List of Titles

Abundant stocks and mobilization of elements in boreal acid sulfate soils

- Yli-Halla, Markku, Virtanen, Seija, Mäkelä, Minna, Simojoki, Asko, Hirvi, Mirva, Innanen, Saila, Mäkelä, Jaakko, Sullivan, Leigh

Authors: Yli-Halla, Markku , Virtanen, Seija , Mäkelä, Minna , Simojoki, Asko , Hirvi, Mirva , Innanen, Saila , Mäkelä, Jaakko , Sullivan, Leigh
Date: 2017
Type: Text , Journal article
Relation: Geoderma Vol. 308, no. (2017), p. 333-340
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Description: Large amounts of sulfate and divalent iron (Fe) are released into the pore water of acid sulfate (AS) soils upon oxidation of sulfidic materials. The simultaneously produced acidity dissolves metals from the soil matrix. Reduced horizons of AS soils commonly have a large mineral nitrogen (N) stock in the form of NH4 +-N, which is a potential source of N leaching and gaseous emissions. This study was carried out at three AS soil sites in Finland. Cation composition of pore water was monitored in a monolithic lysimeter experiment. Timothy samples grown in an AS soil were analysed for mineral elements and the soil was investigated for zinc (Zn) distribution in different chemical species at four depths down to 85 cm. The composition of pipestems formed in previous root channels was investigated by SEM, X-ray EDX and XRD. Emissions of CO2 and N2O were measured in an AS field which had a peaty topsoil. Monitoring by closed chambers was carried out at three sites differing in the depth of peat layer (15, 30 and 60 cm). In the sulfuric horizon, large amounts of calcium and magnesium were mobilized. Reflooding stopped the mobilization of those elements but resulted in abundant dissolution of Fe, which became the dominant cation in the pore water. Timothy growing in an AS soil showed only small deviations from the average composition measured in Finland with the exception of Zn that was at the deficiency level. As Zn in the root zone had been dissolved and subsequently leached, it was recovered in easily soluble forms in the subsoil. Pipestem composition indicated accumulation of Fe and formation of a new solid phase probably mostly in the form of schwertmannite even though jarosite was also detected. The annual CO2 emissions from the peaty AS soil were about 6000 kg C ha− 1 but the N2O emissions were relatively small, with a magnitude more typical of mineral rather than organic soils. Thus, large N stock of an AS soil do not necessarily contribute to abundant gaseous N emissions. © 2017 Elsevier B.V.

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The impact of deforestation and pasture abandonment on soil properties in the wet tropics of Australia

- Rasiah, Velu, Florentine, Singarayer, Williams, B. L., Westbrooke, Martin

Authors: Rasiah, Velu , Florentine, Singarayer , Williams, B. L. , Westbrooke, Martin
Date: 2004
Type: Text , Journal article
Relation: Geoderma Vol. 120, no. 1-2 (2004), p. 35-45
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Description: Limited information exists on the changes in soil properties, particularly from the wet tropics of Australia, under long-term abandoned pasture, which was previously grazed and was established on deforested tropical rainforest. This information may be help in successful forest reestablishment. The objectives of this study were to assess the cumulative impact deforestation, grazed and abandoned pasture on selected soil physico-chemical properties from (i) an abandoned pastureland and (ii) a recently planted rainforest (PRF), planted in the abandoned pastureland. The experimental site is a field in the Northeast Queensland (NEQ) wet tropical region of Australia. This site was deforested approximately 70 years ago and brought under unfertilized grazed pasture for 30 years. Subsequently the grazed pastureland was abandoned and remains un-grazed for 40 years. A section of the abandoned pastureland was planted, 10 years ago, with native forest species, involving different combinations in five treatments in a completely randomised block design. A nearby undisturbed rainforest is used as the background against which assessment was carried out. Soil samples from 0- to 15-cm depth were collected in July 2000 and analyzed for nitrate-N, ammonium-N, total N, total soil organic C (SOC) and labile-C, pH (in water and CaCl2), electrical conductivity (EC), exchangeable Ca, Mg, Na, K, and Al, and bulk density. Compared to the rainforest, the N and C concentrations of different forms under abandoned pasture and PRF were significantly less, exclusive of the total N under abandoned pasture. More specifically, the SOC under the abandoned pasture was 37,600 mg/kg compared with 74,800 mg/kg under rainforest and 27,000 mg/kg in the PRF. The exchangeable Al under rainforest was 8.5 c molc/kg compared with 42. 4 to 80.2 c molc/kg under abandoned pasture and PRF. In general exchangeable cations (sum of Ca, Mg, K, and Na) under the rainforest were higher than the abandoned pasture. Soil under the abandoned pasture and PRF are more acidic by 0.5 to 1 units than the rainforest. Higher bulk densities under abandoned pasture and PRF led to 0.03% to 0.07% reductions in total porosities. Though we did not anticipate the soil under the abandoned pasture to recover 100% in 30-40 years, the results indicate that 40 years under abandoned pasture or 30 years of abandoned pasture plus 10 years under PRF was not sufficient to bring about substantial improvement in soil properties comparable to the rainforest. This implies the resiliency of tropical soils, in general, to recover from deforestation and cultivation induced degradation is poor. © 2003 Elsevier B.V. All rights reserved.
Description: C1
Description: 2003000713

Estimation of vineyard soil structure and preferential flow using dye tracer, X-ray tomography, and numerical simulations

- Filipović, Vilim, Defterdarović, Jasmina, Šimůnek, Jiří, Filipović, Lana, Ondrašek, Gabrijel, Romić, Davor, Bogunović, Igor, Mustać, Ivan, Ćurić, Josip, Kodešová, Radka

Authors: Filipović, Vilim , Defterdarović, Jasmina , Šimůnek, Jiří , Filipović, Lana , Ondrašek, Gabrijel , Romić, Davor , Bogunović, Igor , Mustać, Ivan , Ćurić, Josip , Kodešová, Radka
Date: 2020
Type: Text , Journal article
Relation: Geoderma Vol. 380, no. (2020), p. 114699
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Description: •Proper assessment of the soil structure of arable soils requires a combination of various methods.•Results of evaporation and leaching experiments were fitted using a single-porosity flow model.•Data collected during flow experiments did not provide evidence of non-equilibrium flow.•Additional dye-staining and X-ray imaging revealed a complex biopore network.•The bi-modal flow behavior was revealed using the dual-permeability modeling of dye transport. The appearance and distribution of soil pores have a significant influence on water flow and solute transport in the soil vadose zone. The pore system is highly variable in arable soils where crop rotation, tillage, trafficking, soil amendments, and various management practices are commonly implemented. The aim of this study was to assess the porous system and preferential flow pathways in a vineyard soil using undisturbed soil columns, and by combining laboratory and numerical methods with dye staining and X-ray imaging. It was hypothesized that the integration of various methods could reveal more information about soil structure, and flow and transport behavior of structured arable soil. Soil water retention and hydraulic conductivity curves were obtained using the evaporation method, while water flow was assessed using intermittent leaching experiments. Water flow and the transport of Brilliant Blue were simulated using HYDRUS-1D. A single-porosity model of soil hydraulic properties provided a good description of data collected during the evaporation experiments. Data collected during leaching experiments did not provide enough experimental evidence for the occurrence of nonequilibrium flow patterns and the differentiation between the single- and dual-permeability models of soil hydraulic properties. However, dye staining and X-ray imaging revealed a complex pore-architecture network with large vertical and horizontal biopores. The staining patterns (Brilliant Blue FCF) within the vertical column sections documented the extent of preferential flow. The study showed that the bi-modal character of pore structure could often be hidden when a limited number or non-adequate methods are applied for its quantification from water flow behavior. The impact of preferential pathways on dye transport can be investigated with observations and simulations. A combination of various methods enabled us to adequately assess vineyard soil structure and fine-tune the description and extent of preferential water flow.

Seawater causes rapid trace metal mobilisation in coastal lowland acid sulfate soils : Implications of sea level rise for water quality

- Wong, Vanessa, Johnston, Scott, Burton, Edward, Bush, Richard, Sullivan, Leigh, Slavich, Peter

Authors: Wong, Vanessa , Johnston, Scott , Burton, Edward , Bush, Richard , Sullivan, Leigh , Slavich, Peter
Date: 2010
Type: Text , Journal article
Relation: Geoderma Vol. 160, no. 2 (2010), p. 252-263
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Description: Coastal floodplains are highly vulnerable to inundation with saline water and the likelihood of inundation will increase with sea level rise. Sediment samples from floodplains containing coastal lowland acid sulfate soils (CLASS) in eastern Australia were subjected to increasing seawater concentration to examine the probable effects of sea level rise on acidity and metal desorption. Ten soils were mixed with synthetic seawater concentrations varying from 0% to 100% at a solid:solution ratio of 1:10 for 4h. There was a slight decrease in pH (â‰ˆ0.5 units) with increasing seawater concentration following treatment, yet, calculated acidity increased significantly. In most soil treatments, Al was the dominant component of the calculated acidity pool. Al dominated the exchange complex in the CLASS and, correspondingly, was the major metal ion desorbed. In general, concentrations of soluble and exchangeable Al, Fe2+, Ni, Mn and Zn in all soil extracts increased with increasing salinity. Increasing trace metal concentrations with increasing seawater concentration is attributed to the combined effects of exchange processes and acidity. The increasing ionic strength of the seawater treatments displaces trace metals and protons adsorbed on sediments, causing an initial decrease in pH. Hydrolysis of desorbed acidic metal cations can further contribute to acidity and increase mobilisation of trace metals. These findings imply that saline inundation of CLASS environments, even by relatively brackish water may cause rapid, shorter-term water quality changes and a pulse release of acidity due to desorption of acidic metal cations. © 2010 Elsevier B.V.

Schwertmannite in soil materials : Limits of detection of acidified ammonium oxalate method and differential X-ray diffraction

- Vithana, Chamindra, Sullivan, Leigh, Bush, Richard, Burton, Edward

Authors: Vithana, Chamindra , Sullivan, Leigh , Bush, Richard , Burton, Edward
Date: 2015
Type: Text , Journal article
Relation: Geoderma Vol. 249-250, no. (2015), p. 51-60
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Description: Schwertmannite is a secondary iron mineral, found in acid mine drainage (AMD) and acid sulfate soils (ASS), that generates acidity when it transforms to stable mineral phases. Acidity liberated during schwertmannite transformation can seriously diminish water quality and soil health. Acidified ammonium oxalate (AAO) extraction in the dark coupled with differential X-ray diffraction (DXRD) analysis is routinely used to identify and to quantify poorly crystalline iron oxide phases such as schwertmannite in AMD environments. However, management of ASS environments is largely impacted due to lack of reliable methods to identify/quantify schwertmannite in soil materials. Our study aimed to evaluate the 15. min AAO extraction method to identify/quantify schwertmannite in soil materials. We extracted soil samples spiked with synthetic and natural schwertmannite (termed as natural organic rich schwertmannitic material) with acidified ammonium oxalate (AAO) for 15. min. We also examined soil samples spiked with schwertmannite through the DXRD analysis under ideal conditions assuming that only schwertmannite would dissolve during the extraction. Our data show that synthetic schwertmannite dissolved partially during the 15. min AAO extraction and as a result the recovered Fe content from schwertmannite-spiked soils was underestimated by ~. 20%. The data also show that soil materials could also influence the recovery of schwertmannite. Fe/S molar ratios of schwertmannite spiked at higher rates (2% and 5%) were closer to the expected ratios. In addition to schwertmannite, goethite and other unidentified minerals in natural organic rich schwertmannitic material also dissolved during the 15. min extraction time. The DXRD analysis data show that schwertmannite in soil materials at contents >. 5% may be identifiable through this approach. Our findings highlight that both the 15. min AAO extraction procedure and the DXRD analysis have limited applicability towards detecting schwertmannite accurately in soil materials. © 2015 Elsevier B.V.

Improved identification of sulfidic soil materials by a modified incubation method

- Sullivan, Leigh, Ward, Nicholas, Bush, Richard, Burton, Edward

Authors: Sullivan, Leigh , Ward, Nicholas , Bush, Richard , Burton, Edward
Date: 2009
Type: Text , Journal article
Relation: Geoderma Vol. 149, no. 1-2 (2009), p. 33-38
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Description: This study examines the acidification behaviour and rate of sulfidic-sulfur oxidation in the incubation method that is currently used in soil taxonomies to identify sulfidic materials, for some clayey textured soil materials. 'Sulfidic' in these taxonomies identifies that a soil material is capable of becoming extremely acidic (i.e. pH < 4) as a result of oxidation of sulfide minerals contained in that soil material. As well as examining incubation slabs of acid sulfate soil materials with the standard 10 mm thickness, the utility of thinner (i.e. 2 mm thick) incubation slabs of these soil materials for identification of sulfidic soil materials was also examined. The clayey soil materials in the 2 mm thick slabs exhibited more rapid sulfidic-sulfur oxidation and acidification and resulted in fewer false-negative sulfidic soil material identifications than did the use of 10 mm thick slabs. However, the rates of sulfidic-sulfur oxidation and sulfide-derived acidification within the slabs (whether 2 mm or 10 mm thick) were not always rapid enough during incubation for the full expression of acidification to be evident within the maximum incubation duration of 8 weeks required by soil classification taxonomies. The results indicate the incubation method for determination of the sulfidic nature of soil materials for soil classification purposes could be improved to reduce the risk of false-negative identification by: i. allowing the use of 2 mm thick slabs, and ii. changing the maximum duration of incubation from 8 weeks to until a stable pH is reached after at least 8 weeks of incubation. © 2008.

A sequential extraction procedure for acid sulfate soils : Partitioning of iron

- Claff, Salirian, Sullivan, Leigh, Burton, Edward, Bush, Richard

Authors: Claff, Salirian , Sullivan, Leigh , Burton, Edward , Bush, Richard
Date: 2010
Type: Text , Journal article
Relation: Geoderma Vol. 155, no. 3-4 (2010), p. 224-230
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Description: A new sequential extraction scheme for acid sulfate soil materials has been evaluated for iron partitioning in a range of synthetic iron-bearing minerals and natural acid sulfate soil materials. This sequential extraction procedure employs six steps to quantify (1) exchangeable (magnesium chloride extractable), (2) acid (hydrochloric acid) soluble, (3) reactive organic-bound (pyrophosphate extractable), (4) crystalline oxide (citrate buffered dithionite (CBD)) extractable, (5) pyrite-bound (nitric acid extractable) and (6) residual (acid/peroxide digestible) forms of iron. Given its intended use for acid sulfate soil materials that frequently contain pyrite, a primary aim of this new sequential extraction procedure was to differentiate iron bound in pyrite from iron contained in other minerals. The results demonstrated that dissolution of pyrite was effectively isolated in the pyrite-bound extraction step, with dissolution of other iron mineral phases (i.e. akaganeite, ferrihydrite, goethite, hematite, jarosite, magnetite, and schwertmannite) occurring within the other five extraction steps. Following a systematic examination of these synthetic iron mineral phases, the sequential extraction scheme was applied to an acid sulfate soil profile, with detailed data presented for two soil layers: one representative of the sulfidic (unoxidised) conditions, and the other sulfuric (oxidised) conditions. Partitioning data for pyrite-bound iron in the acid sulfate soil profile showed good agreement with that calculated via the independently measured pyrite-bound reduced sulfur. This study indicates that the new sequential extraction procedure is suitable for the assessment of iron partitioning in acid sulfate soil materials. © 2009 Elsevier B.V. All rights reserved.

Contemporary pedogenesis of severely degraded tropical acid sulfate soils after introduction of regular tidal inundation

- Johnston, Scott, Keene, Annabelle, Bush, Richard, Burton, Edward, Sullivan, Leigh, Smith, Douglas, McElnea, Angus, Martens, Michelle, Wilbraham, Steve

Authors: Johnston, Scott , Keene, Annabelle , Bush, Richard , Burton, Edward , Sullivan, Leigh , Smith, Douglas , McElnea, Angus , Martens, Michelle , Wilbraham, Steve
Date: 2009
Type: Text , Journal article
Relation: Geoderma Vol. 149, no. 3-4 (2009), p. 335-346
Full Text: false
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Description: Marine tidal inundation was partially restored to a severely degraded tropical acid sulfate soil landscape after having been excluded for over 30Â years. The effects on soil acidity and iron-sulfide mineral reformation were investigated by comparing the geochemistry of soils before and after five years of regular tidal inundation. The soil pH increased by 2-3 units and titratable actual acidity (TAA) decreased by âˆ¼ 40-50Â Î¼mol H+ g- 1 within former sulfuric horizons. Relict acidity remained at depth (> 1Â m) in the underlying sulfidic horizons. Î´34S data indicate that tidal inundation caused exchange of marine solutes within former sulfuric horizons, but not within underlying sulfidic material. There was considerable reformation of pyrite within former sulfuric horizons after tidal inundation with reduced inorganic sulfur increasing by âˆ¼ 60Â Î¼mol g- 1. Acid-volatile sulfide also accumulated, but mainly near the soil surface (up to 16Â Î¼mol g- 1). Reduction of Fe(III) minerals strongly influences the geochemistry of the tidally inundated soils. After tidal inundation the soil pH and Eh closely followed the iron redox couple and there was non-sulfidic solid-phase Fe(II) up to 600Â Î¼mol g- 1. There was also substantial diagenetic enrichment of poorly crystalline Fe-oxides near the soil surface following tidal inundation, with reactive Fe spanning 400-1800Â Î¼mol g- 1. While the decreases in soil acidity documented here are likely due to a combination of marine alkalinity inputs and reduction of both Fe and SO42-, the relative importance of each process remains to be determined. This study demonstrates that marine tidal inundation can be an effective landscape-scale strategy for ameliorating severe acidity associated with drained acid sulfate soils. © 2008 Elsevier B.V. All rights reserved.

Estimating the extent of fire induced soil water repellency in Mediterranean environment

- Weninger, Thomas, Filipović, Vilim, Mešić, Mirel, Clothier, Brent, Filipović, Lana

Authors: Weninger, Thomas , Filipović, Vilim , Mešić, Mirel , Clothier, Brent , Filipović, Lana
Date: 2019
Type: Text , Journal article
Relation: Geoderma Vol. 338, no. (2019), p. 187-196
Full Text: false
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Description: The fire occurrence in Mediterranean climate regions and the area affected by fire in general are rising due to prolonged drought periods and redistribution of rainfall. This can have effect on soil properties and local scale hydrology by increasing fire induced soil water repellency (SWR). The main objective of our research was to assess the degree of fire induced SWR in the Mediterranean karst area using multiple easy-to-perform field and laboratory methods. The field infiltration measurements were performed with a tension disc infiltrometer (TI) and a minidisc tension infiltrometer (MD) using water and ethanol as an infiltrating liquid on two locations: burnt (B) and control (C, unaffected by fire). Additionally, water drop penetration time test (WDPT), and molarity of ethanol droplet time test (MED) were applied at the laboratory on disturbed and undisturbed soil samples at various depths. All measurements revealed significant differences between burnt and control plots. Infiltration and hydraulic conductivity were reduced and repellency index (RI) was increased at the fire affected sites. The SWR decreased with depth which can be associated with decreasing organic matter and fire burning effect. The WDPT and MED methods in combination with mini disc tension infiltrometer measurements were found useful for the determination of sub-critical SWR. Further research is needed to develop a framework for the quantitative SWR classification, as well as subsequent estimation of the relevance of SWR on critical hydrological processes such as infiltration, runoff, and preferential flow. •Fire affected plots revealed SWR with significant change in infiltration patterns.•SWR decreased with increasing depth and decreasing organic matter content.•The combination of applied methods is useful in determination of sub-critical SWR.•Hydraulic conductivities decreased with increasing repellency indexes (RI).•All methods confirm SWR at burnt sites, but with some discrepancies between them.

Stability of schwertmannite and jarosite in an acidic landscape : Prolonged field incubation

- Vithana, Chamindra, Sullivan, Leigh, Burton, Edward, Bush, Richard

Authors: Vithana, Chamindra , Sullivan, Leigh , Burton, Edward , Bush, Richard
Date: 2015
Type: Text , Journal article
Relation: Geoderma Vol. 239, no. (2015), p. 47-57
Full Text: false
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Description: Schwertmannite and jarosite are two of the main secondary iron(III) minerals commonly found in acidic, iron and sulfate-rich environments such as acid mine drainage and coastal acid sulfate soils (CASS). Both minerals exert major influence on the water and soil quality in these environments. While there are many studies conducted on the stability of these two minerals under controlled laboratory conditions, the behaviour of schwertmannite and jarosite under field conditions and the factors influencing their behaviour have not been investigated directly. In the present study, we examined the net transformation of introduced schwertmannite and jarosite samples incubated in a typical acidic CASS environment. Pure (synthetic) schwertmannite and jarosite samples were exposed to two main chemical regimes: 1) aerobic-acidic water column and 2) anaerobic-neutral sediment in a CASS environment. Changes in mineralogy, micromorphology, and composition of schwertmannite and jarosite samples were monitored over a period of 12months. Schwertmannite suspended in the water column and buried in sediments transformed to goethite by the end of 12months but more quickly in anoxic, reducing sediments. However, schwertmannite incubated in the acidic water column transformed at a much faster rate than those reported for acidic and aerobic conditions in the laboratory. Jarosite incubated in both the water column and sediments was also transformed to goethite but at a much slower rate than schwertmannite. Dissimilatory microbial reduction and Fe2+-catalysed transformation likely played a major role in accelerating the transformation of both minerals to goethite in sediments. The transformation of both minerals in the water column was sensitive to the hydrological conditions and fluctuations in the water column in relation to antecedent rainfall. In comparison, the sediment's geochemistry was relatively stable and consequently the rate of transformation and dissolution of both schwertmannite and jarosite in this environment was not appreciably affected by variable hydrology. © 2014 Elsevier B.V.

Effect of sample pretreatment on the fractionation of Fe, Cr, Ni, Cu, Mn, and Zn in acid sulfate soil materials

- Claff, Salirian, Burton, Edward, Sullivan, Leigh, Bush, Richard

Authors: Claff, Salirian , Burton, Edward , Sullivan, Leigh , Bush, Richard
Date: 2010
Type: Text , Journal article
Relation: Geoderma Vol. 159, no. 1-2 (2010), p. 156-164
Full Text: false
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Description: A sequential extraction procedure was applied to acid sulfate soil materials from a soil profile to investigate the effect of sample pretreatment on the geochemical fractionation of selected metals. The samples were prepared for analysis by oven-drying, sieving and grinding the soil, or were examined as collected in field condition. The soil profile encompassed oxidising conditions near the surface, through to reducing conditions at depth. Six metals (Fe, Cr, Ni, Mn, Cu, and Zn) were measured during the sequential extraction procedure, and their fractionation determined in the oxidised and in the reduced zone. Although cumulative totals (the sum of all steps in the sequential extraction procedure) for the metals extracted from both the field condition and dried/ground samples were similar, some significant differences in fractionation within individual extraction steps were observed. Of particular interest was the redistribution of metals from the sulfide-bearing (pyrite-bound) fraction to the more readily available fractions (i.e. labile and acid-soluble), as a result of oven-drying and grinding. The results indicate that when assessing metal fractionation in acid sulfate soil materials, samples should be analysed in field condition in order to avoid the considerable metal fractionation artifacts that are induced by drying and grinding. © 2010 Elsevier B.V.

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