ORCID Profile
0000-0002-9751-2971
Current Organisation
University of Sydney
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Research Topics
In Research Link Australia (RLA), "Research Topics" refer to ANZSRC FOR and SEO codes. These topics are either sourced from ANZSRC FOR and SEO codes listed in researchers' related grants or generated by a large language model (LLM) based on their publications.
Top 5 Research Topics
ANZSRC Field of Research (FoR)
Soil Sciences | Carbon Sequestration Science | Geochemistry | Soil Chemistry (excl. Carbon Sequestration Science) | Soil Chemistry | Soil And Water Sciences Not Elsewhere Classified | Archaeological Science | Environmental Management And Rehabilitation | Isotope Geochemistry
ANZSRC Socio-Economic Objective (SEO)
Land and water management | Climate Change Mitigation Strategies | Farmland, Arable Cropland and Permanent Cropland Soils | Land and water management | Climate Variability (excl. Social Impacts) | Climate Change Models | Land and water management | Understanding Australia's Past | Farmland, Arable Cropland and Permanent Cropland Land Management |
Related Links
Publications
Cadmium sorption behavior of natural and synthetic zeolites
Publisher: Informa UK Limited
Date: 10-2000
The Efficacy of Lime, Gypsum and Their Combination to Ameliorate Sodicity in Irrigated Cropping Soils in the Lachlan Valley of New South Wales
Publisher: Informa UK Limited
Date: 03-09-2015
Heavy metal tolerance in common fern species
Publisher: CSIRO Publishing
Date: 2007
DOI: 10.1071/BT06063
Abstract: The effects of cadmium (Cd), chromium (Cr), copper (Cu), nickel (Ni), lead (Pb) and zinc (Zn) on the growth and uptake of 10 fern species was investigated under a controlled environment in order to evaluate their suitability for phytoremediation. Fern species included Adiantum aethiopicum, Blechnum cartilagineum, Blechnum nudum, Calochlaena dubia, Dennstaedtia davallioides, Doodia aspera, Hypolepis muelleri, Nephrolepis cordifolia, Pellaea falcata and the arsenic (As) hyperaccumulating Pteris vittata. Ferns were exposed to four levels of metals at concentrations of 0, 50, 100 and 500 mg kg–1 for a period of 20 weeks. The response of ferns significantly varied among species and metals. In general, heavy-metal translocation was limited, with metals being absorbed and held in roots, suggesting an exclusion mechanism as part of the ferns’ tolerance to the applied metals. Similar metal-accumulation patterns were observed for all species in that accumulation generally increased with increasing metal treatments in most cases a sharp increase in metal accumulation was observed between 100 and 500 mg kg–1 treatments, suggesting a breakdown in tolerance mechanisms and unrestricted metal transport. This was corroborated by enhanced visual toxicity symptoms and a reduction in survival rates among ferns when exposed to 500 mg kg–1 metal treatments and to a lesser extent 100 mg kg–1 metal treatments. Of the species investigated, N. cordifolia and H. muelleri were identified as possible candidates in phytostabilisation of Cu, Pb, Ni or Zn contaminated soils. Similarly, D. davallioides appeared favourable for use in phytostabilisation of Cu and Zn contaminated soils. These species had high survival rates and accumulated high levels of the aforementioned metals relative to other ferns investigated. Ferns belonging to the family Blechnaceae (B. nudum, B. cartilagineum and D. aspera) and C. dubia (Family Dicksoniaceae) were least tolerant to most metals, had a low survival rate and were classified as being unsuitable for phytoremediation purposes. Metal tolerance was also observed in P. vittata when exposed to Cd, Cr and Cu however, no hyperaccumulation was observed.
Nature and properties of iron rich glaebules and mottles from some south-west Australian soils
Publisher: Elsevier BV
Date: 05-1996
Incorporation of Cr, Mn and Ni into goethite (α-FeOOH): Mechanism from extended X-ray absorption fine structure spectroscopy
Publisher: Mineralogical Society
Date: 12-2002
Abstract: The crystal-chemical mechanisms by which transition metals are associated with goethite are fundamental to our understanding of the solubility and bioavailability of micronutrients and heavy metals in soils, and in the formation of laterite ore deposits. Transition metals such as Cr, Mn and Ni may sorb onto goethite by forming surface precipitates, surface complexes or by replacing Fe 3+ in the goethite structure. In the work reported here, we investigated the local coordination environment of Cr, Mn and Ni in synthetic goethite using EXAFS spectroscopy. We demonstrate the isomorphous substitution for Fe 3+ by Cr 3+ (up to 8 mol.%), Mn 3+ (up to 15 mol.%) and Ni 2+ (up to 5 mol.%). We find, however, that the next-nearest-neighbour coordination environment changes with composition. The perturbations are likely to be responsible for limiting the accommodation of Cr 3+ , Mn 3+ or Ni 2+ in the FeOOH structure.
Structural Chemistry of Fe, Mn, and Ni in Synthetic Hematites as Determined by Extended X-Ray Absorption Fine Structure Spectroscopy
Publisher: Springer Science and Business Media LLC
Date: 2000
An integrated GPS-accelerometer data processing technique for structural deformation monitoring
Publisher: Springer Science and Business Media LLC
Date: 07-09-2006
Quantitative elemental localisation in leaves and stems of nickel hyperaccumulating shrub Hybanthus floribundus subsp floribundus using micro-PIXE spectroscopy
Publisher: Elsevier BV
Date: 02-2008
The preparation and characterization of vanadium-substituted goethite: The importance of temperature
Publisher: Elsevier BV
Date: 02-2009
Carbon dynamics from carbonate dissolution in Australian agricultural soils
Publisher: CSIRO Publishing
Date: 2015
DOI: 10.1071/SR14060
Abstract: Land-use and management practices on limed acidic and carbonate-bearing soils can fundamentally alter carbon (C) dynamics, creating an important feedback to atmospheric carbon dioxide (CO2) concentrations. Transformation of carbonates in such soils and its implication for C sequestration with climate change are largely unknown and there is much speculation about inorganic C sequestration via bicarbonates. Soil carbonate equilibrium is complicated, and all reactants and reaction products need to be accounted for fully to assess whether specific processes lead to a net removal of atmospheric CO2. Data are scarce on the estimates of CaCO3 stocks and the effect of land-use management practices on these stocks, and there is a lack of understanding on the fate of CO2 released from carbonates. We estimated carbonate stocks from four major soil types in Australia (Calcarosols, Vertosols, Kandosols and Chromosols). In -mm rainfall zone, which is important for Australian agriculture, the CaCO3-C stocks ranged from 60.7 to 2542 Mt at 0–0.3 m depth (dissolution zone), and from 260 to 15 660 Mt at 0–1.0 m depth. The combined CaCO3-C stocks in Vertosols, Kandosols and Chromosols were about 30% of those in Calcarosols. Total average CaCO3-C stocks in the dissolution zone represented 11–23% of the stocks present at 0–1.0 m depth, across the four soil types. These estimates provide a realistic picture of the current variation of CaCO3-C stocks in Australia while offering a baseline to estimate potential CO2 emission–sequestration through land-use changes for these soil types. In addition, we provide an overview of the uncertainties in accounting for CO2 emission from soil carbonate dissolution and major inorganic C transformations in soils as affected by land-use change and management practices, including liming of acidic soils and its secondary effects on the mobility of dissolved organic C. We also consider impacts of liming on mineralisation of the native soil C, and when these transformations should be considered a net atmospheric CO2 source or sink.
Cadmium and lead desorption from kaolinite
Publisher: Elsevier
Date: 2007
Effect of temperature on biochar priming effects and its stability in soils
Publisher: Elsevier BV
Date: 2015
Influence of Biochars on Nitrous Oxide Emission and Nitrogen Leaching from Two Contrasting Soils
Publisher: Wiley
Date: 07-2010
DOI: 10.2134/JEQ2009.0138
Abstract: The influence of biochar on nitrogen (N) transformation processes in soil is not fully understood. This study assessed the influence of four biochars (wood and poultry manure biochars synthesized at 400 degrees C, nonactivated, and at 550 degrees C, activated, abbreviated as: W400, PM400, W550, PM550, respectively) on nitrous oxide (N2O) emission and N leaching from an Alfisol and a Vertisol. Repacked soil columns were subjected to three wetting-drying (W-D) cycles to achieve a range of water-filled pore space (WFPS) over a 5-mo period. During the first two W-D cycles, W400 and W550 had inconsistent effects on N2O emissions and the soils amended with PM400 produced higher N2O emissions relative to the control. The initially greater N2O emission from the PM400 soils was ascribed to its higher labile intrinsic N content than the other biochars. During the third W-D cycle, all biochar treatments consistently decreased N2O emissions, cumulatively by 14 to 73% from the Alfisol and by 23 to 52% from the Vertisol, relative to their controls. In the first leaching event, higher nitrate leaching occurred from the PM400-amended soils compared with the other treatments. In the second event, the leaching of ammonium was reduced by 55 to 93% from the W550- and PM550-Alfisol and Vertisol, and by 87 to 94% from the W400- and PM400-Vertisol only (cf. control). We propose that the increased effectiveness of biochars in reducing N2O emissions and ammonium leaching over time was due to increased sorption capacity of biochars through oxidative reactions on the biochar surfaces with ageing.
Temperature sensitivity of biochar and native carbon mineralisation in biochar-amended soils
Publisher: Elsevier BV
Date: 06-2014
Simultaneous estimation of several soil properties by ultra-violet, visible, and near-infrared reflectance spectroscopy
Publisher: CSIRO Publishing
Date: 2003
DOI: 10.1071/SR02137
Abstract: Fast and convenient soil analytical techniques are needed for soil quality assessment and precision soil management. Spectroscopy in the ultraviolet (UV, 250–400 nm), visible (VIS, 400–700 nm), and near-infrared (NIR, 700–2500 nm) ranges allows rapid acquisition of soil information at quantitative, and qualitative or indicator, levels for use in agriculture and environmental monitoring. The main objective of this study was to evaluate the ability of reflectance spectroscopy in the UV, VIS, and NIR ranges to predict several soil properties simultaneously. Soil s les (161 surface and subsurface) were used for simultaneous estimation of pH, electrical conductivity (EC), air-dry gravimetric water content, organic carbon (OC), free iron, clay, sand, and silt contents, cation exchange capacity (CEC), and exchangeable calcium (Ca), magnesium (Mg), potassium (K), and sodium (Na). Principal component regression analyses (PCA) were used to develop calibration equations between the reflectance spectral data and measured values for the above soil properties obtained by traditional laboratory methods. By using randomly selected calibration and validation sets of s les, PCA models were able to successfully predict pH, OC, air-dry gravimetric water content, clay, CEC, exchangeable Ca, and exchangeable Mg of soil s les. The predictions, however, were poor for EC, free iron, sand, silt, exchangeable K, and exchangeable Na. The study shows that reflectance spectroscopy in the UV–VIS–NIR range has the potential for the rapid simultaneous prediction of several soil properties.
The nature of soil kaolins from Indonesia and Western Australia
Publisher: Springer Science and Business Media LLC
Date: 04-2002
Layer charge characteristics of smectites from Vertosols (Vertisols) of New South Wales
Publisher: CSIRO Publishing
Date: 2002
DOI: 10.1071/SR02017
Abstract: Premature senescence in cotton has been attributed to K deficiency in the cotton soils of Australia. The availability, release, and fixation of K+ in soils are mainly dependent on the clay mineralogy and layer charge characteristics of 2 : 1 clay minerals. There is a little information on the mineralogy and charge characteristics of the cotton growing soils (Vertosols) of Australia. The aims of this study were to determine the clay mineralogy, the layer charge density, and layer charge distribution of some cotton growing soils by chemical and X-ray diffraction methods.Most soil clays contain abundant smectite associated with small amounts of mica, kaolinite, and an interstratified mineral. The total layer charge as determined by the alkylammonium method ranged between 0.55 and 0.67 mol(–)/(O10(OH)2), indicating a high interlayer charge density. The layer charge of smectites from different valleys and for different size fractions was similar. The Greene-Kelly test showed that most of the charge originated in the tetrahedral sheet. The chemical analysis indicates that the smectite is an iron-rich beidellite, which has possibly formed from the weathering of mica.
Regional considerations for targeted use of biochar in agriculture and rehabilitation in Australia
Publisher: American Society of Agronomy and Soil Science Society of America
Date: 29-10-2015
Application of analytical transmission electron microscopy to identifying intercrystal variations in the composition of clay minerals
Publisher: Royal Society of Chemistry (RSC)
Date: 1995
DOI: 10.1039/AN9952001335
Localisation of trace metals in metal‐accumulating plants using µ‐PIXE
Publisher: Wiley
Date: 25-02-2008
DOI: 10.1002/XRS.1035
Mössbauer spectra of soil kaolins from South-Western Australia
Publisher: Springer Science and Business Media LLC
Date: 1992
Dissolution behaviour of soil kaolinites in acidic solutions
Publisher: Mineralogical Society
Date: 06-2013
DOI: 10.1180/CLAYMIN.2013.048.3.02
Abstract: Highly weathered soils of the tropics and subtropics commonly have kaolinitedominated clay fractions. Under acidic conditions prevailing in these soils kaolinite dissolution occurs, contributing to the high levels of soluble Al in these soils. This study evaluates the dissolution behaviour of kaolinites from subsurface horizons of highly weathered soils from Thailand, along with a soil kaolinite from Western Australia (WA kaolinite) and Georgia kaolinite (KGa-2). Kaolinite-dominated clay fractions were isolated from soils by sedimentation and chemically treated to remove iron oxides. The dissolution rate of kaolinites was measured in 0.01 M NaCl as a function of pH (1–4 HCl) at 25±1°C using non-stirred flow-through reactors. Kaolinite dissolution rates were calculated from the release of Al and Si at the steady state. In most of the experiments and at all pH values, the release of both Si and Al underwent a distinct transition from an initial period of rapid release to significantly slower release at the steady state. Aluminium and Si concentrations at the steady state were higher for soil kaolinites than the reference s le (KGa-2). At the steady state the dissolution of all kaolinites was stoichiometric except for the soil kaolinites from Thailand at pH 4, where the Al/Si ratio was well below the stoichiometric ratio. Log dissolution rate (R Si ) of soil kaolinites ranged from –13.75 to –12.51, with the dissolution rate increasing significantly with decreasing solution pH. However, the dissolution rate was similar or pH independent between pH 2 and 3, which is the pH range of the point of zero net charge (PZNC) for both soil and reference kaolinites. The dissolution rate of soil kaolinite was significantly higher than the KGa-2 s le at pH 3. The results obtained on kaolinite s les from highly weathered soils show that in highly acidic systems kaolinite is a source of soluble Al. Soil kaolinites with poorly ordered small crystals dissolve faster than better crystalline reference kaolinite (KGa-2) with larger crystals.
Arsenic Speciation in Tissues of the Hyperaccumulator P. calomelanos var. austroamericana using X-ray Absorption Spectroscopy
Publisher: American Chemical Society (ACS)
Date: 11-05-2010
DOI: 10.1021/ES1005237
Abstract: The fate and chemical speciation of arsenic (As) during uptake, translocation, and storage by the As hyperaccumulating fern Pityrogramma calomelanos var. austroamericana (Pteridaceae) were examined using inductively coupled plasma-atomic emission spectrometry (ICP-AES) and synchrotron-based micro-X-ray absorption near edge structure (micro-XANES) and micro-X-ray fluorescence (micro-XRF) spectroscopies. Chemical analysis revealed total As concentration was ca. 6.5 times greater in young fronds (5845 mg kg(-1) dry weight (DW)) than in old fronds (903 mg kg(-1) DW). In pinnae, As concentration decreased from the base (6822 mg kg(-1) DW) to the apex (4301 mg kg(-1) DW) of the fronds. The results from micro-XANES and micro-XRF of living tissues suggested that more than 60% of arsenate (As(V)) absorbed was reduced to arsenite (As(III)) in roots, prior to transport through vascular tissues as As(V) and As(III). In pinnules, As(III) was the predominant redox species (72-90%), presumably as solvated, oxygen coordinated compounds. The presence of putative As(III)-sulphide (S(2-)) coordination throughout the fern tissues (4-25%) suggests that S(2-) functional groups may contribute in the biochemical reduction of As(V) to As(III) during uptake and transport at a whole-plant level. Organic arsenicals and thiol-rich compounds were not detected in the species and are unlikely to play a role in As hyperaccumulation in this fern. The study provides important insights into homeostatic regulation of As following As uptake in P. calomelanos var. austroamericana.
Interactive effects of iron oxides and organic matter on charge properties of red soils in Thailand
Publisher: CSIRO Publishing
Date: 2013
DOI: 10.1071/SR13021
Abstract: Iron (Fe) oxides and organic matter (OM) play important roles in maintaining the fertility of highly weathered soils. The main objective of this study was to investigate the interactive effects of variable surface charge minerals, particularly Fe oxide minerals, and OM on the charge properties of red soils from Thailand. We also evaluated the effect of the 5 m NaOH procedure, used to concentrate Fe oxides from soils, on the charge characteristics of Fe oxide concentrates. Fourteen clay fractions (untreated and OM-free clay fractions), and Fe oxide concentrates of these clays, were used in the study. Cation exchange capacity (CEC) and electrophoretic mobility (EM) were measured for the soil clays, artificial mixtures, and goethite adsorbed with humic acid (HA) and phosphate (P). Kaolinite and Fe oxides (predominantly a mixture of hematite and goethite) were the main minerals in the clay fraction. Results indicated that OM or metal–OM complexes may have blocked or neutralised negatively charged sites on clay minerals. After OM removal these sites became accessible, inducing an increase in CEC and shifting the EM values towards more negative values and the isoelectric point (IEP) towards lower pH for many s les. The CEC values of Fe oxide concentrates prepared by 5 m NaOH treatment were overestimated and their EM and IEP shifted towards more negative values. It is possible that the amorphous phase from clay dissolution was still present in the Fe oxide concentrates, or the adsorption of silicate ions modified the surfaces of Fe oxides concentrates. Humic acid and P adsorbed on Fe oxide surfaces caused the IEP to shift to lower values. In natural soil conditions, a variety of anions can be adsorbed on Fe oxide surfaces, which might lead to higher values of negative charge and lower IEP than observed for pure synthetic minerals.
Nickel, Zn and Cd localisation in seeds of metal hyperaccumulators using μ-PIXE spectroscopy
Publisher: Elsevier BV
Date: 06-2009
Antimony Accumulation in Wheat Seedlings Grown in Soil and Water
Publisher: Informa UK Limited
Date: 04-2014
The long-term role of organic amendments in building soil nutrient fertility: a meta-analysis and review
Publisher: Springer Science and Business Media LLC
Date: 04-01-2018
Effect of Soil Properties on Arsenic Hyperaccumulation in Pteris Vittata and Pityrogramma Calomelanos var. Austroamericana
Publisher: Informa UK Limited
Date: 24-12-2010
DOI: 10.1080/15226510903213969
Abstract: Two arsenic (As) hyperaccumulators, Pteris vittata L. and Pityrogramma calomelanos var. austroamericana, were grown in As-contaminated soils of contrasting properties. Ferns were exposed to three levels of As in soil at concentrations of 0,600 and 2400 micromol kg(-1) for a period of 22 weeks. Plant biomass and As concentration in fronds and roots varied significantly between the two species. At 600 micromol kg(-1) As level, As hyperaccumulation was not observed in both the fern species. However at the 2400 micromol kg(-1) As level, both the species accumulated very high levels (> 1000 mg kg(-1)) of As in fronds. Arsenic concentration and uptake in fronds of both species followed the order Kurosol (Box Hill) > Vertosol (Narrabri) > Ferrosol (Robertson). In the studied soils, P. vittata possessed higher frond biomass and As accumulation, and thus was more efficient in removing soil As than P. calomelanos var. austroamericana. Soil properties such as free Fe, clay and organic matter contents appear to have affected the bioavailability of As in the studied soils. These results show that soil properties influence the As extraction efficiency of hyperaccumulating plants and must be considered in context of the phytoextraction technology of As contaminated soils.
Environmental Soil Chemistry
Publisher: Elsevier
Date: 2023
EFFECT OF PLANTS ON THE BIOAVAILABILITY OF METALS AND OTHER CHEMICAL PROPERTIES OF BIOSOLIDS IN A COLUMN STUDY
Publisher: Informa UK Limited
Date: 10-2012
DOI: 10.1080/15226514.2011.636400
Abstract: The effects of metal-accumulating plants (Salix x reichardtii and Populus balsamifera) on the chemical properties and dynamics of metals in biosolids were investigated using different techniques including diffusive gradients in thin films (DGT), sequential extraction procedures and partitioning coefficient (K(d)). Plants could effectively extract Cd, Ni, and Zn and decreased dissolved organic carbon (DOC). The presence of plants increased the potential bioavailability of these metals, as assessed by an increase in the ratio of metal measured by DGT and metals in the solution. The plants affected the Cd, Ni, and Zn pools (soluble/exchangeable Fe/Mn oxide and organic matter bound) characterised by sequential extraction and K(d) but did not reduce the total metals in either substrate. However, plants had no effect on Cu, presumably because of the effective buffering of available Cu by organic matter in both solution and solid phases. A high density of plant roots was associated with increased leaching of metals.
Aged acidic biochar increases nitrogen retention and decreases ammonia volatilization in alkaline bauxite residue sand
Publisher: Elsevier BV
Date: 2017
Simultaneous incorporation of Cr, Zn, Cd, and Pb in the goethite structure
Publisher: Springer Science and Business Media LLC
Date: 04-2009
Carbon storage in cotton soils of northern New South Wales
Publisher: CSIRO Publishing
Date: 2003
DOI: 10.1071/SR02023
Abstract: Soil carbon is an important component of the global carbon cycle with an estimated pool of soil organic carbon of about 1500 Gt. There are few estimates of the pool of inorganic carbon, but it is thought to be approximately 50% of the organic carbon pool. There is no detailed study on the estimation of the soil carbon pool for Australian soils.In order to quantify the carbon pools and to determine the extent of spatial variability in the organic and inorganic carbon pools, 120 soil cores were taken down to a depth of 0.90 m from a typical cotton field in northern NSW. Three cores were also taken from nearby virgin bushland and these s les were used as paired s les. Each soil core was separated into 4 s les, i.e. 0–0.15, 0.15–0.30, 0.30–0.60, and 0.60–0.90 m. Soil organic carbon was determined by wet oxidation and inorganic carbon content was determined using the difference between total carbon and organic carbon, and confirmed by the acid dissolution method. Total carbon was measured using a LECO CHN analyser. Soil organic carbon of the field constituted 62% (0–0.15 m), 58% (0.15–0.30 m), 60% (0.30–0.60 m), and 67% (0.60–0.90 m) of the total soil carbon. The proportion of inorganic carbon in total carbon is higher than the global average of 32%. Organic carbon content was relatively higher in the deeper layers ( .30�m) of the studied soils (Vertosols) compared with other soil types of Australia. The carbon content varied across the field, however, there was little correlation between the soil types (grey, red, or intergrade colour) and carbon content. The total soil carbon pool of the studied field was estimated to be about 78 t/ha for 0–0.90 m layer, which was approximately 58% of the total soil carbon in the soil under nearby remnant bushland (136 t/ha). The total pool of carbon in the cotton soils of NSW was estimated to be 44.8 Mt C, where organic carbon and inorganic carbon constitute 34.9 Mt C and 9.9 Mt C, respectively. Based on the results of a limited number of paired sites under remnant vegetation, it was estimated that about 18.9 Mt of C has been lost from Vertosols by cotton cropping in NSW. With more sustainable management practices such as conservation tillage and green manuring, some of the lost carbon can be resequestered, which will help to mitigate the greenhouse effect, improve soil quality and may increase crop yield.
Temperature sensitivity and carbon release in an acidic soil amended with lime and mulch
Publisher: Elsevier BV
Date: 02-2014
Biochar effects on crop yields with and without fertilizer: A meta-analysis of field studies using separate controls
Publisher: Wiley
Date: 10-12-2020
DOI: 10.1111/SUM.12546
Metal cation substitution in lepidocrocite (gamma-FeOOH)
Publisher: Elsevier BV
Date: 08-2006
Influence of biochar application to soil on the availability of As, Cd, Cu, Pb, and Zn to maize (Zea mays L.)
Publisher: CSIRO Publishing
Date: 2010
DOI: 10.1071/SR10049
Abstract: Biochar has gained importance due to its ability to increase the long-term soil carbon pool and improve crop productivity. However, little research has been done to evaluate the influence of biochar application to soil on the bioavailability of trace elements to plants. A pot experiment was conducted to investigate the influence of biochar on the availability of As, Cd, Cu, Pb, and Zn to maize (Zea mays L.). An activated wood biochar, pyrolysed at 550°C, was applied at 3 rates (0, 5, and 15 g/kg) in factorial combinations with 3 rates (0, 10, and 50 mg/kg) each of As, Cd, Cu, Pb, and Zn separately to a sandy soil. After 10 weeks of growth, plants were harvested, shoot dry matter yield was measured, and concentration of trace elements in shoots was analysed. The soil in pots was analysed for extractable trace elements. The results showed that the addition of wood biochar to soil did not have any significant effect on the dry matter yield of maize plants, even at the highest rate of application. However, trace element application significantly reduced the dry matter yield from 10 to 93% depending on the type of trace element. Biochar application decreased the concentration of As, Cd, and Cu in maize shoots, especially at the highest rate of trace element application, whereas the effects were inconsistent on Pb and Zn concentrations in the shoots. The concentrations of extractable As and Zn in soil increased with biochar application, whereas extractable Cu did not change, Pb decreased, and Cd showed an inconsistent trend. Sorption of trace elements on biochar with initial loadings up to 200 µmol at pH 7 occurred in the order: Pb Cu Cd Zn As. The results show that biochar application can significantly reduce the availability of trace elements to plants and suggest that biochar application may have potential for the management of soils contaminated by trace elements.
Effects of insoluble Zn, Cd, and EDTA on the growth, activities of antioxidant enzymes and uptake of Zn and Cd in Vetiveria zizanioides
Publisher: Elsevier BV
Date: 2009
DOI: 10.1016/S1001-0742(08)62249-4
Abstract: A root-bag experiment was conducted to study the effects of insoluble Zn, Cd, and ethylenediaminetetraacetic acid (EDTA) on the plant growth, activities of antioxidant enzymes, proline, glutathione (GSH), water-soluble proteins and malondialdehyde (MDA) of Vetiveria zizanioides. The V. zizanioides uptake capacity of Zn and Cd also determined. The results showed that plant growth of V. zizanioides was inhibited by Zn and Cd. The shoot dry weight (SDW) and root dry weight (RDW) decrease by 14.2%, 14.1%, 17.0% and 17.3%, 32.5%, 35.7%, respectively, compared to the control without EDTA addition. After adding EDTA, shoot and root dry weight decreased over 10% and 15%, respectively. The toxicity from insoluble Zn and Cd in soil on SDW and RDW of V. zizanioides was in order: Zn+Cd > Cd > Zn. The activities of superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT), and contents of MDA and proline increased significantly, while the contents of GSH and water-soluble proteins decreased markedly with increasing Zn and Cd toxicity. With EDTA, shoot and root Zn concentrations increased in the Zn treatment by 7.3% and 37.4%, and Cd concentrations in the combined Zn and Cd treatment increased by 18.6% and 391.9% compared to the treatment without EDTA. However, Zn and Cd concentrations in shoot and roots decreased in the Cd treatment compared to the plants grown in absence of EDTA, with exception of root Cd concentration in the presence of EDTA.
Chapter 7 Temperature and Aging Effects on the Surface Speciation of Cd(II) at the Goethite-Water Interface
Publisher: Elsevier
Date: 2007
Studies of synthetic kaolinites containing copper and zinc
Publisher: No publisher found
Date: 2003
Evaluation of Spatial Variability of Soil Arsenic Adjacent to a Disused Cattle-Dip Site, Using Model-Based Geostatistics
Publisher: No publisher found
Date: 2011
DOI: 10.1021/ES201726C
Abstract: This study investigated the spatial variability of total and phosphate-extractable arsenic (As) concentrations in soil adjacent to a cattle-dip site, employing a linear mixed model-based geostatistical approach. The soil s les in the study area (n = 102 in 8.1 m(2)) were taken at the nodes of a 0.30 × 0.35 m grid. The results showed that total As concentration (0-0.2 m depth) and phosphate-extractable As concentration (at depths of 0-0.2, 0.2-0.4, and 0.4-0.6 m) in soil adjacent to the dip varied greatly. Both total and phosphate-extractable soil As concentrations significantly (p = 0.004-0.048) increased toward the cattle-dip. Using the linear mixed model, we suggest that 5 s les are sufficient to assess a dip site for soil (As) contamination (95% confidence interval of ±475.9 mg kg(-1)), but 15 s les (95% confidence interval of ±212.3 mg kg(-1)) is desirable baseline when the ultimate goal is to evaluate the effects of phytoremediation. Such guidelines on s ling requirements are crucial for the assessment of As contamination levels at other cattle-dip sites, and to determine the effect of phytoremediation on soil As.
Cd-substituted goethites - A structural investigation by synchrotron X-ray diffraction
Publisher: Springer Science and Business Media LLC
Date: 08-2003
Biochar reduces the rhizosphere priming effect on soil organic carbon
Publisher: Elsevier BV
Date: 09-2015
PROPERTIES OF SOIL KAOLINITES FROM SOUTH-WESTERN AUSTRALIA
Publisher: Wiley
Date: 12-1992
The stability of low- and high-ash biochars in acidic soils of contrasting mineralogy
Publisher: Elsevier BV
Date: 10-2015
A Fourier‐Transform Infrared Study of Biochar Aging in Soils
Publisher: Wiley
Date: 05-2016
Microbial carbon use efficiency of glucose varies with soil clay content: A meta-analysis
Publisher: Elsevier BV
Date: 2022
INFLUENCE OF DROUGHT STRESS ON THE NICKEL-HYPERACCUMULATING SHRUB HYBANTHUS FLORIBUNDUS (LINDL.) F.MUELL. SUBSP FLORIBUNDUS
Publisher: University of Chicago Press
Date: 03-2011
DOI: 10.1086/658154
Surface charge properties of kaolinite from Thai soils
Publisher: Elsevier BV
Date: 2013
Plant-induced changes in the bioavailability of heavy metals in soil and biosolids assessed by DGT measurements
Publisher: Springer Science and Business Media LLC
Date: 20-04-2010
Evaluation of pre-treatment procedures for improved interpretation of mid infrared spectra of soil organic matter
Publisher: Elsevier BV
Date: 10-2017
Acid buffering capacity and potential acidification of cotton soils in northern New South Wales
Publisher: CSIRO Publishing
Date: 2003
DOI: 10.1071/SR02036
Abstract: Soil acidity has been of major concern in Australia since European settlement. Acidification processes have been accelerated due to agricultural activities such as N fertiliser application and leguminous N-fixation in farm rotations. In this paper, we measured the acid buffering capacity (pHBC) of Vertosols, soils used predominantly for growing cotton in northern New South Wales. The pHBC values were used to calculate decrease in soil pH assuming net acid input due to agricultural practices. We combined the acidification results with geostatistics to spatially simulate the decline in soil pH of surface soils over time. The results indicate that it would take 10–417 years for soil pH to decrease by 1 unit on an assumed acid input of 5�kmol�H+/ha.year. Soil pH will drop by 1 unit within 100 years for 90% of the soils and within 15 years for 10% of the soils. This reflects the variability of the pHBC for the studied soils. In 50 years from present, most of the eastern and north-western parts of the study region may become highly acidic with soil pH declining to 5.5. There may be a potential threat to sustainable agriculture from acidification in the region, although more work needs to be done to corroborate the counter-effects of water fluxes and carbonate dissolution. Sensitivity analysis indicates that even at low levels of acid input, some areas in the study region may experience significant decline in soil pH in the surface layer.
Dissolution of Cr, Zn, Cd, and Pb single- and multi-metal-substituted goethite: Relationship to structural, morphological, and dehydroxylation properties
Publisher: Springer Science and Business Media LLC
Date: 06-2010
Rapid estimation of soil variability from the convex hull biplot area of topsoil ultra-violet, visible and near-infrared diffuse reflectance spectra
Publisher: Elsevier BV
Date: 10-2005
PHOSPHORUS SORPTION IN RELATION TO SOIL PROPERTIES FOR THE MAJOR SOIL TYPES OF SOUTH-WESTERN AUSTRALIA
Publisher: CSIRO Publishing
Date: 1991
DOI: 10.1071/SR9910603
Abstract: The P sorption characteristics of 97 soils that are representative of the agricultural areas of Western Australia were described using Langmuir and Freundlich equations. The Langmuir P maximum (xm) ranged from 11 to 2132 �g g-1 soil and the Freundlich k coefficient ranged from 1 to 1681. Clay content, DCB Fe and Al, oxalate Fe and AL, and pyrophosphate Al were positively related to xm and k. By using stepwise regression analysis, the combination of DCB and oxalate-soluble A1 predicted more than 75% Of the variation in the P sorption coefficients. Reactive Al compounds may thus be responsible for much of the P sorption by these soils. Soil pH in 1 M NaF (pH 8.2), which is normally used for the detection of allophanic material, was strongly related to the P sorption coefficients and might therefore be used as a quick test for predicting the P sorption capacity of soils.
Electrophoretic mobility of some tropical soil clays: effect of iron oxides and organic matter
Publisher: Elsevier BV
Date: 12-1999
Dissolution of illite in saline–acidic solutions at 25°C
Publisher: Elsevier BV
Date: 06-2011
NEXAFS and XPS characterisation of carbon functional groups of fresh and aged biochars
Publisher: Elsevier BV
Date: 12-2014
Chemically oxidized biochar increases ammonium-15N recovery and phosphorus uptake in a grassland
Publisher: Springer Science and Business Media LLC
Date: 21-06-2019
Influence of mineral characteristics on the retention of low molecular weight organic compounds: A batch sorption-desorption and ATR-FTIR study
Publisher: Elsevier BV
Date: 10-2014
DOI: 10.1016/J.JCIS.2014.06.036
Abstract: Batch experiments were conducted to evaluate the sorption-desorption behaviour of (14)C-labelled carboxylic acids (citric and oxalic) and amino acids (glutamic, alanine, phenylalanine and lysine) on pure minerals (kaolinite, illite, montmorillonite, ferrihydrite and goethite). The sorption experiments were complemented by ATR-FTIR spectroscopy to gain possible mechanistic insight into the organic acids-mineral interactions. In terms of charge, the organic solutes ranged from strongly negative (i.e., citric) to positively charged solutes (i.e., lysine) similarly the mineral phases also ranged from positively to negatively charged surfaces. In general, sorption of anionic carboxylic and glutamic acids was higher compared to the other compounds (except lysine). Cationic lysine showed a stronger affinity to permanently charged phyllosilicates than Fe oxides. The sorption of alanine and phenylalanine was consistently low for all minerals, with relatively higher sorption and lower desorption of phenylalanine than alanine. Overall, the role of carboxylic functional groups for the sorption and retention of these carboxylic and amino acids on Fe oxides (and kaolinite) and of amino group on 2:1 phyllosilicates was noticeable. Mineral properties (surface chemistry, specific surface area), chemistry of the organic compounds (pKa value, functional groups) and the equilibrium pH of the system together controlled the differences in sorption-desorption patterns. The results of this study aid to understand the effects of mineralogical and chemical factors that affect naturally occurring low molecular weight organic compounds sorption under field conditions.
Field trials to assess the uptake of arsenic by vegetables from contaminated soils and soil remediation with iron oxides
Publisher: Elsevier BV
Date: 07-2003
Sorption-desorption behaviour of caesium in some western australian soils
Publisher: CSIRO Publishing
Date: 1990
DOI: 10.1071/SR9900929
Abstract: Soil caesium-137 derived from past atmospheric nuclear tests is increasingly being used as an indicator of soil erosion and deposition on the basis that fallout 137Cs has been retained by soils, although this assumption has not been thoroughly tested for different soils. The sorption behaviour of some Western Australian soils indicates that Cs is differentially sorbed as a consequence of differences in clay mineralogy. Kaolinitic sandy soils of low exchange capacity sorb Cs in preference to Ca and Na, with the specificity for Cs being higher at lower concentrations of Cs in solution. lllitic and smectitic soils sorbed more Cs than kaolinitic soils and retained more than 50% of sorbed Cs after a series of extractions with salt solutions. Retention by kaolinitic soils was less but, for the concentrations of Cs likely to occur in soils, it seems that most Cs is retained so that it is probable that the 137Cs technique can be used with confidence for the measurement of soil erosion and deposition for many Western Australian soils.
Interactive carbon priming, microbial response and biochar persistence in a Vertisol with varied inputs of biochar and labile organic matter
Publisher: Wiley
Date: 29-04-2019
DOI: 10.1111/EJSS.12808
Potassium and magnesium in clay minerals of some Brazilian soils as indicated by A sequential extraction procedure
Publisher: Informa UK Limited
Date: 24-07-2002
Inorganic and organic carbon dynamics in a limed acid soil are mediated by plants
Publisher: Elsevier BV
Date: 02-2013
Effects of Eucalyptus saligna biochar-amended media on the growth of Acmena smithii, Viola var. hybrida, and Viola X wittrockiana
Publisher: Informa UK Limited
Date: 2015
Characterisation and evaluation of biochars for their application as a soil amendment
Publisher: CSIRO Publishing
Date: 2010
DOI: 10.1071/SR10058
Abstract: Biochar properties can be significantly influenced by feedstock source and pyrolysis conditions this warrants detailed characterisation of biochars for their application to improve soil fertility and sequester carbon. We characterised 11 biochars, made from 5 feedstocks [Eucalyptus saligna wood (at 400°C and 550°C both with and without steam activation) E. saligna leaves (at 400°C and 550°C with activation) papermill sludge (at 550°C with activation) poultry litter and cow manure (each at 400°C without activation and at 550°C with activation)] using standard or modified soil chemical procedures. Biochar pH values varied from near neutral to highly alkaline. In general, wood biochars had higher total C, lower ash content, lower total N, P, K, S, Ca, Mg, Al, Na, and Cu contents, and lower potential cation exchange capacity (CEC) and exchangeable cations than the manure-based biochars, and the leaf biochars were generally in-between. Papermill sludge biochar had the highest total and exchangeable Ca, CaCO3 equivalence, total Cu, and potential CEC, and the lowest total and exchangeable K. Water-soluble salts were higher in the manure-based biochars, followed by leaf, papermill sludge, and wood biochars. Total As, Cd, Pb, and polycyclic aromatic hydrocarbons in the biochars were either very low or below detection limits. In general, increase in pyrolysis temperature increased the ash content, pH, and surface basicity and decreased surface acidity. The activation treatment had a little effect on most of the biochar properties. X-ray diffraction analysis showed the presence of whewellite in E. saligna biochars produced at 400°C, and the whewellite was converted to calcite in biochars formed at 550°C. Papermill sludge biochar contained the largest amount of calcite. Water-soluble salts and calcite interfered with surface charge measurements and should be removed before the surface charge measurements of biochar. The biochars used in the study ranged from C-rich to nutrient-rich to lime-rich soil amendment, and these properties could be optimised through feedstock formulation and pyrolysis temperature for tailored soil application.
Checks and Mass Balances for In Situ Quantification of Mineral Composition using Proximal Soil Sensors
Publisher: Wiley
Date: 07-2019
Phytoremediation of an arsenic-contaminated site using Pteris vittata L. and Pityrogramma calomelanos var. austroamericana: a long-term study
Publisher: Springer Science and Business Media LLC
Date: 22-04-2012
DOI: 10.1007/S11356-012-0910-4
Abstract: This field study investigated the phytoremediation potential of two arsenic (As) hyperaccumulating fern species, Pityrogramma calomelanos var. austroamericana and Pteris vittata over 27-month duration at a disused As-contaminated cattle-dip site located at Wollongbar, NSW, Australia. Ferns planted in January 2009 were harvested following 10, 22 and 27 months of growth. A detailed soil s ling was undertaken in June 2009 (initial, n = 42 per plot) and limited s ling in April 2011 (after 27 months, n = 15 per plot) to measure total and phosphate-extractable As concentrations in soil at 0 - 20-, 20 - 40- and 40 - 60-cm depths. The choice of the limited number of s les was considered sufficient to estimate the changes in soil As concentration following phytoremediation based on a geostatistical model. The average frond dry biomass, As concentration and As uptake were significantly (P < 0.001 - 0.05) greater in P. calomelanos var. austroamericana than P. vittata, at all three harvests (1.6 - 4.3, 1.3 - 1.5 and 2.2 - 5.7 times, respectively). After 27-months of growth, P. calomelanos var. austroamericana removed 8,053 mg As (i.e. cumulative over three harvests) in plot B (25.4 kg As ha(-1)) that was 2.65 times higher than that depleted by P. vittata (3,042 mg As in plot A (9.7 kg As ha(-1))). The cumulative frond As uptake data of the two fern species revealed that P. calomelanos var. austroamericana extracted 1.7 - 3.9 % and P. vittata removed 0.53 - 1.5 % of total As from soil at three depths. However, for the surface (0 - 20 cm) and subsurface (40 - 60 cm) layers, the (post-experiment) soil As data indicated that total As concentration in soil was reduced by 49 and 63 % (P 0.05), respectively, by P. vittata. Our results show that phytoremediation time based on observed changes in soil As based on limited s ling is not reliable hence, it is recommended that the frond As uptake should be considered in order to evaluate the phytoremediation efficiency of the two fern species at the experimental site. Using As uptake of the two fern species, we estimate that with P. calomelanos var. austroamericana it would take 55 - 125 years to decrease mean total As content below the ecological investigation level (20 mg kg(-1)) in the surface and subsurface soils, whereas with P. vittata 143 - 412 years would be required to achieve this target.
Cadmium bioaccumulation in Proisotoma minuta in relation to bioavailability in soils
Publisher: Elsevier BV
Date: 09-2009
DOI: 10.1016/J.ECOENV.2009.05.009
Abstract: Proisotoma minuta are widely distributed in Australian soils, especially in rehabilitated mine sites and in cotton fields. Laboratory studies were conducted to evaluate the accumulation of cadmium (Cd) in the Collembolan, P. minuta, using four Australian soils. Cadmium accumulation in body tissues was measured by atomic absorption spectroscopy of acid digests of the Collembola. Cadmium soil bioavailability of four Australian soils was determined using a sequential extraction method. The highest soluble-exchangeable Cd concentration was observed in Box Hill soil with the lowest pH, organic carbon, CEC, clay and very low iron content. Robertson soil with high pH, CEC, organic carbon, clay and iron content had the highest Cd organic- and oxide-bound concentrations. This may explain why there was higher Cd accumulation in P. minuta in the Box Hill soil than in the Robertson soil. The Cd uptake of P. minuta was predominantly correlated with soluble-exchangeable Cd concentration in soils followed by organic- and oxide-bound Cd concentrations. Presumably, soluble-exchangeable Cd is more readily available for P. minuta uptake than other Cd fractions.
A POTASSIUM-RICH BEIDELLITE FROM A LATERITE PALLID ZONE IN WESTERN AUSTRALIA
Publisher: Mineralogical Society
Date: 06-1991
DOI: 10.1180/CLAYMIN.1991.026.2.07
Abstract: A smectite formed by weathering of mica in a laterite pallid zone at Boddington, Western Australia has been investigated by analytical electron microscopy. The evidence suggests that this mineral has the chemical composition and swelling properties of ideal beidellite but is anomalous in containing abundant non-exchangeable K. This K balances half of the layer charge that arises mostly from tetrahedral substitution of Al 3+ for Si 4+ , with the K + occupying one sixth of the sites occupied by K in mica.
Corrigendum: Organo-mineral interactions in contrasting soils under natural vegetation [Front. Environ. Sci. 2, (2014), 2] DOI: 10.3389/fenvs.2014.00002
Publisher: Frontiers Media SA
Date: 21-12-2015
Dissolution kinetics of soil clays in sulfuric acid solutions: Ionic strength and temperature effects
Publisher: Elsevier BV
Date: 12-2014
Biochar carbon stability in four contrasting soils
Publisher: Wiley
Date: 24-09-2013
DOI: 10.1111/EJSS.12094
Degradation of conventional, biodegradable and oxo-degradable microplastics in a soil using a δ13C technique
Publisher: CSIRO Publishing
Date: 2023
DOI: 10.1071/SR23140
Ultra-violet, visible, near-infrared, and mid-infrared diffuse reflectance spectroscopic techniques to predict several soil properties
Publisher: CSIRO Publishing
Date: 2005
DOI: 10.1071/SR04182
Abstract: Reflectance spectroscopy techniques in the ultraviolet, visible, near-infrared and mid-infrared regions are alternatives for many traditional laboratory methods for measuring soil properties. However, debate exists over whether the near-infrared (700–2500 nm) or the mid-infrared (MIR, 2500–25000 nm) region of the electromagnetic spectrum is more useful for predicting soil properties. Therefore, the aim of this study was to compare UV-VIS-NIR and MIR spectroscopic techniques to predict several soil properties. A total of 415 surface and subsurface soil s les were collected from widely spread locations within New South Wales and south-eastern Queensland of Australia to model the proposed hypothesis. Principal component regression analysis (PCR) was used to develop calibration and validation models from soil spectra and reference laboratory values. The models developed using MIR spectra achieved higher prediction accuracy (regression coefficient, r2 = 0.62–0.85) for pH, organic carbon, clay, sand, CEC, and exchangeable Ca and Mg than that obtained by UV-VIS-NIR spectra (r2 = 0.28–0.76). PCR models were also developed for the combined spectral regions (UV-VIS-NIR+MIR). The models developed using combined spectra were also found to predict pH, organic carbon, clay, sand, CEC, and exchangeable Ca and Mg with acceptable accuracy (r2 = 0.59–0.79). The results of this study indicate that MIR spectra are better than UV-VIS-NIR spectra for estimation of common soil properties.
Evaluation of specimen preparation techniques for micro-PIXE localisation of elements in hyperaccumulating plants
Publisher: Elsevier BV
Date: 04-2008
Plant roots are more important than temperature in modulating carbon release in a limed acidic soil
Publisher: Wiley
Date: 11-12-2019
DOI: 10.1111/EJSS.12899
Soil microbial biomass and microbial biodiversity in some soils from New South Wales, Australia
Publisher: CSIRO Publishing
Date: 2004
DOI: 10.1071/SR03132
Abstract: Eight surface soils (0–15 cm) including 1 Ferrosol, 2 Tenosols, 2 Kurosols, 1 Sodosol, 1 Chromosol, and 1 Kandosol were collected from mainly pasture sites in New South Wales. The soils had different physico-chemical properties and there were some differences between the sites in climatic conditions. Soil microbial biomass carbon (MBC) was estimated by the chloroform-fumigation extraction method, and substrate utilisation patterns determined by the Biolog method were used to assess the amount, functional ersity, substrate richness and evenness, and community structure of the microorganisms in these soils. The amount of MBC (585 µg C/g) and the microbial ersity (H´ = 3.24) were high in soils that had high clay (33%), organic C (5.96%), total N (0.45%), free iron (7.06%), moisture content (50%), and cation exchange capacitiy (133.5 mmolc/kg). These soil properties, e.g. soil moisture (r2 = 0.72), organic C (r2 = 0.58), total N (r2 = 0.63), free iron (r2 = 0.44), and EC (r2 = 0.53), were positively correlated with MBC and microbial ersity index, whereas pH and sand and silt content showed negative correlations. The climatic factors (temperature and rainfall) had no significant influence on either MBC or ersity.
Interactive Priming of Biochar and Labile Organic Matter Mineralization in a Smectite-Rich Soil
Publisher: American Chemical Society (ACS)
Date: 20-10-2011
DOI: 10.1021/ES202186J
Abstract: Biochar is considered as an attractive tool for long-term carbon (C) storage in soil. However, there is limited knowledge about the effect of labile organic matter (LOM) on biochar-C mineralization in soil or the vice versa. An incubation experiment (20 °C) was conducted for 120 days to quantify the interactive priming effects of biochar-C and LOM-C mineralization in a smectitic clayey soil. Sugar cane residue (source of LOM) at a rate of 0, 1, 2, and 4% (w/w) in combination with two wood biochars (450 and 550 °C) at a rate of 2% (w/w) were applied to the soil. The use of biochars (~ -36‰) and LOM (-12.7‰) or soil (-14.3‰) with isotopically distinct δ(13)C values allowed the quantification of C mineralized from biochar and LOM/soil. A small fraction (0.4-1.1%) of the applied biochar-C was mineralized, and the mineralization of biochar-C increased significantly with increasing application rates of LOM, especially during the early stages of incubation. Concurrently, biochar application reduced the mineralization of LOM-C, and the magnitude of this effect increased with increasing rate of LOM addition. Over time, the interactive priming of biochar-C and LOM-C mineralization was stabilized. Biochar application possesses a considerable merit for long-term soil C-sequestration, and it has a stabilizing effect on LOM in soil.
Evaluation of the Influence of Individual Clay Minerals on Biochar Carbon Mineralization in Soils
Publisher: MDPI AG
Date: 03-12-2019
DOI: 10.3390/SOILSYSTEMS3040079
Abstract: Although association between mineral and biochar carbon have been speculated in some studies, still there is no direct evidence for the influence of in idual clay minerals on the mineralization of biochar carbon in soils. To address this, we conducted an incubation study using monomineralic soils constituted by separately mixing pure minerals, i.e., smectite, kaolinite, and goethite, with a sandy soil. Switch grass biochar (400 °C) was added to the artificial soils and s les were incubated for 90 days at 20 °C in the laboratory. The CO2-C mineralized from the control, and biochar amended soil was captured in NaOH traps and the proportion of C mineralized from biochar was determined using δ13C isotopic analysis. The clay minerals significantly decreased the cumulative total carbon mineralized during the incubation period, whereas biochar had no effect on this. The least amount of total C was mineralized in the presence of goethite and biochar amended soil, where only 0.6% of the native soil organic carbon (SOC) (compared to 4.14% in control) and 2.9% of the biochar-C was mineralized during the 90 days incubation period. Native SOC mineralization was significantly reduced in the presence of biochar and the three minerals. Goethite was most effective in stabilizing both biochar and the native soil organic carbon. The short-term data from this study demonstrate that biochar application in Fe oxide rich soils may be an effective strategy to sequester biochar carbon, as well as to stabilize native soil carbon.
Heavy metals contamination in vegetables grown in urban and metal smelter contaminated sites in Australia
Publisher: Springer Science and Business Media LLC
Date: 2006
Competitive adsorption behavior of heavy metals on kaolinite
Publisher: Elsevier BV
Date: 10-2005
DOI: 10.1016/J.JCIS.2005.04.036
Abstract: Polluted and contaminated soils can often contain more than one heavy metal species. It is possible that the behavior of a particular metal species in a soil system will be affected by the presence of other metals. In this study we have investigated the adsorption of Cd(II), Cu(II), Pb(II), and Zn(II) onto kaolinite in single- and multi-element systems as a function of pH and concentration, in a background solution of 0.01 M NaNO3. In adsorption edge experiments, the pH was varied from 3.5 to 10.0 with total metal concentration 133.3 microM in the single-element system and 33.3 microM each of Cd(II), Cu(II), Pb(II), and Zn(II) in the multi-element system. The value of pH50 (the pH at which 50% adsorption occurs) was found to follow the sequence Cu<Zn<Pb<Cd in single-element systems, but Pb<Cu<Zn<Cd in the multi-element system. Adsorption isotherms at pH 6.0 in the multi-element systems showed that there is competition among various metals for adsorption sites on kaolinite. The adsorption and potentiometric titrations data for various kaolinite-metal systems were modeled using an extended constant-capacitance surface complexation model that assumed an ion-exchange process below pH 7.0 and the formation of inner-sphere surface complexes at higher pH. Inner-sphere complexation was more dominant for the Cu(II) and Pb(II) systems.
Prediction of Soil Clay Content and Cation Exchange Capacity Using Visible Near-Infrared Spectroscopy, Portable X-ray Fluorescence, and X-ray Diffraction Techniques
Publisher: American Chemical Society (ACS)
Date: 22-03-2021
Cadmium sorption by hydroxy-aluminium interlayered montmorillonite
Publisher: Springer Science and Business Media LLC
Date: 2001
Changes with time in the potassium content and phyllosilicates in the soil of the Broadbalk continuous wheat experiment at Rothamsted
Publisher: Wiley
Date: 12-1997
Stabilisation of soil organic matter: interactions between clay and microbes
Publisher: Springer Science and Business Media LLC
Date: 25-07-2022
DOI: 10.1007/S10533-022-00956-2
Abstract: Soil organic matter (SOM) plays a central role in the global carbon balance and in mitigating climate change. It will therefore be important to understand mechanisms of SOM decomposition and stabilisation. SOM stabilisation is controlled by biotic factors, such as the efficiency by which microbes use and produce organic compounds varying in chemistry, but also by abiotic factors, such as adsorption of plant- and microbially-derived organic matter onto soil minerals. Indeed, the physicochemical adsorption of organic matter onto soil minerals, forming mineral associated organic matter (MAOM), is one of the significant processes for SOM stabilisation. We integrate existing frameworks of SOM stabilisation and illustrate how microbial control over SOM stabilisation interacts with soil minerals. In our new integrated framework, we emphasise the interplay between substrate characteristics and the abundance of active clay surfaces on microbial processes such as carbon use efficiency and recycling. We postulate that microbial use and recycling of plant- and microbially-derived substrates decline with increased abundance of active clay surfaces, and that the shape of these relationships depend on the affinity of each substrate to adsorb, thereby affecting the efficiency by which organic matter remains in the soil and is stabilised into MAOM. Our framework provides avenues for novel research and ideas to incorporate interactions between clay surfaces and microbes on SOM stabilisation in biogeochemical models. Graphical abstract
Arsenic Speciation and Phytoavailability in Contaminated Soils Using a Sequential Extraction Procedure and XANES Spectroscopy
Publisher: American Chemical Society (ACS)
Date: 15-08-2011
DOI: 10.1021/ES201677Z
Abstract: In this study, a sequential extraction procedure (SEP) and X-ray absorption near edge structure (XANES) spectroscopy were used to determine the solid-phase speciation and phytoavailability of arsenic (As) of historically contaminated soils from As containing pesticides and herbicides and soils spiked with As in the laboratory. Brassica juncea was grown in the contaminated soils to measure plant available As in a glasshouse experiment. Arsenic associated with amorphous Fe oxides was found to be the dominant phase using both SEP and XANES spectroscopy. Arsenic predominantly existed in arsenate (As(V)) form in the soils in a few s les As was also present in arsenite (As(III)) form or in scorodite mineral. Arsenic concentration in shoots showed significant (p < 0.001-0.05) correlations with the exchangeable As (r = 0.85), and amorphous Fe oxides associated As evaluated by the SEP (r = 0.67), and As associated with amorphous Fe oxides as determined by XANES spectroscopy (r = 0.51). The results show that As in both fractions was readily available for plant uptake and may pose a potential risk to the environment. The combination of SEP and XANES spectroscopy allowed us the quantitative speciation of As in the contaminated soils and the identification of valence and mineral forms of As. Such detailed knowledge on As speciation and availability is vital for management and rehabilitation of As-contaminated soils.
Copper and arsenate co-sorption at the mineral-water interfaces of goethite and jarosite
Publisher: Elsevier BV
Date: 06-2008
DOI: 10.1016/J.JCIS.2008.02.044
Abstract: The co-sorption reaction products of arsenate (As(V)) and copper (Cu(II)) on goethite (alpha-FeOOH) and natro-jarosite (Na(3)Fe(3)(SO(4))(2)(OH)(6)) were investigated with extended X-ray absorption fine structure (EXAFS) spectroscopy to determine if Cu(II) and As(V) would form precipitates or compete with each other for surface sites. The reaction products were prepared by mixing 250 microM Cu(SO(4)) with 10, 25, or 50 microM Na(2)HAsO(4) at pH 5.65 and allowing the mixture to react in 10 m(2) L(-1) goethite or jarosite suspensions for 12 days. In addition, EXAFS data of Cu(SO(4)) and As(V) sorbed on goethite and jarosite were collected as control species. All reaction conditions were under-saturated with respect to common copper bearing minerals: tenorite (CuO), brochantite (Cu(4)(OH)(6)SO(4)), and hydrated clinoclase (Cu(3)(AsO(4))(2)2H(2)O). The extents of the As(V) and Cu(II) surface adsorption reactions showed a strong competitive effect from Cu(II) on As(V) adsorption for a nominal Cu:As mole-ratio of 25:1. With increasing nominal As(V) concentration, As(V) sorption on goethite and jarosite increased without diminishing the amount of Cu(II) sorption. In the absence of either co-sorbate, As(V) and Cu(II) formed the expected surface adsorption species, i.e., bidentate binuclear and edge-sharing surface complexes, consistent with previously published results. In each other's presence, the local bonding environments of As(V) and Cu(II) showed that the co-sorbates form a precipitate on the goethite and jarosite surface at nominal concentrations of 10:1 and 5:1. At nominal Cu:As mole-ratios of 25:1, Cu(II) did not form significantly different surface complexes on goethite or jarosite from those in the absence of As(V), however, As K-edge EXAFS results distinctly showed Cu(II) atoms in As(V)'s local bonding environment on the goethite surface. The structures of the two precipitates were different and depended on the anion-layer structure and possibly the presence of structural oxyanions in the case of jarosite. On goethite, the copper-arsenate precipitate was similar to hydrated clinoclase, while on jarosite, a euchroite-like precipitate (Cu(2)[AsO(4)](OH)3H(2)O, P 2(1)2(1)2(1)) had formed. Despite under-saturated solution conditions, the formation of these precipitates may have occurred due to a seed-formation effect from densely surface adsorbed Cu(II) and As(V) for which the "new" saturation index was significantly lower than homogeneous values would otherwise suggest. Synergistic reactions between two co-sorbates of fundamentally different surface adsorption behaviour can thus be achieved if the number of available sites for surface adsorption is limited.
Aged biochar affects gross nitrogen mineralization and recovery: a 15N study in two contrasting soils
Publisher: Wiley
Date: 13-03-2017
DOI: 10.1111/GCBB.12430
Temperature sensitivity of soil and root respiration in contrasting soils
Publisher: Springer Science and Business Media LLC
Date: 06-2014
Potassium adsorption characteristics and potassium forms in some New South Wales soils in relation to early senescence in cotton
Publisher: CSIRO Publishing
Date: 2004
DOI: 10.1071/SR03143
Abstract: The occurrence of premature senescence (PS) in cotton in Australia has been related to decreased potassium (K) concentration in the affected plants. Soil s les (0–120 cm) were taken from paired cotton fields, i.e. PS fields and similar soils not affected by PS (Non-PS fields), in northern New South Wales. The s les were analysed for different forms of K in soil, mineralogy of various size fractions, and K adsorption characteristics to evaluate differences in their K availability. Smectite was the dominant clay mineral in the studied soils. The K-bearing mineral illite was present in the clay fraction of all s les and its content was generally higher in soils from the Non-PS sites than the PS sites from Moree, Pilliga, and Warren. Water-soluble K (H2O-K) ranged from 0.03 to 2.64 mg/kg (median 0.35 mg/kg), exchangeable K (Exch-K) from 43 to 687 mg/kg (median 107 mg/kg), non-exchangeable K (Nonexch-K) from 164 to 1981 mg/kg (median 819 mg/kg), and total K (Total-K) from 16 811 to 23 207 mg/kg (median 14 740 mg/kg). The values of various K forms were generally higher in s les from the Non-PS fields than the PS fields from Pilliga and Warren sites and the reverse trend occurred for the s les from Trangie. Similar H2O-K and Exch-K values were found for the PS and Non-PS s les from Moree, whereas Nonexch-K and Total-K contents were higher in the top 60 cm soil depth from the Non-PS field than the PS field. The equilibrium activity ratio (ARKe) values were significantly higher for surface s les from the Non-PS sites than the PS sites from Pilliga and Warren and the reverse was true for the Trangie site. There was a sharp decrease in ARKe with depth for the studied s les. The potential buffering capacity (PBCK) for both surface and subsurface s les from the Non-PS site (mean 31.5 (mmol/kg)/(mol/L)1/2) from Trangie was substantially higher than the corresponding s les from the PS sites (mean 14.7 (mmol/kg)/(mol/L)1/2). There was a significant increase in K adsorption for the subsurface s les than the surface s les for all sites, as indicated by the higher values of Freundlich adsorption coefficient, k. At the Pilliga and Warren sites, the occurrence of premature senescence in cotton plants can be explained on the basis of differences in the levels of different forms of K, mineralogy, and K adsorption characteristics of soils from the PS and Non-PS fields. At the Moree site, higher illite content in the Non-PS than the PS soil may explain the difference in their K availability. For the paired Trangie s les, greater PBCK of the Non-PS soil than the PS soil may be responsible for increased K availability in the Non-PS soil. The occurrence of PS symptoms in cotton at Narrabri site cannot be directly contributed to K supplying parameters analysed in the study. The results also show that Exch-K alone may not be adequate to measure K availability to cotton in these soils.
Mid-infrared spectroscopy and partial least-squares regression to estimate soil arsenic at a highly variable arsenic-contaminated site
Publisher: Springer Science and Business Media LLC
Date: 29-04-2014
The effects of cadmium, copper, lead, and zinc on the growth and reproduction of Proisotoma minuta Tullberg (Collembola)
Publisher: Elsevier BV
Date: 03-2005
DOI: 10.1016/J.ECOENV.2004.05.001
Abstract: Laboratory studies were conducted to evaluate Proisotoma minuta sensitivity toward selected heavy metals (Cd, Cu, Pb, and Zn). The experimental results showed a reduction in adult survival and no reproduction at the highest concentrations of Cd and Zn. Application of Pb at all levels resulted in large numbers of progeny and no significant mortality compared to controls. EC50 reproduction values for Cd, Cu, and Zn were 125, 696, and 283 microg g(-1), respectively. No significant difference in time from the introduction of adults into the test soils to the appearance of the first-instar animals was observed between different metal treatments. The growth rate of adults decreased for all metal treatments compared to the controls. It is suggested that the accumulation of metals in P. minuta affects metabolism and results in a slower growth rate. The absence of any statistically significant effect on mortality at all concentrations of Pb may be due to greater tolerance of P. minuta to Pb than to other metals.
Aging Induced Changes in Biochar’s Functionality and Adsorption Behavior for Phosphate and Ammonium
Publisher: American Chemical Society (ACS)
Date: 11-07-2017
Abstract: Biochar, a form of pyrogenic carbon, can contribute to agricultural and environmental sustainability by increasing soil reactivity. In soils, biochar could change its role over time through alterations in its surface chemistry. However, a mechanistic understanding of the aging process and its role in ionic nutrient adsorption and supply remain unclear. Here, we aged a wood biochar (550 °C) by chemical oxidation with 5-15% H
Effect of ageing on surface charge characteristics and adsorption behaviour of cadmium and arsenate in two contrasting soils amended with biochar
Publisher: CSIRO Publishing
Date: 2014
DOI: 10.1071/SR13187
Abstract: Biochar has been recognised as an effective amendment for the remediation of contaminated soils however, there is limited knowledge on the effects of biochar ageing in soil on its adsorption behaviour for cationic and anionic species. Biochars are considered to develop negative charge from oxidation with ageing, which may create additional interaction mechanisms for adsorption processes. In the present study, surface charge characteristics and cadmium (Cd) and arsenate (AsO43–) adsorption behaviour of aged biochar were investigated in two soils with variable charge, an Oxisol and an Inceptisol, by comparing (i) unamended soils, and soils amended with (ii) fresh biochar (450°C) and (iii) biochar (450°C) aged for 12 months, applied at a rate of 2% w/w. Surface charge characteristics were assessed using the ‘index’ ion adsorption method, with a LiCl electrolyte. Batch adsorption studies were conducted using fresh and aged soil–biochar mixtures. In contrast to previous studies, the results provided no evidence of an increase in cation exchange capacity as a consequence of biochar ageing. There was an increase in Cd adsorption in the presence of aged biochar in both soil types compared with unamended soils and soils amended with fresh biochar. Results also indicated an increase in AsO43– adsorption in the Inceptisol amended with aged biochar, whereas a decrease in AsO43– adsorption was observed in the Oxisol amended with aged biochar. Overall, the study has highlighted that adsorption behaviour of aged biochar varies depending on the ion it interacts with, soil properties and solution pH.
The role of low molecular weight ligands in nickel hyperaccumulation in Hybanthus floribundus subspecies floribundus
Publisher: CSIRO Publishing
Date: 2010
DOI: 10.1071/FP10080
Abstract: The mechanisms responsible for nickel (Ni) hyperaccumulation in Hybanthus floribundus (Lindl.) F.Muell. subspecies floribundus are obscure. In this study, organic acids and free amino acids (AAs) were quantified in 0.025 M HCl H. floribundus subsp. floribundus shoot extracts using HPLC and ultra performance liquid chromatography (UPLC). In a 20 week pot experiment, plants exposed to five levels of Ni (0–3000 mg kg–1 Ni) accumulated up to 3200 mg Ni kg–1 dry weight in shoots, and the shoot : root Ni concentration ratios were .4. Concentration of organic acids followed the order malic acid citric acid oxalic acid. Citric acid concentration significantly increased upon Ni exposure, with concentrations between 2.3- and 5.9-fold higher in Ni treated plants that in control plants. Molar ratios of Ni to citric acid ranged from 1.3 : 1 to 1.7 : 1 equivalent to % of the accumulated Ni. Malic acid concentration also increased upon exposure to applied Ni. However, concentrations were statistically at par across 0–3000 mg kg–1 Ni treatments, suggesting that the production of malic acid is a constitutive property of the subspecies. Total AA concentrations were stimulated upon exposure to external Ni treatment, with glutamine, alanine and aspartic acids being the predominant acids. These AAs accounted for up to 64% of the total free AA concentration in control plants and up to 75% for the 2000 mg kg–1 Ni treatment plants. These results suggest that citric acid in addition to the aforementioned AAs are synthesised in H. floribundus subsp. floribundus plants following exposure to elevated concentrations of Ni and may act as potential ligands for detoxification and possibly storage of accumulated Ni.
Arsenic hyperaccumulation and localization in the pinnule and stipe tissues of the gold-dust fern (Pityrogramma calomelanos (L.) Link var. austroamericana (Domin) Farw.) using quantitative micro-PIXE spectroscopy
Publisher: Springer Science and Business Media LLC
Date: 14-09-2007
Phytoremediation Potential of Pityrogramma Calomelanos Var. Austroamericana and Pteris Vittata L. Grown at a Highly Variable Arsenic Contaminated Site
Publisher: Informa UK Limited
Date: 10-2011
DOI: 10.1080/15226514.2011.568023
Abstract: This study examined the phytoextraction potential of two arsenic (As) hyperaccumulators, Pteris vittata L. and Pityrogramma calomelanos var. austroamericana at a historical As-contaminated cattle dip site in northern New South Wales (NSW), Australia. Total As concentration in the surface soil (0-20 cm) showed a better spatial structure than phosphate-extractable As in the surface and sub-surface soil at this site. P. calomelanos var. austroamericana produced greater frond dry biomass (mean = 130 g plant(-1)) than P. vittata (mean = 81 g plant(-1)) after 10 months of growth. Arsenic concentration and uptake in fronds were also significantly higher in P. calomelanos var. austroamericana (means = 887 mg kg(-1) and 124 mg plant(-1)) than in P. vittata (means = 674 mg kg(-1) and 57 mg plant(-1)). Our results showed that under the field conditions and highly variable soil As at the site, P. calomelanos var. austroamericana performed better than P. vittata. We predict that P. calomelanos var. austroamericana would take approximately 100 years to reduce the total As to below 20 mg kg(-1) at the site compared to > or =200 years estimated for P. vittata. However, long-term data are required to confirm these observations under field conditions.
Surface speciation of Cd(II) and Pb(II) on kaolinite by XAFS spectroscopy
Publisher: Elsevier BV
Date: 11-2007
DOI: 10.1016/J.JCIS.2007.05.022
Abstract: Little spectroscopic evidence exists in the literature describing the surface complexation of cadmium (Cd) and lead (Pb) on kaolinite, the dominant clay mineral present in highly weathered soils of tropical and humid climates. X-ray absorption fine structure (XAFS) spectroscopy data at the Cd K and Pb L(III) edges were collected on Cd- and Pb-sorbed kaolinite s les and compared to a suite of reference materials including Pb and Cd sorbed on amorphous (am-)gibbsite. Cadmium formed dominantly (>75%) outer sphere complexes on kaolinite and a small fraction of CdOHCl complexes. In contrast Cd adsorbed as an inner sphere complex on gibbsite, suggesting that the Si tetrahedral sheet hindered Cd sorption to the Al octahedral sheet on kaolinite. Lead formed polymeric complexes, which bonded to kaolinite via edge sharing with surface Al octahedra. Two distinct Pb-Al edge-sharing distances on am-gibbsite, as opposed to one on kaolinite, suggested a similar steric hindrance effect for the surface complexation of polymeric Pb complexes on kaolinite. The results of this study show that the Si tetrahedral sheet limited the surface complexation of Cd and Pb on kaolinite, elevating kaolinite's permanent negative charge properties in retaining these heavy metals at its surface.
Salinity-induced acidification in a wetland sediment through the displacement of clay-bound iron(II)
Publisher: CSIRO Publishing
Date: 2010
DOI: 10.1071/EN10057
Abstract: Environmental context Acidification of inland waterways is an emerging issue worldwide, mostly because it disturbs the balance of reduced sulfur species in soils, sediments and mine tailings. We describe a pathway for wetland acidification through salt displacement and oxidation of Fe2+ from clay minerals. This alternative pathway for acidification raises environmental concerns because an increasing number of inland waterways are affected by increasing salinity. Abstract A wetland near the Murray River (south-eastern Australia) was found to have significant levels of exchangeable reduced iron (Fe2+) in the sediment clay-zone, and the potential for acidification under high salinity and oxidising conditions. Cation exchange experiments using purified clay from this site show relative affinities consistent with the lyotrophic series: Fe2+ Ca2+ Mg2+ H+ K+ Na+. This relative affinity is confirmed in Fe2+ displacement experiments using natural sediment clay. Proton production during oxidation of salt-treated sediments corresponds to that expected for the oxidation and hydrolysis of Fe2+ displaced from clay interlayers, taking into account the buffering properties of the sediment matrix. This work shows that wetland acidification can occur in low sulfur-containing wetlands and is not exclusively a problem associated with sulfidic sediments.
Mineralogy and chemistry of ochre sediments from an acid mine drainage near a disused mine in Cornwall, UK
Publisher: Mineralogical Society
Date: 1999
Akaganéite (β-FeOOH) precipitation in inland acid sulfate soils of south-western New South Wales (NSW), Australia
Publisher: Elsevier BV
Date: 11-2011
PROPERTIES AND DISTRIBUTION OF IRON-OXIDES AND THEIR ASSOCIATION WITH MINOR ELEMENTS IN THE SOILS OF SOUTH-WESTERN AUSTRALIA
Publisher: Wiley
Date: 03-1992
Desorption of cadmium from goethite: Effects of pH, temperature and aging
Publisher: Elsevier BV
Date: 07-2006
DOI: 10.1016/J.CHEMOSPHERE.2005.10.041
Abstract: Cadmium is perhaps environmentally the most significant heavy metal in soils. Bioavailability, remobilization and fate of Cd entering in soils are usually controlled by adsorption-desorption reactions on Fe oxides. Adsorption of Cd on soil colloids including Fe oxides has been extensively studied but Cd desorption from such soil minerals has received relatively little attention. Some factors that affect Cd adsorption on goethite include pH, temperature, aging, type of index cations, Cd concentrations, solution ionic strength and presence of organic and inorganic ions. This research was conducted to study the influence of pH, temperature and aging on Cd desorption from goethite. Batch experiments were conducted to evaluate Cd desorption from goethite with 0.01 M Ca(NO3)2. In these experiments Cd desorption was observed at 20, 40 and 70 degrees C in combination with aging for 16 h, 30, 90 and 180 d from goethite that adsorbed Cd from solutions containing initial Cd concentrations of 20, 80 and 180 microM. Following the adsorption step Cd desorption was measured by 15 successive desorptions after aging at various temperatures. At the lowest amount of initially adsorbed Cd and equilibrium pH 5.5, cumulative Cd desorption decreased from 71% to 17% with aging from 16 h to 180 d and the corresponding decrease at equilibrium pH 6.0 was from 32% to 3%. There was a substantial decrease in Cd desorption with increasing equilibration temperature. For ex le, in goethite with the lowest amount of initial adsorption at equilibrium pH 5.5, cumulative Cd desorption decreased from 71% to 31% with increase in temperature from 20 to 70 degrees C, even after 16 h. Dissolution of Cd adsorbed goethite in 1M HCl, after 15 successive desorptions with 0.01 M Ca(NO3)2, indicated that approximately 60% of the Cd was surface adsorbed. Overall, dissolution kinetics data revealed that 23% to 88% Cd could not be desorbed, which could possibly be diffused into the cracks and got entrapped in goethite crystals. At elevated temperature increased equilibrium solution pH favoured the formation of CaCO3 and CdCO3 which reasonably decreased Cd desorption. Cadmium speciation showed the formation of calcite and otavite minerals at 40 and 70 degrees C due to increase in pH (>9.5) during aging. X-ray diffraction analysis (XRD) of these s les also revealed the formation of CaCO3 at elevated temperatures with aging. While mechanisms such as Cd diffusion and/or entrapment into fissures and cracks in goethite structure with increase in temperature and aging are possible.
Biochar field study: Greenhouse gas emissions, productivity, and nutrients in two soils
Publisher: Wiley
Date: 09-2016
Soil warming and liming impacts on the recovery of 15 N in an acidic soil under soybean cropping
Publisher: Wiley
Date: 23-02-2016
Influence of Gypsum Enhanced Chicken-Manure-and-Wheat-Straw Compost on Amelioration of an Irrigated Sodic Brown Vertisol – Laboratory Experiment
Publisher: Informa UK Limited
Date: 07-08-2015
Reply to Ashton: The putative guanylyl cyclase domain of AtPepR1 and similar plant receptors
Publisher: Proceedings of the National Academy of Sciences
Date: 28-04-2011
Substitution of multimetals in goethite
Publisher: Elsevier BV
Date: 08-2006
Iron in soil kaolins from Indonesia and Western Australia
Publisher: Mineralogical Society
Date: 12-2002
Abstract: Soil kaolins from Indonesia and Western Australia and a range of reference kaolins were studied using Mössbauer spectroscopy, electron paramagnetic resonance (EPR) spectroscopy and SQUID magnetometry. Mössbauer spectra indicate that the Fe within the kaolins is in the highspin Fe 3+ oxidation state and that a large fraction of the Fe is present as dispersed atoms residing within the octahedral sites of the kaolinite crystal structure. The EPR spectra are typical for soil kaolins except for the absence of radiation-induced defects for the Indonesian kaolins. The Fe (I) spectra are dominant with a strong symmetric peak at g = 4.3, the presence of Fe(II) spectra is shown by a shoulder on this peak at g = 4.9 and a small phase up peak at g = 9.2. Low-temperature (5 K) magnetization ( M ) measurements over large field ( H ) sweeps (±70 kOe) yielded M ( H ) curves which are fitted well with Brillouin functions indicating the paramagnetic nature of the kaolins at temperatures down to 5 K. A very small remanent magnetization was detectable in the kaolins. Remanent magnetization to saturation magnetization ratios ranged from 10 –4 to 10 –3 for the Indonesian kaolins and were all ∼10 –3 for the Western Australian kaolins, indicating that at high fields the vast majority of the magnetization of the kaolins is due to paramagnetic ions. Zero-field-cooled and field-cooled magnetization measurements in small fields (500 Oe) indicate that the Indonesian kaolins are generally free from magnetically-blocked material down to a temperature of 5 K. The magnetic susceptibility of the Indonesian kaolins shows Curie Law behaviour indicating paramagnetic behaviour over all temperatures down to 5 K. Measurements on the Western Australian kaolins indicated the presence of some magnetic material that is magnetically blocked at temperatures below ∼200 250 K. As a consequence, the magnetic susceptibility showed large deviations from Curie Law behaviour.
Celebrating 60 years of
Publisher: CSIRO Publishing
Date: 14-11-2022
DOI: 10.1071/SR22223
Abstract: An editorial to celebrate the 60th anniversary of the Soil Research journal.
Enhanced biological nitrogen fixation and competitive advantage of legumes in mixed pastures diminish with biochar aging
Publisher: Springer Science and Business Media LLC
Date: 19-01-2018
Agronomic performance of a high ash biochar in two contrasting soils
Publisher: Elsevier BV
Date: 06-2014
BIOCHAR APPLICATION TO SOIL: AGRONOMIC AND ENVIRONMENTAL BENEFITS AND UNINTENDED CONSEQUENCES
Publisher: Elsevier
Date: 2011
Organic carbon characteristics in density fractions of soils with contrasting mineralogies
Publisher: Elsevier BV
Date: 12-2017
Spatial variability of ammonium and nitrate in soils near a poultry farm
Publisher: Elsevier BV
Date: 12-2002
DOI: 10.1016/S0269-7491(02)00185-9
Abstract: This paper assesses the distribution of ammonium (NH4+) and nitrate (NO3-) nitrogen deposition in native bushland soil adjacent to an open ventilated poultry farm. The farm is located in Thirlmere 150 km south west of Sydney, Australia. A total of 104 geographically referenced soil cores were obtained from the study area. Soil pH, electrical conductivity (EC), NH4(+) - and NO3(-)-nitrogen concentrations were analysed for variable trends at three depths, i.e. 0-30, 30-60, and 60-90 cm. Significantly higher concentrations of the two nitrogen forms and EC were observed nearer to the farm in the surface soil s les (0-30 cm). The distribution of NH4+, NO3- and EC were all correlated in surface s les throughout the study area. There was no indication of NH4+ and NO3- leaching within soil profile s led and it appears that weeds and native vegetation had utilised the accumulated nitrogen. The level of N deposition adjacent to the poultry farm decreased downwind due to dispersion of plume and to the buffering effects from the bushland.
Copper substitution alone and in the presence of chromium, zinc, cadmium and lead in goethite (a-FeOOH)
Publisher: Mineralogical Society
Date: 09-2009
DOI: 10.1180/CLAYMIN.2009.044.3.293
Abstract: A series of Cu-substituted goethites, single and co-substituted with Cr, Zn, Cd and/or Pb was prepared, having molar ratios equal to 2.00, 3.33 and 5.00 mol%. All the s les contained only goethite, except Cu-, (Cu,Zn)- and (Cu,Pb)-s les synthesized at 5.00 mol% where hematite was also formed. The presence of Cr/Cd suppressed the hematite-forming effects of Cu. The general sequence of metal entry into the single-metal-substituted goethites was Zn = Cr Cd Cu Pb and in di- (5.00 mol%) and tri- (3.33 mol%) metal-substituted goethites was Cu Zn Cd Cr Pb. Cu incorporation increased all the unit-cell parameters in single-metal-substituted goethite, and these parameters increased in combination with other metals as follows: Cd Zn Cr Pb in the multimetal-substituted goethites. The Cu-substituted goethite dissolved faster than pure goethite. Co substitutions of Cr/Pb reduced the dissolution rate ( k Fe ), while substitutions of Cd/Zn increased k Fe .
Effects of phytoextraction on heavy metal concentrations and pH of pore-water of biosolids determined using an in situ sampling technique
Publisher: Elsevier BV
Date: 12-2008
DOI: 10.1016/J.ENVPOL.2008.05.021
Abstract: Heavy metal concentrations and pH of pore-water in contaminated substrates are important factors in controlling metal uptake by plants. We investigated the effects of phytoextraction on these properties in the solution phase of biosolids and diluted biosolids in a 12-month phytoextraction column experiment. Phytoextraction using Salix and Populus spp. temporarily decreased pore-water pH of the substrates over the experimental period followed by a return to initial pH conditions. Salixxreichardtii and Populus balsamifera effectively extracted Ni, Zn and Cd and actively mobilized these metals from the solid to the solution phase. S.xreichardtii had the stronger effect on mobilization of metals due to its larger root system. Phytoextraction did not affect Cu in the solution phase of the biosolids. Heavy metals were leached down to lower depths of the columns during the phytoextraction process.
Edaphic Soil Science, Introduction to
Publisher: Elsevier
Date: 2014
Concentration of iron oxides from soil clays by 5 M NaOH treatment: the complete removal of sodalite and kaolin
Publisher: Mineralogical Society
Date: 12-1991
DOI: 10.1180/CLAYMIN.1991.026.4.02
Abstract: The Kämpf & Schwertmann (1982) procedure for concentrating iron oxides in soil clays by dissolution of kaolin and gibbsite by boiling for 1 h in 5 m NaOH may not dissolve all kaolin, and also results in the precipitation of sodalite. For the complete dissolution of kaolin in kaolin-rich soil clays a boiling time of 2 h in 5 m NaOH was required. The large amounts of sodalite produced were not removed by the prescribed single wash in 0·5 m HCl. Oxalate soluble Al contents of iron oxide concentrates were sometimes very high and dithionite Fe contents were very low both in concentrates containing sodalite, and in those for which sodalite was not detected by XRD, but where a previously unsuspected amorphous sodalite-like phase may have been present. Complete removal of precipitated sodalite was achieved by two extractions with 0·5 m HCl at 25°C for 20 min. This modified procedure does not alter the Al-substitution and crystal size of goethite, hematite and maghemite as determined by XRD measurements.
Regional considerations for targeted use of biochar in agriculture and rehabilitation in Australia
Publisher: American Society of Agronomy and Soil Science Society of America
Date: 29-10-2015
Cadmium adsorption and desorption behaviour on goethite at low equilibrium concentrations: effects of pH and index cations
Publisher: Elsevier BV
Date: 12-2004
DOI: 10.1016/J.CHEMOSPHERE.2004.08.087
Abstract: The transport and bioavailability of cadmium is governed mainly by its adsorption-desorption reactions with minerals such as goethite--a common iron oxide mineral in variable charged and highly weathered tropical soils. Soil factors such as pH, temperature, solution Cd concentration, ionic strength and ageing affect Cd adsorption on goethite. The desorption behaviour of Cd from goethite at low concentrations is not fully understood. This study investigates the adsorption-desorption of Cd at low Cd concentrations (Cd adsorbed on goethite from 20 to 300 microM Cd solutions) in Na and Ca nitrate solutions of 0.03 M nominal ionic strengths. Synthetic goethite prepared by ageing a ferric hydroxide gel at high pH and room temperature was used for Cd adsorption and desorption studies. For desorption experiment 10 successive desorptions were made for the whole range of initial Cd concentrations (20-300 microM) in the presence of 0.01 M Ca(NO3)2 or 0.03 M NaNO3 solutions. Cadmium adsorption was found to be higher in Na+ than Ca2+ probably due to the competition of Ca2+ ions with Cd2+ ions for adsorption sites on the surfaces of goethite. The effect of index cation on Cd adsorption diminished with increase in pH from 5.0 to 6.0. Cadmium desorption decreased with increase in pH from 5.0 to 6.0 in both Na and Ca systems. After 10 successive desorptions with 0.03 M NaNO3 at the lowest initially adsorbed Cd approximately 45%, 20% and 7% of the adsorbed Cd was desorbed at pH 5.0, 5.5 and 6.0, respectively. The corresponding desorptions in the presence of 0.01 M Ca(NO3)2 were 49%, 22% and 8%, respectively. The Freundlich parameter, k, based on each progressive step of desorption at different adsorbed concentration increased with increasing desorption step, which may indicates that a fraction of Cd was resistant to desorption. Low Cd desorbability from goethite may be due to its specific adsorption and/or possibly as a result of Cd entrapment in the cracks or defects in goethite structure.
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