface reactivity of poorly-ordered minerals in podzol B horizons2000In: Geoderma, ISSN 0016-7061, E-ISSN 1872-6259, Vol. 94, no 04-feb, p. 265-288Article in journal (Refereed)
    Abstract [en]

    The surface reactivity of mineral soil horizons from three podzolised forest soils in Scandinavia was examined. The amount of accumulated C was low, between 1.8 and 2.3% in the top of the B horizons. Selective extractions in combination with infrared (IR) spectroscopy and transmission electron microscopy (TEM) indicated a predominance of poorly-ordered imogolite-type materials (ITM) in the oxalate extractable fraction in an examined B horizons. The presence of well-ordered imogolite was only indicated in the Nyanget B3 horizon. A large proportion of free Fe was removed by ammonium oxalate. Comparisons of Mossbauer spectra (both at room temperature and at 4.2 K) before and after treatment with ammonium oxalate showed that the oxalate treatment resulted in a removal of a (super)paramagnetic Fe3+ phase? probably ferrihydrite. A comparison of the Mossbauer Fe3+ parameters at room temperature and 4.2 K indicated a close intergrowth of a ferrihydrite-like oxide with a magnetically neutral matrix, e.g., allophane. The specific surface area (SSA) was determined by N-2 adsorption before and after treatment of the samples with acid ammonium oxalate. The loss of SSA after oxalate treatment was considerable in the B horizon where only between 3.8 to 13.38 of the original SSA remained after treatment. The point of zero charge salt effect (PZSE) increased with depth in the B horizon from between 4.4 and 5.1 in the upper horizons to between 5.7 and 7.7 in the lower part of the B horizon. The increased PZSE with depth paralleled a decrease in the ratio of pyrophosphate soluble C to oxalate soluble Fe + Al. The affinity for SO42-. a goad indicator of the presence of active surface hydroxyls, was measured by comparing the H+ buffering capacity of a sample titrated in 2.5 mM Na2SO4 with a sample titrated in 5 mh I NaNO3,. The buffering capacity of the soil in the Na2SO4, electrolyte was well correlated with the amount of oxalate minus pyrophosphate soluble Fe + Al (r(2) = 0.88). The sulphate exchange capacity was considerably higher than CEC, especially in lower parts of the B horizon. The calculated surface area of the oxalate soluble material (OSM) ranged between 74 and 289 m(2) g(-1) and the calculated surface site density of the same material ranged between 0.6 to 3.3 site nm(-2). It was concluded that the surface reactivity in the B horizons is dominated by the poorly-ordered variable-charge oxides resulting in a low capacity to retain cations but a high capacity for adsorption of weak acid anions like SO42- and organic acids.

  • 23.
    Kothawala, Dolly
    et al.
    McGill Univ, Dept Geog, Montreal, PQ H3A 2K6, Canada; McGill Univ, Global Environm & Climate Change Ctr, Montreal, PQ H3A 2K6, Canada.
    Roehm, C.
    SUNY Coll Buffalo, Dept Geog & Planning, Buffalo, NY 14222 USA; SUNY Coll Buffalo, Great Lakes Ctr, Buffalo, NY 14222 USA.
    Blodau, C.
    Univ Guelph, Sch Environm Sci, Guelph, ON M1G 2W1, Canada.
    Moore, T.
    McGill Univ, Dept Geog, Montreal, PQ H3A 2K6, Canada; McGill Univ, Global Environm & Climate Change Ctr, Montreal, PQ H3A 2K6, Canada.
    Selective adsorption of dissolved organic matter to mineral soils2012In: Geoderma, ISSN 0016-7061, E-ISSN 1872-6259, Vol. 189, p. 334-342Article in journal (Refereed)
    Abstract [en]

    As soil solutions pass through forested mineral soils, the chemical and structural compositions of dissolved organic carbon (DOC) can alter substantially due to interactions with soil particle surfaces. Typically, adsorp- tion processes dominate in mineral soils and the resulting concentration of DOC is reduced substantially. We studied changes in the molecular and structural compositions of DOC during equilibration with mineral soils collected across Canada (n=43) and found that the overall aromatic content of DOC decreased with equili- bration in almost all cases from using specific absorbance (SUVA) and the fluorescence index. The fluores- cence index revealed that podzolic B horizons, with typically large adsorption capacity (Qmax), had the greatest reduction in aromaticity, which was partially explained by the much lower aromatic content of DOC desorbed from soils surfaces. In contrast, a decrease in DOC aromaticity for volcanic B horizons, also with high Qmax, was primarily due to adsorption. An unexpected finding was the release of extremely high (2.6×106 Da) and low (420 Da) molecular weight (MW) organic materials during equilibration using high performance size exclusion chromatography (HPLC), for luvisols and podzols, respectively. In general, the average number–average MW (Mn) of DOC decreased for all soil types, but the greatest decrease in Mn was observed for mineral soils with large Qmax, including the podzolic and volcanic B horizons. Analysis of changes in FTIR spectra revealed that the most prominent change to DOC functional groups was a reduction in carboxyl groups, which was even greater than the removal of aromatic DOC. The findings of this study em- phasize that while DOC concentrations may decrease substantially during passage through mineral soils, it is valuable to consider the contribution of DOC from desorption of pre-existing soil C. Essential to the findings of this study was the inclusion of multiple analytical techniques to track changes to DOC character, and the in- clusion of a wide range of mineral soils.

  • 24.
    Larsson, Maja A.
    et al.
    Swedish Univ Agr Sci,Uppsala.
    D'Amato, Marilena
    Italian Natl Hlth Inst, Rome.
    Cubadda, Francesco
    Italian Natl Hlth Inst, Rome.
    Raggi, Andrea
    Italian Natl Hlth Inst, Rome.
    Oborn, Ingrid
    Swedish University of Agricultural Sciences, Uppsala and World Agroforestry Centre (ICRAF) Nairobi.
    Kleja, Dan Berggren
    Swedish Univ Agr Sci, Uppsala and Swedish Geotechnical Institute, Gothenburg.
    Gustafsson, Jon Petter
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering, Land and Water Resources Engineering. Swedish Univ Agr Sci, Sweden, Uppsala.
    Long-term fate and transformations of vanadium in a pine forest soil with added converter lime2015In: Geoderma, ISSN 0016-7061, E-ISSN 1872-6259, Vol. 259, p. 271-278Article in journal (Refereed)
    Abstract [en]

    A field-trial with different application rates of converter lime (0.2, 0.7 and 1.0 kg m(-2)) was set up in a pine forest stand in southern Sweden in 1984. The lime contained 14.6 g kg(-1) vanadium. The aim with this study was to evaluate the vanadium concentration and speciation in the soil 26 years after application. Samples of the organic mar layer and the mineral soil were analyzed separately. The vanadium concentration decreased with soil depth, from 680 to 8 mg kg(-1) soil. Analysis by vanadium K-edge}CANES spectroscopy showed that vanadium(IV) was the predominant species in the mar layer. Further, iron and/or aluminum (hydr)oxides were important sorbents for vanadium(V) in the mineral soil. The spedation of dissolved vanadium, as determined by HPLC-ICP-MS, was dominated by vanadium(V), which is considered the most toxic vanadium species. However, the vanadium sorption capacity of the soil was sufficient to reduce the total bioavailable vanadium below phytotoxic levels. By combining two different vanadium spedation methods, this study was able to conclude that vanadium speciation in soils is governed by soil properties such as pH, organic matter content and the content of metal (hydr)oxides, but not by the vanadium species added to the soil.

  • 25.
    Lundmark, Annika
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Land and Water Resources Engineering.
    Jansson, Per-Erik
    KTH, School of Architecture and the Built Environment (ABE), Land and Water Resources Engineering.
    Generic soil descriptions for modelling water and chloride dynamics in the unsaturated zone based on Swedish soils2009In: Geoderma, ISSN 0016-7061, E-ISSN 1872-6259, Vol. 150, no 1-2, p. 85-95Article in journal (Refereed)
    Abstract [en]

    Information about soil hydraulic properties is a prerequisite for modelling water and solute dynamics in the unsaturated zone. Providing that this information is available and the uncertainty is within an acceptable range, computer models can be helpful tools in quantifying environmental effects. This study describes the water retention curve and hydraulic conductivity for three soil types: clay, glacial till and sand. These soils originated from a Swedish database containing 2200 measured soil layers representing 260 soil profiles. A simulation experiment was conducted where daily variations in water and chloride were simulated for a 20-year period in central Sweden, using the different soil profiles sampled from the database. Two approaches to calculate effective parameters were tested, in order to obtain generic soil descriptions and examine their ability to represent the average of the variation in chloride and water characteristics obtained for the respective soil type. In general, the use of these effective parameters was successful but overestimations of the water and chloride outflow occurred in the clay, which presented high spatial variability, and of the chloride concentration in the sand, which presented high temporal variability. Overall, the generic soil descriptions were useful in producing reasonable behaviour regarding water and chloride dynamics and could be recommended for general assessments of the environmental impact of non-reactive solutes from ;areas where simplified soil classifications are available.

  • 26. Lundstrom, U. S.
    et al.
    van Breemen, N.
    Bain, D. C.
    van Hees, P. A. W.
    Giesler, R.
    Gustafsson, Jon Petter
    KTH, Superseded Departments, Land and Water Resources Engineering.
    Ilvesniemi, H.
    Karltun, E.
    Melkerud, P. A.
    Olsson, M.
    Riise, G.
    Wahlberg, O.
    Bergelin, A.
    Bishop, K.
    Finlay, R.
    Jongmans, A. G.
    Magnusson, T.
    Mannerkoski, H.
    Nordgren, A.
    Nyberg, L.
    Starr, M.
    Strand, L. T.
    Advances in understanding the podzolization process resulting from a multidisciplinary study of three coniferous forest soils in the Nordic Countries2000In: Geoderma, ISSN 0016-7061, E-ISSN 1872-6259, Vol. 94, no 04-feb, p. 335-353Article in journal (Refereed)
    Abstract [en]

    Geochemical, mineralogical, micromorphological, microbiological, hydrochemical and hpdrological joint investigations were performed at two coniferous podzolic sites in the north of Sweden and at one in the south of Finland. Mycorrhizal fungi were found to create numerous pens (3-10-mu m diameter) in many weatherable mineral grains in the eluvial (E) horizon. During the growing season, identified low molecular weight (LMW) organic acids such as citric, shikimic, oxalic and fumaric acids comprised 0.5-5% of the DOC and 0.5-15% of the total acidity in soil solutions. Between 20% and 40% of the dissolved Al was bound to the identified LMW organic acids. Mineral dissolution via complexing LMW acids, probably exuded in part by the mycorrhiza hyphae, is likely to be a major weathering process in podzols. We found no evidence for a decreasing C/metal ratio of the migrating organo-metal complexes that could explain the precipitation of secondary Fe and AL in the illuvial (B) horizon. Instead, microbial degradation of organic ligands resulting in the release of ionic,Al and Fe to the soil solution may he an important process facilitating the formation of solid Al-SI-OH and Fe-OH phases in the podzol B horizon. However, within the B horizon transport as proto-imogilite (PI) sols might be possible. In the B horizon, the extractable,Al and Fe was predominantly inorganic. The large specific surface area (SSA) removable by oxalate extraction, the high point of zero charge salt effect (PZSE), the low cation exchange capacity (CEC) and the high sulphate exchange capacity (SEC), painted to the presence of short-range ordered variable charge phases. Imogolite type material (ITM) was indeed identified in all B horizons by IR spectroscopy and crystalline imogolite was found in the deep B horizon of one profile. Mossbauer spectroscopy indicated that Fe in the form of ferrihydrite was formed by intergrowth with an Al-Si-OH phase. The high amounts of Fe and Al transported from the O to the E horizon indicate that there could be an upward transport of these elements before they are leached to the B horizon. We hypothesize that the LMW Al complexes an transported by hyphae to the mor (O) layer, partly released and subsequently complexed by high molecular weight (HMW) acids.

  • 27.
    Mendes, Lipe Renato Dantas
    et al.
    Aarhus Univ, Denmark.
    Tonderski, Karin
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Kjaergaard, Charlotte
    Aarhus Univ, Denmark; SEGES, Denmark.
    Phosphorus accumulation and stability in sediments of surface-flow constructed wetlands2018In: Geoderma, ISSN 0016-7061, E-ISSN 1872-6259, Vol. 331, p. 109-120Article in journal (Refereed)
    Abstract [en]

    Surface-flow constructed wetlands (CWs) are systems that replicate the nutrient reduction processes of natural wetlands and are considered suitable measures to reduce the nutrient losses from agricultural drainage discharge to surface waters. The present study aimed to investigate the biogeochemical stability of phosphorus (P) in three CWs. Intact soil cores were collected from each CW zone and included the soil and the sediment layer (average 28 mm thickness) formed by deposition of the incoming sediments with the water flow. Soil and sediment layer were analysed geochemically, including bulk density, pH, and total contents of carbon, nitrogen, P as well as different extracts of iron (Fe), aluminium and P. In situ measurements of soil redox potential, dissolved oxygen concentration and temperature were carried out in the CWs during 16 months. Grab water samples were collected across the CWs for determination of P species, total Fe, sulphate and pH. Soil core analysis revealed that the major P storage in the CWs was attributed to retention of Fe-bound P in the sediment layer. The Fe and total P (TP) retention differed significantly between CWs (11-63 g Fe m(-2) yr(-1) and 1-9 g TP m(-2) yr(-1)). Amorphous Fe oxides constituted the major P sorbent fraction in the soil and sediments of all CWs, and the higher P sorption capacity in the sediment layer demonstrated the continuous supply of P sorbents to this layer. The stability of Fe bound P in the anaerobic sediments seemed to be controlled by the high molar ratios of bicarbonate-dithionite extractable Fe (Fe-BD) to associated P, which varied from 21 to 49, and the presence of an aerobic sediment-water

  • 28. Nambu, K.
    et al.
    van Hees, Patrick A. W.
    Jones, D. L.
    Örebro University, Department of Natural Sciences.
    Vinogradoff, S.
    Lundström, U. S.
    Composition of organic solutes and respiration in soils derived from alkaline and non-alkaline parent materials2008In: Geoderma, ISSN 0016-7061, E-ISSN 1872-6259, Vol. 144, no 3-4, p. 468-477Article in journal (Refereed)
    Abstract [en]

    Parent material greatly influences pedogenesis and soil nutrient availability and consequently we hypothesized that it would significantly affect the amount of organic solutes in soil, many of which have been implicated in rhizosphere processes linked to plant nutrient uptake. Consequently, we investigated the influence of two contrasting parent materials in which calcite was present or absent (alkaline and non-alkaline soils) on the concentrations of dissolved organic carbon (DOC), low-molecular weight organic acids (LMWOA) and glucose in soil solution. Both soils were under Norway spruce. The dynamics of LMWOAs in soil were also investigated using 14C-labelled citrate and oxalate. Some of the mineral horizons of the alkaline soils showed significantly higher concentrations of DOC, phenolics, and fumarate in soil solution and also a higher basal respiration. No major differences were seen in organic solute status in the organic horizons of the two soil types. LMWOAs were present at low concentrations in soil solution (< 1 to 25 ΌM). Their mineralization rate significantly decreased with soil depth, however, overall neither their concentration or half-life in soil was markedly affected by parent material. The alkaline soils had significantly higher CO2-to-soil organic C (SOC) ratios, and consequently SOC in the alkaline soils did not seem more chemically stable against mineralization. Considering possible DOC and CO2 efflux rates it was suggested that the equal or larger SOC stocks in alkaline mineral soils were most likely linked to a higher net primary productivity. In conclusion, our study found that parent material exerted only a small effect on the concentration and dynamics of organic solutes in soil solution. This suggests that in comparison to other factors (e.g. vegetation cover, climate etc) parent material may not be a major regulator of the organic solute pool in soil. © 2008 Elsevier B.V. All rights reserved.

  • 29.
    Nambu, Kei
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    van Hees, P. A. W.
    Essén, Sofia
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Lundström, Ulla
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Assessing centrifugation technique for obtaining soil solution with respect to leaching of low molecular mass organic acids from pine roots.2005In: Geoderma, ISSN 0016-7061, E-ISSN 1872-6259, Vol. 127, no 3-4, p. 263-269Article in journal (Refereed)
    Abstract [en]

    Centrifugation is a common technique to obtain soil solution. However, this method may disrupt living cells in the soil and release their contents into the soil solution. To examine this possibility, we compared leaching of low molecular mass organic acids (LMMOAs) and dissolved organic carbon (DOC) from the root of Scots pine (Pinus sylvestris) packed in quartz sand via extraction by centrifugation and milder procedures of water immersion and suction. Centrifugation enhanced leaching of shikimate appreciably; leaching of DOC, lactate, malate, and phosphate was also significantly enhanced. The concentration leached from the root was greater than 10 mu M for shikimate, and generally ranged between 0.5 and 5 mu M for the other acids. As for actual soil samples, this level of leaching could be appreciably large in upper mineral horizon(s) if the root density is as large as in our experiments and if the concentrations of LMMOAs in the soil matrix are relatively small.

  • 30.
    Nambu, Kei
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences, Engineering and Mathematics.
    van Hees, P A W
    Jones, D L
    Vinogradoff, S
    Lundström, Ulla S
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences, Engineering and Mathematics.
    Composition of organic solutes and respiration in soils derived from alkaline and non-alkaline parent materials2008In: Geoderma, ISSN 0016-7061, E-ISSN 1872-6259, Vol. 144, no 3-4, p. 468-477Article in journal (Refereed)
    Abstract [en]

    Parent material greatly influences pedogenesis and soil nutrient availability and consequently we hypothesized that it would significantly affect the amount of organic solutes in soil, many of which have been implicated in rhizosphere processes linked to plant nutrient uptake. Consequently, we investigated the influence of two contrasting parent materials in which calcite was present or absent (alkaline and non-alkaline soils) on the concentrations of dissolved organic carbon (DOC), low-molecular weight organic acids (LMWOA) and glucose in soil solution. Both soils were under Norway spruce. The dynamics of LMWOAs in soil were also investigated using 14C-labelled citrate and oxalate. Some of the mineral horizons of the alkaline soils showed significantly higher concentrations of DOC, phenolics, and fumarate in soil solution and also a higher basal respiration. No major differences were seen in organic solute status in the organic horizons of the two soil types. LMWOAs were present at low concentrations in soil solution (< 1 to 25 µM). Their mineralization rate significantly decreased with soil depth, however, overall neither their concentration or half-life in soil was markedly affected by parent material. The alkaline soils had significantly higher CO2-to-soil organic C (SOC) ratios, and consequently SOC in the alkaline soils did not seem more chemically stable against mineralization. Considering possible DOC and CO2 efflux rates it was suggested that the equal or larger SOC stocks in alkaline mineral soils were most likely linked to a higher net primary productivity. In conclusion, our study found that parent material exerted only a small effect on the concentration and dynamics of organic solutes in soil solution. This suggests that in comparison to other factors (e.g. vegetation cover, climate etc) parent material may not be a major regulator of the organic solute pool in soil.

  • 31.
    Norström, Sara H
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of applied science and design.
    Bylund, Dan
    Mid Sweden University, Faculty of Science, Technology and Media, Department of applied science and design.
    Vestin, Jenny L. K.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of applied science and design.
    Lundström, Ulla S
    Mid Sweden University, Faculty of Science, Technology and Media, Department of applied science and design.
    Initial effects of wood ash application to soil and soil solution chemistry in a small, boreal watershed2012In: Geoderma, ISSN 0016-7061, E-ISSN 1872-6259, Vol. 187, p. 85-93Article in journal (Refereed)
    Abstract [en]

    With the conception that whole tree harvesting leads to an impoverishment of forest soils wood ash application is recommended, with the foremost benefits being increased pH in soil and subsequent surface waters, and recycling of nutrients from the wood ash.

    In this investigation a small boreal catchment in central Sweden was studied for two years before and two years after treatment with the maximum recommended dose, 3 tonnes/ha, of crushed, self-hardened wood ash. The sampling area was situated in a slope towards a stream, to include the effect on both recharge- and discharge areas with different soil constitutions. The soil solution chemistry, exchangeable pool of cations and potential heavy metal accumulation in berries were studied. Temporary increases in soil solution concentration were found for K in the recharge area and Ca and SO4 in the discharge area when comparing ashed and control areas. No change in exchangeable cations was observed during the study period, and no increase of heavy metals in bilberries did occur. These small changes in the constitution of the soil solution do not suggest wood ash application as a method to improve soil quality in an initial phase.

  • 32.
    Odlare, Monica
    et al.
    Mälardalen University, School of Sustainable Development of Society and Technology.
    Svensson, Kalle
    SLU.
    Pell, Mikael
    SLU.
    Near infrared reflectance spectroscopy for assessment of spatial soil variation in an agricultural field2005In: Geoderma, ISSN 0016-7061, E-ISSN 1872-6259, Vol. 126, no 3-4, p. 193-202Article in journal (Refereed)
  • 33.
    Olofsson, Madelen
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Norström, Sara
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Bylund, Dan
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Evaluation of sampling and sample preparation procedures for the determination of aromatic acids and their distribution in a podzol soil using liquid chromatography-tandem mass spectrometry2014In: Geoderma, ISSN 0016-7061, E-ISSN 1872-6259, Vol. 232-234, p. 373-380Article in journal (Refereed)
    Abstract [en]

    In this work the distribution of free and weekly adsorbed aromatic acids (phthalic acid and ten phenolicacids; gallic, p-hydroxybenzoic, salicylic, vanillic, protocatechuic, p-coumaric, syringic, sinapic, ferulic and caffeicacid), which could participate in weathering and soil formation processes, were studied for O, E and Bhorizons in a podzol soil in central Sweden. For the analysis a simple and rapid quantitative and qualitative liquidchromatography–tandem mass spectrometry method (using gradient elution) was developed with LODs rangingfrom 5 to 25 nM. Different soil solution sampling techniques (tension-lysimeter and soil centrifugation) and soilextraction with either 10 mM phosphate buffer (pH 7.2) or 50:50 (v/v) 10 mM phosphate buffer:MeOHwere compared. All eleven acids were found in detectable or trace concentrations. The most abundant aromaticacids were vanillic and phthalic acid with concentrations around 1 μM for O and E horizon respectively.Lysimeter samples resulted in the lowest concentrations followed by centrifugation samples. Ingeneral, buffer:MeOH extraction resulted in the highest concentrations for the O horizon, likely due toMeOH's ability to compete for hydrophobic sites on soil organic matter (SOM). Then again, pure bufferwith its higher ion strength, interfering with the acids electrostatic interactions with clay particles, leads tohigher extracted concentrations for the E and B horizons. Since the efficiency of the extraction solutions, to alarge extent, depends on the sample properties, a general approach is hard to appoint. However, the extractionof substituted cinnamic acids is in general facilitated by adding MeOH to the extraction solution. The use of statisticalmethods for the evaluation of the results showed a large and significant difference in aromatic acid concentrationsreceived using different sampling techniques and sample preparations. In fact, sampling methodsresulted in higher variations in aromatic acid concentrations than sampled horizon.

  • 34. Ruth, Katja Viventsova
    et al.
    Kumpiene, Jurate
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Gunneriusson, Lars
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    Holmgren, Allan
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    Changes in soil organic matter composition and quantity with distance to a nickel smelter: a case study on the Kola Peninsula, NW Russia2005In: Geoderma, ISSN 0016-7061, E-ISSN 1872-6259, Vol. 127, no 3-4, p. 216-226Article in journal (Refereed)
    Abstract [en]

    The capacity of soils to absorb contamination depends on a number of factors, such as soil organic matter (SOM) that plays an essential role in adsorption of metal ions, especially in Podzols with their low content of clay minerals. Detailed analysis of SOM can provide information about the potential capacity of a soil to mobilise or immobilise contaminating substances, which in turn can be used to predict potential recovery of the soil ecosystem following heavy metal pollution. The purpose of this study was to learn how an increasing load of heavy metals (Cu and Ni) affects SOM content and structure, and which of the SOM functional groups are responsible for metal retention. The study area is located in the central part of the Kola Peninsula, south of Monchegorsk city and the nickel smelting complex ‘Severonickel’. The amount of total carbon in the soil decreased from 86% to 0.6% as the distance from the smelting complex decreased from 34 to 2 km. Functional groups of the SOM had a larger diversity in less polluted soils than in the soils located closer to the smelting complex. Carboxyl groups had a higher intensity of infra red (IR) bands in soils collected at the distance of 34–27 km than those located closer to the smelter. The most disturbed soil at the site closest to the smelter showed almost no presence of COOH groups. We conducted a laboratory experiment using soils from the least polluted sampling site to assess which SOM functional groups may be responsible for metal retention. Experimental contamination of the soil with the Cu/Ni solution resulted in an overall decrease in the absorbance for all studied functional groups within the measured range, except for COOH. This could be attributed both to changes in the structure of the SOM caused by its reaction with the contaminating substances, and to the leaching of some of the organic compounds from the soil during the experiment. Further studies are needed to better understand which functional groups in the SOM are active in the adsorption processes.

  • 35. van Breemen, Nico
    et al.
    Lundström, Ulla
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Jongmans, Antoine
    Do plants drive podzolization via rock-eating mycorrizhal fungi?2000In: Geoderma, ISSN 0016-7061, E-ISSN 1872-6259, Vol. 94, no 2-4, p. 163-171Article in journal (Refereed)
    Abstract [en]

    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 before plant uptake. Jongmans et al. [Jongmans, A.G., van Breemen, N., Lundstrom, U.S., van Hees, P.A.W., Finlay, R.D., Srinivasan M., Unestam, T., Giesler, R., Melkerud, P.-A., Olsson, M., 1997. Rock-eating fungi. Nature, 389, 682-683] showed that (ectomycorrhizal) fungi drill innumerable narrow cylindrical pores (diameter 3-10 μm) into weatherable minerals in podzol E horizons. The fungi probably form micropores by exuding strongly complexing low-molecular weight organic acids at their hyphal tips, causing highly local dissolution of Al silicates. Micropores occurred in all thin sections of podzols under Pinus sylvestris and Picea abies available from Sweden (3), Finland (2), Switzerland (2), Denmark (2) and the Netherlands (3), but not in the few available thin sections of non-podzolic soils under broadleaves. Many weatherable minerals in the podzol E horizon appeared to be perforated, as opposed to few if any in the abruptly underlying B horizon, suggesting a link to podzolization. High concentrations of Al and Si in organic surface horizons under boreal and temperate conifers can be explained by transfer by hypha of weathering products from the minerals to mycorrhizal roots in the O horizon, followed by release of weathering products that are not taken up by the plants. Rock-eating ectomycorrhizal fungi suggest a more direct role for plants in podzolization than hitherto realized, providing tight coupling between podzolization and mineral weathering. Preliminary observations, however, indicate that mycorrhizal fungi do not play a role in podzolization under Kauri (Agathis australis) in New Zealand. (C) 2000 Elsevier Science B.V.

  • 36.
    van Hees, P. A. W.
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Lundström, Ulla
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Equilibrium models of aluminium and iron complexation with different organic acids in soil solution2000In: Geoderma, ISSN 0016-7061, E-ISSN 1872-6259, Vol. 94, no 2-4, p. 201-221Article in journal (Refereed)
    Abstract [en]

    The percentage of Al and Fe bound to identified low molecular weight (LMW) organic acids and phosphate in soil solution was calculated using a chemical equilibrium model. The highest fractions were obtained for the O1 horizon solutions with median values between 38-49% for Al and 18-29% for Fe. Generally the percentage declined in the deeper horizons. Acceptable agreement with experimental values using ultrafiltration (< 1000 D) was found especially for the spring and summer samplings. In the autumn samples, larger deviations between the modelled and ultrafiltered fractions were found. The major part of the remaining Al and Fe in solution was calculated to be bound to undefined organic acids most likely of higher molecular weight. Speciation studies of some individual organic acids are presented. Citric acid proved to be the most important complex former of the LMW acids in the O and E horizons while oxalic acid was dominant in the B horizon solutions. The total level of organic complexation of Al, Fe, Ca and Mg was also studied. It was found that > 85% of the Al and > 95% of the Fe were organically bound. The opposite was seen for Ca and Mg for which > 85% was modelled to occur as inorganic ions. The modelling results support the theory that LMW organic acids contribute to the translocation of Al and Fe in the podzolization process.

  • 37.
    van Hees, P. A. W.
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Lundström, Ulla
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Giesler, R.
    Low molecular weight acids and their Al-complexes in soil solution- Composition, distribution and seasonal variation in three podzolized soils.2000In: Geoderma, ISSN 0016-7061, E-ISSN 1872-6259, Vol. 94, no 2-4, p. 173-200Article in journal (Refereed)
    Abstract [en]

    Low molecular weight organic acids have been determined qualitatively and quantitatively over a growing season in the soil solution of three podzolized soil profiles. Several low molecular weight (LMW) acids such as citric, shikimic, oxalic, fumaric, formic, acetic, malonic, malic, lactic and t-aconitic acids were identified in the range < 1-1100 μM. Citric acid was the acid generally present at the highest concentrations (15-250 μM) in the upper layers while shikimic and oxalic acids could be observed in all horizons at lower concentrations. The levels of LMW organic acids were always greatest in the organic (O) horizon, and declined in the deeper layers. The fraction of the dissolved organic carbon and total acidity made up by LMW acids was generally in the range 0.5-5% and 0.5-15%, respectively. No apparent seasonal variations were observed, and the differences between the sites were little. The fraction of Al in soil solution bound to LMW organic acids was evaluated using ultrafiltration (< 1000D) and size exclusion chromatography. Fe < 1000D was also determined. For the O1 horizon about 40% and 20% of the Al and Fe, respectively, were detected in the LMW fraction (< 1000D). The LMW fraction of the two elements decreased deeper down in the profile, but relative increases were sometimes observed in the B1 horizon. Labile and LMW (< 1000D) Si were determined by FIA and ultrafiltration, respectively. The results show that a major fraction (80-100%) of the Si is labile and of low molecular weight, most likely silicic acid. (C) 2000 Elsevier Science B.V.

  • 38.
    van Hees, P. A. W.
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Lundström, Ulla
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Starr, M.
    Giesler, R.
    Factors influencing aluminium concentrations in soil solution of podzols2000In: Geoderma, ISSN 0016-7061, E-ISSN 1872-6259, Vol. 94, no 2-4, p. 289-310Article in journal (Refereed)
    Abstract [en]

    Mechanisms controlling the concentrations of free Al3+ and total Al in the soil solution from three podzolic soils were evaluated. Saturation indices (SI) were calculated for five mineral phases, but no single phase determined the Al3+ activity. E horizon samples were found to be undersaturated with respect to all phases. A more detailed equilibrium study indicated that formation of proto-imogolite sols was commonly possible in B horizon solutions with pH > 5. The poor relationship between pH and pAl3+ in the E and B1 horizons did not support control by exchange reactions with solid organic matter, although partial least square (PLS) regressions indicated importance of soil-exchangeable Al in the B and C horizons. It was concluded that in the E and most of the B1 horizon solutions, Al3+ activity is controlled by equilibrium with soluble organic acids which was supported by the PLS regressions. (C) 2000 Elsevier Science B.V.

  • 39.
    van Hees, P. A. W.
    et al.
    Örebro University.
    Rosling, A.
    Swedish University of Agricultural Sciences (SLU), Uppsala.
    Lundström, Ulla
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Finlay, R. D.
    Swedish University of Agricultural Sciences (SLU), Uppsala.
    The biogeochemical impact of ectomycorrhizal conifers on major soil elements (Al, Fe, K and Si)2006In: Geoderma, ISSN 0016-7061, E-ISSN 1872-6259, Vol. 136, no 1-2, p. 364-377Article in journal (Refereed)
    Abstract [en]

    Mobilisation of nutrients and dissolution of minerals are of key importance for plant growth and soil formation, as well as long term ecosystem sustainability. The effects of Pinus sylvestris seedlings, ectomycorrhizal colonisation and potassium supply on the mobilisation of Al, Fe, K and Si were studied in a soil column experiment. Budgets were constructed considering amounts in drainage water, accumulation in plants and changes in the pools of exchangeable ions (BaCl2 extractions). Drainage was the most important sink under the experimental conditions imposed, but the other two pools were also of quantitative significance. Plants had a significant positive effect on the total quantities of all elements mobilized. Mycorrhizal colonisation had limited quantitative impact on the mobilization, probably because the chosen mycorrhizal fungi did not cause any growth promotion in this experiment. Despite this, a multivariate analysis (PCA) showed a clear separate grouping of mycorrhizal, non-mycorrhizal and no-plant treatments, and in particular Si and K mobilization was related to soil biological variables which in turn were affected by the presence of mycorrhiza. When K was omitted from the watering solution, plants were able to mobilise significantly more K, which was reflected in plant uptake and a potential replenishment of the exchangeable pool. Up-scaling of total Al, K and Si mobilization to field conditions resulted in rates between equal to and up to 10 times higher than the average historical weathering rate.

  • 40.
    van Hees, Patrick A. W.
    et al.
    Örebro University, Department of Natural Sciences.
    Rosling, A.
    Lundstrom, U. S.
    Finlay, R. D.
    The biogeochemical impact of ectomycorrhizal conifers on major soil elements (Al, Fe, K and Si)2006In: Geoderma, ISSN 0016-7061, E-ISSN 1872-6259, Vol. 136, no 1-2, p. 364-377Article in journal (Refereed)
    Abstract [en]

    Mobilisation of nutrients and dissolution of minerals are of key importance for plant growth and soil formation, as well as long term ecosystem sustainability. The effects of Pinus sylvestris seedlings, ectomycorrhizal colonisation and potassium supply on the mobilisation of Al, Fe, K and Si were studied in a soil column experiment. Budgets were constructed considering amounts in drainage water, accumulation in plants and changes in the pools of exchangeable ions (BaCl2 extractions). Drainage was the most important sink under the experimental conditions imposed, but the other two pools were also of quantitative significance. Plants had a significant positive effect on the total quantities of all elements mobilized. Mycorrhizal colonisation had limited quantitative impact on the mobilization, probably because the chosen mycorrhizal fungi did not cause any growth promotion in this experiment. Despite this, a multivariate analysis (PCA) showed a clear separate grouping of mycorrhizal, non-mycorrhizal and no-plant treatments, and in particular Si and K mobilization was related to soil biological variables which in turn were affected by the presence of mycorrhiza. When K was omitted from the watering solution, plants were able to mobilise significantly more K, which was reflected in plant uptake and a potential replenishment of the exchangeable pool. Up-scaling of total Al, K and Si mobilization to field conditions resulted in rates between equal to and up to 10 times higher than the average historical weathering rate. (c) 2006 Elsevier B.V. All rights reserved.

  • 41.
    Vestin, Jenny L. K.
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences, Engineering and Mathematics.
    Norström, Sara H
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences, Engineering and Mathematics.
    Bylund, Dan
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences, Engineering and Mathematics.
    Lundström, Ulla S
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences, Engineering and Mathematics.
    Soil solution and stream water chemistry in a forested catchment II: Influence of organic matter2008In: Geoderma, ISSN 0016-7061, E-ISSN 1872-6259, Vol. 144, no 2008, p. 271-278Article in journal (Refereed)
    Abstract [en]

    Differences between recharge and discharge areas in soil forming processes and nutrient conditions were observed in an earlier study of a catchment area in central Sweden (63°07′N, 16°70′E; Vestin, J.L.K., Norström, S.H., Bylund, D., Mellander, P-E., Lundström, U.S., submitted for publication to Geoderma. Soil solution and stream water chemistry in a forested catchment, I Dynamics.). To further examine the factors that determine the soil and stream water properties in the catchment area, the present study focused on the organic dynamics and the association of cations to different size fractions of organic matter. Six sampling plots were established in each of the recharge and discharge areas, respectively, with samples taken in June 2004. Dissolved organic carbon (DOC) and cation concentrations in the soil solution and stream water were determined. In the recharge area, low molecular mass (LMM) organics played an important role in transportation of several cations through the soil profile, inducing the podzolisation process by associating with Al and Fe. In the discharge area close to the stream, high molecular mass (HMM) organics appeared to play a crucial role in transportation of cations. Here the majority of recovered cations were associated with HMM organic matter, inhibiting the podzolisation process. The total concentration of C and DOC was higher than in the recharge area, and the concentration of cations increased with depth in the mineral soil. In the stream water, as in the discharge area soil solution, all carboxylic groups were associated to cations. Both Al and Fe were completely associated with the HMM DOC fraction, which indicated a rapid turnover of LMM DOC in stream water. Thus we conclude that DOC plays an important role in soil forming processes, and that its different size fractions have large effects on the transportation of elements in different soils and in stream water.

  • 42.
    Vestin, Jenny L. K.
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences, Engineering and Mathematics.
    Norström, Sara H
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences, Engineering and Mathematics.
    Bylund, Dan
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences, Engineering and Mathematics.
    Mellander, Per-Erik
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences, Engineering and Mathematics.
    Lundström, Ulla S
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences, Engineering and Mathematics.
    Soil solution and stream water chemistry in a forested catchment I: Dynamics2008In: Geoderma, ISSN 0016-7061, E-ISSN 1872-6259, Vol. 144, no 1/2, p. 256-270Article in journal (Refereed)
    Abstract [en]

    Soil solution and stream water chemistry were studied during two years in a catchment in Bispgården in central Sweden (63°07′N, 16°70′E). Soil samples and soil solution were collected in a slope at two distances (10 and 80 m) from a stream. The aims were to examine interactions between recharge (podzol) and discharge (arenosol) areas and to investigate the relations between soil solution and stream water chemistry. The parent material was similar within the catchment, but the content of C and N were higher in the discharge area most likely due to the difference in hydrological conditions compared to the recharge area. Exchangeable cations and base saturation were higher in the discharge area than in the recharge area, which may be due to the higher content of C. The concentrations in soil solution of H, DOC, NO3, SO4, Al, Si, Ca and K charge area compared to the recharge area which was probably caused by transportation of elements in soil and retention due to the increased content of C. During snow melt, the concentrations in soil solution of DOC, SO4, Al, Si, Ca and K were low due to dilution and low biological activity. The concentrations were then increasing during the seasons as an effect of biological activity and mineral weathering. NO3 concentration in soil solution was found in higher concentrations during snow melting and was then diminishing during summer likely as a result of biological uptake. After a dry period followed by an intensive rain in August 2003, the stream water chemistry was markedly altered for a few days. The concentrations of H, DOC SO4, Al and Ca were increased and the concentration of Si was decreased in the stream water. It therefore appeared that the stream water mirrored the upper soil horizons in the discharge area during high flows, while reflecting the lower soil horizons and ground water during low flows.

  • 43.
    Vestin, Jenny
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Nambu, Kei
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    van Hees, P. A. W.
    Örebro University.
    Bylund, Dan
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Lundström, Ulla
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    The influence of alkaline and non-alkaline parent material on soil chemistry2006In: Geoderma, ISSN 0016-7061, E-ISSN 1872-6259, Vol. 135, p. 97-106Article in journal (Refereed)
    Abstract [en]

    The gneiss bedrock at Alnö Island, (62o24N, 17o30E) in the middle of Sweden, has alkaline intrusions interspersed in narrow dikes. This gives an opportunity to study the impact of different parent material on soil solution in a homogeneous spruce stand. In this study, the alkaline parent materials gave rise to a soil solution with significantly (p 0.05) higher concentrations of DOC, SO4, NO3, Ca and Mg compared to the non-alkaline sites. For the deepest mineral horizons, 25-30cm, F and pH were also higher in the alkaline soil solutions. There were almost no differences between the organic horizons at alkaline and non-alkaline sites, probably explained by the influence of litter and recirculation of nutrients. The multivariate analyses emphasized the correlation between the parent material and the soil solution concentrations of Ca, Mg, PO4 and Al. The data were statistically evaluated by t-tests, ANOVA (Analysis of variances), PCA (Principal Component Analysis) and PLS (Partial Least Squares regression).

  • 44.
    Wu, Mousong
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering.
    Wu, Jingwei
    Wuhan Univ, State Key Lab Water Resources & Hydropower Engn S, Wuhan 430072, Hubei, Peoples R China..
    Tan, Xiao
    Wuhan Univ, State Key Lab Water Resources & Hydropower Engn S, Wuhan 430072, Hubei, Peoples R China.;Sichuan Univ, Coll Water Resource & Hydropower, State Key Lab Hydraul & Mt River Engn, Chengdu 610065, Sichuan, Peoples R China..
    Huang, Jiesheng
    Wuhan Univ, State Key Lab Water Resources & Hydropower Engn S, Wuhan 430072, Hubei, Peoples R China..
    Jansson, Per Erik
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering.
    Zhang, Wenxin
    Univ Copenhagen, Ctr Permafrost, Dept Geosci & Nat Resource Management, DK-1350 Copenhagen, Denmark..
    Simulation of dynamical interactions between soil freezing/thawing and salinization for improving water management in cold/arid agricultural region2019In: Geoderma, ISSN 0016-7061, E-ISSN 1872-6259, Vol. 338, p. 325-342Article in journal (Refereed)
    Abstract [en]

    In cold/arid agricultural regions seasonal freezing/thawing of soils can result in soil salinization in winter; therefore, it is crucial to understand the mechanisms behind soil salinization during winter for better water management in agriculture. In Hetao Irrigation District of Inner Mongolia, northern China, we used the CoupModel (version 5) considering dynamical impacts of salt on soil freezing point to simulate soil salt dynamics and soil freezing/thawing in three winters during 2012-2015. The simulated soil temperature at different depths was improved by 10% with respect to the Nash-Sutcliffe coefficient NSE R-2 when dynamical salt impact on freezing point was taken into accounted. Simulations revealed that ice coverage on soil surface as well as water stored in drainage ditches during winter cause more severe salinization in spring due to improper Al (Autumn Irrigation) practices combining poor drainage systems. A new Al practice with earlier irrigation date (i.e. 10 d earlier than 2012/2013 winter regulation), longer irrigation period (i.e. 7 d instead of 3 d), but with less irrigation water (reduced by 20% from 2012/2013 winter regulation) was then proposed. The new AI practice can control groundwater level and salt accumulation better during winters, Our results highlight the importance of combining detailed field irrigation tests with a process-based model accounting for interactions between soil freezing/thawing and salinization to improve water management efficiency in cold/arid agricultural regions.

  • 45.
    Yang, P.
    et al.
    Fujian Normal Univ, Peoples R China.
    Wang, M. H.
    Fujian Normal Univ, Peoples R China.
    Lai, Derrick Y. F.
    Chinese Univ Hong Kong, Peoples R China.
    Chun, K. P.
    Hong Kong Baptist Univ, Peoples R China.
    Huang, J. F.
    Fujian Normal Univ, Peoples R China.
    Wan, S. A.
    Fujian Normal Univ, Peoples R China.
    Bastviken, David
    Linköping University, Department of Thematic Studies, Tema Environmental Change. Linköping University, Faculty of Arts and Sciences.
    Tong, C.
    Fujian Normal Univ, Peoples R China.
    Methane dynamics in an estuarine brackish Cyperus malaccensis marsh: Production and porewater concentration in soils, and net emissions to the atmosphere over five years2019In: Geoderma, ISSN 0016-7061, E-ISSN 1872-6259, Vol. 337, p. 132-142Article in journal (Refereed)
    Abstract [en]

    Wetlands can potentially affect global climate change through their role in modulating the atmospheric concentrations of methane (CH4). Their overall CH4 emissions, however, remain the greatest uncertainty in the global CH4 budget. One reason for this is the paucity of long-term field measurements to characterize the variability of CH4 emissions from different types of wetlands. In this study, we quantified CH4 emissions from a brackish, oligohaline Cyperus malaccensis marsh ecosystem in the Min River Estuary in southeast China over five years. Our results showed substantial temporal variability of CH4 emissions from this brackish marsh, with hourly fluxes ranging from 0.7 +/- 0.6 to 5.1 +/- 3.7 mg m(-2) h(-1) (mean +/- 1 SD) during the study period. The inter-annual variability of CH4 emissions was significantly correlated with changes in soil temperature, precipitation and salinity, which highlighted the importance of long-term observations in understanding wetland CH4 dynamics. Distinct seasonal patterns in soil CH4 production rates and porewater CH4 concentrations also were observed, and were both positively correlated with CH4 emissions. The seasonal variations of CH4 emissions and production were highly correlated with salinity and porewater sulfate levels. The mean annual CH4 efflux from our site over the five-year period was 23.8 +/- 18.1 g CH4 m(-2) yr(-1), indicating that subtropical brackish tidal marsh ecosystems could release a large amount of CH4 into the atmosphere. Our findings further highlight the need to obtain high-frequency and continuous field measurements over the long term at multiple spatial scales to improve our current estimates of wetland CH4 emissions.

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