This website is using a security service to protect itself from online attacks The action you just performed triggered the security solution There are several actions that could trigger this block including submitting a certain word or phrase You can email the site owner to let them know you were blocked Please include what you were doing when this page came up and the Cloudflare Ray ID found at the bottom of this page Metrics details Growing evidence of silicon (Si) playing an important role in plant health and the global carbon cycle triggered research on its biogeochemistry sorption of silicic acid (H4SiO4) to mineral surfaces is a main control on Si mobility We examined the competitive sorption of Si and phosphorus in forest floor leachates (pH 4.1–4.7) to goethite in order to assess its effects on Si mobility at weathering fronts in acidic topsoil a decisive zone of nutrient turnover in soil we varied the extent of competition between solutes by varying the amount of added goethite (α-FeOOH) and the Si pre-loading of the goethite surfaces Results suggest weaker competitive strength of Si than of dissolved organic matter and ortho-phosphate hardly any dissolved Si (< 2%) but much of the dissolved organic carbon (48–80%) was sorbed Pre-loading the goethite surfaces with monomeric Si hardly decreased the sorption of organic carbon and phosphate whereas up to about 50% of the Si was released from surfaces into solutions indicating competitive displacement from sorption sites We conclude sorption competition with dissolved organic matter and other strongly sorbing solutes can promote Si leaching in soil Such effects should thus be considered in conceptual models on soil Si transport the Si cycle is tightly related to the cycling of carbon which makes Si biogeochemistry a crucial topic within climate change research may be a central factor in Si mobilization and phytoavailability We hypothesized that pre-sorbed Si decreases the sorption of these components by occupying sorption sites passivating the mineral surface’s reactivity towards anionic forest floor leachate components phosphate and part of the DOM are expected to be highly competitive sorbents causing release of the pre-sorbed Si into solution We specifically assessed Si–OH complexation by surface Fe potentially hampering the surface complexation of organic ligands and phosphate as the possible cause of sorption competition The binding of Si was studied using sorption isotherm data and subsequent analysis of surface species by X-ray photoelectron spectroscopy (XPS) Relationship between equilibrium Si concentrations in solution and amounts of Si sorbed at the goethite surfaces for different experiments (Si sorption test and Si pre-loading of goethite for the experiments with forest floor solutions) denoting the standard deviation of replicates (n = 3) Data were plotted using SigmaPlot 11.0 from Systat Software On basis of the data presented above, we selected the levels of Si pre-loading for the subsequent experiments with natural forest floor solutions. The results on Si sorption during the pre-loading procedure matched the results of the prior sorption experiment (Fig. 1) indicating good experimental reproducibility Rinsing the goethite for removal of residual salts removed weakly bound Si from the surfaces; the losses averaged 5% of the initial surface-bound Si The final Si loading levels of the samples (after sorption and washing) were 20 and 76% of the maximum Si surface loading achieved in the prior sorption experiment No higher loading levels were used to avoid Si polymerization at the surfaces other Si binding types being involved in the sorption competition The Si pre-loading levels of samples are denoted in the following with ‘low’ surface area and charge of the different Si pre-loading levels were no factors in the sorption experiments with natural forest floor solutions Examples of XPS spectra of the Si 2s region for goethite with variable Si pre-loadings prior to the sorption experiments with forest floor solutions The vertical red line at 152.0 eV highlights that there were no differences in peak position between pre-loading levels thus indicating the prevalence of monomeric Si Given the higher molar C/Si ratio and similar SUVA280 values we expected that the DOM of the Mitterfels solution is more competitive against Si for sorption sites than those of the Bad Brückenau solution The total P and phosphate-P concentrations were higher in the Mitterfels than in the Bad Brückenau solution (Table 2) the initial phosphate-P concentrations made only about 3% of the total P concentrations suggesting most P to be present in organic form as phosphate-P concentrations made less than 1% of the dissolved Si concentrations it played only a minor role as a competitor for sorption sites in the present study Amount of organic C and Si at goethite surfaces after interaction with the two forest floor solutions upon different additions of goethite with and without Si pre-loadings The error bars indicate the standard deviation for experimental replicates; stars indicate significant differences between treatments (p < 0.05; ANOVA on ranks) at least two treatments differ significantly from each other This also points at a lower sorption affinity of Si than of C Si only sorbs to a larger extent when excess sorption sites are available for goethite additions of up to 2 g l−1 (Mitterfels solution) or 6 g l−1 (Bad Brückenau solution) the molar ratios between DOC and dissolved Si decreased with increasing goethite input (Mitterfels solution: from 27 to 8; Bad Brückenau solution: from 15 to 4) they increased again (Mitterfels solution: from 8 to 92; Bad Bückenau solution: from 4 to 13) This suggests that Si was only sorbed when all strongly sorbing organic matter components were already removed from solution and still some sorption sites were available Effects of pre-loaded Si on changes in DOC (Fig. 3) as well as on C loadings of the goethite surfaces (Fig. 4) were rather small compared to the effects of adding different amounts of goethite no significant differences between Si pre-loading levels were found and for the Bad Brückenau solution the difference were significant only in few cases our data indicate that the Si pre-loadings reduced the sorption of DOM components This reduction (as calculated by changes in DOC concentrations) made up to 13% of the amounts of DOC sorbed to goethite without Si pre-loading Percentage of Si desorbed from the goethite surfaces with high Si pre-loading due to interactions with the two forest floor solutions as a function of the goethite amounts added (data for other Si-preloading levels are not shown because less pronounced or no desorption occurred); the error bars indicate the standard deviation for experimental replicates Nature and implications of sorption competition between Si (blue symbols) and phosphorus (green symbols) at the variable-charge surfaces of pedogenic minerals The specific surface area (SSA) was determined by N2 gas adsorption at 77 K based on 11 adsorption points in the relative pressure range of 0.05–0.3 and applying the Brunnauer–Emmett–Teller (BET) equation (Autosorb iQ MP Moisture was removed before measurement by degassing the sampling at 60 °C for 6 h All Si solutions were prepared from stock solution of mono-silicic acid (1,000 mg Si l−1 in 2% NaOH; Certipur In order to prevent solution phase polymerization the stock solution was diluted by at least 25 times before adjusting the pH of all Si solution to 4 (close to the pH of the forest floor leachates) with HCl and the ionic strength to 0.015 M with NaCl Silicon sorption experiments were conducted using suspensions with 1.82 g l−1 goethite and twelve different initial Si concentrations (4–1,060 µM Si; pH 4; n = 3 experimental replicates) The suspensions were agitated in polypropylene bottles on a horizontal shaker at 200 rpm for 24 h at 22–24 °C and then centrifuged at 8,525 g for 35 min The supernatant was passed through 0.1-µm polyethersulfone membranes (Supor-100 USA) before analysis for Si by inductively coupled plasma–optical emission spectroscopy (ICP-OES; Ultima 2 The amounts of Si sorbed to the goethite equaled the difference of the initial Si concentration and the equilibrium Si concentrations after 24 h Based on the results of these sorption experiments we selected Si pre-loading levels of the goethite for the experiments with forest floor solutions suspensions with 1.82 g l−1 goethite and Si concentrations of 0 and treated as described above for the Si sorption experiment In order to remove soluble salts from the goethite samples they were re-suspended several times in doubly deionized water followed by centrifugation at 8,525 g for 35 min and discarding of the supernatant until the electric conductivity of the supernatant was ≤ 50 µS cm−1 The Si-loaded goethite samples were then freeze-dried The Si binding environment on the Si-loaded goethite as well as Si-to-Fe element ratios were assessed using XPS (Axis Supra instrument The analyses were obtained for freeze-dried goethite powders that were mounted on double-sided adhesive carbon tape we obtained detail scans of (1) the C 1s signal (between 274 and 300 eV) for correcting the binding energies of all analyses (2) the Si 2s signal (between 142 and 160 eV) to deduce the Si binding environment and (3) the region between 4 and 160 eV in order to calculate Si-to-Fe element ratios from the Si 2s and Fe 3p peaks Three measurement positions (each 300 × 700 µm) per powder sample were analyzed Settings were: emission current of 25 mA (detail scans) and up to five sweeps (the number was less in case a quality control value was reached that was calculated by the software on basis of differences in peak height and peak to peak variation between sweeps) Data were evaluated using the ESCApe software (vs Peak maxima were obtained from first derivatives of the signal curves (using five point stencil differentiation) to test for possible Si polymerization at the surfaces Electrophoretic mobility measurements were carried out at room temperature using the laser Doppler electrophoresis approach (Nano-ZS Goethite samples were suspended in ultrapure water adjusted to pH 4 and five measurements per sample were conducted within less than seven minutes The ζ potential was derived from the electrophoretic mobility data using the Smoluchowski equation The SSA of the pre-loaded goethite was determined as described above the sorption capacity was assumed to be almost completely exhausted causing maximum competition among for sorption sites; the extent of competition should gradually decrease with increasing goethite additions Sorption experiments were conducted for 24 h during which the suspensions were agitated in polyethylene bottles on a horizontal shaker at 200 rpm at 22–24 °C the goethite was settled by centrifugation (8,525 g for 35 min) and the supernatant solutions were filtered through 0.1-µm polyethersulfone filters (Supor-100) before analyses for DOC and total Si as described above for the initial solutions and Si sorbed to the mineral surfaces were calculated via changes in the respective concentrations in solutions during the experiments The ANOVA on ranks method of the SigmaPlot 11.0 software (Systat Software CA) was used to test for statistically significant effects of the Si pre-loading levels on concentrations of DOC and phosphate and on the SUVA280 in solutions as well as on C and Si loadings at the goethite surfaces after the sorption experiment The non-parametric method was chosen as the underlying assumptions of one-way ANOVA (normal distribution of data groups as tested using Levene’s test) were in many cases not met The datasets generated during and/or analyzed during the current study are available from the corresponding author on reasonable request Silicon pools and fluxes in soils and landscapes—a review Effects of Si fertilization on Si in soil solution and resistance of rice to biotic stresses in Southern Vietnam Adsorption and polymerisation of silicic acid on ferrihydrite Modeling silica sorption to iron hydroxide An attenuated total reflectance IR study of silicic acid adsorbed onto a ferric oxyhydroxide surface Silicic acid adsorption and oligomerization at the ferrihydrite−water interface: interpretation of ATR-IR spectra based on a model surface structure Binding geometries of silicate species on ferrihydrite surfaces A contemporary overview of silicon availability in agricultural soils Soil processes drive the biological silicon feedback loop Kinetics of arsenic adsorption on goethite in the presence of sorbed silicic acid Polymerization of silicate on hematite surfaces and its influence on arsenic sorption Competition between selenium (IV) and silicic acid on the hematite surface Quantification and isotherm modelling of competitive phosphate and silicate adsorption onto micro-sized granular ferric hydroxide The mechanism of phosphate fixation by iron oxides 1 Ferrihydrite interaction with silicate and competing oxyanions: geometry and hydrogen bonding of surface species Silicon availability modifies nutrient use efficiency and content and productivity of winter wheat (Triticum aestivum L.) Silicon increases the phosphorus availability of Arctic soils Implications of aqueous silica sorption to iron hydroxide: mobilization of iron colloids and interference with sorption of arsenate and humic substances Contribution of dissolved organic matter to carbon storage in forest mineral soils Terrestrial phosphorus limitation: mechanisms Water balance creates a threshold in soil pH at the global scale Soil phosphorus supply controls P nutrition strategies of beech forest ecosystems in Central Europe Controls on the dynamics of dissolved organic matter in soils: a review The influence of surface structure on H4SiO4 sorption and oligomerization on goethite surfaces: an XPS study using goethites differing in morphology Insights into H4SiO4 surface chemistry on ferrihydrite suspensions from ATR-IR diffuse layer modeling and the adsorption enhancing effects of carbonate Sorption of natural organic matter fractions to goethite (α-FeOOH): effect of chemical composition as revealed by liquid-state 13C NMR and wet-chemical analysis Contrasting effects of different types of organic material on surface area and microaggregation of goethite Assessing the role of silicate polymerization on metal oxyhydroxide surfaces using X-ray photoelectron spectroscopy Silicate sorption and desorption by a Si-deficient soil—effects of pH and period of contact Small scale variability of vertical water and dissolved organic matter fluxes in sandy Cambisol subsoils as revealed by segmented suction plates Adsorption of dissolved organic matter (DOM) onto the synthetic iron pipe corrosion scales (goethite and magnetite): effect of pH The apparent disappearance of aromatic litter components in soils Reaction of forest floor organic matter at goethite Sorptive stabilization of organic matter by microporous goethite: sorption into small pores vs Biodegradation of forest floor organic matter bound to minerals via different binding mechanisms Processes controlling the production of aromatic water-soluble organic matter during litter decomposition Effects of pH and ionic strength on the adsorption of phosphate and arsenate at the goethite–water interface Dissolved organic phosphorus and sulphur as influenced by sorptive interactions with mineral subsoil horizons Organic phosphorus in soil water under a European beech (Fagus sylvatica L.) stand in northeastern Bavaria Germany: seasonal variability and changes with soil depth Changes in properties of soil-derived dissolved organic matter induced by biodegradation Download references This work has been funded by the German Research Foundation (DFG MI 1377/16-1) and Shuling Chen for their support in the laboratory wrote the manuscript with contributions of all authors The authors declare no competing interests Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations Download citation DOI: https://doi.org/10.1038/s41598-020-68042-x Anyone you share the following link with will be able to read this content: a shareable link is not currently available for this article Sign up for the Nature Briefing: Microbiology newsletter — what matters in microbiology research Our editors will review what you’ve submitted and determine whether to revise the article made the first nonstop trans-North American balloon flight Anderson and his son Kristian launched the helium balloon Kitty Hawk from Fort Baker the first trans-North American nonstop balloon flight Anderson was killed in an accident during a balloon race Markus del Monego MW is Regional Chair for Germany and Austria at the Decanter World Wine Awards (DWWA) 2024 Markus Del Monego MW holds additionally the title of Best Sommelier of the World 1998 He was the first person in the history of these titles to succeed in being able to hold both of them Markus is owner and managing director of consultancy company tasteTainment GmbH based in Germany beginning hotelier training at the Dorint Resort & Spa in Bad Brückenau He worked as sommelier in the Fairmont Hotel Vier Jahreszeiten in Hamburg and later at the Dorint Park Hotel Bremen and The Savoy in London a Sake Samurai and ambassador of the Ordre des Coteaux de Champagne in Germany Markus also publishes on his own website See more 2024 Regional Chairs. 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