Can supervise: YES
Eeshwarasinghe, D, Loganathan, P & Vigneswaran, S 2019, 'Simultaneous removal of polycyclic aromatic hydrocarbons and heavy metals from water using granular activated carbon', Chemosphere, vol. 223, pp. 616-627.View/Download from: Publisher's site
© 2019 Elsevier Ltd Polycyclic aromatic hydrocarbons (PAHs) and heavy metals are dangerous pollutants that commonly co-occur in water. An adsorption study conducted on the simultaneous removal of PAHs (acenaphthylene, phenanthrene) and heavy metals (Cd, Cu, Zn) by granular activated carbon (GAC) showed that, when these pollutants are present together, their adsorption was less than when they were present individually. The adsorptive removal percentage of PAHs (initial concentration 1 mg/L) was much higher than that of heavy metals (initial concentration (20 mg/L). The reduction in adsorption of PAHs by heavy metals followed the heavy metals' adsorption capacity and reduction in the negative zeta potential of GAC order (Cu > Zn > Cd). In contrast, PAHs had little effect on the zeta potential of GAC. The Langmuir adsorption capacities of acenaphthylene (0.31–2.63 mg/g) and phenanthrene (0.74–7.36 mg/g) on GAC decreased with increased metals' concentration with the reduction following the order of the metals' adsorption capacity. The kinetic adsorption data fitted to Weber and Morris plots, indicating intra-particle diffusion of both PAHs and heavy metals into the mesopores and micropores in GAC with the diffusion rates. This depended on the type of PAH and metal and whether the pollutants were present alone or together.
Ekanayake, D, Aryal, R, Johir, MAH, Loganathan, P, Bush, C, Kandasamy, J & Vigneswaran, S 2019, 'Interrelationship among the pollutants in stormwater in an urban catchment and first flush identification using UV spectroscopy', CHEMOSPHERE, vol. 233, pp. 245-251.View/Download from: UTS OPUS or Publisher's site
Jamil, S, Loganathan, P, Kandasamy, J, Listowski, A, Khourshed, C, Naidu, R & Vigneswaran, S 2019, 'Removal of dissolved organic matter fractions from reverse osmosis concentrate: Comparing granular activated carbon and ion exchange resin adsorbents', Journal of Environmental Chemical Engineering, vol. 7, no. 3.View/Download from: Publisher's site
© 2019 Elsevier Ltd. All rights reserved. Reverse osmosis (RO) generates a concentrate (ROC) containing dangerous levels of pollutants including dissolved organic carbon (DOC). Adsorption experiments were conducted to study the effectiveness of removing DOC and its fractions from ROCs produced in a water reclamation plant using three adsorbents tested individually and in sequential combination. The ROCs had 23-42 mg/L DOC which contained 83-90% hydrophilics. These hydrophilics comprised 72-76% humics, 2-3% biopolymers, 5-7% building blocks, and 16-18% low molecular weight neutrals. Granular activated carbon (GAC) removed a larger amount of DOC than two strong base anion exchange resins (Purolite A502PS, Purolite A860S). In both batch and column experiments, the adsorptive removal of the hydrophobic fraction was greater for GAC than for the Purolites. Humics present in hydrophilic fraction was completely removed by Purolites but only partially by GAC. In the sequential adsorption batch experiment, GAC followed by Purolite treatment removed more hydrophobics, however, Purolite followed by GAC removed more humics. Almost 100% of humics was removed for all doses of adsorbents when Purolite served as the first treatment. It is concluded that the order of adsorbent use for effectively treating ROC depends on the target DOC fraction intended to be removed.
Jamil, S, Loganathan, P, Listowski, A, Kandasamy, J, Khourshed, C & Vigneswaran, S 2019, 'Simultaneous removal of natural organic matter and micro-organic pollutants from reverse osmosis concentrate using granular activated carbon', WATER RESEARCH, vol. 155, pp. 106-114.View/Download from: Publisher's site
Kalaruban, M, Loganathan, P, Tien, VN, Nur, T, Johir, MAH, Thi, HN, Minh, VT & Vigneswaran, S 2019, 'Iron-impregnated granular activated carbon for arsenic removal: Application to practical column filters', JOURNAL OF ENVIRONMENTAL MANAGEMENT, vol. 239, pp. 235-243.View/Download from: UTS OPUS or Publisher's site
Nur, T, Loganathan, P, Ahmed, MB, Johir, MAH, Tien, VN & Vigneswaran, S 2019, 'Removing arsenic from water by coprecipitation with iron: Effect of arsenic and iron concentrations and adsorbent incorporation', CHEMOSPHERE, vol. 226, pp. 431-438.View/Download from: UTS OPUS or Publisher's site
Eeshwarasinghe, D, Loganathan, P, Kalaruban, M, Sounthararajah, DP, Kandasamy, J & Vigneswaran, S 2018, 'Removing polycyclic aromatic hydrocarbons from water using granular activated carbon: kinetic and equilibrium adsorption studies', Environmental Science and Pollution Research, vol. 25, no. 14, pp. 13511-13524.View/Download from: UTS OPUS or Publisher's site
© 2018, Springer-Verlag GmbH Germany, part of Springer Nature. Polycyclic aromatic hydrocarbons (PAHs) constitute a group of highly persistent, toxic and widespread environmental micropollutants that are increasingly found in water. A study was conducted in removing five PAHs, specifically naphthalene, acenaphthylene, acenaphthene, fluorene and phenanthrene, from water by adsorption onto granular activated carbon (GAC). The pseudo-first-order (PFO) model satisfactorily described the kinetics of adsorption of the PAHs. The Weber and Morris diffusion model's fit to the data showed that there were faster and slower rates of intra-particle diffusion probably into the mesopores and micropores of the GAC, respectively. These rates were negatively related to the molar volumes of the PAHs. Batch equilibrium adsorption data fitted well to the Langmuir, Freundlich and Dubinin–Radushkevich models, of which the Freundlich model exhibited the best fit. The adsorption affinities were related to the hydrophobicity of the PAHs as determined by the log Kow values. Free energies of adsorption calculated from the Dubinin–Radushkevich model and the satisfactory kinetic data fitting to the PFO model suggested physical adsorption of the PAHs. Adsorption of naphthalene, acenaphthylene and acenaphthene in fixed-bed columns containing a mixture of GAC (0.5 g) + sand (24.5 g) was satisfactorily simulated by the Thomas model.
Kalaruban, M, Loganathan, P, Kandasamy, J & Vigneswaran, S 2018, 'Submerged membrane adsorption hybrid system using four adsorbents to remove nitrate from water.', Environmental Science and Pollution Research, vol. 25, no. 21.View/Download from: UTS OPUS or Publisher's site
Nitrate contamination of ground and surface waters causes environmental pollution and human health problems in many parts of the world. This study tests the nitrate removal efficiencies of two ion exchange resins (Dowex 21K XLT and iron-modified Dowex 21K XLT (Dowex-Fe)) and two chemically modified bio-adsorbents (amine-grafted corn cob (AG corn cob) and amine-grafted coconut copra (AG coconut copra)) using a dynamic adsorption treatment system. A submerged membrane (microfiltration) adsorption hybrid system (SMAHS) was used for the continuous removal of nitrate with a minimal amount of adsorbents. The efficiency of membrane filtration flux and replacement rate of adsorbent were studied to determine suitable operating conditions to maintain the effluent nitrate concentration below the WHO drinking standard limit of 11.3 mg N/L. The volume of water treated and the amount of nitrate adsorbed per gramme of adsorbent for all four flux tested were in the order Dowex-Fe > Dowex > AG coconut copra > AG corn cob. The volumes of water treated (L/g adsorbent) were 0.91 and 1.85, and the amount of nitrate removed (mg N/g adsorbent) were 9.8 and 22.2 for AG corn cob and Dowex-Fe, respectively, at a flux of 15 L/(m2/h).
Kalaruban, M, Loganathan, P, Shim, WG, Kandasamy, J & Vigneswaran, S 2018, 'Mathematical modelling of nitrate removal from water using a submerged membrane adsorption hybrid system with four adsorbents', Applied Sciences (Switzerland), vol. 8, no. 2.View/Download from: UTS OPUS or Publisher's site
© 2018 by the authors. Excessive concentrations of nitrate in ground water are known to cause human health hazards. A submerged membrane adsorption hybrid system that includes a microfilter membrane and four different adsorbents (Dowex 21K XLT ion exchange resin (Dowex), Fe-coated Dowex, amine-grafted (AG) corn cob and AG coconut copra) operated at four different fluxes was used to continuously remove nitrate. The experimental data obtained in this study was simulated mathematically with a homogeneous surface diffusion model that incorporated membrane packing density and membrane correlation coefficient, and applied the concept of continuous flow stirred tank reactor. The model fit with experimental data was good. The surface diffusion coefficient was constant for all adsorbents and for all fluxes. The mass transfer coefficient increased with flux for all adsorbents and generally increased with the adsorption capacity of the adsorbents.
Loganathan, P, Shim, WG, Sounthararajah, DP, Kalaruban, M, Nur, T & Vigneswaran, S 2018, 'Modelling equilibrium adsorption of single, binary, and ternary combinations of Cu, Pb, and Zn onto granular activated carbon', ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH, vol. 25, no. 17, pp. 16664-16675.View/Download from: UTS OPUS or Publisher's site
Nguyen, TC, Loganathan, P, Nguyen, TV, Kandasamy, J, Naidu, R & Vigneswaran, S 2018, 'Adsorptive removal of five heavy metals from water using blast furnace slag and fly ash.', Environmental science and pollution research international, vol. 25, no. 21, pp. 20430-20438.View/Download from: UTS OPUS or Publisher's site
Heavy metals can be serious pollutants of natural water bodies causing health risks to humans and aquatic organisms. The purpose of this study was to investigate the removal of five heavy metals from water by adsorption onto an iron industry blast furnace slag waste (point of zero charge (PZC) pH 6.0; main constituents, Ca and Fe) and a coal industry fly ash waste (PZC 3.0; main constituents, Si and Al). Batch study revealed that rising pH increased the adsorption of all metals with an abrupt increase at pH 4.0-7.0. The Langmuir adsorption maximum for fly ash at pH 6.5 was 3.4-5.1 mg/g with the adsorption capacity for the metals being in the order Pb > Cu > Cd, Zn, Cr. The corresponding values for furnace slag were 4.3 to 5.2 mg/g, and the order of adsorption capacities was Pb, Cu, Cd > Cr > Zn. Fixed-bed column study on furnace slag/sand mixture (1:1 w/w) revealed that the adsorption capacities were generally less in the mixed metal system (1.1-2.1 mg/g) than in the single metal system (3.4-3.5 mg/g). The data for both systems fitted well to the Thomas model, with the adsorption capacity being the highest for Pb and Cu in the single metal system and Pb and Cd in the mixed metal system. Our study showed that fly ash and blast furnace slag are effective low-cost adsorbents for the simultaneous removal of Pb, Cu, Cd, Cr and Zn from water.
Nur, T, Loganathan, P, Ahmed, MB, Johir, M, Kandasamy, J & Vigneswaran, S 2018, 'Struvite production using membrane-bioreactor wastewater effluent and seawater', Desalination, vol. 444, pp. 1-5.View/Download from: UTS OPUS or Publisher's site
© 2018 Elsevier B.V. Wastewater phosphorus (P) released into natural water bodies such as lakes and rivers, can cause water pollution as a result of eutrophication. If this P is effectively removed from wastewaters and economically recovered for use as fertilisers, not only can the water pollution be controlled, but also reduce the anticipated global shortage of P. This scarcity will result from the natural phosphate rock reserve being exhausted. Three experiments were conducted using membrane-bioreactor effluent (MBR, 35 mg PO 4 /L) and reverse osmosis concentrate (ROC, 10 mg PO 4 /L) waters to supply phosphate, and sea water (1530 mg Mg/L) to supply Mg for the production of struvite. The phosphate in the MBR and ROC was concentrated approximately 15 times by adsorption onto an ion exchange resin column followed by desorption. Struvite was precipitated by mixing the desorbed solution with seawater and NH 4 Cl. The chemical composition and mineral structure of the precipitates agreed with those of the reference struvite. When Ca in seawater (300 mg Ca/L) was removed before mixing the water with MBR or ROC, the purity of the struvite improved.
Nur, T, Loganathan, P, Johir, MAH, Kandasamy, J & Vigneswaran, S 2018, 'Removing rubidium using potassium cobalt hexacyanoferrate in the membrane adsorption hybrid system', Separation and Purification Technology, vol. 191, pp. 286-294.View/Download from: UTS OPUS or Publisher's site
© 2017 Elsevier B.V. Highly-priced rubidium (Rb) can be effectively extracted from seawater using potassium cobalt hexacyanoferrate (KCoFC) and ammonium molybdophosphate (AMP) adsorbents in the membrane adsorption hybrid system (MAHS). KCoFC ( < 0.075 mm), KCoFC (0.075–0.15 mm), and AMP ( < 0.075 mm) had Langmuir adsorption capacities of 145, 113, and 77 mg/g at pH 6.5–7.5, respectively. When KCoFC ( < 0.075 mm) at a dose of 0.2 g/L was initially added to 4 L of a solution containing 5 mg Rb/L in the MAHS and 25% of the initial dose was repeatedly added every hour, the amount of Rb removed remained steady at 90–96% for the experiment's 26 h duration. The removal of Rb by AMP under similar conditions was 80–82%. The cumulative Rb removed by KCoFC ( < 0.075 mm) in MAHS was only 33% reduced in the presence of high concentrations of other cations in synthetic seawater compared to that in solution containing only Rb. Approximately 30% of the adsorbed Rb was desorbed using 1 M KCl. When the desorbed solution was passed through a column containing resorcinol formaldehyde (RF), 35% of the Rb in the desorbed solution was adsorbed on RF. Furthermore 50% of the Rb adsorbed on RF was recovered by 1 M HCl leaching of the column. This sequence of concentration and separation of Rb in the presence of other cations in synthetic seawater is an efficient method for recovering pure Rb from real seawater and seawater reverse osmosis brine.
Kalaruban, M, Loganathan, P, Kandasamy, J, Naidu, R & Vigneswaran, S 2017, 'Enhanced removal of nitrate in an integrated electrochemical-adsorption system', Separation and Purification Technology, vol. 189, pp. 260-266.View/Download from: UTS OPUS or Publisher's site
© 2017 Elsevier B.V. The electrochemical (EC) method of removing pollutants in water is a widely used process in water and wastewater treatment. An EC-adsorption integrated system was investigated to test whether the simultaneous removal of nitrate by the two processes would be better than removal utilising the individual EC and adsorption methods. In the integrated system, an adsorbent (ion exchange resin - Dowex 21k XLT) was placed inside a stainless steel box that served as an anode with a Cu plate as cathode. In an experiment using 2 L nitrate solution containing 20 mg N/L and 2 g adsorbent the rate of nitrate removal in the integrated system was initially fast with 35% removed in 30 min, though slowing down later. The rate of removal increased with increasing current, voltage and pH up to 7 but decreased as the distance between the electrodes also increased. The optimum nitrate removal of 67% was obtained at pH 7, 1 A, and 31 V for a distance of 1 cm between the electrodes after 180 min. The amount of nitrate removed fell when sulphate was present in the integrated system due to sulphate competing with nitrate for adsorption. Concentration of ammonium produced by nitrate reduction in the EC system was reduced in the presence of adsorbent. Nitrate removal in the integrated system is approximately equal to the sum of the removals in the two individual processes.
Loganathan, P, Naidu, G & Vigneswaran, S 2017, 'Mining valuable minerals from seawater: A critical review', Environmental Science: Water Research and Technology, vol. 3, no. 1, pp. 37-53.View/Download from: UTS OPUS or Publisher's site
©2017 The Royal Society of Chemistry. Seawater contains large quantities of valuable minerals, some of which are very scarce and expensive in their land-based form. However, only a few minerals, the ones in high concentrations, are currently mined from the sea. Due to recent problems associated with land-based mining industries as a result of depletion of high-grade ores, sustainable water and energy demand and environmental issues, seawater mining is becoming an attractive option. This paper presents a comprehensive and critical review of the current methods of extracting valuable minerals from seawater and seawater brines generated in desalination plants, and suggests ways to overcome some of the limitations and challenges associated with the extraction process. The extraction methods discussed are solar evaporation, electrodialysis (ED), membrane distillation crystallisation (MDC), and adsorption/desorption.
Nur, T, Loganathan, P, Kandasamy, J & Vigneswaran, S 2017, 'Removal of strontium from aqueous solutions and synthetic seawater using resorcinol formaldehyde polycondensate resin', Desalination, vol. 420, pp. 283-291.View/Download from: UTS OPUS or Publisher's site
© 2017 Elsevier B.V. Strontium (Sr) is a valuable metal found in abundance in seawater. However, its recovery from seawater has received little attention despite its many industrial applications. Batch and column adsorption experiments were conducted on the removal of Sr by resorcinol formaldehyde (RF) resin in the presence of co-existing cations at pH 7.5–8.5, where maximum adsorption was found. Batch adsorption capacities of cations followed the decreasing order of Sr > Ca > Mg > K, the order being the same as that of reduction of negative zeta potential. The adsorption data for Sr, Ca and Mg satisfactorily fitted to the Langmuir adsorption model with maximum adsorption capacities of 2.28, 1.25 and 1.15 meq/g, respectively. Selectivity coefficients for Sr with respect to other metals showed that Sr was selectively adsorbed on RF. Column adsorption data for Sr only solution fitted well to the Thomas model. Sr adsorption capacity in the presence of seawater concentrations of Ca, Mg, K and Na was reduced in both batch and column experiments with highest effect from Ca and Mg. However, if Ca and Mg are removed prior to RF adsorption process by precipitation, the negative effect of these ions on Sr removal can be significantly reduced.
Shanmuganathan, S, Loganathan, P, Kazner, C, Johir, MAH & Vigneswaran, S 2017, 'Submerged membrane filtration adsorption hybrid system for the removal of organic micropollutants from a water reclamation plant reverse osmosis concentrate', Desalination, vol. 401, pp. 134-141.View/Download from: UTS OPUS or Publisher's site
© 2016 Elsevier B.V. Reverse osmosis (RO) is a widespread water treatment process utilised in water reuse applications. However, the improper discharge of RO concentrate (ROC) containing organic micropollutants such as pharmaceuticals into the environment may cause potential health risks to non-target species and particularly those in aquatic environments. A study was conducted using a submerged membrane-filtration/granular activated carbon (GAC) adsorption hybrid system to remove organic micropollutants from a water treatment plant ROC by initially adding 10 g GAC /L of membrane reactor volume with 10% daily GAC replacement. The percentage of dissolved organic carbon removal varied from 60% to 80% over an operation lasting 10 days. Removal of organic micropollutants was almost complete for virtually all compounds. Of the 19 micropollutants tested, only two remained (the less hydrophobic DEET 27 ng/L and the hydrophilic sulfamethoxazole 35 ng/L) below 80% removal on day 1, while five of the most hydrophobic micropollutants were detectable in very small concentrations ( < 5–10 ng/L) with > 89%– > 99% being removed. High percentages of micropollutants were removed probably because of their high hydrophobicity or they had positive or neutral charges and therefore they were electrostatically adsorbed to the negatively charged GAC.
Sounthararajah, DP, Loganathan, P, Kandasamy, J & Vigneswaran, S 2017, 'Removing heavy metals using permeable pavement system with a titanate nano-fibrous adsorbent column as a post treatment.', Chemosphere, vol. 168, pp. 467-473.View/Download from: UTS OPUS or Publisher's site
Permeable pavement systems (PPS) are a widely-used treatment measure in sustainable stormwater management and groundwater recharge. However, PPS are not very efficient in removing heavy metals from stormwater. A pilot scale study using zeolite or basalt as bed material in PPS removed 41-72%, 67-74%, 38-43%, 61-72%, 63-73% of Cd, Cu, Ni, Pb, and Zn, respectively, from synthetic stormwater (pH 6.5; Cd, Cu, Ni, Pb, and Zn concentrations of 0.04, 0.6, 0.06, 1.0, and 2.0 mg L-1, respectively) over a period of 80 h. The total volume of stormwater that passed through the PPS was equivalent to runoff in 10 years of rainfall in Sydney, Australia. The concentrations of metals in the PPS effluent failed fresh and marine water quality trigger values recommended in the Australian and New Zealand guidelines. An addition of a post-treatment of a horizontal filter column containing a titanate nano-fibrous (TNF) material with a weight < 1% of zeolite weight and mixed in with granular activated carbon (GAC) at a GAC:TNF weight ratio of 25:1 removed 77% of Ni and 99-100% of all the other metals. The effluent easily met the required standards of marine waters and just met those concerning fresh waters. Batch adsorption data from solutions of metals mixtures fitted the Langmuir model with adsorption capacities in the following order, TNF ≫ zeolite > basalt; Pb > Cu > Cd, Ni, Zn.
Kalaruban, M, Loganathan, P, Shim, WG, Kandasamy, J, Ngo, HH & Vigneswaran, S 2016, 'Enhanced removal of nitrate from water using amine-grafted agricultural wastes', SCIENCE OF THE TOTAL ENVIRONMENT, vol. 565, pp. 503-510.View/Download from: UTS OPUS or Publisher's site
Johir, MAH, Pradhan, M, Loganathan, P, Kandasamy, J & Vigneswaran, S 2016, 'Phosphate adsorption from wastewater using zirconium (IV) hydroxide: Kinetics, thermodynamics and membrane filtration adsorption hybrid system studies', JOURNAL OF ENVIRONMENTAL MANAGEMENT, vol. 167, pp. 167-174.View/Download from: UTS OPUS or Publisher's site
Kalaruban, M, Loganathan, P, Shim, WG, Kandasamy, J, Naidu, G, Tien, VN & Vigneswaran, S 2016, 'Removing nitrate from water using iron-modified Dowex 21K XLT ion exchange resin: Batch and fluidised-bed adsorption studies', SEPARATION AND PURIFICATION TECHNOLOGY, vol. 158, pp. 62-70.View/Download from: UTS OPUS or Publisher's site
Naidu, G, Loganathan, P, Jeong, S, Johir, MAH, Vu, HPT, Kandasamy, J & Vigneswaran, S 2016, 'Rubidium extraction using an organic polymer encapsulated potassium copper hexacyanoferrate sorbent', CHEMICAL ENGINEERING JOURNAL, vol. 306, pp. 31-42.View/Download from: UTS OPUS or Publisher's site
Naidu, G, Nur, T, Loganathan, P, Kandasamy, J & Vigneswaran, S 2016, 'Selective sorption of rubidium by potassium cobalt hexacyanoferrate', SEPARATION AND PURIFICATION TECHNOLOGY, vol. 163, pp. 238-246.View/Download from: UTS OPUS or Publisher's site
Nur, T, Loganathan, P, Kandasamy, J & Vigneswaran, S 2016, 'Phosphate Adsorption from Membrane Bioreactor Effluent Using Dowex 21K XLT and Recovery as Struvite and Hydroxyapatite', INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH, vol. 13, no. 3.View/Download from: UTS OPUS or Publisher's site
Nur, T, Naidu, G, Loganathan, P, Kandasamy, J & Vigneswaran, S 2016, 'Rubidium recovery using potassium cobalt hexacyanoferrate sorbent', DESALINATION AND WATER TREATMENT, vol. 57, no. 55, pp. 26577-26585.View/Download from: UTS OPUS or Publisher's site
Sounthararajah, DP, Loganathan, P, Kandasamy, J & Vigneswaran, S 2016, 'Column studies on the removal of dissolved organic carbon, turbidity and heavy metals from stormwater using granular activated carbon', DESALINATION AND WATER TREATMENT, vol. 57, no. 11, pp. 5045-5055.View/Download from: UTS OPUS or Publisher's site
Karunanithi, R, Szogi, AA, Bolan, N, Naidu, R, Loganathan, P, Hunt, PG, Vanotti, MB, Saint, CP, Ok, YS & Krishnamoorthy, S 2015, 'Phosphorus Recovery and Reuse from Waste Streams', Advances in Agronomy, vol. 131, pp. 173-250.View/Download from: UTS OPUS or Publisher's site
Phosphorus (P) is a macronutrient essential for all living organisms. Regrettably, it is a finite resource since phosphate rock (PR) is the main material used for production of P fertilizers. Globally, the demand for quality PR is escalating due to many factors including increasing human population. Inevitably, the demand for PR will exceed its supply capacity. This condition will be very difficult to manage as living systems have no alternative for P. Moreover, P use efficiency is low; only 15-20% of applied P is used by crops and animals. Globally, the remaining P is shunted into various waste streams. These waste streams include large quantities of effluents rich in P from both municipal and industrial wastewater treatment systems and manure from livestock production. The P present in these waste streams poses a threat to the environment by nutrient enrichment resulting in serious ecological issues such as eutrophication of waterways. However, P in these waste streams, if economically recovered, can contribute to a sustainable management of P resources. This review covers the following aspects: global importance of P as an essential nutrient; efficient and sustainable utilization of P; waste stream production, their suitability for P recovery, and limitations; current and emerging technologies for recovery of P; and the use of recovered P material. Finally, future research needs are identified associated with P recovery from waste streams and reuse in agriculture.
Jamil, S, Loganathan, P, Kazner, C & Vigneswaran, S 2015, 'Forward osmosis treatment for volume minimisation of reverse osmosis concentrate from a water reclamation plant and removal of organic micropollutants', DESALINATION, vol. 372, pp. 32-38.View/Download from: UTS OPUS or Publisher's site
Nguyen, TC, Loganathan, P, Nguyen, TV, Pham, TTN, Kandasamy, J, Wu, M, Naidu, R & Vigneswaran, S 2015, 'Trace elements in road-deposited and waterbed sediments in Kogarah Bay, Sydney: enrichment, sources and fractionation', Soil Research, vol. 53, no. 4, pp. 401-411.View/Download from: UTS OPUS or Publisher's site
Road-deposited sediments (RDS) are a potential source of trace elements (TE) that can be transported by stormwater to neighbouring water bodies and cause aquatic pollution. A study in Sydney, Australia showed that of the 11 TE analysed, Zn, Cu, V, Cr, and Sb were greatly enriched in RDS compared to those in baseline soils (BS). All TE concentrations in water bed-sediments (WBS) in the catchment area were similar to those in the BS. Correlation and principal component analyses revealed that of the five TE enriched in RDS, Zn, Cu, Cr and Sb were related to each other, and they probably originated from vehicle components such as tyres and brake linings. Vanadium was separated into another component, likely to have originated mainly from road surface asphalt abrasion. Trace element concentrations in the mobile fraction of RDS, determined using a sequential extraction method, were: Fe >Mn, Zn > Cu, Pb> Cr, Ni, V, Cd, Sb. However, this fraction as a percentage of total elemental concentration was highest for Cd and Zn and lowest for Fe, Cr, Ni, and V. The RDS sites had low-medium ecological risk whereas WBS and BS sites had low risk.
Nur, T, Shim, WG, Loganathan, P, Vigneswaran, S & Kandasamy, J 2015, 'Nitrate removal using Purolite A520E ion exchange resin: batch and fixed-bed column adsorption modelling', International Journal of Environmental Science and Technology, vol. 12, no. 4, pp. 1311-1320.View/Download from: UTS OPUS or Publisher's site
Removing excessive nitrate from water is essential because it causes eutrophication which in turn has a harmful effect on aquatic life, resulting in a reduction in biodiversity and posing a danger to peoples health when the water is used for drinking. In this study, nitrate removal from aqueous solutions was studied using an ion exchange resin (Purolite A520E) in batch and fixed-bed column experiments. Batch adsorption kinetics was very well described by pseudo-first-order, pseudo-second-order and homogeneous surface diffusion models for resin doses 1.5 and 3.0 g/L at a nitrate concentration 20 mg N/L. Column kinetic data satisfactorily fitted to the empirical Thomas model and a numerical model based on advection dispersion equation for filtration velocities 2.5 and 5.0 m/h at a column height of 12 cm and inlet concentration 20 mg N/L. The experimental and Thomas model predicted breakthrough adsorption capacity ranges for the two filtration rates were 12.013.5 and 8.29.7 mg N/g, respectively, whereas the maximum adsorption capacity determined using Langmuir adsorption isotherm model in the batch study was 32.2 mg N/g.
Shanmuganathan, S, Vigneswaran, S, Nguyen, TV, Loganathan, P & Kandasamy, J 2015, 'Use of nanofiltration and reverse osmosis in reclaiming micro-filtered biologically treated sewage effluent for irrigation', DESALINATION, vol. 364, pp. 119-125.View/Download from: UTS OPUS or Publisher's site
Sounthararajah, DP, Loganathan, P, Kandasamy, J & Vigneswaran, S 2015, 'Adsorptive removal of heavy metals from water using sodium titanate nanofibres loaded onto GAC in fixed-bed columns', JOURNAL OF HAZARDOUS MATERIALS, vol. 287, pp. 306-316.View/Download from: UTS OPUS or Publisher's site
Sounthararajah, DP, Loganathan, P, Kandasamy, J & Vigneswaran, S 2015, 'Effects of Humic Acid and Suspended Solids on the Removal of Heavy Metals from Water by Adsorption onto Granular Activated Carbon', INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH, vol. 12, no. 9, pp. 10475-10489.View/Download from: UTS OPUS or Publisher's site
Thankappan, R, Nguyen, TV, Srinivasan, SV, Vigneswaran, S, Kandasamy, J & Loganathan, P 2015, 'Removal of leather tanning agent syntan from aqueous solution using Fenton oxidation followed by GAC adsorption', JOURNAL OF INDUSTRIAL AND ENGINEERING CHEMISTRY, vol. 21, pp. 483-488.View/Download from: UTS OPUS or Publisher's site
Thuy, CN, Loganathan, P, Tien, VN, Vigneswaran, S, Kandasamy, J & Naidu, R 2015, 'Simultaneous adsorption of Cd, Cr, Cu, Pb, and Zn by an iron-coated Australian zeolite in batch and fixed-bed column studies', CHEMICAL ENGINEERING JOURNAL, vol. 270, pp. 393-404.View/Download from: UTS OPUS or Publisher's site
Jeyakumar, P, Loganathan, P, Anderson, CWN, Sivakumaran, S & McLaren, RG 2014, 'Comparative tolerance of Pinus radiata and microbial activity to copper and zinc in a soil treated with metal-amended biosolids', Environmental Science and Pollution Research, vol. 21, no. 5, pp. 3254-3263.View/Download from: UTS OPUS or Publisher's site
A study was conducted to evaluate the effects of elevated concentrations of copper (Cu) and zinc (Zn) in a soil treated with biosolids previously spiked with these metals on Pinus radiata during a 312-day glasshouse pot trial. The total soil metal concentrations in the treatments were 16, 48, 146 and 232 mg Cu/kg or 36, 141, 430 and 668 mg Zn/kg. Increased total soil Cu concentration increased the soil solution Cu concentration (0.03-0.54 mg/L) but had no effect on leaf and root dry matter production. Increased total soil Zn concentration also increased the soil solution Zn concentration (0.9-362 mg/L). Decreased leaf and root dry matter were recorded above the total soil Zn concentration of 141 mg/kg (soil solution Zn concentration, >4.4 mg/L). A lower percentage of Cu in the soil soluble + exchangeable fraction (5-12 %) and lower Cu2+ concentration in soil solution (0.001-0.06 μM) relative to Zn (soil soluble + exchangeable fraction, 12-66 %; soil solution Zn2+ concentration, 4.5-4,419 μM) indicated lower bioavailability of Cu. Soil dehydrogenase activity decreased with every successive level of Cu and Zn applied, but the reduction was higher for Zn than for Cu addition. Dehydrogenase activity was reduced by 40 % (EC40) at the total solution-phase and solid-phase soluble + exchangeable Cu concentrations of 0.5 mg/L and 14.5 mg/kg, respectively. For Zn the corresponding EC50 were 9 mg/L and 55 mg/kg, respectively. Based on our findings, we propose that current New Zealand soil guidelines values for Cu and Zn (100 mg/kg for Cu; 300 mg/kg for Zn) should be revised downwards based on apparent toxicity to soil biological activity (Cu and Zn) and radiata pine (Zn only) at the threshold concentration. © 2013 Springer-Verlag Berlin Heidelberg.
Tien, VN, Loganathan, P, Vigneswaran, S, Krupanidhi, S, Thi, TNP & Huu-Hao, N 2014, 'Arsenic waste from water treatment systems: characteristics, treatments and its disposal', Water Science and Technology-Water Supply, vol. 14, no. 6, pp. 939-950.View/Download from: UTS OPUS or Publisher's site
Loganathan, P, Vigneswaran, S, Kandasamy, J & Bolan, NS 2014, 'Removal and Recovery of Phosphate From Water Using Sorption', CRITICAL REVIEWS IN ENVIRONMENTAL SCIENCE AND TECHNOLOGY, vol. 44, no. 8, pp. 847-907.View/Download from: UTS OPUS or Publisher's site
Nguyen, T, Loganathan, L, Nguyen, V, Vigneswaran, S, Kandasamy, JK, Slee, S, Gavin, S & Naidu, R 2014, 'Polycyclic aromatic hydrocarbons in road-deposited sediments, water sediments, and soils in Sydney, Australia: Comparisons of concentration distribution, sources and potential toxicity', Ecotoxicology And Environmental Safety, vol. 104, pp. 339-348.View/Download from: UTS OPUS or Publisher's site
Nur, T, Johir, MAH, Loganathan, P, Nguyen, T, Vigneswaran, S & Kandasamy, J 2014, 'Phosphate removal from water using an iron oxide impregnated strong base anion exchange resin', Journal of Industrial and Engineering Chemistry, vol. 20, pp. 1301-1307.View/Download from: UTS OPUS or Publisher's site
Removing phosphate from water is important as it causes eutrophication, which in turn has a harmful effect on aquatic life, resulting in a reduction in biodiversity. On the other hand, recovery of phosphate from phosphorus containing wastewater is essential for developing an alternative source of phosphorus to overcome the global challenge of phosphorus scarcity. Phosphate removal from aqueous solutions was studied using an iron oxide impregnated strong base anion exchange resin, Purolite FerrIX A33E in batch and fixed-bed column experiments. Phosphate adsorption in the batch study satisfactorily fitted to the Langmuir isotherm with a maximum adsorption capacity of 48 mg P/g. In the column study, increase in inlet phosphate concentration (530 mg P/L), and filtration velocity (2.510 m/h) resulted in faster breakthrough times and increase in breakthrough adsorption capacities. Increase in bed height (3 19 cm) also increased adsorption capacity but the breakthrough time was slower. The breakthrough data were reasonably well described using the empirical models of BohartAdams, Thomas, and Yoon Nelson, except for high bed heights. Phosphate adsorbed was effectively desorbed using 1 M NaOH and the adsorbent was regenerated after each of three adsorption/desorption cycles by maintaining the adsorption capacity at >90% of the original value. Greater than 99.5% of the desorbed P was recovered by precipitation using CaCl2.
Nur, T, Loganathan, L, Nguyen, T, Vigneswaran, S, Singh, G & Kandasamy, JK 2014, 'Batch and column adsorption and desorption of fluoride using hydrous ferric oxide: Solution chemistry and modelling', Chemical Engineering Journal, vol. 247, pp. 93-102.View/Download from: UTS OPUS or Publisher's site
Loganathan, L, Vigneswaran, S & Kandasamy, JK 2013, 'Enhanced removal of nitrate from water using surface modification of adsorbents - A review', Journal of Environmental Management, vol. 131, no. 1, pp. 363-374.View/Download from: UTS OPUS or Publisher's site
Elevated concentration of nitrate results in eutrophication of natural water bodies affecting the aquatic environment and reduces the quality of drinking water. This in turn causes harm to peoples health, especially that of infants and livestock. Adsorbents with the high capacity to selectively adsorb nitrate are required to effectively remove nitrate from water. Surface modifications of adsorbents have been reported to enhance their adsorption of nitrate. The major techniques of surface modification are: protonation, impregnation of metals and metal oxides, grafting of amine groups, organic compounds including surfactant coating of aluminosilicate minerals, and heat treatment. This paper reviews current information on these techniques, compares the enhanced nitrate adsorption capacities achieved by the modifications, and the mechanisms of adsorption, and presents advantages and drawbacks of the techniques. Most studies on this subject have been conducted in batch experiments. These studies need to include continuous mode column trials which have more relevance to real operating systems and pilot-plant trials. Reusability of adsorbents is important for economic reasons and practical treatment applications. However, only limited information is available on the regeneration of surface modified adsorbents.
Loganathan, L, Vigneswaran, S & Kandasamy, JK 2013, 'Road-deposited sediment pollutants: A critical review of their characteristics, source apportionment, and management', Critical Reviews in Environmental Science and Technology, vol. 43, no. 13, pp. 1315-1348.View/Download from: UTS OPUS or Publisher's site
Road-deposited sediments (RDS) often contain elevated concentrations of inorganic and organic pollutants such as heavy metals, metalloids, and polycyclic aromatic hydrocarbons. The authors trace new developments and trends on RDS pollutant characteristics with respect to their distribution in time and space, total and labile fractions in the different particle size and density fractions, source apportionment, and chemical speciation, as well as on the management of the pollutants. Recent research provides more reliable information to understand pollutants origin, bioavailability, transport pathways, and methods to minimize their risks. Use of special chemical, physical, mineralogical, and statistical methods has contributed to a better understanding of source apportionment of many of the pollutants but more research is needed on others. The degree of accumulation of pollutants in RDS that are derived from roads and vehicles has been quantified by using enrichment factors. Many of the studies on RDS pollutant management dealt with reducing pollutants by road sweeping and water flushing but these have not been found to be very effective. Pollutants that enter the water bodies through stormwater runoff need to be removed to protect the aquatic environment in the receiving water. The current knowledge on stormwater treatment methods to remove pollutants is also presented.
Loganathan, L, Vigneswaran, S, Kandasamy, JK & Naidu, R 2013, 'Defluoridation of drinking water using adsorption processes', Journal of Hazardous Materials, vol. 248-249, pp. 1-19.View/Download from: UTS OPUS or Publisher's site
Excessive intake of fluoride (F), mainly through drinking water, is a serious health hazard affecting humans worldwide. There are several methods used for the defluoridation of drinking water, of which adsorption processes are generally considered attractive because of their effectiveness, convenience, ease of operation, simplicity of design, and for economic and environmental reasons. In this paper, we present a comprehensive and a critical literature review on various adsorbents used for defluoridation, their relative effectiveness, mechanisms and thermodynamics of adsorption, and suggestions are made on choice of adsorbents for various circumstances. Effects of pH, temperature, kinetics and co-existing anions on F adsorption are also reviewed. Because the adsorption is very weak in extremely low or high pHs, depending on the adsorbent, acids or alkalis are used to desorb F and regenerate the adsorbents. However, adsorption capacity generally decreases with repeated use of the regenerated adsorbent. Future research needs to explore highly efficient, low cost adsorbents that can be easily regenerated for reuse over several cycles of operations without significant loss of adsorptive capacity and which have good hydraulic conductivity to prevent filter clogging during the fixed-bed treatment process.
Khan, RU, Anderson, CWN, Loganathan, P, Xue, J & Clinton, PW 2012, 'Response of Pinus radiata D. Don to Boron Fertilization in a Glasshouse Study', Communications in Soil Science and Plant Analysis, vol. 43, no. 10, pp. 1412-1426.View/Download from: UTS OPUS or Publisher's site
Limited information is available on the effect of slow-release boron (B) fertilizer on Pinus radiata growth and physiological properties and soil microbiological activities. A 7-month-long pot experiment was carried out under glasshouse conditions to investigate the response of Pinus radiata to different rates (0.0222, 0.0446, 0.089, and 0.178 mg B g-1 soil), equivalent to 0, 4, 8 16, and 32 kg B ha-1 of ulexite, a slow-release B fertilizer. Hot 0.02 M calcium chloride (CaCl2)-extractable soil B, soil dehydrogenase activity, plant B concentration, growth, and photosynthesis were measured at the time of harvest. The B concentrations in the soil and plant organs (needles, stem, and roots) significantly increased with increasing rates of B fertilizer. The optimum B fertilizer rates of 4-8 kg B ha-1 produced the greatest plant growth and net photosynthetic rate. However, the B rates of 16 and 32 kg B ha-1 significantly reduced net photosynthetic rate, and the rate of 32 kg B ha-1 significantly reduced stem diameter growth when compared to the optimum B rates. Soil dehydrogenase activity, an indicator of soil microbiological activities, was significantly reduced by B application at the rates of 16 and 32 kg ha-1. This study confirms the narrow range between B deficiency and toxicity in a tree crop and stresses the need for selection of the optimum rate of B fertilizer application. © 2012 Copyright Taylor and Francis Group, LLC.
Yunusa, IA, Loganathan, L, Nissanka, SP, Manoharan, V, Burchett, M, Skilbeck, G & Eamus, D 2012, 'Application of coal fly ash in agriculture: A strategic perspective', Critical Reviews in Environmental Science and Technology, vol. 42, no. 6, pp. 559-600.View/Download from: UTS OPUS or Publisher's site
Fly ash is a major waste of coal-power generation and its management is a major environmental and economic challenge, and it will become even more critical with a projected increase in the reliance on coal for power generation. The authors discuss how th
Das Gupta, M, Loganathan, L & Vigneswaran, S 2012, 'Adsorptive Removal Of Nitrate And Phosphate From Water By A Purolite Ion Exchange Resin And Hydrous Ferric Oxide Columns In Series', Separation Science and Technology, vol. 47, no. 12, pp. 1785-1792.View/Download from: UTS OPUS or Publisher's site
Elevated concentrations of nitrate and phosphate in surface and ground waters can lead to eutrophication, and nitrate can also cause health hazards to humans. The adsorption process is generally considered to be an efficient technique in removing these ions provided that the adsorbent is highly selective for these ions. Removal of nitrate and phosphate from a synthetic water (50 mg N/L as nitrate, 15 mg P/L as phosphate) and a wastewater (12.9 mg N/L as nitrate, 5.9 mg P/L as phosphate) using a Purolite A500P anion exchange resin and a hydrous ferric oxide (HFO) columns (60 cm height, 2 cm diameter, flow rate 1 m/h) in series containing 1â10% (w/w) of these adsorbents and the remainder anthracite (90â99%) were studied. Data from batch adsorption experiment at various concentrations of adsorbents satisfactorily fitted to Langmuir adsorption isotherm for nitrate and phosphate on Purolite with adsorption maxima of 64 mg N/g and 7 mg P/g and only for phosphate on HFO with adsorption maxima of 14 mg P/g. Both batch and column experiments showed that Purolite selectively removed nitrate and HFO selectively removed phosphate. The Purolite column BTC time was greater for nitrate than for phosphate. At the highest percentage by weight of Purolite almost all nitrate was removed in batch study and up to 1000 min in column study, but it was not able to remove a comparatively high percentage of phosphate. However, when the effluent from the Purolite column was passed through the HFO column almost all phosphate was removed. The two columns when set up in series also removed almost all nitrate and phosphate from the wastewater.
Loganathan, L, Vigneswaran, S, Kandasamy, JK & Naidu, R 2012, 'Cadmium Sorption And Desorption In Soils: A Review', Critical Reviews in Environmental Science and Technology, vol. 42, no. 5, pp. 489-533.View/Download from: UTS OPUS or Publisher's site
Cadmium (Cd) is an environmental pollutant that can be readily taken up by plants and may enter the food chain, causing risk to human health. It can also affect soil quality and, if easily leached, has the potential to pollute surface and ground waters. Sorption and desorption are critical processes controlling the phytoavailability and mobility of Cd in soils. The authors present the present knowledge on the mechanisms and hysteresis of Cd sorption and desorption in soils and factors such as pH, ionic strength, index cation, other heavy metal cations, inorganic anions, organic ligands, Cd loading rate, and the type and amounts of organic matter and inorganic colloids influencing these processes. The methods used to determine the nature and magnitude of Cd sorption and desorption are also critically reviewed.
Mohammed, TM, Aryal, R, Vigneswaran, S, Loganathan, L, Kandasamy, JK & Naidu, R 2012, 'Removal of heavy metals in stormwater by hydrous ferric oxide', Water Management, vol. 165, no. WM3, pp. 171-178.View/Download from: UTS OPUS or Publisher's site
Stormwater runoff from urban and industrial areas contains several types of heavy metals that have negative ecological impacts on receiving waters, and therefore methods need to be developed to remove these pollutants. Combined removal of a mixture of heavy metal cations (Cu2Ã¾, Zn2Ã¾, Cd2Ã¾, and Ni2Ã¾) and an oxy anion (selenate, SeO42) from an artificially prepared stormwater was investigated by sorption of these heavy metals on hydrous ferric oxide (HFO) in a column experiment under intermittent runoff (wetting and drying) condition, as occurs between rainfall events in the field. The heavy metal removal behaviour varied between ions as well as with time. In each continuous column run (8 h) the amount of ions removed progressively decreased with time and reached a constant level at approximately 4â6 h. However, stopping the runoff for 40 h and starting the next runoff after this period removed a large quantity of heavy metals in the first few hours of this run. The intermittent runoff for seven runs showed that HFO has a high capacity to remove copper and zinc, which were present in higher concentrations in the stormwater than cadmium, nickel and selenium.
Mohammed, TM, Loganathan, L, Kinsela, A, Vigneswaran, S & Kandasamy, JK 2012, 'Enrichment, Inter-Relationship, And Fractionation Of Heavy Metals In Road-Deposited Sediments Of Sydney, Australia', Australian Journal of Soil Research, vol. 50, no. 3, pp. 229-238.View/Download from: UTS OPUS or Publisher's site
Urban road-deposited sediments (RDS) are potential sources of heavy metal pollution of both terrestrial and aquatic environments. We determined the heavy metals enrichments, their possible sources, and potential bioavailability and mobility in RDS from n
Mohammed, TM, Vigneswaran, S, Loganathan, L, Kandasamy, JK & Aryal, R 2012, 'Removal of inorganic contaminants from simulated stormwater by three sorbents in columns under intermittent runoff condition', Separation Science and Technology, vol. 42, no. 14, pp. 2340-2347.View/Download from: UTS OPUS or Publisher's site
Combined removal of inorganic contaminants from a synthetic tormwater was investigated by their sorption on hydrous ferric oxide (HFO) (5%), HFO + Ca(OH)2(6%), and HFO + Ca(OH)2 + MnO2 (7%) in columns containing 93-95% anthracite, conducted under seven intermittent runoffs, each of 8 h duration with a 40 h (drying) period between them. At the initial period when Ca(OH)2 produced elevated pHs, the HFO column removed less metals but more Se than the HFO + Ca(OH)2 columns. With increased time when the pH effect of Ca(OH)2 became insignificant, the MnO2 in the column increased the removal of all contaminants. The removal efficiencies (%) at the flow rate of 0.75 m/h for Cd, Cu, Ni, Zn by the HFO + Ca(OH)2 + MnO2 column were 88-100%, and Se by the HFO column were 92-94% for the 1st and 3rd runs. The corresponding values for the 5th and 7th runs were 51-88% and 82-88%, respectively.
Nur, T, Johir, MAH, Loganathan, P, Vigneswaran, S & Kandasamy, J 2012, 'Effectiveness of purolite A500PS and A520E ion exchange resins on the removal of nitrate and phosphate from synthetic water', Desalination and Water Treatment, vol. 47, no. 1-3, pp. 50-58.View/Download from: UTS OPUS or Publisher's site
Water pollution due to the excessive presence of nutrients (nitrogen and phosphorus) is a serious environmental worldwide problem, because both species are implicated in the eutrophication of receiving surface waters and elevated nitrate concentration in drinking water can be toxic to infants. The removal efficiencies of nitrate and phosphate from water spiked with different ratios and concentrations of these nutrients by two ion-exchange resins (Purolite A500PS and Purolite A520E) were studied in batch kinetics and equilibrium adsorption experiments. Both purolites were found to be selective towards nitrate removal at all ratios of nitrate to phosphate in solution. Purolite A520E showed higher (<85%) removal efficiency of nitrate than Purolite A500PS (about 65%) from a solution containing 20mgN/L as nitrate and 10mgP/L as phosphate at a resin dose of 1.5 g/L. However, Purolite A500PS showed higher (65%) removal of phosphate than Purolite A520E (48%). Langmuir and Freundlich isotherm models fitted well for the adsorption of nitrate on Purolite A520E (R2 = 0.950.96). However, the adsorption of nitrate on Purolite A500PS can be explained satisfactorily only by Freundlich model (R2 = 0.98). The adsorption of phosphate on the resins fitted well to Freundlich model (R2 = 0.90) for Purolite A500PS as well as for Purolite A520E (R2 = 0.90). The adsorption of phosphate and nitrate on both ion-exchange resins was much better described by pseudo-second-order kinetic model (R2P0.99) than by pseudo-first-order kinetic model (R2 = 0.250.94).
Aryal, R, Baral, B, Vigneswaran, S, Naidu, R & Loganathan, L 2011, 'Seasonal influence on urban dust PAH profile and toxicity in Sydney, Australia', Water Science And Technology, vol. 63, no. 10, pp. 2238-2243.View/Download from: UTS OPUS or Publisher's site
Road dust is one of the major threats to the urban environment due to wash-off of dust to the surrounding catchments during wet weather period. The dust contains wide range of toxic contaminants such as heavy metals, polycyclic aromatic hydrocarbons (PAHs) and endocrine disrupting chemicals. Among the toxic contaminants, PAHs are of environmental concern due to their potential carcinogenic and mutagenic effect besides endocrine disruptive behaviour. Eighteen road dust samples from Sydney were collected in different time periods for a year and analysed for 16 US EPA PAHs. Total PAHs content range in the dust was 9â105 Î¼g/g. Total and individual PAH contents were highest in the finest size fraction (<75 Î¼m) and in winter compared to the other seasons. The PAH profiles in the different particle sizes were similar but different between the four seasons. The concentrations of higher molecular weight PAHs (4- and 5-rings) were much greater than the concentrations of lower molecular weight PAHs (2- and 3-rings). Toxicity equivalency factor application showed that the longer the dry weather period the higher the total PAHs content and toxicity in the dust.
Aryal, R, Vigneswaran, S, Loganathan, L, Kandasamy, JK & Mohammed, TM 2011, 'Hydrous iron oxide for removal of inorganic contaminants in simulated stormwater: A batch sorption kinetics study', Korean Journal of Chemical Engineering, vol. 28, no. 8, pp. 1706-1712.View/Download from: UTS OPUS or Publisher's site
Urban stormwater runoff, which consists of inorganic and organic contaminants, is a major source of pollutants to receiving waters and therefore they need to be removed. Simultaneous removal of contaminants, Cd2+, Cu2+, Ni2+, Zn2+ (heavy metal cations), and SeO4 2â (oxyanion) from a simulated stormwater by a hydrous ferric oxide (HFO) was studied in batch and column sorption experiments. In the batch experiment the rate of sorption of the ions was rapid at the beginning and reached equilibrium in approximately 300 min. The amounts of ions sorbed were proportionate to the respective initial concentration of the ions added to the HFO. Cluster analysis showed that all heavy metals had similar sorption behavior, whereas Se had a distinctly different sorption process. Of the three different kinetic models tested the pseudo-first order kinetic model fitted the data the best. The column experimental results beyond 180 min were consistent with those of the batch experiment that the removal efficiencies of the ions were in proportion to the ion concentration in the feed. Below 180 min, Cu appeared to be preferentially removed than Zn.
Jeyakumar, P, Loganathan, P, Sivakumaran, S, Anderson, CWN & McLaren, RG 2010, 'Bioavailability of copper and zinc to poplar and microorganisms in a biosolids-amended soil', Australian Journal of Soil Research, vol. 48, no. 5, pp. 459-469.View/Download from: Publisher's site
The effects of high concentrations of copper (Cu) and zinc (Zn) in a soil treated with biosolids previously spiked with these metals on poplar (Populus deltoidesyunnanensis) were investigated in a pot trial. The total soil metal concentrations in the treatments were 12, 46, 137, and 226mg Cu/kg and 25, 141, 433, and 686mg Zn/kg. Copper accumulation was lower in poplar leaves than Zn and the maximum bioconcentration factor was 0.8 for Cu and 10 for Zn. Copper was not found to be toxic to plants at any level of application or to mycorrhiza up to 137mg/kg, but it was found to be toxic to soil microorganisms at all levels of Cu addition. Copper application increased mycorrhiza colonisation up to 137mg Cu/kg and root dry matter at 226mg Cu/kg, but had no effect on leaf dry matter. Increasing Zn rate decreased all plant and soil parameters. Lower percentages of Cu in the soil exchangeable fraction, and a lower Cu2+ concentrations in soil solution relative to Zn indicated lower bioavailability of Cu. Dehydrogenase activity was reduced by 50% at total solution-phase Cu and Zn concentrations of 0.1 and 27mg/L, respectively, and solid-phase exchangeable Cu and Zn concentrations of 5 and 169mg/kg, respectively. © 2010 CSIRO.
Rivaie, AA & Loganathan, P 2010, 'Phosphorus fertiliser source and weed control effects on growth of three-year-old second-rotation pinus radiata on orthic pumice soil in New Zealand', Southern Forests, vol. 72, no. 2, pp. 75-81.View/Download from: Publisher's site
Little information is available on the interactive effects of soluble and less-soluble phosphorus (P) fertilisers and weed control on growth and P nutrition of second-rotation Pinus radiata plantations. A study was initiated on three-year-old secondrotation P. radiata and to determine the relationship between needle P concentrations and soil P forms in an Orthic Pumice soil two years after application. Four rates of P (0, 50, 100, and 200 kg P ha -1 ) were applied as two forms of P fertilizer sources (triple superphosphate [TSP] and Ben-Guerir phosphate rock [BGPR]) in combination with weed control (weedy and weed-free). The results showed that the applied TSP and BGPR can increase tree needle P concentrations even when the needle P concentrations before fertiliser application were marginally higher than the critical P concentrations. The application of P fertilisers had no effect on tree growth during the two-year period of the trial, though it increased P. radiata needle P concentrations. However, the weed removal increased tree height, diameter at breast height, and basal area. In this plantation site the higher needle P concentrations than the critical P concentration suggests that the growth increase dueto weed removal treatment was probably due to an increase in the availability of soil water and nutrients other than P. The needle P concentrations of P. radiata can be predicted by soil tests, Bray-2 P, Olsen P, resin-P i , and NaOH-P i tests. Of these soil tests, Bray-2 P seems to be the best test in predicting soil P availability to P. radiata. The P concentrations in the needles had a relationship with the NaOH-P i fraction but had no relationship with the H 2 SO 4 -P i fraction. These results suggest that P. radiata was probably taking up P mainly from the pool of P-adsorbed to allophane and Fe+Al oxides (NaOH-P i ) in this high P-fixing acidic soil. © NISC (Pty) Ltd.
Veeragathipillai, M, Yunusa, IA, Loganathan, L, Lawrie, R, Murray, B, Skilbeck, G & Eamus, D 2010, 'Boron contents and solubility in Australian fly ashes and its uptake by canola (Brassica napus L.) from the ash-amended soils', Australian Journal of Soil Research, vol. 48, no. 5, pp. 480-487.View/Download from: UTS OPUS or Publisher's site
Phytotoxicity due to excessive boron (B) uptake by plants impedes routine agronomic utilisation of coal fly ash. We assessed 11 fly ashes (pH 3.14â10.77) having total B content (Bt) of 12â136 mg/kg, of which 20â30% was hot water soluble (Bs) in the acidic ashes (pH <5) and 5â10% in the alkaline ashes, for their potential to supply B to plants and their risk associated with phytotoxicity. We found the Bs/Bt to be negatively correlated (R2 = 0.63**, N = 11) with ash pH. We conducted two trials in which canola was grown in soils amended with fly ash. In the first trial, an alkaline fly ash (Bt 66 mg/kg) was incorporated at 5 rates of up to 625 Mg/ha into the top 50mm of 2 acidic soils in 0.30-m-long intact cores, and sown with canola. Boron concentration in leaves at flowering reached the phytotoxic threshold, and both plant growth and seed yield were reduced, only at 625 Mg/ha. In the second trial, 4 fly ashes (pH 3.29â10.77, Bt 12â127 mg/kg) were incorporated at 4 rates of up to 108 Mg/ha into the top 0.10mof 2 acidic soils in 1.0-m-long intact cores and then sown with canola. Ashes with highest Bt, when applied at 108 Mg/ha, increased B concentration in the topsoil only. Of the 2 ashes with the highest Bt, only that which produced low soil pH and applied at 108 Mg/ha increased B concentration in the shoot, but was still below phytotoxic threshold. The results suggest that B derived from these ashes may not cause phytotoxicity and excessive soil B accumulation if the ashes are applied at modest rates (<36 Mg/ha) to the topsoil layers.
Veeragathipillai, M, Yunusa, IA, Loganathan, L, Lawrie, R, Skilbeck, G, Burchett, M, Murray, B & Eamus, D 2010, 'Assessments of Class F fly ashes for amelioration of soil acidity and their influence on growth and uptake of Mo and Se by canola', Fuel, vol. 89, no. 11, pp. 3498-3504.View/Download from: UTS OPUS or Publisher's site
Coal fly ash can be used to ameliorate productivity constraints in agricultural soils, but their efficacy still remains highly variable. To ascertain the capacity of Class F fly ashes to modify pH of acidic soils, and their effects on the yield and uptake of molybdenum (Mo) and selenium (Se) by canola (Brassica napus L.), we applied two acidic and two alkaline Class F ashes at rates equivalent to 0, 12, 36, and 108 Mg/ ha to the top layer (0â10 cm) of 100 cm long intact cores of acidic sandy clay and clay loam soils. Only the alkaline ash which had the highest calcium carbonate equivalent (2.43%) increased the pH of the top 10 cm of the sandy clay soil. However, this ash was also highly saline and when applied at P36 Mg/ha it increased the electrical conductivity in the top soil layer. Increases in soil pH as a result of alkaline ash addition also elevated concentrations of Se in the plant shoot. The ashes with high concentrations of Mo and Se generally increased uptake of these elements in the plant shoot and/or seed. When these ashes were applied at 108 Mg/ha they increased the concentrations of these elements in the treated topsoil.
Aye, TM, Hedley, MJ, Loganathan, P, Lefroy, RDB & Bolan, NS 2009, 'Effect of organic and inorganic phosphate fertilizers and their combination on maize yield and phosphorus availability in a Yellow Earth in Myanmar', Nutrient Cycling in Agroecosystems, vol. 83, no. 2, pp. 111-123.View/Download from: Publisher's site
Phosphorus (P) deficiency is a major constraint for crop production in many parts of the world including Myanmar and field research into management of P fertilizers and P responsiveness of crops on infertile soils has been limited. The purpose of this study is to determine maize yield response to different forms of P fertilizers on an acidic (pH 4.9) P deficient (Olsen-P 8 mg kg -1) Yellow Earth (Acrisol) in Southern Shan State, Myanmar and to establish relationships between soil Olsen-P test values (0.5 M sodium bicarbonate extracted P) and maize yield. Field experiments were conducted during two cropping seasons. There were 15 treatments in total: P was applied at seven rates of a soluble P fertilizer as Triple superphosphate (TSP) (0-120 kg P ha-1) to establish a P response curve; one rate of a partially soluble P fertilizer (Chinese partially acidulated phosphate rock, CPAPR) and two organic P fertilizers (farmyard manure (FYM) and Tithonia diversifolia) at 20 kg P ha-1; combination of TSP and CPAPR at 20 kg P ha-1 with FYM and Tithonia at 20 kg P ha-1; an additional treatment (TSP 20 kg P ha-1 plus 2.5 t ha-1 dolomite) for assessing the liming effect of a local dolomite. In Year 1, applications of TSP at 40-60 kg P ha-1 produced near maximum grain yields, whereas in Year 2 this could be achieved with a reapplication of 20-30 kg P ha-1 on top of the residual value of the Year 1 application. In both years, CPAPR, TSP and Tithonia at 20 kg P ha-1 significantly increased maize grain yield, but FYM failed to increase grain yield. In Year 1, CPAPR and TSP effects on grain yield were higher than that of Tithonia but in Year 2 the effects were same for all these three treatments. In both years the combination of FYM (20 kg P ha -1) with TSP (20 kg P ha-1) produced significantly higher grain yield than TSP at 20 kg P ha-1 whereas 40 kg P ha-1 of TSP application did not significantly increase grain yield over the TSP application at 20 kg P ha-1. Similar results were o...
Grace, ND, Loganathan, P & Hedley, MJ 2008, 'The effect of age on the fluoride concentration in the metacarpus of grazing sheep in New Zealand', New Zealand Veterinary Journal, vol. 56, no. 3, pp. 115-119.View/Download from: Publisher's site
Aim: To determine the concentration of fluoride (F) in the metacarpi from ewes of varying age, which had been grazing pastures that had been regularly topdressed with phosphatic fertilisers, which contain F as a contaminant, for at least 30 years. Methods: Three groups of 10 ewes aged 6–8, 18–20 and 60–72 months were selected from seven research farms with a known fertiliser history, representing the major sheep farming regions of New Zealand. Lambs were born and remained on the property. The sheep were collected and slaughtered in autumn, and the right metacarpus removed for determination of F content. Representative samples of topsoil (0–30- and 30–60-mm depths) were also collected for determination of F content. Results: The total concentration of F in topsoil on the farms ranged from 161 to 712 mg/kg. The overall mean concentrations of F in metacarpi from 6–8-, 18–20- and 60–72-month-old ewes were 170 (SE 9.9), 308 (SE 13.9) and 480 (SE 28.4) mg/kg dry matter (DM), respectively. On six farms, lambs which had been exposed to limited or no ingestion of soil had the lowest concentration of F in their metacarpi. Generally, there was a curvilinear relationship between age and concentration of F in the metacarpi of sheep. On the seventh farm, the concentrations of F in the metacarpi from the 6–8- and 18–20-month-old sheep were similar but lower than those of the 60–72-month-old ewes. The area of soils on the farm where the 6–8-month-old-sheep were grazing had higher total concentrations of F in topsoil (271 mg/kg) than those soils grazed by the 18–20-month-old sheep (205 mg/kg), and this may be one reason for the elevated concentration of F in the metacarpi of the younger ewes. The concentrations of F in metacarpi, at any age, were not related to the concentration of F in topsoils. Conclusions: Many factors can influence the amounts of F in soil ingested by grazing sheep and the concentration of F in their bone. The concentration of F in the metacarpi of ewes gener...
Jeyakumar, P, Loganathan, P, Sivakumaran, S, Anderson, CWN & McLaren, RG 2008, 'Copper and zinc spiking of biosolids: Effect of incubation period on metal fractionation and speciation and microbial activity', Environmental Chemistry, vol. 5, no. 5, pp. 347-354.View/Download from: Publisher's site
Biosolids were amended separately with three levels of copper and zinc sulfate, and anaerobically incubated for 117 days. Copper in the unamended-biosolids solid phase was mainly found in the organic and residual fractions (8595%). Copper addition decreased the percentage of Cu in these fractions and increased the percentage of Cu in the oxide and specifically adsorbed fractions. Zinc in the solid phase was mainly associated with the oxide (3565%), specifically adsorbed (2530%), and the exchangeable fractions (1040%). Relatively, all Cu in the solution phase was complexed with organic matter; Zn was present mainly as Zn2+ and as an electrically neutral ion pair, ZnSO40. Metals were almost completely incorporated into the biosolids matrix by Day 55. Dehydrogenase activity was reduced by 50% (EC50, effective concentration for 50% activity reduction) at the total solution-phase Cu and Zn concentrations of 0.1 and 20 mg L-1, respectively, and solid-phase exchangeable Cu and Zn concentrations of 410 and 670 mg kg-1, respectively. © CSIRO 2008.
Liu, Q, Loganathan, P, Hedley, MJ & Grace, LJ 2008, 'Effect of mycorrhizal inoculation on rhizosphere properties, phosphorus uptake and growth of pine seedlings treated with and without a phosphate rock fertilizer', Journal of Plant Nutrition, vol. 31, no. 1, pp. 137-156.View/Download from: Publisher's site
A pot trial was carried out for 10 months to investigate the effects of ectomycorrhizal (ECM) fungal infection and phosphorus (P) fertilization on the growth of newly germinated Pinus radiata D. Don seedling, P uptake by the seedlings and rhizosphere properties. The experiment consisted of two phosphate rock (PR)-P application rates [0 and 100 mg P kg- 1 soil supplied as Ben Guire PR (BGPR)] and 5 soil treatments (autoclaved soil, fungicide-treated soil, untreated natural soil, and Rhizopogon rubescens Tul. and Suillus luteus (L. ex. Fr.) S. F. Gray inoculated soils). The results showed that the treatment effects were more striking in P-fertilized treatments. In P-fertilized soils, all the non-autoclaved treatments significantly increased seedling growth and P concentration and P uptake in plant tissues compared with the autoclaved treatment. The ECM inoculation produced greater phosphatase activities, higher oxalate concentration, and more plant-available P (soil solution P and resin extractable P) in the rhizosphere soils than in the bulk soils in P-fertilized soil. Compared with S. luteus, R. rubescens inoculation resulted in greater ECM tip density in seedling roots in P-fertilized treatments, indicating that R. rubescens are more susceptible to infection of radiata seedling roots. Approximately 57-69% of the BGPR added to the soil had been dissolved in 10 months after application and BGPR significantly increased seedling height, ECM root tip density, and P concentration in shoots in both autoclaved and non-autoclaved treatments. Copyright © Taylor & Francis Group, LLC.
Loganathan, P, Hedley, MJ & Grace, ND 2008, 'Pasture soils contaminated with fertilizer-derived cadmium and fluorine: Livestock effects', Reviews of Environmental Contamination and Toxicology, vol. 192, pp. 29-66.View/Download from: Publisher's site
Pasture-based livestock production is a major system of agriculture in many parts of the world. Approximately one-fifth of the world's land area is used for livestock production, twice the area used for growing crops. Grazing livestock occupy approximately 3.5 billion ha of permanent pasture (FAO Statistics 2006). In the more intensively stocked pastures, pasture production has been increased through introduction of improved pasture species and regular application of fertilizers. In ryegrass and clover-based pastures, common in temperate climates, the main nutrients applied in fertilizers have been phosphorus (P) and sulfur (S). Nitrogen, sulfur, and potassium fertilizers are relatively free of contaminants, but P fertilizers, e.g., single and triple superphosphate (SSP, TSP), and diammonium phosphate (DAP) often contain many contaminants derived from the phosphate rocks (PR) used in their manufacture. If not managed appropriately, these fertilizer contaminants may cause adverse effects on livestock health, food quality, and environment. © 2008 Springer.
Rivaie, AA, Loganathan, P, Graham, JD, Tillman, RW & Payn, TW 2008, 'Effect of phosphate rock and triple superphosphate on soil phosphorus fractions and their plant-availability and downward movement in two volcanic ash soils under Pinus radiata plantations in New Zealand', Nutrient Cycling in Agroecosystems, vol. 82, no. 1, pp. 75-88.View/Download from: Publisher's site
Changes in phosphorus (P) fractions and their plant-availability and downward movement in two strongly P fixing acidic Andosols (Allophanic and Pumice Soils) under Pinus radiata plantations in New Zealand were studied 2 years after triple superphosphate (TSP) and a phosphate rock (BGPR, origin Ben Guerir, Morocco) application, each at four rates, to determine the fate and plant availability of fertilizer-derived P in these soils. The rate of increase of the concentrations of the P fractions was highest for NaOH-Pi (inorganic P associated with Fe and Al oxides and allophane) when TSP was applied and highest for H2SO4-Pi (predominantly calcium phosphates or apatite-type P minerals) when BGPR was applied. The largest pool of soil P, the NaOH-Po (labile organic P), was unaffected by the P fertilizer applications. The rate of NaOH-Pi concentration increase was higher in the higher P fixing Allophanic Soil than in the Pumice Soil. Both types of fertilizers increased resin-Pi (Inorganic P freely available to the plant) and Bray-2 P concentrations but only the TSP application increased Olsen P concentration. Phosphorus derived from TSP and BGPR applications moved down to 10-20 cm soil depth within 2 years of application in the Pumice Soil, but did not move below 10 cm depth in the higher P fixing and less porous Allophanic Soil. The fertilizers significantly increased needle P concentrations 2, 3 and 4 years after fertilizer application, but did not have any significant effect on tree growth. © 2008 Springer Science+Business Media B.V.
Grace, ND, Loganathan, P & Hedley, MJ 2007, 'The effect of a temporal change in ingestion rates of fluorine (F) in soil on the concentration of F in serum and bone of young sheep', New Zealand Veterinary Journal, vol. 55, no. 2, pp. 77-80.View/Download from: Publisher's site
Aim: To determine the changes in concentrations of fluorine (F) in serum and bone of young sheep given a high intake of F, as F in soil, followed by a low intake of F, to simulate the varying intakes experienced by grazing sheep. Methods: Sixty autumn-born, weaned, mixed-sex lambs were randomly divided into two groups (n=30). One group (Control) was fed a low-F (12 mg/kg dry matter; DM) lucerne/grain diet for 345 days, while the other group (High soil-F) was fed a high-F (224 mg/kg DM) lucerne/grain diet containing 10% soil for 94 days and then a low-F diet for a further 251 days. Blood samples were collected on Days 1, 32, 94, 108, 153, 214, 280 and 345, to determine concentrations of F in serum. Groups of five or six animals from each group were killed on Days 1, 94, 153, 214, 280 and 345, to collect radii and hu- meri for determination of F content. The sheep were weighed at about 6–8-weekly intervals. Results: Initial liveweight of the sheep was 22.1 (standard error (SE) 1.12) kg and the mean liveweight gains were 270 (SE 22.1) and 170 (SE 12.4) g/day from Days 1 to 94 and 95 to 330, respectively. The mean initial (Day 1) concentration of F in serum was 0.03 (SE 0.005) mg/L, and this changed very little for animals on the low-F diet. In sheep on the high soil-F diet, the concentration of F in serum reached 0.38 (SE 0.021) mg/L at Day 94 but after being placed on the low-F diet concentrations decreased to 0.04 (SE 0.006) mg/L after 14 days (Day 108) and then remained at about this low level for the remainder of the duration of the study. The mean concentrations of F in the humerus and radius of the lambs at Day 1 were 161 (SE 19.4) and 159 (SE 20.4) mg/kg DM, respectively, which increased to 2, 784 (SE 80.6) and 1, 805 (SE 51.5) mg/kg DM, respectively, at Day 94 in lambs fed the high soil-F diet, then decreased to 1, 075 (SE 58.1) and 1, 064 (SE 61.6) mg/kg DM at Day 153, and then progressively increased to 1, 669 (SE 57.7) and 1, 312 (SE 30.8) mg/kg DM at Day...
Loganathan, P, Bretherton, MR & Hedley, MJ 2007, 'Effect of soil cultivation and winter pugging on fluorine distribution in soil profiles under pasture following long-term applications of phosphate fertilisers', Australian Journal of Soil Research, vol. 45, no. 1, pp. 41-47.View/Download from: Publisher's site
In situations where large amounts of soil are ingested, elevated fluorine (F) concentrations in topsoil under pasture may pose a potential F risk to grazing livestock. A study conducted on a Pallic Soil (Aeric Fragiaqualf in US Soil Taxonomy) under pasture in New Zealand showed that 21 years of annual applications of phosphate fertilisers (mostly single superphosphate; mean P rate of 27 kg/ha.year; 1985-2005) significantly increased total soil F concentrations down to 150 mm soil depth but had no effect at 180-210 mm depth. The topsoil (0-30 mm depth) F concentration increased from 140 to approximately 210 mg F/kg. For agricultural soils, these topsoil F concentrations are low and are unlikely to present any risk of chronic F toxicity to livestock at present, but continuous inputs of large amounts of F through P fertiliser applications will increase topsoil F concentrations to levels that may cause F toxicity in the future if accompanied by large amounts of soil ingestion. Cultivation of soil to 150 mm depth using a mouldboard plough once every 6-9 years during pasture renovation significantly increased total soil F concentration at 60-150 mm depth but had no effect on the surface and deeper soil horizons (0-60 and 150-210 mm depths). However, the amount of post-1985 fertiliser-derived F in the 0-60 mm depth as a percentage of the total amount of post-1985 fertiliser-derived F recovered in all depths within 210 mm was less for cultivated soil (31%) than for uncultivated soil (51%), indicating that cultivation can reduce the topsoil F concentration and hence the F risk to grazing animals. Moderate winter pugging of soil caused by dairy cattle had no effect on F distribution in soil profiles. The F distribution in the surface soil horizons (0-30 and 30-60 mm depths) predicted by an empirical computer-based F model corresponded reasonably well with the measured F values. © CSIRO 2007.
Loganathan, P, Liu, Q, Hedley, MJ & Gray, CW 2007, 'Chemical fractionation of fluorine in soils with a long-term phosphate fertiliser history', Australian Journal of Soil Research, vol. 45, no. 5, pp. 390-396.View/Download from: Publisher's site
Elevated concentrations of fluorine (F) in pasture topsoils resulting from phosphorus (P) fertiliser (1-4% F) use are potentially toxic to grazing livestock if F absorption from ingested soil is high. Fluorine absorption by animals and the potential F toxicity is expected to vary depending on the chemical nature of the F in the ingested soil. In this paper we assess the solubility of F in 6 acidic topsoils (0-75 mm depth) under grazed pastures in New Zealand with widely different chemical characteristics, using a sequential soil P fractionation technique involving a cation/anion exchange resin, 0.1 m NaOH, 0.5 m H2SO4, and a residual fraction (17 m NaOH fusion). The results showed that F accumulates mainly in the NaOH-Fi fraction (inorganic F (Fi) adsorbed to Fe and Al oxides) and residual fractions (occluded F and recalcitrant organic F). In contrast, P accumulates mainly in the NaOH-Po (labile organic P fraction) and H2SO4-P (calcium phosphate compounds) fractions, with minor amounts in the NaOH-Pi fraction. The NaOH-Fo (labile organic F) fraction was not determined but the total F concentration calculated by summing all the extracted F fractions, except NaOH-Fo, was approximately equal to the total F concentration determined by NaOH fusion, indicating negligible F was in the NaOH-Fo fraction. Therefore, we suggest that the mechanisms of release of P and F in soils are different. Some of the F found in the residual fraction may have been derived from the previously extracted H2SO4-F fraction which was precipitated by the Al dissolved during H2SO4 extraction. It may therefore have been an artefact of the fractionation method. © CSIRO 2007.
Veeragathipillai, M, Loganathan, L, Tillman, RW & Parfitt, RL 2007, 'Interactive effects of soil acidity and fluoride on soil solution aluminium chemistry and barley (Hordeum vulgare L.) root growth', Environmental Pollution, vol. 145, no. 3, pp. 778-786.View/Download from: UTS OPUS or Publisher's site
A greenhouse study was conducted to determine if concentrations of fluoride (F), which would be added to acid soils via P fertilisers, were detrimental to barley root growth. Increasing rates of F addiction to soil significantly increased the soil solution concentration of aluminium (Al) and F irrespective of the initial adjusted soil pH, which ranged from 4.25 to 5.48. High rates of F addition severely restricted root growth; the effect was more pronounced inthe strongly acidic soil. Speciation calculations demonstrated that increasing rates of F additions substantially increased the concentrations of Al-F complexes inthe soil. Stepwise regression analsys showed that it was the combination of the activities of Alf1/2+ and Alfsuperscript 2+ complexes that primarily controlled barley root gorwth. the result suggested that continuous input of F to soils,and increased soil acidification, may become an F risk issue in the future.
Liu, Q, Loganathan, P, Hedley, MJ & Skinner, MF 2006, 'Root processes influencing phosphorus availability in volcanic soils under young Pinus radiata plantations', Canadian Journal of Forest Research, vol. 36, no. 8, pp. 1913-1920.View/Download from: Publisher's site
Phosphorus (P) availability was investigated in rhizosphere soils under 4- to 5-year-old, second-rotation Pinus radiata D. Don and understorey grass (browntop, Agrostis capillaris L.) in two P-deficient Andosols (a Pumice Soil and an Allophanic Soil). Pinus radiata rhizosphere had more soil organic matter, greater mycorrhizal hyphal length density, higher acid phosphatase activity, and more concentrated dissolved organic carbon than bulk soil or the rhizosphere of grass species in one or both soils. Concentrations of resin P and organic P in the P. radiata rhizosphere were higher than those in the grass rhizosphere and bulk soils, suggesting that P. radiata rhizosphere processes have a greater potential to accumulate organic P and mobilize soil P than understorey grass rhizosphere processes. This effect was less marked in the Allophanic Soil than in the Pumice Soil, probably because of the higher P-fixing capacity and lower plant-available P concentrations in the Allophanic Soil. © 2006 NRC.
Liu, Q, Loganathan, P, Hedley, MJ & Skinner, MF 2006, 'Root processes influencing phosphorus availability in volcanic soils under young Pinus radiata plantations', CANADIAN JOURNAL OF FOREST RESEARCH-REVUE CANADIENNE DE RECHERCHE FORESTIERE, vol. 36, no. 8, pp. 1913-1920.View/Download from: Publisher's site
Loganathan, P & Hedley, MJ 2006, 'Spatial and time-dependent patterns of selenium (Se) release from selected Se fertiliser granules', Australian Journal of Soil Research, vol. 44, no. 2, pp. 155-163.View/Download from: Publisher's site
The spatial and time-dependent patterns of selenium (Se) release from similar-sized granules of 4 Se fertilisers, 3 containing sodium selenate (Unitech Agsel, Ravensdown A, and Ravensdown B) and the fourth containing sodium selenate and barium selenate (Selcote Ultra), were evaluated using ryegrass grown on a Se-deficient soil under glasshouse conditions. Four granules (2-3 mm diameter) from each of the 4 fertiliser types having uniform shape and similar weight were placed on the soil surface of trays (0.51 m length, 0.42 m width, 0.15 m depth) at a distance 0.10 m from 2 adjacent sides of the trays, and the Se content of herbage in concentric rings around each granule was periodically measured over 1 year. The amount of Se applied to the trays, calculated by adding herbage Se to the residual fertiliser Se in soil at the end of the trial, was 12-31 g Se/ha. Soil Se concentration at the end of the trial for the Selcote Ultra and Ravensdown A treatments and herbage Se concentration at 10 harvests for all fertiliser treatments decreased exponentially with increased distance from the granules. Herbage Se concentration reached the level considered deficient to animals (0.05 mg/kg) at the centre of the tray (0.12 m from the granules) 4 months after Unitech Agsel application (7% of paddock area). By 9 months all plants in this treatment became deficient in Se. In contrast, 7% of the sward area in the Ravensdown A treatment, and 41% of the sward area in the Ravensdown B and Selcote Ultra treatments, were deficient in Se at this time, but the average herbage Se concentration for the entire tray was above the deficiency level for these 3 fertiliser treatments. The efficiency of the fertilisers in increasing herbage Se concentration per unit weight of Se applied for the first 3 months was: Unitech Agsel ≥ Ravensdown B ≥ Ravensdown A > Selcote Ultra. During the last 3 months, this order was: Selcote Ultra = Ravensdown A > Ravensdown B > Unitech Agsel. © CSIRO 2006.
Loganathan, P, Gray, CW, Hedley, MJ & Roberts, AHC 2006, 'Total and soluble fluorine concentrations in relation to properties of soils in New Zealand', European Journal of Soil Science, vol. 57, no. 3, pp. 411-421.View/Download from: Publisher's site
Soil fluorine (F) concentrations continue to increase in agricultural soils receiving regular applications of phosphatic fertilizer. Continued accumulation of soil F poses a risk to grazing ruminants and may pose a future risk to groundwater quality. This paper examines the range of total F (Ft) concentrations and forms of soluble F species and their relationship to selected soil properties in New Zealand agricultural soils. The Ft and soluble F (soil F extracted with water (Fwater) and 0.01 m KCl (FKCl)) concentrations in 27 soil samples (0-75 mm depth) taken from predominantly pasture sites in the North and South Islands of New Zealand were much less than those reported in the literature for sites contaminated with F from industry. The Ft concentrations ranged from 212 to 617 μg F g-1 soil. The F-toxicity risk to grazing animals in farms at these sites through soil ingestion is small at present, but farms with very large Ft concentrations (i.e. > 500 μg F g-1) need to adopt suitable grazing and fertilizer management practices to avoid future F-toxicity risk. The Ft concentration had very strong positive correlations with both total soil P and total soil Cd concentrations, reflecting the link between P fertilizer use and F accumulation in the soils. It also had significant positive correlations with organic matter and amorphous Al oxides contents, indicating that F is strongly bound to Al polymers adsorbed to organic matter and amorphous Al oxides. The Fwater and FKCl concentrations and free F- ion concentrations in water (F -water) and 0.01 m KCl (F-KCl) extracts were generally two and three orders of magnitude, respectively, less than the Ft concentrations and were much less than the concentrations considered phytotoxic. The Fwater and FKCl concentrations were positively related to soil organic matter content and negatively related to soil pH. Regression models relating Fwater and FKCl concentrations to soil organic matter content and soil pH suggest that F ca...
Grace, ND, Loganathan, P, Deighton, MW, Molano, G & Hedley, MJ 2005, 'Ingestion of soil fluorine: Its impact on the fluorine metabolism of dairy cows', New Zealand Journal of Agricultural Research, vol. 48, no. 1, pp. 23-27.View/Download from: Publisher's site
In grazing cattle high fluoride (F) intakes are associated with soil ingestion. The ingestion of soil (F) (93% of dietary F) at a rate of 1562 mg F day–1 by mature dairy cows over 63 days, when compared with animals on basal diet (no soil) providing 110 mg F day–1, resulted in an increase in mean serum F concentrations from 0.10 to 0.22 mg litre–1, and no detectable change in mean metacarpal F concentrations (1125 mg F kg–1 DM), while the apparent absorption of soil F was 44%. However, an intake of soil F (77% of dietary F) at 446 mg F day–1 had no detectable effect on mean serum or bone F concentrations of the dairy cows. The relationship between soil F intake (x) and serum F concentration (y) was curvilinear (y = 0.0837e0.0007x). The observed changes in serum and bone concentrations indicate that the potential risk of fluorosis occurring in grazing dairy cows is very low. © 2005 Taylor & Francis Group, LLC.
Hanly, JA, Loganathan, P & Currie, LD 2005, 'Effect of serpentine rock and its acidulated products as magnesium fertilisers for pasture, compared with magnesium oxide and epsom salts, on a pumice soil. 1. Dry matter yield and magnesium uptake', New Zealand Journal of Agricultural Research, vol. 48, no. 4, pp. 451-460.View/Download from: Publisher's site
Low pasture magnesium (Mg) intakes by grazing dairy and beef cows is a main cause of hypomagnesaemia in these animals soon after calving. Magnesium fertiliser application to pasture can increase pasture mixed-herbage (hereafter 'herbage") Mg concentration and reduce the risk of this disorder. However, the effectiveness of Mg fertilisers is variable depending on fertiliser type and soil properties. A 32-month Mg fertiliser field trial was conducted on dairy pasture on an Immature Orthic Pumice Soil (near Taupo, New Zealand; exchangeable Mg 0.4 cmolc kg–1, pasture Mg 0.13%) to compare the effectiveness of a range of Mg fertilisers in elevating herbage Mg concentration. The fertilisers used were ground serpentine rock, three acidulated serpentine rock products, Epsom salts, and E-mag (magnesium oxide). All fertilisers were applied at 100 kg Mg ha–1 at the start of the trial. The trial also had two treatments where Epsom salts was applied at 25 and 50 kg Mg ha–1 and a treatment where serpentine rock was reapplied during the second and third year at 100 kg Mg ha–1. Magnesium fertiliser treatments did not affect pasture dry matter yield significantly at any harvest, however, the effect of treatments on herbage Mg concentration was highly significant (P < 0.001) at all harvests. The single application of serpentine significantly increased herbage Mg concentration at 10 harvests, with five of these harvests having Mg concentrations ≥ 0.20%, which is generally considered to be the minimum 'threshold level' for stock health. In comparison, the Mg concentration in pasture not receiving Mg fertiliser remained below the minimum threshold level throughout the trial. Application of serpentine rock annually further increased herbage Mg concentration and accumulation. The herbage Mg concentrations for this treatment were similar to those of the Epsom salts (50 kg Mg ha–1) treatment at the majority of the harvests. These results indicate that the annual application of serpentine r...
Liu, Q, Loganathan, P & Hedley, MJ 2005, 'Influence of ectomycorrhizal hyphae on phosphate fractions and dissolution of phosphate rock in rhizosphere soils of Pinus radiata', Journal of Plant Nutrition, vol. 28, no. 9, pp. 1525-1540.View/Download from: Publisher's site
A study was conducted to determine the effect of ectomycorrhizal hyphae on phosphate rock dissolution and soil properties in the rhizosphere of one-year-old Pinus radiata D. Don seedlings established on an allophanic soil (Andosol) in the field. High and low ectomycorrhizal hyphal activities were produced in soils inside the lower compartments of rhizosphere study containers by using either 26 μm or <10 μm pore-size nylon mesh(es) at the interfaces between the lower and upper compartments. The meshes at the interfaces allowed (26 μm) or reduced (<10 μm) hyphae penetration into the lower compartment. Pairs of containers, one with 26 μm mesh and the other with <10 μm mesh, were buried under Pinus radiata seedlings for 10 months in a forest plantation. The effect of ectomycorrhizal (ECM) hyphal activity on phosphate rock dissolution and soil properties was determined. The increased ECM hyphal activity induced increased soil acidification and promoted greater production of acid phosphatase enzyme, causing greater changes in phosphorus (P) fractions in the rhizosphere soils. The increased ECM hyphal activity also stimulated higher dissolution of phosphate rock and mobilization of soil organic P. The results suggest that ECM hyphal strand has a significant role in mobilizing low-solubility P forms and soil organic P for utilization by the tree. Copyright © Taylor & Francis Inc.
Loganathan, P, Hanly, JA & Currie, LD 2005, 'Effect of serpentine rock and its acidulated products as magnesium fertilisers for pasture, compared with magnesium oxide and epsom salts, on a pumice soil. 2. Dissolution and estimated leaching loss of fertiliser magnesium', New Zealand Journal of Agricultural Research, vol. 48, no. 4, pp. 461-471.View/Download from: Publisher's site
The dissolution rate of magnesium (Mg) fertilisers controls their effectiveness in supplying Mg to plants and the potential for fertiliser-Mg to be lost via leaching. Results from a field trial, conducted on pasture on an Immature Orthic Pumice Soil (pHwater 6.3) treated with different types of Mg fertilisers (100 kg Mg ha–1), showed that Mg dissolution over a 29-month period differed, being 15–20% for serpentine rock products, 50–98% for acidulated serpentine products, 95% for E-mag (magnesium oxide), and 98% for Epsom salts. The percentage dissolution of applied fertiliser-Mg was related to the water solubilities for all the fertilisers except E-mag, which had a high dissolution rate in soil but a very low solubility in water. However, E-mag had high Mg solubility in citric acid, consistent with its dissolution rate in soil. Epsom salts, E-mag, and acidulated serpentine products significantly increased exchangeable Mg in soil samples collected 9 and 29 months after fertiliser application, whereas the unacidulated serpentine rock increased exchangeable Mg only in soil samples collected after 29 months and only when it was re-applied annually for 3 years. The recovery of fertiliser Mg in pasture herbage was positively related to the Mg dissolution rate over the duration of the trial, being 4–8% for serpentine rock products, 19–22% for acidulated serpentine products, 17% for E-mag, and 25% for Epsom salts. For all fertilisers, except E-mag, total recovery of fertiliser Mg in the soil (0–15 cm depth) and herbage combined was lower for fertilisers with the higher rates of Mg dissolution, being 51% for Epsom salts, 53–90% for acidulated serpentine products, 91–95% for serpentine rock products, and 90% for E-mag. Fertiliser Mg not recovered was assumed to have been leached below the 0–15 cm soil depth (49% for Epsom salts, 10–47% for acidulated serpentine products, 5–9% for serpentine products, and 10% for E-mag). The very high fertiliser Mg recoveries in soil (0–15 c...
Loganathan, P, Hedley, MJ, Bolan, NS & Currie, LD 2005, 'Field evaluation of the liming value of two phosphate rocks and their partially acidulated products after 16 years of annual application to grazed pasture', Nutrient Cycling in Agroecosystems, vol. 72, no. 3, pp. 287-297.View/Download from: Publisher's site
Measuring pH of soil samples (at four to five depths down to 300 mm) collected three times from a long-term (16 years) field trial involving annual application of six forms of phosphate fertilizers at the rate of 30 kg P ha -1 yr-1 showed that soil acidity in all treatments, including the untreated control, increased with time. The rates of acidification (pH unit yr-1 during the first 10 years) in the topsoil (0-75 mm depth) were in the order, diammonium phosphate (0.038)>control, single superphosphate>Jordan partially acidulated phosphate rock (JPAPR)>North Carolina partially acidulated phosphate rock (NCPAPR), Jordan phosphate rock (JPR)>North Carolina phosphate rock (NCPR) (0.010). Of the 480 kg P ha -1 applied over the 16 year period, 71 and 57% of P from NCPR and JPR dissolved. The theoretical liming values derived from the dissolution of NCPR and JPR were 1698 and 1303 kg CaCO3 ha-1 respectively. Liming values of the two PRs calculated from the increase in soil pH over control treatment (ΔpH) down to 300 mm soil depth were 640 and 414 kg CaCO3 ha-1 for NCPR and JPR, respectively. The lower liming values estimated from the ΔpH method is probably due to proton transfer resulting from the secondary reactions of dissolved fertilizer phosphate with soil constituents, the unaccounted liming effect of the PRs below 300 mm soil depth and the lower soil pH buffering capacities measured from a short-term pH titration method used in the estimation of the liming values. The results of this long-term field study showed that continuous use of certain phosphate rocks (PRs) can significantly slow down the rate of acidification in pastoral soils. © Springer 2005.
Loganathan, P, Mitchell, AD, Hanly, JA & Aye, TM 2005, 'An improved procedure for determining magnesium fertilizer dissolution in field soils', Communications in Soil Science and Plant Analysis, vol. 36, no. 15-16, pp. 2121-2128.View/Download from: Publisher's site
The sequential extraction procedure currently used to measure magnesium (Mg) fertilizer dissolution in soils consists of removing dissolved Mg (step 1), and partially dissolved Mg (step 2), followed by an 18-h extraction with 2 M HCl at room temperature to determine undissolved Mg (step 3). This procedure is satisfactory for soluble and moderately soluble Mg fertilizers but is not an accurate procedure for slightly soluble fertilizers, such as serpentine. When step 3 is replaced by a digestion procedure using 2 M HCl for 4 h at 90-95°C (improved step 3), the total serpentine Mg recovery (dissolved and undissolved Mg) from soil samples, either immediately after serpentine was added to soil or after a 21-day incubation with moist soil, was about 100% compared to 40-50% by the original procedure. The improved procedure also increased the recovery of serpentine Mg applied to field soils. Therefore, this study recommends that the third step of the sequential extraction procedure be replaced by a 4 h digestion using 2 M HCl (90-95°C). Copyright © Taylor & Francis, Inc.
Liu, Q, Loganathan, P, Hedley, MJ & Skinner, MF 2004, 'The mobilisation and fate of soil and rock phosphate in the rhizosphere of ectomycorrhizal Pinus radiata seedlings in an Allophanic soil', Plant and Soil, vol. 264, no. 1-2, pp. 219-229.View/Download from: Publisher's site
Phosphorus (P) characteristics and the fate of a finely divided Sechura phosphate rock (SPR) applied to a P deficient Allophanic Soil (Andosol) were investigated in the rhizosphere of 1-year-old Pinus radiata seedlings grown for 10 months in pots. The rates of SPR (13.9% P) application were 0, 50, 100 and 150 μg P g-1 soil. Increased rate of application of SPR increased seedling growth and P uptake by P. radiata, but SPR rates had no consistent effect on mycorrhizal tip density. The highest mycorrhizal tip density (tips per metre root) was observed at the P rate of 50 μg P g-1 soil. Increased seedling growth with increased SPR rates was due to increased SPR dissolution. The SPR dissolution at plant harvest was high (> 80%) but was significantly higher in the rhizosphere soil than in the bulk soil, probably due to increased soil acidification and oxalate production in the rhizosphere. The seedling roots induced significantly higher acid and alkaline phosphatase activities in the rhizosphere soil. This was associated with significant decreases in the concentration of labile organic P (0.1 M NaOH-Po) in the rhizosphere soil. Rhizosphere acidification and decrease in 0.1 M NaOH-Po resulted in accumulation of 0.1 M NaOH extractable inorganic P in the rhizosphere soil, but no difference was recorded in resin-P concentration between the rhizosphere and bulk soils. These results suggest that mycorrhizal root-induced conversion of organic P to inorganic P is a major process of P supply to P. radiata seedlings in P deficient Allophanic Soils. © 2004 Kluwer Academic Publishers.
Loganathan, P, Hedley, MJ, Bretherton, MR & Rowarth, JS 2004, 'Accounting for particle movement when assessing the dissolution of slow release fertilizers in field soils', Nutrient Cycling in Agroecosystems, vol. 70, no. 1, pp. 77-84.View/Download from: Publisher's site
Cronin, SJ, Neall, VE, Lecointre, JA, Hedley, MJ & Loganathan, P 2003, 'Environmental hazards of fluoride in volcanic ash: A case study from Ruapehu volcano, New Zealand', Journal of Volcanology and Geothermal Research, vol. 121, no. 3-4, pp. 271-291.View/Download from: Publisher's site
The vent-hosted hydrothermal system of Ruapehu volcano is normally covered by a c. 10 million m3 acidic crater lake where volcanic gases accumulate. Through analysis of eruption observations, granulometry, mineralogy and chemistry of volcanic ash from the 1995-1996 Ruapehu eruptions we report on the varying influences on environmental hazards associated with the deposits. All measured parameters are more dependent on the eruptive style than on distance from the vent. Early phreatic and phreatomagmatic eruption phases from crater lakes similar to that on Ruapehu are likely to contain the greatest concentrations of environmentally significant elements, especially sulphur and fluoride. These elements are contained within altered xenolithic material extracted from the hydrothermal system by steam explosions, as well as in residue hydrothermal fluids adsorbed on to particle surfaces. In particular, total F in the ash may be enriched by a factor of 6 relative to original magmatic contents, although immediately soluble F does not show such dramatic increases. Highly soluble NaF and CaSiF6 phases, demonstrated to be the carriers of 'available' F in purely magmatic eruptive systems, are probably not dominant in the products of phreatomagmatic eruptions through hydrothermal systems. Instead, slowly soluble compounds such as CaF2, AlF3 and Ca5(PO4)3F dominate. Fluoride in these phases is released over longer periods, where only one third is leached in a single 24-h water extraction. This implies that estimation of soluble F in such ashes based on a single leach leads to underestimation of the F impact, especially of a potential longer-term environmental hazard. In addition, a large proportion of the total F in the ash is apparently soluble in the digestive system of grazing animals. In the Ruapehu case this led to several thousand sheep deaths from fluorosis. © 2002 Elsevier Science B.V. All rights reserved.
Grace, ND, Loganathan, P, Hedley, MJ & Wallace, GC 2003, 'Ingestion of soil fluorine: Its impact on the fluorine metabolism and status of grazing young sheep', New Zealand Journal of Agricultural Research, vol. 46, no. 4, pp. 279-286.View/Download from: Publisher's site
When young sheep ingested soil fluorine (F) at moderate to high rates (69–184 mg F day−1 for 63 days) the apparent absorption of F ranged from 44 to 53%, while apparent retention of F ranged from 28 to 42%. The respective values for ingestion of sodium fluoride (NaF) at 69 mg F day−1 were 69% and 39–45%. Increasing F intakes had little effect on kidney and liver F concentrations, but markedly increased the bone F concentrations in the sheep fed NaF or soil with high levels of F. Further, serum F concentration and the rate of F accumulation in bone were related to soil F intake. The rate of F accumulation in bone was curvilinearly related to serum F concentration, and serum F concentration had to be > 0.25 mg litre−1 before a significant accumulation of F occurred in bone. Serum F concentration could be a useful index to assess the soil F intakes and F status of grazing sheep. An examination of the sheep during and at the end of the study showed no clinical signs of fluorosis, such as mottled teeth or bone abnormalities. © 2003 Taylor & Francis Group, LLC.
Mitchell, AD, Loganathan, P, Payn, TW & Olykan, ST 2003, 'Magnesium and potassium fertiliser effects on foliar magnesium and potassium concentrations and upper mid-crown yellowing in Pinus radiata', New Zealand Journal of Forestry Science, vol. 33, no. 2, pp. 225-243.
Upper mid-crown yellowing (UMCY) is a disorder in Pinus radiata D.Don caused mainly by a high potassium/magnesium (K/Mg) ratio in the soil exchange complex and in the tree needles. To study the effects of a range of soil exchangeable K/Mg ratios on potassium and magnesium uptake and UMCY in P. radiata, a trial was established in September 1996 on a Pumice Soil in northern Kaingaroa Forest in the central North Island of New Zealand in a second-rotation stand of 20-year-old P. radiata. The trial tested the effects of magnesium applied as kieserite at 200 kg Mg/ha and potassium applied as potassium sulphate at 200 and 400 kg K/ha on soil-exchangeable and soil-solution magnesium and potassium, on free needle magnesium and potassium, and on severity of UMCY. The applications of magnesium and the two rates of potassium significantly (p<0.05) increased soil-exchangeable and soil-solution magnesium and potassium concentrations respectively in the top 10 cm soil depth during the first 2 years of the trial (1997 and 1998). Magnesium application significantly (p<0.05) reduced the soil-exchangeable K/Mg ratio from 0.7-1.3 (control treatment) to 0.2-0.3, whereas the low and high rates of potassium application significantly increased this ratio to 0.8-1.7 and 1.3-2.5 respectively in the 2 years. The magnesium fertiliser application significantly (p<0.1) increased tree foliage magnesium concentration in 1999, but had no effect on foliage K/Mg ratios in any of the 4 years of sampling (1997, 1998, 1999, and 2002). Potassium fertiliser at the high rate significantly (p<0.1) increased the foliar potassium concentration in 1998 and 2002. Neither magnesium nor potassium fertiliser application had any effect on the change in foliar magnesium, potassium, or K/Mg ratio between 1997 and any of the other years sampled. Individual tree UMCY values ranged from 1 to 6 in a system of increasing severity from 1 to 8. Magnesium fertiliser significantly (p=0.074) reduced UMCY values (assessed in...
Loganathan, P, Hedley, MJ, Wallace, GC & Roberts, AHC 2001, 'Fluoride accumulation in pasture forages and soils following long-term applications of phosphorus fertilisers', Environmental Pollution, vol. 115, no. 2, pp. 275-282.View/Download from: Publisher's site
Ingestion of soils with high flouride (F) concentration may cause chronic flourosis in grazing animals. Analysis of New Zealand pasture solis with long-term phosphorus (P) fertilisation histories showed that the total surface soil (0-75 mm depth) F concentration increased up to 217-454 mg kg-1 with P fertiliser application. One-third to two-thirds of F applied in fertilisers resides in the top 75 mm soil depth. Pasture forage accumulation of F was low, and therefore, F intake by grazing animals through pasture consumption is expected to be much lower than F intake by soil ingestion. Ten annual applications of single superphosphate (30 and 60 kg P ha-1 year-1) to a Palllic Soil (Aeric Fragiaqualf) significantly increased total F and labile F (0.01 M CaCl2 extract) concentrations to 200 and 120 mm depths, respectively, of the 300 mm depth investigated. The mobility of F in the soil profile was similar to two other elements, P and cadmium derived fom the fertiliser. © 2001 Elsevier Science Ltd. All rights reserved.
Zoysa, AKN, Loganathan, P & Hedley, MJ 2001, 'Comparison of the agronomic effectiveness of a phosphate rock and triple superphosphate as phosphate fertilisers for tea (Camellia sinensis L.) on a strongly acidic Ultisol', Nutrient Cycling in Agroecosystems, vol. 59, no. 2, pp. 95-105.View/Download from: Publisher's site
Phosphorus deficiency is a major problem affecting tea production in the highly weathered acid soils of humid and sub-humid tropics which are known to have high P fixing capacities. As many of these soils are strongly acidic and receive high rainfall, low-cost phosphate rock (PR) may effectively supply the plant P needs and limited preliminary experiments suggest this is so. A long-term glasshouse trial was conducted on 8-month old tea seedlings to compare the agronomic effectiveness of a locally available PR (Eppawala phosphate rock, EPR) with triple superphosphate (TSP) applied to a strongly acidic (pH water 4.55) marginally P deficient Rhodustult from Sri Lanka at six rates ranging from 10 to 60 kg P ha-1. The results showed that TSP or EPR fertiliser at a rate as low as 10 or 20 kg P ha-1 was sufficient to obtain maximun tea yield. The agronomic effectiveness of EPR was equal to that of TSP at the 5- and 10-month samplings. The concentration of soil P extracted by a cation-anion exchange resin membrane (resin-P) was higher in the TSP treated soil at 5 months due to its greater solubility but at 10 months, the EPR produced higher resin-P due to its increased dissolution over time. In the presence of tea plants, 52% of P from the EPR applied at the rate of 10 kg ha-1, was dissolved at 5 months compared to 75% of dissolution at the 10-month sampling. In the absence of plants, the corresponding dissolution figures were 40% at 5 months and 55% at 10 months. The concentration of inorganic P extracted by 0.1 M NaOH (NaOH-Pi) (loosely characterising Fe + Al bound P) was significantly higher in the TSP treated soil and concentration of P extracted by 0.5 M H2SO4 (Ca bound P) was higher in the EPR treated soil. The results suggest that the low-cost, locally available EPR may be used profitably as a maintenace P fertiliser for tea plantations in moderately P deficient soils, which need to be confirmed by field studies.
Cronin, SJ, Manoharan, V, Hedley, MJ & Loganathan, P 2000, 'Fluoride: A review of its fate, bioavailability, and risks of fluorosis in grazed-pasture systems in New Zealand', New Zealand Journal of Agricultural Research, vol. 43, no. 3, pp. 295-321.View/Download from: Publisher's site
Fluoride (F) is an essential element for animal growth, not readily taken up by plants from soils, yet cases of acute fluorosis in grazing animals caused by ingestion of phosphatic fertilisers, volcanic ash, and industrial wastes remind us of its potential hazard. Fluoride concentrations in topsoils slowly increase where annual inputs through atmospheric pollution and phosphatic fertilisers exceed losses. This paper reviews information on the fate of F in grazed pasture systems with the aim of assessing the potential toxicity of accumulating soil F. A preliminary F-cycling model for grazed pastures, based on the review of international literature and F concentrations in selected New Zealand pasture soils, indicated that grazing sheep and cattle obtain over 50% of their dietary F (and this may be >80% during winter) from soil ingestion. The model suggests that at the extremes of the ranges of the measured winter soil ingestion (143–300 g d-1 for sheep and 900–1600 g d-1 for cattle) and dietary F absorptivity (bioavailability) of soil F (20–38%), total topsoil F concentrations in the range of 372–1461 μg F g-1 could cause chronic fluorosis in sheep and 326–1085 μg F g-1in cattle. We recommend that research is undertaken to measure F accumulation rates and soil F dietary absorptivity for a range of intensively managed New Zealand pasture soils. © 2000 Taylor & Francis Group, LLC.
Mitchell, AD, Loganathan, P, Payn, TW & Tillman, RW 2000, 'Magnesium fertiliser dissolution rates in pumice soils under Pinus radiata', Australian Journal of Soil Research, vol. 38, no. 3, pp. 753-767.View/Download from: Publisher's site
Application of Mg fertilisers has been suggested as a means of reducing the incidence of Mg deficiency of forest trees in New Zealand and Europe. The objective of this study was to determine the rates of dissolution of a range of Mg fertilisers applied to a pumice soil (Typic Udivitrand). The rate of fertiliser dissolution was little influenced by whether the fertiliser was applied directly on to the soil surface (litter removed) or on to the litter layer in a Pinus radiata plantation. Twenty-seven months since fertiliser application the mean (with and without litter) percentage of Mg dissolved was in the sequence: Epsom salts > calcined magnesite 1-2 mm > granmag (a partially acidulated and granulated calmag product) > calcined magnesite 2-4 mm > forestry grade dolomite. The specific dissolution rate constants (μg/cm2.day of fertiliser) for the slowly soluble Mg fertilisers calculated using an elemental sulfur oxidation cubic model were 587 for calcined magnesite 1-2 mm, 426 for calcined magnesite 2-4 mm, 385 for granmag, and 18 for forestry grade dolomite. In a laboratory incubation study the elemental sulfur oxidation cubic model described the rate of dissolution of Mg fertilisers within narrow fertiliser particle size ranges. The specific fertiliser dissolution rate constants, however, increased with decreases in particle size, suggesting that the rate of dissolution depends on factors other than surface area when particle sizes varied widely. Slowly soluble, alkaline Mg fertilisers had a significant liming effect on the soil. They were more effective in increasing soil exchangeable Mg than soluble Mg salts over a long-period and therefore, they are better fertilisers for P. radiata.
Loganathan, P, Louie, K, Lee, J, Hedley, MJ, Roberts, AHC & Longhurst, RD 1999, 'A model to predict kidney and liver cadmium concentrations in grazing animals', New Zealand Journal of Agricultural Research, vol. 42, no. 4, pp. 423-432.View/Download from: Publisher's site
Cadmium (Cd) accumulation in the kidneys and liver of older grazing animals is a major concern in New Zealand and Australian agriculture. Use of phosphate fertilisers containing high Cd concentration is the main cause of this accumulation. A simple mathematical model running in a user-friendly computer package was developed to predict annual accumulation of Cd in kidneys and liver of animals grazing pastures of known herbage Cd concentration and phosphate fertiliser history. Results from the model showed that kidney and liver Cd concentration of sheep were most sensitive to fertiliser Cd concentration, moderately sensitive to pasture ingestion rate, and least sensitive to soil ingestion rate. The model was validated using kidney Cd data from a farmlet-scale sheep-grazing trial. Kidney Cd concentrations predicted by the model were strongly correlated with measured mean kidney Cd concentrations. The relationship between the measured and predicted Cd concentrations is not statistically different from the 1:1 relationship indicating that the model can explain the variation in the measured mean kidney Cd concentration. © 1999 Taylor & Francis Group, LLC.
Loganathan, P, Payn, TW, Mitchell, AD & Tillman, RW 1999, 'A sequential extraction method for the determination of dissolution of magnesium from fertilizers applied to pumice soils', Communications in Soil Science and Plant Analysis, vol. 30, no. 1-2, pp. 199-211.View/Download from: Publisher's site
A major factor controlling the effectiveness of magnesium (Mg) fertilizers in correcting Mg deficiency in crops is their rate of dissolution in soils. The commonly used method of determining the rate of dissolution of fertilizers by measuring the increase in dissolved Mg in soils under field conditions can lead to errors because part of the dissolved Mg would normally be lost from the site of application by plant uptake and leaching. A more accurate method of estimating the rate of dissolution is to determine the amount of undissolved Mg and subtract it from the amount of Mg applied. A simple sequential extraction method was developed to measure the undissolved Mg in soils treated with a range of fertilizers with different solubilities. The method consisted of two 30-minute extractions of a soil sample with 0.5M BaCl2-TEA, pH 8.2 to determine dissolved Mg in the sample followed by a 1- hour extraction with 0.5M HCl to determine difficulty-soluble or slow- release Mg, and finally an 18-hour extraction with 2M HCl to determine undissolved Mg. The method gave nearly a 100% recovery of Mg applied in fertilizers to two pumice soils (Vitrands). The rates of dissolution of the fertilizers in the two soils were in the order of Epsom salts = fine magnesium oxide (calcined magnesite) > coarse magnesium oxide (calcined magnesite), coarse partially acidulated magnesium oxide (Granmag(TM)), free dolomitic limestone > fused magnesium phosphate.
Mitchell, AD, Loganathan, P, Payn, TW & Tillman, RW 1999, 'Effect of calcined magnesite on soil and Pinus radiata foliage magnesium in pumice soils of New Zealand', Australian Journal of Soil Research, vol. 37, no. 3, pp. 545-560.View/Download from: Publisher's site
Magnesium (Mg) deficiency is common in a number of forest regions in the world. It has been linked to a condition in P. radiata called 'upper mid crown yellowing' (UMCY) in New Zealand and 'new type forest decline' in Europe. Mg concentrations are low in many of New Zealand's forest soils. With increases in the number of rotations and increased growth rates through tree breeding, Mg deficiency is expected to increase. This study was conducted to determine the fate of calcined magnesite (calmag) fertiliser applied at 150 kg Mg/ha at 2 sites in the Kaingaroa Forest near Rotorua, New Zealand. It also investigated the effectiveness of calmag in increasing the soil solution and soil exchangeable Mg in pumice soils and Mg concentrations in the pine needles, and in reducing the likelihood of UMCY 2 and 3 years after fertiliser application. In both sites and for both years of sampling the application of calmag fertiliser resulted in a significant increase in soil exchangeable and soil solution Mg in the 0-5 cm soil layer. Soil and soil solution pH had also been increased in the top 5 cm soil layer. Two years after application about 90% of the fertiliser applied had dissolved and about 70-80% of the Mg remained in a plant-available form (ammonium acetate exchangeable Mg) in the top 10 cm of soil. Calculations suggest that 3-10% of applied fertiliser had been lost due to leaching. Magnesium fertiliser application also resulted in significant reduction in the exchangeable K:Mg ratio and reduced exchangeable Al in the 0-5 cm soil layer. After 3 years, foliar Mg concentrations increased at all sites in the fertilised trees compared with the control trees, although differences were not yet significant. UMCY severity in the trees was also not significantly affected by the application of Mg fertiliser.
Zoysa, AKN, Loganathan, P & Hedley, MJ 1999, 'Phosphorus utilisation efficiency and depletion of phosphate fractions in the rhizosphere of three tea (Camellia sinensis L.) clones', Nutrient Cycling in Agroecosystems, vol. 53, no. 2, pp. 189-201.View/Download from: Publisher's site
Tea (Camellia sinensis L.) is mostly grown on highly weathered acidic Ultisols in the humid and sub-humid tropics. Phosphorus (P) availability in Ultisols is naturally low due to it's low diffusivity caused by high P-fixation of Fe and Al oxides. Tea is generally fertilised with low-cost reactive phosphate rocks (RPR) because of enhanced solubility of RPR under acidic conditions. In many countries, new tea clones have been developed to improve yield, drought tolerance and resistance to pest and diseases, but the effectiveness of these clones in utilising P from RPR and native soil P forms has not been studied. A study was conducted to investigate the effects of triple superphosphate (TSP) and a sparingly soluble phosphate rock (Eppawala phosphate rock, EPR) on plant P uptake and soil P fractions in the rhizosphere of three tea clones developed in Sri Lanka (S 106, TRI 2023 and TRI 2025). Phosphate uptake by TRI 2023 (3.3 ± 0.02 mg P plant-1) and TRI 2025 (2.6 ± 0.08 mg P plant-1) was significantly greater than S 106 (1.1 ± 0.01 mg P plant-1) for both P treatments. However the type of P fertiliser did not show any significant difference in P uptake by any of the clones. In all tea clones, the rhizosphere soil pH decreased significantly compared to that of the bulk soil in both P fertiliser treatments. The decrease of pH near the rhizoplane (0-0.5 mm) for TRI 2023, TRI 2025 and S 106 were 0.30 ± 0.02, 0.19 ± 0.03 and 0.17 ± 0.05 respectively. Dissolution of EPR in the rhizosphere of TRI 2023 and TRI 2025 was greater than S 106, which could be attributed to enhanced H+ efflux. TRI 2023 and TRI 2025 depleted more resin-P, NaOH-P(i) and H2SO4-P(i) in the rhizosphere compared to S 106, which is consistent with the P uptake results. NaOH-P(o) accumulated in the rhizosphere of all clones suggesting that soluble inorganic P was transformed into organic P forms possibly as a result of increased microbial activity in the rhizosphere. TRI 2023 and TRI 2025 showed a higher ex...
Zoysa, AKN, Loganathan, P & Hedley, MJ 1998, 'Effect of forms of nitrogen supply on mobilisation of phosphorus from a phosphate rock and acidification in the rhizosphere of tea', Australian Journal of Soil Research, vol. 36, no. 3, pp. 373-387.View/Download from: Publisher's site
Nitrogen (N) is the main fertiliser input to tea plantations because of the large removal of this element with regular harvests of young shoots in the field. The form of N supply is known to influence the uptake of other plant nutrients, notably phosphorus (P), through its effect on soil pH in the rhizosphere. A glasshouse study was conducted to test the effect of N form (NH4/+, NO3/-, or both) on the transformation of soil P in the rhizosphere and its availability to tea (Camellia sinensis L.) plants fertilised with sparingly soluble Eppawala phosphate rock (EPR). Four-month-old tea (TRI 2025) plants were grown in rhizosphere study containers containing an Ultisol from Sri Lanka (pH 4.5 in water) amended with EPR and KCl at 200 μg P or K/g soil, and mixed with (NH4)2SO4 (100% NH4/+-N), NH4NO3 (50% NH4/+-N and 50% NO3/--N), and Ca(NO3)2 (100% NO3/--N) at the rate of 200 μg N/g soil, with a control (no N fertiliser), as treatments. Rhizosphere pH decreased compared with the bulk soil when N was supplied as NH4/+ or NH4/+-NO3/- forms, and increased when N was supplied as NO3/-. The cation-anion balance estimations in the plants showed that the plants had taken up more NO3/- than NH4/+ even in (NH4)2SO4 treated soil, suggesting high nitrification rates, especially in the rhizosphere, in spite of using a nitrification inhibitor. More EPR dissolved in the rhizosphere compared with that in the bulk soil, regardless of the N form applied. The (NH4)2SO4 treatment had the highest dissolution rate of EPR in the rhizosphere, whereas Ca(NO3)2 treatment had the lowest, reflecting the degree of acidification in the rhizosphere. Resin-P and NaOH-P(i) (inorganic P) concentrations were lower and NaOH-P(o) (organic P) concentration was higher in the rhizosphere than in the bulk soil. Plant and possible microbial uptake of P is the main reason for the decrease in resin-P and NaOH-P(i). The increase in NaOH-P(o) concentration in the rhizosphere is believed to be due to transformatio...
Zoysa, AKN, Loganathan, P & Hedley, MJ 1998, 'Phosphate rock dissolution and transformation in the rhizosphere of tea (Camellia sinensis L.) compared with other plant species', European Journal of Soil Science, vol. 49, no. 3, pp. 477-486.View/Download from: Publisher's site
Tea (Camellia sinensis L.) is generally grown in highly weathered acidic Ultisols of the humid tropics. The low pH, large P fixing capacity and moisture content of these soils favour the dissolution of phosphate rock. Plant species differ widely in their ability to take up P from phosphate rock, and we have compared phosphate mobilization in the rhizosphere of tea with that under calliandra (Calliandra calothyrsus L.), Guinea grass (Panicum maximum L.) and bean (Phaseolus vulgaris L.) by studying the changes in the concentration of P fractions at known distances from the root surface in an acidic (pH in water 4.5) Ultisol from Sri Lanka treated with a phosphate rock. Plants were grown in the top compartment of a two-compartment device, comprising two PVC cylinders physically separated by a 24-μm pore-diameter polyester mesh. A planar mat of roots was formed on the mesh in the top compartment, and the soil on the other side of the mesh in the lower compartment was cut into thin slices parallel to the rhizosphere and analysed for pH and P fractions. All plant species acidified the rhizosphere (pH [water] difference between bulk and rhizosphere soils was 0.17-0.26) and caused more rock to dissolve in the rhizosphere (10-18%) than in the bulk soil (8-11%). Guinea grass was most effective, though the rate of acidification per unit root surface area was least (0.02 μmol H+ cm-2) among the four species. Tea produced the largest rate of acidification per unit root surface area (0.08 μmol H+ cm-2). All species depleted P extracted by a cation-anion exchange resin and inorganic P extracted by 0.1 m NaOH. All except tea depleted organic P extracted by 0.1 m NaOH in the rhizosphere. The external P efficiencies (mg total P uptake) of Guinea grass, bean, tea and calliandra in soil fertilized with phosphate rock were 4.82 ± 0.42, 4.02 ± 0.32, 1.06 ± 0.02 and 0.62 ± 0.02, respectively, and the corresponding internal P efficiencies (mg shoot dry matter production per mg plant P) ...
Loganathan, P & Hedley, MJ 1997, 'Downward movement of cadmium and phosphorus from phosphatic fertilisers in a pasture soil in New Zealand', Environmental Pollution, vol. 95, no. 3, pp. 319-324.View/Download from: Publisher's site
Total cadmium (Cd) and phosphorus (P) concentrations in a pastoral soil, amended annually for 10 years with four forms of P fertilisers, decreased with soil depth. Single superphosphate (SSP) and North Carolina phosphate rock (NCPR) which had higher Cd contents (32 and 41 mg kg-1, respectively) produced higher total soil Cd than diammonium phosphate (DAP - 10 mg kg-1), Jordan phosphate rock (JPR - 5 mg kg-1) and control treatments to a depth of 120 mm. Total soil P in SSP treated plots to a depth of 120 mm and NCPR treated plots to a depth of 75 mm was also higher than the control plots. No significant fertiliser P and Cd moved below 120 mm depth. Approximately 90% of the applied Cd was recovered in the soil of which 93% remained within the top 120 mm. Plant recovery of applied Cd was 1.5-4.5%. Plant available P (Olsen P) also decreased with depth. Plant available Cd (0.01 M CaCl2 extractable Cd) was higher in the 30-75 and 75-120 mm soil depths compared to 0-30 mm soil depth. This may be die to strong adsorption of Cd by the surface soils which have a higher organic matter content and higher pH; factors which are known to increase Cd adsorption in soils.
Zoysa, AKN, Loganathan, P & Hedley, MJ 1997, 'A technique for studying rhizosphere processes in tree crops: Soil phosphorus depletion around camellia (camellia japonica l.) roots', Plant and Soil, vol. 190, no. 2, pp. 253-265.View/Download from: Publisher's site
Rhizosphere studies on tree crops have been hampered by the lack of a satisfactory method of sampling soils at various distances in the rhizosphere. A modified root study container (RSC) technique developed for annual crops, grasses and legumes was used to study the mechanisms by which camellia plants (Camellia japonica L.) utilise soil P in the glasshouse and field. Plants belonging to the Camellia family (e.g. tea) have the ability to utilise P from relatively unavailable native P sources and for this reason camellia plants were selected for this study. In the glasshouse trial, the RSCs were filled with a Recent soil, treated with P fertilisers; North Carolina phosphate rock (NCPR), diammonium phosphate (DAP), mono calcium phosphate (MCP) and single superphosphate (SSP) at 200 μg Pg-1 soil. A planar mat of roots was physically separated by a 24 μm polyester mesh and the soil on the other side of this mesh was cut into thin slices parallel to the rhizoplane and analysed for pH, and different forms of P (organic, P(o) and inorganic, P(i)) to understand P depletion at different distances from camellia roots. In the field trial this technique was modified and used to study the rhizosphere processes in mature camellia trees fertilised with only SSP and NCPR. In both field and glasshouse trials, all P fertilisers increased all the bulk soil P fractions except NaOH-P(o) over unfertilised soil with the greatest increases being in the H2SO4-P(i) fraction in the NCPR treatment and NaOH-P(i) in the SSP treatment. Resin-P, NaOH-P(i) and H2SO4-P(i), were significantly lower in the rhizosphere soil compared to the bulk soil whereas NaOH-P(o) was higher in the rhizosphere soil than in the bulk soil. Plant and microbial P uptake were thought to be the major causes for the low resin-P rather than P fixation by Fe and Al because the NaOH-P(i) fraction which is a measure of Fe-P and Al-P, also decreased in the rhizosphere soil. The rhizo-deposition of NaOH-P(o) suggests that labi...
Andrewes, P, Town, RM, Hedley, MJ & Loganathan, P 1996, 'Measurement of plant-available cadmium in New Zealand soils', Australian Journal of Soil Research, vol. 34, no. 3, pp. 441-452.
Several methods of measuring plant-available cadmium (Cd) were compared using soils that had accumulated Cd under normal New Zealand agricultural practices (low total Cd concentrations, and phosphatic fertiliser as the dominant Cd source). The study encompassed 9 New Zealand soils with different Cd input histories. Cadmium was extracted from these soils by demineralised water, 0.05 M Na2EDTA, l M NH4OAC (pH 7), 0.01 M CaCl2, and 0.05 M CaCl2 and quantified by differential pulse anodic stripping voltammetry (DP-ASV) and graphite furnace atomic absorption spectrophotometry (AAS). The DP-ASV measures the free Cd ion and that associated with labile complexes, but not large organic Cd complexes. Extractable Cd levels were compared with those which are plant-available, as determined by pot studies (lettuce). The 0.01 M CaCl2-extractable Cd measured by AAS and 0.05 M CaCl2-extractable Cd measured by DP-ASV gave the best estimate of plant availability of Cd.
Gurung, SR, Stewart, RB, Loganathan, P & Gregg, PEH 1996, 'Aluminium-organic matter-fluoride interactions during soil development in oxidised mine waste', Soil Technology, vol. 9, no. 4, pp. 273-279.View/Download from: Publisher's site
A three year field trial assessing the suitability of mine waste rock as a surrogate subsoil with different depths of topsoil showed that pasture yield was significantly lower in the unmodified waste rock (UWR) treatments compared to waste rock modified with lime and potassic superphosphate (MWR) during the first two years but there was no difference in yield in the third year between the waste rock treatments. The reduced yield in UWR during the first two years was considered to be due to phytotoxic levels of aluminium (Al) in the UWR soil solution. Soil samples from the waste rock interface (A) and waste rock at depth ≤ 300 mm (B) collected at the end of the three year trial were analysed for different forms of soil Al, total soluble fluoride (F), dissolved organic carbon (DOC) and soil pH to determine whether organic matter and F leachate from the topsoil reduced Al toxicity at the waste rock interface (A) during soil development over 3 years. Results showed that after 3 years, 0.02 M CaCl2 extractable Al (Al(Ca)) and 1 M KCl extractable exchangeable + soluble Al (Al(K)) were effectively reduced in the MWR interface (A) by lime and fertiliser applications but they remained at very high phytotoxic levels (Al(Ca) = 17-21 μg g-1, Al(K)=261-339 μg g-1) in the UWR interface (A) irrespective of topsoil depth treatment. The corresponding organic bound Al (Al(OM)) ranged from 200 to 214 μg g-1 and DOC was in the range 169-203 μg g-1 in both UWR and MWR interfaces (A). These values were a significant two-fold higher than the values at depth ≤300 mm (B) which were considered to be the original levels of Al(OM) and DOC in UWR. The increase in Al(OM) and DOC by the third year is probably due to progressive leaching of organic ligands produced from the decomposition of organic matter in the topsoil subject to an annual rainfall of 2500 mm. This evidence for the reduction in Al toxicity by organic matter is further supported by significant dry root density (DRD) in the UWR ...
Loganathan, P, Hedley, MJ, Gregg, PEH & Currie, LD 1996, 'Effect of phosphate fertiliser type on the accumulation and plant availability of cadmium in grassland soils', Nutrient Cycling in Agroecosystems, vol. 46, no. 3, pp. 169-178.View/Download from: Publisher's site
Cadmium (Cd), a potentially toxic heavy metal for humans and animals, accumulates in the liver and kidneys of older animals grazing New Zealand and Australian pastoral soils. Phosphorus (P) fertiliser is the major input of Cd into these farming systems. A study was conducted to evaluate the effects, over 10 years, of annual application (30 kg P ha-1 yr-1) of four forms of P fertilisers having different solubilities and Cd contents [41, 32, 10 and 5 μg Cd g-1 for North Carolina phosphate rock (NCPR), single superphosphate (SSP), diammonium phosphate (DAP) made from low Cd phosphate rocks and Jordan phosphate rock (JPR) respectively] on soil and herbage Cd concentrations. Ten years of fertiliser application caused a marked increase in surface soil Cd concentrations. Total soil Cd was significantly higher in SSP and NCPR treatments compared to control (no P fertiliser), JPR and DAP treatments in the 0-30 and 30-75 mm soil depths. Plant-available Cd (0.01 M CaCl2 extractable Cd) was higher in SSP treatments than in control and other fertiliser treatments. Chemical analysis of herbage samples showed that there was no significant difference in Cd concentration in pasture grasses between treatments in the second year of the trial but in the eighth and tenth year, plots fertilised with SSP and NCPR had significantly higher Cd in pasture grasses in most of the seasonal cuts compared to control, JPR and DAP. Cadmium recovery by both grasses and clover was less than 5% of Cd applied in fertiliser. Clover Cd concentration and yield were much lower than those for grass and therefore its contribution to pasture Cd uptake was very low (< 7%). A strong seasonal effect on grass Cd concentration, which is inversely related to pasture growth rate, was observed in all three sampling years - Cd concentration was highest during autumn and lowest in spring. Total Cd contents of the fertilisers and their rate of dissolution rather than soil pH [pH (H2O) at 30-75 mm depth of 5.39, 5.20, ...
Manoharan, V, Loganathan, P, Parfitt, RL & Tillman, RW 1996, 'Changes in soil solution composition and aluminium speciation under legume-based pastures in response to long-term phosphate fertiliser applications', Australian Journal of Soil Research, vol. 34, no. 6, pp. 985-998.View/Download from: Publisher's site
This study describes some of the effects of 8 years of annual application of 6 types of phosphatic fertilisers on the chemical composition and aluminium (Al) speciation in soil solution extracted from a soil under pasture. Soil samples at 2 depths, 0-30 and 30-75 mm, were collected at the end of 8 years. Soil solutions were extracted by centrifuging at 12 000 RCF and analysed for Al, Na, K, Ca, Mg, F, NO3, Cl, and SO4, as well as pH and ionic strength. Soil and soil solution pH were significantly increased at both depths by application of North Carolina phosphate rock (NCPR) compared with the control. In contrast, diammonium phosphate (DAP) significantly decreased the soil and solution pH. Single superphosphate (SSP) did not have any significant effect on soil or solution pH compared with the untreated control. The surface soil (0-30 mm) solution pH was on average 0.6 of a unit higher than the subsurface soil (30-75 mm) solution pH. Total monomeric Al concentration [Al], measured by the pyrocatecol violet (PCV; 4 min) method, ranged from 1.5 to 4.8 μM in the surface soil and 2.5 to 12.2 μM in the subsurface soil. The DAP and higher rates of SSP application resulted in a large increase in total and inorganic monomeric [Al] in the soil solution extracted from the subsurface soil. Total soluble [F] ranged from 2.7 to 23.5 μM and 3.2 to 25.6 μM in the surface and subsurface soils, respectively, and was significantly increased by the application of NCPR and by higher rates of SSP. The predominant forms of inorganic monomeric Al present in the soil solution were estimated to be the non-phytotoxic Al-F complexes, AIF2+, and AIF2/+. There was a marked decrease in toxic Al species (Al3+, Al(OH)2+, Al(OH)2/+) in soil solution following NCPR and SSP application. This was due primarily to complexation of Al with F derived from these fertilisers forming non-toxic Al-F complexes. The results suggest that the long-term application of reactive phosphate rock such as NCPR may con...
Manoharan, V, Loganathan, P, Tillman, RW & Parfitt, RL 1996, 'Assessing aluminum phytotoxicity in long-term phosphate fertilized pasture soils', Communications in Soil Science and Plant Analysis, vol. 27, no. 5-8, pp. 1731-1748.View/Download from: Publisher's site
Loganathan, P, Dickson, AA & Isirimah, NO 1995, 'Potassium supplying capacity of soils formed on different geological deposits in the Niger Delta region of Nigeria', Geoderma, vol. 65, no. 1-2, pp. 109-120.View/Download from: Publisher's site
The potassium supplying capacity of soils formed on three geological deposits along an east-west transect in the Niger Delta region of Nigeria was investigated by determining the various forms of soil K and K uptake by repeated maize croppings in pots. Soils (Inceptisols and Entisols) formed on recent alluvial materials of the Meander Belt deposits (MBD) had mica and feldspars resulting in very high levels of total K (4.4 and 5.1%) and nonexchangeable K (NEK) extracted by concentrated H2SO4 and boiling HNO3 (H2SO4K: 378 and 477 μg g-1; HNO3z.sbnd;K: 158 and 174 μg g-1. Soils formed on the other two geological deposits (Sombreiro-Warri deposits, SWD, and Coastal Plain Sands, CPS) had low levels of total K (CPS, 0.18-0.37% and SWD, 0.28-1.76%) and NEK H2SO4K and HNO3K for CPS were 40-87 and 18-49 μg gt1̄ respectively and for SWD they were 40-158 and 14-80 μg g-1 respectively) indicative of the highly weathered nature of these soils (Ultisols) with traces of K-containing minerals. The trend in soil K levels in the three deposits are opposite of the previously reported soil P trend. Potassium uptake by maize induced release of NEK to the plant-available K pool. Potassium supply to plants from the NEK pool for 3 successive maize crops in MBD, SWD and CPS soils were 303-435, 32-57 and 21-38 μg K g-1 soil, respectively. NEK uptake, as a percentage of total K uptake, decreased with successive croppings in CPS soils and reached zero at the third cropping, while in MBD soils the percentage remained constant up to the third and last crop. In this respect, some SWD soils behaved similar to MBD soils and others to CPS soils. © 1995.
Loganathan, P, Mackay, AD, Lee, J & Hedley, MJ 1995, 'Cadmium distribution in hill pastures as influenced by 20 years of phosphate fertilizer application and sheep grazing', Australian Journal of Soil Research, vol. 33, no. 5, pp. 859-871.View/Download from: Publisher's site
Cadmium (Cd) accumulating in the kidneys of older grazing animals threatens the continued access of New Zealand offal products to traditional markets. Phosphatic fertilizers represent the largest input of Cd into pastoral farming systems. Little research has been conducted on the cycling of Cd in grazed pastures. To estimate the distribution of Cd in grazed pastures, soil samples were collected from self-contained farmlets which had received either high superphosphate (HF) inputs (765 kg P ha-1), low superphosphate (LF) inputs (113 kg P ha-1) or no phosphate fertilizer (UF) inputs over the previous 20 years. The average total Cd concentration in the surface soil (0-30 mm; bulk density 0 * 64 g cm-3) of the farmlets which had received HF inputs was 0-40 mg kg-1 soil (range 0-18-0-60 mg kg-1), whereas farmlets which had received LF or no fertilizer inputs had an average Cd concentration of 0 * 10 mg kg-1 (range 0 * 02-0 * 19 mg kg-1). Cadmium concentration decreased with soil depth. The concentration of Cd in mixed herbage reflected the difference in soil Cd between the HF (meamtstandard error = 0-321±0-033 mg Cd kg-1 dry matter) and LF (0 * 063±0 * 004 mg Cd kg-1 dry matter) farmlets. Soil Cd accumulation was highest on low slopes (0-12°) and lowest on high slopes (>26°) in both LF and HF farmlets, whereas pasture Cd concentration in the HF farmlet increased with slope from 0 ■ 178±0 * 035 mg Cd kg-1 on low slopes to 0-487±0-053 mg Cd ha-1 on high slopes. A strong relationship was obtained between soil Cd and P in the 0-30 mm layer of the HF farmlet, demonstrating the link between phosphate fertilizer use and Cd accumulation. Zinc to Cd ratios were much lower in this layer compared with those in LF and UF sites, providing further evidence of the contribution of phosphate fertilizer to soil Cd.A model originally developed to explain the distribution of soil P in sheep-grazed fertilized hill pastures gave good predictions of present day soil Cd distribution in the H...
Loganathan, P, Hedley, MJ & Bretherton, MR 1994, 'The agronomic value of co-granulated Christmas Island Grade C phosphate rock and elemental sulphur', Fertilizer Research, vol. 39, no. 3, pp. 229-237.View/Download from: Publisher's site
Certain low grade phosphate rocks have low agronomic value as direct applied fertilizers and make poor quality superphosphates. With some rocks there is potential to increase their solubility in soils and hence the fertilizer value by mixing with finely divided elemental sulphur (S°). The agronomic value of a prototype 'low cost', granular P and S fertilizer, Christmas Island Grade C phosphate rock/elemental sulphur (Xmas C/S°), was compared against single superphosphate (SSP) and reactive phosphate rock (RPR)/S° dry blends, North Carolina phosphate rock/S° (NCPR/S°) and NCPR/50% S-super (granular SSP + 44% S°). An eight- month glasshouse trial using ryegrass (Lolium perenne L. cv. Nui), grown in a central yellow-grey earth (Aeric Fragiaqualf), indicated that fertilization with Xmas C/S° produced dry matter yields, between 54 to 73% and 10 to 40% lower than SSP and NCPR/S° blends respectively, and lower plant P and S uptake. Fertilization with Xmas C/S° however produced significantly higher yield and P and S uptake than unfertilized pots and pots receiving Xmas C PR and S° alone. The two RPR/S° dry blends, namely NCPR/S° and NCPR/50% S-super, produced significantly lower yield and P and S uptake than the same two fertilizers granulated with water. The difference in yields and P and S uptake between blends and granulated forms increased with time. The recovery of fertilizer P and S by plants ranged from 3 to 35% and 2 to 45% respectively with the lowest recoveries for Xmas C PR alone and S° alone and the highest for SSP and SSP + S°. During the period of plant growth the percentage of S° oxidised from the S°, Xmas C/S° co-granule, NCPR/S° physical blend and NCPR/S° granular treatments were 37, 32, 32 and 45% respectively. Field evaluations, or use, of the co-granule should consider it's slow P and S release rates. © 1994 Kluwer Academic Publishers.
Bolan, NS, Hedley, MJ & Loganathan, P 1993, 'Preparation, forms and properties of controlled-release phosphate fertilizers', Fertilizer Research, vol. 35, no. 1-2, pp. 13-24.View/Download from: Publisher's site
Controlled-release phosphate fertilizers include phosphate rocks (PRs) for direct application, partially acidulated phosphate rocks (PAPRs) and thermal phosphates. Phosphate rocks contain apatite as the main P containing mineral, the composition and the chemical nature of which vary between PRs. Based on the solubility in chemical extractants PRs are broadly grouped into 'reactive' and 'unreactive'. The 'reactivity' of PRs is influenced strongly by the extent of carbonate substitution for phosphate in the apatite minerals. Under certain soil and climatic conditions reactive PRs (RPRs) can be used as a source of P for direct application. Partially acidulated phosphate rocks (PAPRs) are produced either by direct partial acidulation of PRs with mineral acids or by mixing PRs with fully acidulated superphosphate reaction mixtures. Partial acidulation of PRs with H3PO4 generally results in higher water soluble P contents than those acidulated with H2SO4. Mixing of RPRs with superphosphate reaction mixtures sometimes results in the preferential consumption of free acid and thereby increases the amounts of residual unreacted PRs. Thermal phosphates are produced by either heating PRs below melting point both in the presence and the absence of silica (calcined phosphates) or heating PRs with silica above melting point (fused phosphate). These phosphates are alkaline in nature and hence suitable for acidic soils. © 1993 Kluwer Academic Publishers.
Loganathan, P & Hedley, MJ 1993, 'Single superphosphate - reactive phosphate rock mixtures. 3. The use of concentration ratios of elements to identify the nature and amounts of unacidulated rock residues in the mixtures', Fertilizer Research, vol. 36, no. 3, pp. 203-210.View/Download from: Publisher's site
Water insoluble residues (WIR) of unreactive phosphate rocks in single superphosphate-reactive phosphate rock (SSP-RPR) mixtures are considered to reduce the agronomic value of these mixtures. A technique using concentration ratios of elements to identify the quantities of WIR of ground North Carolina (NC), ground Nauru and as received NC phosphate rocks in a SSP-RPR was developed. Of 22 elements tested P/Sr ratios were found to be the only element ratios that could be used to distinguish between WIR's derived from Nauru and NC. P/Sr ratios in Nauru and NC were markedly different and provided a useful index for differentiating between the two rocks. During acidulation the P/Sr concentration ratio remained essentially constant in the WIR's from both rocks. Using the element ratio technique the percentage of total P in the SSP-RPR sample was determined to be 60-61% water soluble, 5% water insoluble Nauru, 2% water insoluble ground NC and 32-33% water insoluble as received NC. The element ratio technique developed in this study can be applied to partially acidulated P fertilizers made with rocks other than NC and Nauru provided elements which satisfy the same conditions as Sr in this study can be found. © 1993 Kluwer Academic Publishers.
Loganathan, P, Hedley, MJ & Clark, SA 1992, 'The manufacture and evaluation of granular potassium chloride fertilizers', Fertilizer Research, vol. 31, no. 3, pp. 291-304.View/Download from: Publisher's site
A finely divided red potassium chloride (KCl) (particle size distribution: 79% <0.5 mm, 20% 1-0.5 mm and 1% 1-2 mm) was granulated by adding eight readily available and relatively inexpensive binders using a rotating drum in the laboratory. The binders used were: urea, pulp and paper waste liquor containing lignosulphonate, urea + pulp and paper waste liquor, Borrebond powder (a commercial product containing lignosulphonate), urea + formaldehyde, ammonium sulphate, ammonium sulphate + pulp and paper waste liquor and a waste liquor containing ammonium sulphate from a Ferritin production plant. Of these, except for urea and urea + pulp and paper waste liquor which produced KCl granules having low critical relative humidity at 30°C (CRH) (<55%) and Borrebond which produced KCl granules of low crushing strength (1.1 kg for 2-3 mm granules) the other five binders produced granules with good size distributions, high crushing strengths (2.0-2.5 kg for 2-3 mm granules), CRH (65-70%) and suitable nutrient contents (K, 46-50%, Cl, 42-47%). These values are very close to those of the standard chipped KCl (crushing strength, 2.5 kg; CRH, 65-70%; K, 50%; Cl, 47%). Crushed chipped KCl (74% <1 mm, 25% 1-2 mm, 1% 2-3 mm) when cogranulated in the pilot plant with the 5 binders found successful in the laboratory, produced granules having similar characteristics as the corresponding ones produced in the laboratory. Granules produced both in the laboratory and the pilot plant had lower abrasion resistance (higher % degradation) than chipped KCl. The abrasion resistance however markedly increased when the fines (<1.4 mm) in the granules were removed. Glasshouse trials using barley as test crop demonstrated that the agronomic values of the KCl prototype granules produced with the 5 binders were similar to chipped KCl and granules produced from the feedstock KCl and water. © 1992 Kluwer Academic Publishers.
Loganathan, P, Hedley, MJ, Clark, SA & Bolan, NS 1992, 'Granulation of finely crystalline ammonium sulphate using calcium oxide and sulphuric acid', Fertilizer Research, vol. 31, no. 1, pp. 85-93.View/Download from: Publisher's site
Two types of finely crystalline ammonium sulphate (particle size distributions: white type 7% 2-3 mm, 45% 1-2 mm, 48% <1 mm; blue type 1% 2-3 mm, 8% 1-2 mm, 91% <1 mm) were granulated by adding calcium oxide and concentrated sulphuric acid using a rotating drum in the laboratory and pilot plant. The granules had satisfactory physical and chemical properties. The granules made in the pilot plant with 25 kg ammonium sulphate, 0.5 kg CaO, 1.26 litres of water and 0.9 to 1.125 litres of 98.5% H2SO4 had 80 to 97% of the granules within the size range of 1-3 mm, abrasion resistance of 0.4 to 0.8% <1 mm, crushing strength of 1.4 to 2.3 kg, critical relative humidity of 65-70%, pH 1.8 to 1.9 and N, S and Ca contents of 19, 24 and 1%. The quality of the granules when stored for 6 months alone or blended together with common fertilizers did not change. A glass house trial using barley demonstrated that the agronomic values of 4 prototype ammonium sulphate granules produced in the laboratory were similar to 3 standard granular ammonium sulphate fertilizers. The process of granulation which could easily be adopted in superphosphate manufacturing plants is recommended for plant scale testing. © 1992 Kluwer Academic Publishers.
Nwachuku, DA & Loganathan, P 1991, 'The effect of liming on maize yield and soil properties in southern nigeria', Communications in Soil Science and Plant Analysis, vol. 22, no. 7-8, pp. 623-639.View/Download from: Publisher's site
Effects of four rates of lime applications to maize grown in 12 strongly acidic soils of southern Nigeria belonging to Ultisol and Inceptisol orders were studied under greenhouse conditions. Five of these soils (A1 saturation, 26%-33%; Ca saturation, 3%-16%) showed marked responses to lime with % relative yield (percentage of maximum yield) ranging from 5 to 73, 2 soils (A1 saturation, 1% and 5%; Ca saturation, 52% and 59%) showed no response (about 95% relative yield) and the remaining 5 soils (A1 saturation, 15%-28%; Ca saturation, 10%-31%) showed marginal responses (79% to 90% relative yield). Percent relative yield was highly correlated with initial soil values of % A1 saturation (r = 0.923), 0.02M CaCl2 soluble A1 (r = 0.906), % Ca saturation (r = 0.806) and exchangeable Ca (r = 0.729) and poorly correlated with soil pH (r = 0.559). Overall, A1 saturation, soluble Al, Ca saturation and exchangeable Ca values corresponding to 90% relative yield were 27%, 13 mg/L, 21% and 0.7 cmol(+)/kg, respectively. On an individual soil basis, near maximum yield was obtained when liming reduced the soil Al saturation to 25% and increased Ca saturation to 28%. No increase in yields was obtained by liming beyond pH 5.5. © 1991, Taylor & Francis Group, LLC. All rights reserved.
The effect of pH on phosphate sorption by soil samples from two coarse-textured pedons of typic Paleudults in the perhumid tropical zone of Nigeria was studied by equilibrating air-dried soil samples adjusted to pH 3.5–6.5 for 48 h with 10 ppm P and 60 ppm P solutions at two concentrations of CaCl2 and NaCl. Phosphate sorption was generally unaffected by pH at low P additions at the two concentrations of the salts, whereas at high P additions sorption generally decreased with increase in soil pH, except in the presence of the high concentration of CaCl2 (10−2 M) where sorption decreased up to pH 5.0–5.5; beyond this pH range it increased. In both 10−2 M CaCl2 and 3 × 10−2 M NaCl systems, phosphate sorption decreased by 19–89% as a result of dithionite-citrate-bicarbonate (DCB) treatment. The effects of pH on phosphate sorption by treated samples were similar to those by untreated samples. Phosphate sorption increased with increase in depth, probably due to the increase in oxalate and dithionite-citrate-bi-carbonate extractable Fe and Al and the decrease in organic matter content down the pedons. Phosphate sorption by samples from the B horizon increased with increase in period of incubation with lime, whereas in the samples of Ap horizons no consistent trend was obtained. © 1990 Williams and Wilkins.
Zuofa, K, Loganathan, P & Isirimah, NO 1988, 'Effects of crude oil applications to soil on the growth and yield of maize, okro and cassava in Nigeria', Oil and Chemical Pollution, vol. 4, no. 4, pp. 249-259.View/Download from: Publisher's site
The effects of different doses (0, 1, 2, 4 and 8 litres/m2) of crude oil applications to soil on the growth and yield of maize, okro and cassava as well as on soil properties were investigated in two field experiments with mixed croppings (maize/okro and maize/cassava) in an acidic sandy loam soil at Port Harcourt, Nigeria. Crude oil applications above 2 litres/m2 significantly affected crop germination, plant height and yield of maize and okro but not of cassava. Weed population in all the plots decreased significantly with increase in oil doses. Oil application slightly increased organic matter content, pHand total nitrogen content in the soils. © 1988 Elsevier Science Publishers Ltd, England.
Loganathan, P & Sutton, PM 1987, 'Phosphorus fractions and availability in soils formed on different geological deposits in the niger delta area of Nigeria', Soil Science, vol. 143, no. 1, pp. 16-25.View/Download from: Publisher's site
We investigated in phosphorus (P) status of 12 well-drained to moderately well-drained soil profiles along an east-west transect in the Niger Delta area of Nigeria, by determining available P estimated by the methods of Bray and Kurz no. 1, Bray and Kurtz no. 2, Olsen and Truog, and the various P fractions. Total P in the six profiles of soils developed on Coastal Plain sands (CPS) ranged from 281 to 1469 ppm mean, 821), and total P in the four profiles of soils developed on Meander Belt deposits (MBD) and Sombreiro Warri deposits (SWD) ranged from 63 to 293 ppm (mean, 133). The two profiles in the transitional zone between CPS and SWD had total P of 326 to 595 ppm (mean, 441). Organic P ranged from 11 to 338 ppm and constituted 3 to 44% of total P. Inactive inorganic P accounted for 9 to 65% of total P. The relative abundance of the various active inorganic P forms was, in decreasing or der, Fe-P, Al-P, and Ca-P, except in three of the profiles of MBD-SWD region, where Ca-P was nearly equal to or slightly higher than Al-P. The results showed high availability of P in CPS soils, medium availability of P in the transitional zone, and low P in the MBD and SWD regions. The distribution of P fractions indicated a low degree of development of the soils, especially the MBD and SWD soils. Total P was significantly correlated positively with percentage of clay and negatively with pH and percentage of sand. Fe-P and Al-P had significant correlation with total P, percentage of sands, percent-age of clay, and available P extracted by the methods of Bray and Kurtz no. 1, Bray and Kurtz no. 2, and Truog. © 1987 The Williams & Wilkins Co.
Loganathan, P, Isirimah, NO & Nwachuku, DA 1987, 'Phosphorus sorption by ultisols and inceptisols of the niger delta in southern nigeria', Soil Science, vol. 144, no. 5, pp. 330-338.View/Download from: Publisher's site
Phosphorus (P) sorption at equilibrium concentrations of 0.1–2 ppm in 0.01 M CaCl2by 42 samples of highly acidic surface layers of Ultisols and Inceptisols from three major geomorphological regions of the Niger Delta of Nigeria, West Africa, conformed to the Langmuir isotherm. Langmuir sorption maxima and sorption at 0.2 ppm equilibrium P concentration ranged from 100–767 μ P/g soil and 30–240 fig μ P/g soil, respectively, indicating that the soil samples have low to medium P fertilizer requirements. No significant difference in sorption capacities among the soils of the three geomorphological regions or the two soil orders was noticed. Sorption capacities were significantly correlated with percentages of clay and silt, surface area, and different forms of Fe and Al, but not with pH or organic matter. Multiple regression equations relating P sorption to exchangeable Al, amorphous Al, amorphous Fe, and crystalline Fe are presented, and the relative contributions of these factors in the soils of the three geomorphological regions are discussed. © 1987 The Williams and Wilkins.
LOGANATHAN, P & ATPUTHARAJAH, PP 1986, 'EFFECTS OF FERTILIZERS ON YIELD AND LEAF NUTRIENT CONCENTRATIONS IN COCONUT', TROPICAL AGRICULTURE, vol. 63, no. 2, pp. 143-148.
LOGANATHAN, P, DAYARATNE, PMN & SHANMUGANATHAN, RT 1982, 'EVALUATION OF THE PHOSPHORUS STATUS OF SOME COCONUT-GROWING SOILS OF SRI-LANKA', JOURNAL OF AGRICULTURAL SCIENCE, vol. 99, no. AUG, pp. 25-33.
Loganathan, P & Balakrishnamurti, TS 1980, 'Effects of NPK fertilizers on young coconut (cocos nucifera) on a sandy soil in Sri Lanka', Experimental Agriculture, vol. 16, no. 1, pp. 41-48.View/Download from: Publisher's site
In a 4 × 4 × 4 NPK field experiment with coconut on a sandy soil, N increased girth, height and leaf production during the pre-bearing period, but phosphorus (up to 6½ years) and K (up to 3½ years) had no effect on any vegetative growth parameters. The rates of fertilizers for optimum copra and nut yield (13 to 16 years) were 0.35, 0.73 and 0.64 kg N, PO and KO/palm/ year respectively. The high P requirement was due to the low solubility of the saphos phosphate in these sandy soils. A positive N × P interaction was also observed. © 1980, Cambridge University Press. All rights reserved.
Loganathan, P & Fernando, WT 1980, 'Phosphorus sorption by some coconut‐growing acid soils of Sri Lanka and its relationship to selected soil properties', Journal of the Science of Food and Agriculture, vol. 31, no. 7, pp. 709-717.View/Download from: Publisher's site
Phosphorus (P) sorption in the presence of 10−2M calcium chloride by ten coconut‐growing acid soil samples of Sri Lanka belonging to the Ultisol, Alfisol and Entisol orders was evaluated using the Langmuir sorption isotherm. The data for all samples fitted the single‐site Langmuir sorption isotherm when equilibrium P was less than 1 μg ml−1, but showed some deviations at larger concentrations of P. A two‐site Langmuir sorption isotherm was successfully used to describe the sorption data of three samples at these high concentrations. The single‐site Langmuir sorption maxima were greater for Ultisols (349–825 μg g−1) than for the other soils (136–345 μg g−1). These sorption maxima were significantly correlated with %‐clay, %‐silt, dithionite‐extractable iron, and 1M ammonium acetate (pH 4.8)‐extractable aluminium. Regression analysis of P sorption on different forms of iron (Fe) and aluminium (Al) indicated that crystalline 'free Fe oxides' (dithionite‐extractable Fe minus 0.3M oxalate‐extractable Fe) and 'active Al' which consists of hydroxy Al monomers and polymers [1M ammonium acetates, (pH 4.8)‐extractable Al minus 1M potassium chloride extractable Al] were the important factors contributing towards P sorption. Copyright © 1980 John Wiley & Sons, Ltd
Loganathan, P & Nalliah, V 1977, 'Downward movement and transformation of phosphorus in soils after long-continued fertilizer application to coconut (Cocos nucfera)', The Journal of Agricultural Science, vol. 89, no. 2, pp. 279-284.View/Download from: Publisher's site
Determinations of sodium bicarbonate (pH 8.5) extractable P made on profiles of a sandy loam soil 7 and 8 years after fertilizer application to coconut in the Dry zone of Sri Lanka showed that the downward movement of P from concentrated superphosphate was greater than from rock phosphate (saphos). The surface layers (0.15 cm) of soil given concentrated superphosphate had higher P values (60 and 89 mg/kg for the 8th and 9th year respectively) than those given rock phosphate (3 and 16.5 mg/kg). At 40 cm depth the concentrated superphosphate treatment had 6 and 30 mg P/kg but the rock phosphate treatment had almost zero P at and below 40 cm. Phosphorus in the soil profile 8 years after fertilizer application was fractionated by the method of Chang &Jackson. Concentrated superphosphate treatment increased the Al-P and to a lesser degree Fe-P and Ca-P. Rock phosphate treatment increased the Ca-P and to a lesser extent Fe-P and Al-P. Phosphorus concentration in the 14th leaf was significantly correlated with Al-P, Fe-P and NaHCO3-P but not with Ca-P and organic P. The significance of the findings to phosphorus fertilizer application to coconut is discussed. © 1977, Cambridge University Press. All rights reserved.
LOGANATHAN, P & NALLIAH, V 1977, 'DOWNWARD MOVEMENT AND TRANSFORMATION OF PHOSPHORUS IN SOILS AFTER LONG-CONTINUED FERTILIZER APPLICATION TO COCONUT (COCOS-NUCIFERA)', JOURNAL OF AGRICULTURAL SCIENCE, vol. 89, no. OCT, pp. 279-284.
LOGANATHAN, P, BURAU, RG & FUERSTENAU, DW 1977, 'INFLUENCE OF PH ON SORPTION OF CO-2+, ZN-2+ AND CA-2+ BY A HYDROUS MANGANESE OXIDE', SOIL SCIENCE SOCIETY OF AMERICA JOURNAL, vol. 41, no. 1, pp. 57-62.
Loganathan, P & Maier, WJ 1975, 'Some surface chemical aspects in turbidity removal by sand filtration', Journal / American Water Works Association, vol. 67, no. 6, pp. 336-342.
In order to determine the effects of pH levels, ionic concentrations and polymer dosages on surface chemical properties and the efficiencies of sand filters, a study was conducted using 2 anionic, 2 cationic, and 2 nonionic polymers. Filtration of kaolinite suspensions with sand that had been pretreated with polymers was studied to describe the effects of the presence of Na+, Ca++ and Mg++ ions at different pH levels and at approximately constant ionic strength on particle capture and hence, turbidity removal. Zeta potentials of kaolinite particles and filter sands were determined to help clarify the mechanisms of particle capture in sand filtration. Adsorption of polymers by sand was also measured. The results show that Ca++ and Mg++ ions have a significant effect on removal of kaolinite turbidity by polymer treated filter sand. Calcium and Mg++ ions enhance turbidity removal for all polymer treatments. The enhancement was greatest for anionic polymers and least for cationic ones. There was no significant removal of turbidity in the absence of Ca++ and Mg++ ions when using highly anionic polymer. Zeta potential measurements showed that cationic polymer pretreatment reversed the zeta potential of sand from negative to positive, thus making conditions favorable for the attachment of kaolinite particles (negatively charged) to the surface of the filter sand. The presence of Ca++ and Mg++ ions has no effect on the zeta potential of cationic polymer treated sand and thus not much effect on turbidity removal. The increased effectiveness of turbidity removal obtained with cationic polymer pretreatment indicates that electrostatic forces are dominant.
Sorption of Co, Zn, Ca and Na by δ-MnO2 was studied at 24.0 ± 0.5°C and pH 4. During the sorption of Co and Zn, Mn was released to the solution phase; however, Mn release was not detected during the sorption of Ca and Na. On the basis of crystal field theory, it is proposed that Zn may interchange with Mn2+ in the δ-MnO2 structure, whereas Co may interchange with both Mn2+ and Mn3+. It is suggested that the interchangeable Mn2+ and Mn3+ sites were in the disordered layers in the δ-MnO2 structure. Sorption of Co, Zn and Ca at pH 4 fitted single-site Langmuir isotherm expressions at all Ca concentrations, but only at concentrations greater than 10-4 M for Co and Zn. Mn release by δ-MnO2 at pH 4 during Co and Zn sorption also fitted single-site Langmuir isotherms. An expression for the case of multisite Langmuir sorption was derived and applied to the cases of Co and Zn sorption and to the case of Mn release during Co sorption. The data of these cases were used to calculate statistically the coefficients of multiple regression equations from which the sum of the capacities of all sites in each case were obtained. From all of these derived capacities, it is proposed that there was only one site where Ca interchanged with surface bound H. Zn was postulated to interchange not only with these bound H sites, but also with another site where it interchanged with structural Mn2+. Co was postulated to interchange with both of these sites, and additionally, with a third site where it interchanged with structural Mn3+. Using a pH-stat set at pH 4, it was determined that approximately 2 moles of H were released per mole of Co or Zn sorbed at bound H sites. © 1973.
Winterkorn, HF, Christensen, RW, Das, B, Wischmeier, WH, Meyer, LD, Akky, MR, Shen, CK, Arulanandan, K, Sargunam, A, Loganathan, P, Krone, RB & Paaswell, RE 1973, 'SOIL EROSION: CAUSES AND MECHANISMS; PREVENTION AND CONTROL.', Highw Res Bd, Spec Rep, no. 135.
Proceedings includes 14 papers dealing with the causes and mechanisms of soil erosion and methods of preventing and controlling erosion. Following is part I of the list of titles and authors of the papers presented: Experimental Study of the Attack of Water on Dry Cohesive Soil Systems. By Hans F. Winterkorn. Hydraulic Erosion of Remolded Cohesive Soils. By Richard W. Christensen and Braja M. Das. Soil Erodability on Construction Areas. by M. R. Akky and C. K. Shen. Hydraulic Erosion of Remolded Cohesive Soils. By W. H. Wischmeier and L. D. Meyer. Erodibility of a Cement-Stabilized Sandy Soil. By M. R. Akky and C. K. Shen. Application of Chemical and Electrical Parameters to Prediction of Erodibility. by K. Arulanandan, A. Sargunam, P. Loganathan, and R. B. Krone. Causes and Mechanisms of Cohesive Soil Erosion: The State of the Art. By Robert E. Paaswell.
Loganathan, P, Hedley, MJ, Grace, ND, Lee, J, Cronin, SJ, Bolan, NS & Zanders, JM 2003, 'Fertiliser contaminants in New Zealand grazed pasture with special reference to cadmium and fluorine: A review', Australian Journal of Soil Research, pp. 501-532.View/Download from: Publisher's site
Phosphorus (P) fertilisers are an essential input for the economic production of legume-based pastures in New Zealand (NZ) and Australia, but they often contain some unwanted elements that can contaminate the soil, thereby creating potential risks to the health of grazing animal, food quality, and soil quality. Fluorine (F) and cadmium (Cd) are considered to be the elements of most concern. Incidences of F toxicity (from direct ingestion of fertiliser), and accumulation of Cd in offal products above the maximum permissible concentration (MPC) set by the food authorities, have been reported in NZ. Similarly, Cd concentrations in some food grains may exceed the newly proposed MPCs by the Australian and New Zealand Food Authority. Cadmium and F continue to accumulate in the topsoils of NZ and Australian pastures as a result of P fertiliser use. The mobility of both these elements in soils is low and is similar to that of P. Risk of ground water contamination from F and Cd applied to most NZ pastures is low. The plant uptake of these elements, especially F, is also low in most pastoral soils. Cadmium accumulates mainly in liver and kidney of grazing animals mostly through herbage ingestion, whereas F accumulates mainly in the bones of these animals, mostly through soil ingestion. Soil ingestion is highest during the wetter winter months and at high stocking rates. Models have been developed to assess the impact of fertiliser use on the potential risks associated with F and Cd accumulation in soils. Measures to control F and Cd accumulation in soils, plants, and grazing animals are presented and future research needs are identified.
Trolove, SN, Hedley, MJ, Kirk, GJD, Bolan, NS & Loganathan, P 2003, 'Progress in selected areas of rhizosphere research on P acquisition', Australian Journal of Soil Research, pp. 471-499.View/Download from: Publisher's site
Large reserves of P have accumulated in soils of developed countries because additions of P fertiliser to sustain agricultural production have exceeded crop removal. By contrast, in many developing countries in the tropics and subtropics, soil P reserves are gravely low and large additions are required before maintenance requirements begin to decline. In addition, the cost of P fertiliser will increase as the currently accessible deposits of high-grade phosphate rock (PR) diminish. Developing plants that efficiently tap soil P reserves and low grade PR is therefore a priority for agricultural research. For the 50th anniversary of the New Zealand Soil Science Society, this paper reviews research on P efficiency in plants, conducted by staff, students, and research associates of Massey University, in the context of other research into plant mechanisms that enhance P uptake, including effects of root geometry, mycorrhizal associations, and root-induced changes in the soil. Techniques for fractionation of soil P are highlighted.