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Sample records for calcareous soils

  1. Integrated management in calcareous soils

    International Nuclear Information System (INIS)

    Rice growing is developed in different kinds of soils, and some of the have high bases saturation, especially calcium and magnesium, as well as medium to high carbonate contents. This causes negative effects in the development and growth of the rice plant. As a consequence, several researching actions have been under-taken, and they are aimed at becoming this problem in economically manageable. Among the strategies we have, some of them are as follows: evaluating rice varieties presenting tolerance to these soils; using inorganic fertilizers looking for a response to elements, sources, dose and application times; evaluating organic fertilizers, mainly the green ones; using amendments, and physical soil management. According to the results, we have the fertilization response with major and minor elements and with the statistical differences at a 0.05% level. A response was found with elements such as zinc, copper, boron, iron, phosphorus and potassium. However, the efficiency of these elements depends on the addition of amendments as sulfur, the use of green fertilizers and farming systems that eliminate the superficial compaction of these soils, besides the use of varieties which are more tolerant to alkalinity, just like Fedearroz-50

  2. Designer, acidic biochar influences calcareous soil characteristics.

    Science.gov (United States)

    Ippolito, J A; Ducey, T F; Cantrell, K B; Novak, J M; Lentz, R D

    2016-01-01

    In a proof-of-concept study, an acidic (pH 5.8) biochar was created using a low pyrolysis temperature (350 °C) and steam activation (800 °C) to potentially improve the soil physicochemical status of an eroded calcareous soil. Biochar was added at 0%, 1%, 2%, and 10% (by wt.) and soils were destructively sampled at 1, 2, 3, 4, 5, and 6 month intervals. Soil was analyzed for gravimetric water content, pH, NO3-N, plant-available Fe, Zn, Mn, Cu, and P, organic C, CO2 respiration, and microbial enumeration via extractable DNA and 16S rRNA gene copies. Gravimetric soil water content increased with biochar application regardless of rate, as compared to the control. Soil pH decreased between 0.2 and 0.4 units, while plant-available Zn, Mn, and P increased with increasing biochar application rate. Micronutrient availability decreased over time likely due to insoluble mineral species precipitation. Increasing biochar application raised the soil organic C content and remained elevated over time. Increasing biochar application rate also increased respired CO2, yet the CO2 released decreased over time. Soil NO3-N concentrations significantly decreased with increasing biochar application rate likely due to microbial immobilization or denitrification. Depending on application rate, biochar produced a 1.4 to 2.1-fold increase in soil DNA extracted and 1.4- to 2.4-fold increase in 16S rRNA gene abundance over control soils, suggesting microbial stimulation and a subsequent burst of activity upon biochar addition. Our results showed that there is promise in designing a biochar to improve the quality and water relations of eroded calcareous soils. PMID:26077798

  3. Hardwood biochar influences calcareous soil physicochemical and microbiological status

    Science.gov (United States)

    The effects of biochar application to calcareous soils are not well documented. In a laboratory incubation study, a hardwood-based, fast pyrolysis biochar was applied (0, 1, 2, and 10% by weight) to a calcareous soil. Changes in soil chemistry, water content, microbial respiration, and microbial com...

  4. Mobile nickel content in calcareous black soils of Rajac

    OpenAIRE

    Đorđević Aleksandar R.

    2002-01-01

    A description of mobile Ni contents in various subtypes of calcareous black soils from the area of the mountain massif of Rajac, is given in the present paper. A hundred soil samples were analysed in all, originating from four subtypes of calcareous black soil (organogenic, organo-mineral, brownized and loessivized black soils). The extraction of mobile Ni was carried out with 1.0 N HCl and its content was determined by atomic absorption spectrophotometry. The obtained results indicate that m...

  5. Organic matter dynamics in coarse sandy calcareous soils

    NARCIS (Netherlands)

    Pronk, A.A.; Reuler, van H.

    2011-01-01

    The decomposition of organic matter in coarse sandy calcareous soils (beach sand) is thought to be much higher than in acid fine sandy soils but relatively little research is performed on these soils. Laboratory incubation experiments in which the release of soil carbon (C) is determined may overest

  6. Endogenous and bioaugmented sulphate reduction in calcareous gypsiferous soils

    NARCIS (Netherlands)

    Alfaya, F.; Cuenca-Sanchez, M.; Garcia-Orenes, F.; Lens, P.N.L.

    2009-01-01

    Gypsiferous soils have a high agricultural value, but their utilization is limited by the presence of gypsum that can induce hardpan and vertical crusting. This paper reports on sulphate reduction in this soil type as a basis of a bioremediation technology to remove the gypsum content of calcareous

  7. Transformation of Phosphate Fertilizers with Different Solubilities in Calcareous Soils

    Institute of Scientific and Technical Information of China (English)

    JIANGBAI-FAN; GUYI-CHU; 等

    1993-01-01

    In this research work,the authors,using the recently developed method of fractionating the forms of inorganic phosphorus in calcareous soils,have studied the transformation processes of inorgnic phosphorus in three different phosphate fertilizers,i.e.,superphosphate,diammonium phosphate and calcium magnesium phyosphate,being commonly used in China,during a period of 3 years after their application to calcareous soils,and based on the experimental results obtained,some problems in current use of phosphate fertilizers are discussed.

  8. Organic matter dynamics in coarse sandy calcareous soils

    OpenAIRE

    Pronk, A.A.; Reuler, van, H.

    2011-01-01

    The decomposition of organic matter in coarse sandy calcareous soils (beach sand) is thought to be much higher than in acid fine sandy soils but relatively little research is performed on these soils. Laboratory incubation experiments in which the release of soil carbon (C) is determined may overestimate the release of the soil organic C, as part of the measured C may have been released from the soil carbonates. In addition, it is not clear if the contribution of organic applications to the s...

  9. The Use of AIS Data for Identifying and Mapping Calcareous Soils in Western Nebraska

    Science.gov (United States)

    Samson, S. A.

    1985-01-01

    The identification of calcareous soils, through unique spectral responses of the vegetation to the chemical nature of calcareous soils, can improve the accuracy of delineating the boundaries of soil mapping units over conventional field techniques. The objective of this experiment is to evaluate the use of the Airborne Imaging Spectrometer (AIS) in the identification and delineation of calcareous soils in the western Sandhills of Nebraska. Based upon statistical differences found in separating the spectral curves below 1.3 microns, calcareous and non-calcareous soils may be identified by differences in species of vegetation. Additional work is needed to identify biogeochemical differences between the two soils.

  10. Low-Temperature Biochar Affects an Eroded Calcareous Soil

    Science.gov (United States)

    Previous research showed little benefit from using a high temperature, high pH biochar for improving the fertility of eroded calcareous soils. We thus explored the potential of an activated, low-temperature, low pH biochar to improve their fertility status. In a microcosm study conducted at 20 de...

  11. BIO-DIAGNOSTICS OF STABILITY OF BROWN CALCAREOUS SOIL OF UTRISH NATURAL RESERVE TO CHEMICAL POLLUTION

    OpenAIRE

    Kolesnikov S. I.; Vernigorova N. A.; Kuzina A. A.; Laptinova A. S.; Kazeev K. S.

    2015-01-01

    In this article, we have presented a number of modeling experiments to investigate the chemical pollution of brown calcareous soil. It assesses the stability of brown calcareous soil of a nature reserve called Utrish to contamination with heavy metals in biological parameters. Pollution of brown calcareous soil with Cr, Cu, Ni, Pb and oil causes a significant reduction in biological parameters. The degree of reduction depends on the nature of the contaminant and its concentration in the soil....

  12. Kinetics of Cd Release from Some Contaminated Calcareous Soils

    Energy Technology Data Exchange (ETDEWEB)

    Sajadi Tabar, S.; Jalali, M., E-mail: jalali@basu.ac.ir [Bu-Ali Sina University, Department of Soil Science, College of Agriculture (Iran, Islamic Republic of)

    2013-03-15

    Contamination of soils with heavy metals may pose long-term risk to groundwater quality leading to health implications. Bioavailability of heavy metals, like cadmium (Cd) is strongly affected by sorption and desorption processes. The release of heavy metals from contaminated soils is a major contamination risks to natural waters. The release of Cd from contaminated soils is strongly influenced by its mobility and bioavailability. In this study, the kinetics of Cd desorption from ten samples of contaminated calcareous soils, with widely varying physicochemical properties, were studied using 0.01 M EDTA extraction. The median percentage of Cd released was about 27.7% of the total extractable Cd in the soils. The release of Cd was characterized by an initial fast release rate (of labile fractions) followed by a slower release rate (of less labile fractions) and a model of two first-order reactions adequately describes the observed release of Cd from the studied soil samples. There was positive correlation between the amount of Cd released at first phase of release and Cd in exchangeable fraction, indicating that this fraction of Cd is the main fraction controlling the Cd in the kinetic experiments. There was strongly negative correlation between the amount of Cd released at first and second phases of release and residual fraction, suggesting that this fraction did not contribute in Cd release in the kinetic experiments. The results can be used to provide information for evaluation of Cd potential toxicity and ecological risk from contaminated calcareous soils.

  13. Fractionation of applied 32P labeled TSP in calcareous soils

    International Nuclear Information System (INIS)

    Calcareous dark brown red soil (calcixerollic xerochrept) from northern Syria was used in a pot experiment to study the fate of triple super phosphate fertilizer (TSP) with and without a crop (Local durum wheat (Triticum turgidum L. group durum (Desf)) c v. Bohouth). The soil received 17μg P/g soil of 32 P labeled TSP, and samples were collected from soils and plants at successive dates. Soil inorganic P was ≅94% of total soil P, with only 50-80% being soluble. Calcium phosphate compounds were the dominant fraction (≤68%) of the soluble inorganic soil P followed by occluded iron phosphate (≤48%) and all other fractions were ≤9%. Isotopic measurements showed that ≅ 50% of fertilizer P was nonexchangeable within 2 days, and TSP values in each fraction of soil inorganic P fluctuated in relatively similar proportions to the concentrations of fractions in soil. Available P (soil and TSP) in cropped soil was more than that in the uncropped soil, and plants had no effect on the distribution of P from fertilizer amongst the different P fractions. (author)

  14. Phosphorus Release to Floodwater from Calcareous Surface Soils and Their Corresponding Subsurface Soils under Anaerobic Conditions.

    Science.gov (United States)

    Jayarathne, P D K D; Kumaragamage, D; Indraratne, S; Flaten, D; Goltz, D

    2016-07-01

    Enhanced phosphorus (P) release from soils to overlying water under flooded, anaerobic conditions has been well documented for noncalcareous and surface soils, but little information is available for calcareous and subsurface soils. We compared the magnitude of P released from 12 calcareous surface soils and corresponding subsurface soils to overlying water under flooded, anaerobic conditions and examined the reasons for the differences. Surface (0-15 cm) and subsurface (15-30 cm) soils were packed into vessels and flooded for 8 wk. Soil redox potential and concentrations of dissolved reactive phosphorus (DRP) and total dissolved Ca, Mg, Fe, and Mn in floodwater and pore water were measured weekly. Soil test P was significantly smaller in subsurface soils than in corresponding surface soils; thus, the P release to floodwater from subsurface soils was significantly less than from corresponding surface soils. Under anaerobic conditions, floodwater DRP concentration significantly increased in >80% of calcareous surface soils and in about 40% of subsurface soils. The increase in floodwater DRP concentration was 2- to 17-fold in surface soils but only 4- to 7-fold in subsurface soils. With time of flooding, molar ratios of Ca/P and Mg/P in floodwater increased, whereas Fe/P and Mn/P decreased, suggesting that resorption and/or reprecipitation of P took place involving Fe and Mn. Results indicate that P release to floodwater under anaerobic conditions was enhanced in most calcareous soils. Surface and subsurface calcareous soils in general behaved similarly in releasing P under flooded, anaerobic conditions, with concentrations released mainly governed by initial soil P concentrations. PMID:27380087

  15. Boron and Zinc Transport Through Intact Columns of Calcareous Soils

    Institute of Scientific and Technical Information of China (English)

    M. MAHMOOD-UL-HASSAN; M. S. AKHTAR; G. NABI

    2008-01-01

    Leaching of boron (B) and zinc (Zn) can be significant in some pedomorphic conditions, which can cause contamination of shallow groundwater and economic losses. Boron and Zn adsorption and transport was studied using 8.4 cm diameter ×28 cm long intact columns from two calcareous soil series with differing clay contents and vadose zone structures:Lyallpur soil series, clay loam (fine-silty, mixed, hyperthermic Ustalfic Haplargid), and Sultanpur soil series, sandy loam (coarse-silty, mixed, hyperthermic Ustollic Camborthid). The adsorption isotherms were developed by equilibrating soil with 0.01 mol L-1 CaCl2 aqueous solution containing varying amounts of B and Zn and were fitted to the Langmuir equation. The B and Zn breakthrough curves were fitted to the two-domain convective-dispersive equation. At the end of the leaching experiment, 0.11 L 10 g L-1 blue dye solution was also applied to each column to mark the flow paths.The Lyallpur soil columns had a slightly greater adsorption partition coefficient both for B and Zn than the Sultanpur soil columns. In the Lyallpur soil columns, B arrival was immediate but the peak concentration ratio (the concentration in solution at equilibrium/concentration applied) was lower than that in the Sultanpur soil columns. The breakthrough of B in the Sultanpur soil columns occurred after about 10 cm of cumulative drainage in both the columns; the rise in effluent concentration was fast and the peak concentration ratio was almost 1. Zinc leaching through the soil columns was very limited as only one column from the Lyallpur soil series showed Zn breakthrough in the effluent where the peak concentration ratio was only 0.05. This study demonstrates the effect of soil structure on B transport and has implications for the nutrient management in field soils.

  16. Lead Retention in a Calcareous Soil Influenced by Calcium and Phosphate Amendments

    Science.gov (United States)

    Phosphate amendments in calcareous lead (Pb)-contaminated soils to immobilize Pb may be hindered due to competition of Pb with calcium (Ca) that may inhibit the retention of Pb as a precipitation mechanism. This study explored the retention of Pb in a calcareous soil spiked and ...

  17. Arsenopyrite weathering under conditions of simulated calcareous soil.

    Science.gov (United States)

    Lara, René H; Velázquez, Leticia J; Vazquez-Arenas, Jorge; Mallet, Martine; Dossot, Manuel; Labastida, Israel; Sosa-Rodríguez, Fabiola S; Espinosa-Cristóbal, León F; Escobedo-Bretado, Miguel A; Cruz, Roel

    2016-02-01

    Mining activities release arsenopyrite into calcareous soils where it undergoes weathering generating toxic compounds. The research evaluates the environmental impacts of these processes under semi-alkaline carbonated conditions. Electrochemical (cyclic voltammetry, chronoamperometry, EIS), spectroscopic (Raman, XPS), and microscopic (SEM, AFM, TEM) techniques are combined along with chemical analyses of leachates collected from simulated arsenopyrite weathering to comprehensively examine the interfacial mechanisms. Early oxidation stages enhance mineral reactivity through the formation of surface sulfur phases (e.g., S n (2-)/S(0)) with semiconductor properties, leading to oscillatory mineral reactivity. Subsequent steps entail the generation of intermediate siderite (FeCO3)-like, followed by the formation of low-compact mass sub-micro ferric oxyhydroxides (α, γ-FeOOH) with adsorbed arsenic (mainly As(III), and lower amounts of As(V)). In addition, weathering reactions can be influenced by accessible arsenic resulting in the formation of a symplesite (Fe3(AsO4)3)-like compound which is dependent on the amount of accessible arsenic in the system. It is proposed that arsenic release occurs via diffusion across secondary α, γ-FeOOH structures during arsenopyrite weathering. We suggest weathering mechanisms of arsenopyrite in calcareous soil and environmental implications based on experimental data. PMID:26498805

  18. Influence of several soil components and their interaction on plutonium extractability from a calcareous soil

    International Nuclear Information System (INIS)

    The influence of calcium carbonate, organic matter, and the inorganic fraction of a calcareous soil on the chemical extractability of 239Pu(IV) was examined using an equilibrium batch technique. The results showed that humic acids, CaCO3, the inorganic phase of the soil, and interaction of these materials could be important factors on the extractability of plutonium

  19. PHOSPHORUS FORMS IN CALCAREOUS SOIL AS AFFECTED BY IRRIGATION WATER SALINITY

    OpenAIRE

    ABOU HUSSIEN, E.A.; RADWAN, S.A.; KHALIL, R.A.; HAMAD, M.M.

    2012-01-01

    This study was carried out on five calcareous soils of Egypt characterized by different content (%) of calcium carbonate (CaCO3) and other physical and chemical properties to study their content of different forms of phosphorus and its affected by soil properties and irrigation water salinity. The tested calcareous soils were used in a greenhouse experiment, where these soils were planted by barley and irrigated by tap water and four sources of artificial saline water. The artificial saline ...

  20. Acoustic-Physical Properties of Calcareous Seafloor Soils and Their Significance in Engineering Geology

    Institute of Scientific and Technical Information of China (English)

    LU Bo; LI Ganxian; HUANG Shaojian

    2000-01-01

    The basic features and acoustic-physical properties of calcareous seafloor soils in the tropicsea area are obviously different fiom those of sediments mainly composed of terrigenons materials in the Sonth China Sea. Generally, calcareous soils, composed of carbonate particles of marine organism reimains, have the characteristics of high water content, high porosity, low wet density, high sound velocity and greatly varied compressive strength. Recognizing the differences between calcareons soils and terrigenous sedimeuts and engineering geologic significance of calcareous soils is crucial for seafloor geologic research and geotechnical survey for pile-jacket plattorm foundation design.

  1. CaCO3-N Relationships 4.Ln Calcareous Soil

    OpenAIRE

    Aydeniz, A.; BROHİ, A.R.

    1990-01-01

    Calcium carbonate at the rate of 0, 0.5; 1.0; 2.0; 5.0 and 10.0 per¬cent was applied to a highly calcareous soil (% 17.8 CaC03) , collected from South-East Anatolia region so as to see the effect of different ra¬tes of nitrogen (0, 1, 5; 20, 50, 100 and 200 ppm Wbeing applied ao ammonium ;. chloride to tomato© plant grown in growth cnarob.r conditions for 87 days In control (without IJmming) pots of acid so;I the dry matter yield of tomatoe; plant was 9.95 mg/pot as compared to 53.78 mg/pot ...

  2. The chemical characteristics of soil which determine phosphorus partitioning in highly calcareous soils

    OpenAIRE

    ANA TOPALOVIC; LIDIJA B. PFENDT; NATALIJA PEROVIC; DRAGANA DJORDJEVIC; SNEZANA TRIFUNOVIC; PETAR A. PFENDT

    2006-01-01

    Phosphorus fractions from three highly calcareous soils (average, 24.9 ± 4.8 %CO32-) from sampling sites with aMediterranean climate were isolated by sequential extraction. In order to provide a more reliable basis for the definition of the obtained P-fractions, principal component analysis was applied and from the chemical characteristics of the 14 investigated soils, those characteristics which define the content and association features of the P-fractions were assessed. The soils are chara...

  3. Methodological Modifications for Accurate and Efficient Determination of Contaminant Biodegradation in Unsaturated Calcareous Soils

    OpenAIRE

    Watwood, Mary E.; White, Carleton S.; Dahm, Clifford N.

    1991-01-01

    Many techniques for quantifying microbial biodegradation of 14C-labeled compounds use soil-water slurries and trap mineralization-derived 14CO2 in solution wells suspended within the incubation flasks. These methods are not satisfactory for studies of arid-region soils that are highly calcareous and unsaturated because (i) slurries do not simulate unsaturated conditions and (ii) the amount of CO2 released from calcareous soils exceeds the capacity of the suspended well. This report describes ...

  4. COMPARISON OF AL P AND OLSEN P TEST IN CALCAREOUS SOILS IN CROATIA

    Directory of Open Access Journals (Sweden)

    Brigita Popović

    2010-06-01

    Full Text Available The purpose of this article was to compare soil P extraction by sodium bicarbonate solution (Olsen P and by ammonium lactate (AL P in calcareous soils in Croatia and to create a model for predicting AL P values using the correlation of these soil tests and common soil analysis data in Croatia. Soil samples were collected, near Opuzen city, in the valley of the River Neretva, in 2005. The results of these studies confirmed significant correlation between soil P extracted by Olsen (NaHCO3 and by ammonium lactate (AL P solution in calcareous soils from the Neretva river valley. The developed model is useful for providing fertilizer recommendations based on AL P soil-test results from Croatian soils using existing ammonium lactateextractable P calibration expecially for the calcareous soils in Croatia in the valley of the Neretva River.

  5. Response of rice to zinc fertilizer in calcareous soils

    International Nuclear Information System (INIS)

    Three greenhouse experiments were conducted to study the response of rice crop to zinc fertilizer under waterlogged conditions using 65Zn-labelled ZnSO4 in 30 calcareous soils of North Bihar and Punjab having 2 to 36 per cent free CaCO3 content. Application of 5 kg Zn/ha gave significant increase in drymatter yield, total Zn content of rice in the first experiment. The soils differed significantly in drymatter yield, total Zn content, per cent Zn derived from fertilizer (Zndff) and Zn utilization by rice. Application of 5 ton/ha compost with 5 kg Zn/ha gave significantly higher drymatter production over 5 kg Zn/ha treatment but the total Zn content of plant showed significant reduction due to compost application. The per cent Zndff and utilization of Zn by rice remained at par in both the treatments. The soils differed significantly with respect to these characters as well as in the total Zn content in drymatter. The residual effect of Zn fertilizer treatments on the drymatter yield, per cent Zndff and Zn utilization by wheat crop did not differ significantly. The Zn content of wheat showed significant depression due to compost application along with Zn. (author). 11 refs., 3 tabs

  6. Silicomolybdenum Blue Colorimetric Determination of Available Si in Calcareous Soils

    Institute of Scientific and Technical Information of China (English)

    XUGUOHUA; ZHENGWENJUAN; 等

    1996-01-01

    This paper deals with the determination of available Si content in calcareous soils with Mo blue colorimetric analysis method.The experimental results showed that two acid reagents of sodium acetate buffering solution (pH 4) and 0.025 mol/L citric acid generally had a strong ability of extracting soil available Si,and theri soil filtrates were colorless,On the contrary,two alkaline extractants of 20 mg/mL sodium carbonate and 0.5 mol/L sodium bicarbonate only got a relevantly lower soil avaiable Si and theri extracts appeared deep color of organic and other pigments,which could be decolorized by adding certain amounts of P-free activated charcoal (about 0.1g/g soil),Int the procedure of Mo blue colorimetry,adding proper amount of oxalic acid and K(SbO)C4H4O6 could eliminate the interference of P to Si and Si to P,respectively.The concentration of acids was not the major factor suppressing the interferences between P and Si in the colorimetric analysis.In the medium of 0.2-0.8mole H×+/L sulfuric acid,the intensity of the silicomolybdate blue color did not vary with acidity,no matter whether(NH4)2 Fe(SO4)2 or ascorbic acid was used as reductive reagent.About 10 minutes was needed to from a fully blue complex at 20-25°C,After 30 minutes,the blue color would slowly change into light one,and hence,the colorimetric process should be finished within a short time.

  7. Sodium hypochlorite oxidation of petroleum aliphatic contaminants in calcareous soils.

    Science.gov (United States)

    Picard, François; Chaouki, Jamal

    2016-02-01

    This research project investigated the sodium hypochlorite (NaClO) oxidation of aliphatic petroleum contaminants (C10-C50) in a calcareous soil (average 5473 ppm C10-C50, 15 wt% Ca), which had been excavated from a contaminated industrial site. The decontamination objective was to lower the C10-C50 concentration to 700 ppm. CO2 acidity was used in the project to boost the NaClO oxidation yield and seems to have played a role in desorbing the natural organic matter. The experimental conditions were a 2- to 16-h reaction time, at room temperature, with a 1 to 12.5 wt% NaClO oxidative solution and a fixed 2:1 solution-to-soil ratio. With a 3 wt% NaClO solution and with a CO2 overhead, the NaClO dosage requirement was maintained below 60 g NaClO/g of oxidized C10-C50 over the entire decontamination range. The strong chlorine smell remaining after the reaction was completed suggests that part of the NaClO requirement can be recycled. Except traces of chloroform, there were no regulation-listed organochloride contaminants detected on either the treated soil samples or leachates and the total count of chlorinated compounds in treated soil samples was below the detection limit of 250 mg/kg. The NaClO oxidation mechanism on aliphatic substrates might be triggered by transition metals, such as manganese, but no attempt has been made to investigate the oxidation mechanism. Further investigations would include a constant-fed NaClO system and other techniques to lower the required NaClO dosage. PMID:26702553

  8. Recharge in northern clime calcareous sandy soils: soil water chemical and carbon-14 evolution

    International Nuclear Information System (INIS)

    Chemical analyses were performed on soil water extracted from two cores taken from a sandy calcareous soil near Delhi, Ontario. Calcite saturation is attained within the unsaturated zone over short distances and short periods of time, whereas dolomite undersaturation persists to the groundwater table. The progressive dissolution of dolomite by soil water, within the unsaturated zone, after calcite saturation is reached results in calcite supersaturation. Deposition of iron and manganese oxyhydroxide phases occurs at the carbonate leached/unleached zone boundary. This is a result of soil water neutralization due to carbonate dissolution during infiltration but may also reflect the increased rate of oxidation of dissolved ferrous and manganous ions at higher pH's. The role of bacteria in this process has not been investigated. The depth of the carbonate leached/unleached zone boundary in a calcareous soil has important implications for 14C groundwater dating. The depth of this interface at the study site (= approximately 2 m) does not appear to limit 14C diffusion from the root zone to the depth at which carbonate dissolution occurs. Thus, soil water achieves open system isotopic equilibrium with the soil CO2 gas phase. It is calculated that in soils with similar physical properties to the study soil but with depths of leaching of 5 m or more, complete 14C isotopic equilibration of soil water with soil gas would not occur. Soil water, under these conditions would recharge to the groundwater exhibiting some degree of closed system 14C isotopic evolution. (author)

  9. Phosphorus retention in calcareous soils and the effect of organic matter on its mobility

    OpenAIRE

    von Wandruszka Ray

    2006-01-01

    Abstract A survey of the interactions between phosphorus (P) species and the components of calcareous soils shows that both surface reactions and precipitation take place, especially in the presence of calcite and limestone. The principal products of these reactions are dicalcium phosphate and octacalcium phosphate, which may interconvert after formation. The role of calcium carbonate in P retention by calcareous soils is, however, significant only at relatively high P concentrations – non-ca...

  10. Electron Microscopic Observation of Clays of Calcareous and Noncalcareous Soils in Bangladesh

    OpenAIRE

    ALAM, Md. Lutfe; KAKOI, Teruzane; MIYAUCHI, Nobufumi; SHINAGAWA, Akio; カコイ, テルザネ; ミヤウチ, ノブフミ; シナガワ, アキオ

    1993-01-01

    Electron microscopic observation of calcareous and noncalcareous floodplain soils of Bangladesh were carried out by TEM and SEM. Morphological changes in relation to clay formation and weathering process were investigated. Unweathered, partially weathered and weathered micaceous mineralsaccompanying with poorly crystallized kaolinite and halloysite and other primary minerals were observed in silt and coarse clay of both calcareous and noncalcareous soil. Smectite and vermiculite which aredomi...

  11. Electron Microscopic Observation of Clays of Calcareous and Noncalcareous Soils in Bangladesh

    OpenAIRE

    ALAM, Md. Lutfe; KAKOI, Teruzane; MIYAUCHI, Nobufumi; SHINAGAWA, Akio; カコイ, テルザネ; ミヤウチ, ノブフミ; シナガワ, アキオ

    1993-01-01

    Electron microscopic observation of calcareous and noncalcareous floodplain soils of Bangladesh were carried out by TEM and SEM. Morphological changes in relation to clay formation and weathering process were investigated. Unweathered, partially weathered and weathered micaceous minerals accompanying with poorly crystallized kaolinite and halloysite and other primary minerals were observed in silt and coarse clay of both calcareous and noncalcareous soil. Smectite and vermiculite which are...

  12. Bioavailability of zinc and phosphorus in calcareous soils as affected by citrate exudation

    OpenAIRE

    Duffner, A.; Hoffland, E.; Temminghoff, E.J.M.

    2012-01-01

    Aims Zinc (Zn) and phosphorus (P) deficiency often occurs at the same time and limits crop production in many soils. It has been suggested that citrate root exudation is a response of plants to both deficiencies. We used white lupin (Lupinus albus L.) as a model plant to clarify if citrate exuded by roots could increase the bioavailability of Zn and P in calcareous soils. Methods White lupin was grown in nutrient solution and in two calcareous soils in a rhizobox. Rhizosphere soil solution wa...

  13. Fate and Distribution of Heavy Metals in Wastewater Irrigated Calcareous Soils

    OpenAIRE

    Mohammed Hashem Stietiya; Mohammad Duqqah; Theophilus Udeigwe; Ruba Zubi; Tarek Ammari

    2014-01-01

    Accumulation of heavy metals in Jordanian soils irrigated with treated wastewater threatens agricultural sustainability. This study was carried out to investigate the environmental fate of Zn, Ni, and Cd in calcareous soils irrigated with treated wastewater and to elucidate the impact of hydrous ferric oxide (HFO) amendment on metal redistribution among soil fractions. Results showed that sorption capacity for Zarqa River (ZR1) soil was higher than Wadi Dhuleil (WD1) soil for all metals. The ...

  14. Relation between various soil phosphorus extraction methods and sorption parameters in calcareous soils with different texture.

    Science.gov (United States)

    Jalali, Mohsen; Jalali, Mahdi

    2016-10-01

    The aim of this study was to investigate the influence of soil texture on phosphorus (P) extractability and sorption from a wide range of calcareous soils across Hamedan, western Iran. Fifty seven soil samples were selected and partitioned into five types on the basis of soil texture (clay, sandy, sandy clay loam, sandy loam and mixed loam) and the P extracted with calcium chloride (PCaCl2), citrate (Pcitrate), HCl (PHCl), Olsen (POls), and Mehlich-3 (PM3) solutions. On the average, the P extracted was in the order PHCl>PM3>Pcitrate>POls>PCaCl2. The P extracted by Pcitrate, PHCl, POls, and PM3 methods were significantly higher in sandy, sandy clay loam and sandy loam textures than clay and mixed loam textures, while soil phosphorus buffer capacity (PBC) was significantly higher in clay and mixed loam soil textures. The correlation analysis revealed a significant positive relationship between silt content Freundlich sorption coefficient (KF), maximum P sorption (Qmax), linear distribution coefficient (Kd), and PBC. All extractions were highly correlated with each other and among soil components with silt content. The principal component analysis (PCA) performed on data identified five principal components describing 74.5% of total variation. The results point to soil texture as an important factor and that silt was the crucial soil property associated with P sorption and its extractability in these calcareous soils. DPSM3-2 (PM3PM3+Qmax×100) and DPScitrate (PcitratePcitrate+Qmax×100) proved to be good indicators of soil's potential P release in these calcareous soils. Among the DPS, 21% of soils reported DPSM3-2, values higher than the environmental threshold, indicating build-up of P and P release. Most of the studied sandy clay loam soils had exceeded the environmentally unacceptable P concentration. Various management practices should be taken into account to reduce P losses from these soils. Further inorganic and organic P fertilizer inputs should be reduced

  15. A simple, gravimetric method to quantify inorganic carbon in calcareous soils

    Science.gov (United States)

    Total carbon (TC) in calcareous soils has two components: inorganic carbon (IC) as calcite and or dolomite and organic carbon (OC) in the soil organic matter. The IC must be measured and subtracted from TC to obtain OC. Our objective was to develop a simple gravimetric technique to quantify IC. Th...

  16. ADSORPTION, DEGRADATION, AND PLANT AVAILABILITY OF 2,4-DINITROPHENOL IN SLUDGE-AMENDED CALCAREOUS SOILS

    Science.gov (United States)

    Dinitrophenol (DNP) is a moderately weak acid that is expected to be highly labile (leachable and plant available) in high-pH soils. The adsorption and degradation behavior of DNP in two sludge-amended, calcareous soils was determined and used to explain DNP uptake by plants grow...

  17. Gravimetric Determination of Inorganic Carbon in Calcareous Soils Using the Carbonate-Meter

    Science.gov (United States)

    Organic carbon affects many important physical, chemical and microbiological soil properties. In calcareous soils, the inorganic carbon has to be measured and subtracted from the total carbon to obtain organic carbon. Our objective was to develop a gravimetric technique to quantify inorganic carbon ...

  18. Highly calcareous lacustrine soils in the Great Konya Basin, Turkey

    NARCIS (Netherlands)

    Meester, de T.

    1971-01-01

    The Great Konya Basin is in the south of the Central Anatolian Plateau in Turkey. It is a depression without outlet to the sea. The central part of the Basin is the floor of a former Pleistocene lake, the Ancient Konya Lake. This area, called the LacustrinePlain, has highly calcareous clayey sedimen

  19. Physical and microbiological properties of alluvial calcareous Çumra province soils (Central Anatolia, Turkey)

    OpenAIRE

    Ahmet Sami Erol; Evgeny Shein; Evgeny Milanovskiy; Fariz Mikailsoy; Fatih Er; Sabit Ersahin

    2015-01-01

    Alluvial calcareous soils in Central Anatolia (Konya province, Çumra district) has a heavy granulometric composition (average clay), low organic carbon content (less than 1%), but stable pore space structure and favorable agrophysical properties. Studies of the water regime in drip irrigation confirm favorable hydrological properties of these soils. It is assumed that the favorable structure of the pore space due to vigorous activity a large and diverse soil biota. Four phyla dominate in soil...

  20. Bacteria transport and retention in intact calcareous soil columns under saturated flow conditions

    OpenAIRE

    Firouzi, Ahmad Farrokhian; HOMAEE, Mehdi; Klumpp, Erwin; Kasteel, Roy; Tappe, Wolfgang

    2015-01-01

    Study of bacterial transport and retention in soil is important for various environmental applications such as groundwater contamination and bioremediation of soil and water. The main objective of this research was to quantitatively assess bacterial transport and deposition under saturated conditions in calcareous soil. A series of leaching experiments was conducted on two undisturbed soil columns. Breakthrough curves of Pseudomonas fluorescens and Cl were measured. After the leaching experim...

  1. The potential of residues of furfural and biogas as calcareous soil amendments for corn seed production.

    Science.gov (United States)

    Zhao, Yunchen; Yan, Zhibin; Qin, Jiahai; Ma, Zhijun; Zhang, Youfu; Zhang, Li

    2016-04-01

    Intensive corn seed production in Northwest of China produced large amounts of furfural residues, which represents higher treatment cost and environmental issue. The broad calcareous soils in the Northwest of China exhibit low organic matter content and high pH, which led to lower fertility and lower productivity. Recycling furfural residues as soil organic and nutrient amendment might be a promising agricultural practice to calcareous soils. A 3-year field study was conducted to evaluate the effects of furfural as a soil amendment on corn seed production on calcareous soil with compared to biogas residues. Soil physical-chemical properties, soil enzyme activities, and soil heavy metal concentrations were assessed in the last year after the last application. Corn yield was determined in each year. Furfural residue amendments significantly decreased soil pH and soil bulk density. Furfural residues combined with commercial fertilizers resulted in the greater cumulative on soil organic matter, total phosphorus, available phosphorus, available potassium, and cation exchange capacity than that of biogas residue. Simultaneously, urease, invertase, catalase, and alkaline phosphatase increased even at the higher furfural application rates. Maize seed yield increased even with lower furfural residue application rates. Furfural residues resulted in lower Zn concentration and higher Cd concentration than that of biogas residues. Amendment of furfural residues led to higher soil electrical conductivity (EC) than that of biogas residues. The addition of furfural residues to maize seed production may be considered to be a good strategy for recycling the waste, converting it into a potential resource as organic amendment in arid and semi-arid calcareous soils, and may help to reduce the use of mineral chemical fertilizers in these soils. However, the impact of its application on soil health needs to be established in long-term basis. PMID:26606935

  2. Estimation of the Biological Methods of Assessing Soil N-Supplying Capacity in Calcareous Soil

    Institute of Scientific and Technical Information of China (English)

    JIN Fa-hui; LI Shi-qing; LU Hong-ling; LI Sheng-xiu

    2007-01-01

    Although many biological methods are used to determine soil nitrogen supplying capacity, there are certain differences in the results for different types of soils and various ways of measurement due to the complexity of soil N conformation, the high variance of soil and microorganism, and the difference of environment. Therefore, it is not clear about which biologic incubation method is better for calcareous soil. In this study, pot experiments were performed by using 25 different calcareous surface soil samples on the Loess Plateau and taking the N uptake of wheat and corn with leaching soil initial nitrate and without leaching in pot experiments as the control to investigate the difference of eight biological incubation methods for reflecting soil nitrogen supply capacity. The eight biological methods are waterlogged incubation, aerobic incubation for 2 weeks and for 4 weeks, dry-wet alternation aerobic incubation for 2 weeks, long-term alternate leaching aerobic incubation (and N mineralization potential, N0), short-term leaching aerobic incubation, microbial biomass carbon (BC), and microbial biomass nitrogen (BN) method, respectively. Among these methods, the dry-wet alternation aerobic incubation and aerobic incubation for 4 weeks were the modification of the method of aerobic incubation for 2 weeks according to the actual farmland moisture. The results showed that the correlation coefficients between these methods and crop uptake N with leaching soil initial nitrate were 0.530, 0.700, 0.777, 0.768, 0.764 (and 0.790, N0), 0.650, 0.555, and 0.465, respectively (r0.05 = 0.369, r0.01 = 0.505). While without leaching soil initial nitrate, their coefficients were 0.351, 0.963, 0.962, 0.959, 0.825 (and 0.812, N0), 0.963, 0.289, and 0.095, respectively (r0.05=0.369, r0.01 =0.505). In conclusion,excluding the soil initial nitrate, the correlation coefficients between the eight methods and crop uptake N were, from high to low, N0, aerobic incubation for 4 weeks, dry

  3. Calcareous Sodic Soil Reclamation as Affected by Corn Stalk Application and Incubation:A Laboratory Study

    Institute of Scientific and Technical Information of China (English)

    LI Fa-Hu; R.KEREN

    2009-01-01

    A laboratory lysimeter experiment was conducted to investigate the effects of forage corn (Zea mays L.) stalk application on the CO2 concentration in soil air and calcareous sodic soil reclamation.The experimental treatments tested were soil exchangeable sodium percentage (ESP) levels of 1,11,and 19,added corn stalk contents of 0 to 36 g kg-1,and incubation durations of 30 and 60 days.The experimental results indicated that corn stalk application and incubation significantly increased CO2 partial pressure in soil profile and lowered pH value in soil solution,subsequently increased native CaCO3 mineral dissolution and electrolyte concentration of soil solution,and finally significantly contributed to reduction on soil sodicity level.The reclamation efficiency of calcareous sodic soils increased with the added corn stalk.When corn stalks were added at the rates of 22 and 34 g kg-1 into the soil with initial ESP of 19,its ESP value was decreased by 56% and 78%,respectively,after incubation of 60 days and the leaching of 6.5 pore volumes (about 48 L of percolation water) with distilled water.Therefore,crop stalk application and incubation could be used as a choice to reclaim moderate calcareous sodic soils or as a supplement of phytoremediation to improve reclamation efficiency.

  4. Fate and Distribution of Heavy Metals in Wastewater Irrigated Calcareous Soils

    Directory of Open Access Journals (Sweden)

    Mohammed Hashem Stietiya

    2014-01-01

    Full Text Available Accumulation of heavy metals in Jordanian soils irrigated with treated wastewater threatens agricultural sustainability. This study was carried out to investigate the environmental fate of Zn, Ni, and Cd in calcareous soils irrigated with treated wastewater and to elucidate the impact of hydrous ferric oxide (HFO amendment on metal redistribution among soil fractions. Results showed that sorption capacity for Zarqa River (ZR1 soil was higher than Wadi Dhuleil (WD1 soil for all metals. The order of sorption affinity for WD1 was in the decreasing order of Ni > Zn > Cd, consistent with electrostatic attraction and indication of weak association with soil constituents. Following metal addition, Zn and Ni were distributed among the carbonate and Fe/Mn oxide fractions, while Cd was distributed among the exchangeable and carbonate fractions in both soils. Amending soils with 3% HFO did not increase the concentration of metals associated with the Fe/Mn oxide fraction or impact metal redistribution. The study suggests that carbonates control the mobility and bioavailability of Zn, Ni, and Cd in these calcareous soils, even in presence of a strong adsorbent such as HFO. Thus, it can be inferred that in situ heavy metal remediation of these highly calcareous soils using iron oxide compounds could be ineffective.

  5. Integrated use of boiler ash as organic fertilizer and soil conditioner with NPK in calcareous soil

    Directory of Open Access Journals (Sweden)

    Muhammad Jamil Khan

    2008-05-01

    Full Text Available characteristics and provide a reasonable economic means to recycle these wastes in an environmentally friendly manner. To achieve this objective, sugar industry boiler ash was applied to wheat crop in pots having 20 kg soil @ 3, 12, 25,50, 125 and 250 t ha-1 respectively, compared to the control. Same doses of boiler ash were also applied to wheat crop in the field experiment. A basal dose of NPK, 120, 90, and 60 kg ha-1 respectively, was also applied with boiler ash before sowingof wheat crop in both experiments. The soil under investigation was calcareous in nature, having a high pH (8.2, low in organic matter (8200 mg kg-1, and deficient in N (300 mg kg-1, P (7.5 mg kg-1 and Zn (6.2 mg kg-1. Boiler ash was rich inmicronutrients like Fe, Mn, Zn and Cu and also contained sufficient amount of Ca, Mg, Na, S, K and P. Consequently, total porosity of soil, available P, S and K, Fe, Mn, Zn and Cu content in soil, increased with the levels of boiler ash application.On the other hand, dry bulk density declined which is a positive effect. ECe and pH of the soil was minutely increased. Yields and most of the yield components of wheat crop in pots, as well as in the field experiment, also increased due to boiler ashapplication. It is recommended that application of boiler ash @ 50 t ha-1 will result in enhanced yield of wheat in calcareous soil.

  6. Evidence For Different Reaction Pathways For Liquid And Granular Micronutrients In A Calcareous Soil

    Science.gov (United States)

    The benefits of Mn and Zn fluid fertilizers over conventional granular products in calcareous sandy loam soils have been agronomically demonstrated. We hypothesized that the differences in the effectiveness between granular and fluid Mn and Zn fertilizers is due to different Mn ...

  7. The potential of willow for remediation of heavy metal polluted calcareous urban soils

    DEFF Research Database (Denmark)

    Jensen, J K; Holm, P E; Nejrup, J;

    2009-01-01

    Growth performance and heavy metal uptake by willow (Salix viminalis) from strongly and moderately polluted calcareous soils were investigated in field and growth chamber trials to assess the suitability of willow for phytoremediation. Field uptakes were 2-10 times higher than growth chamber...

  8. Effect of Submergence on Iron Transformation and Phosphorus Availability in Calcareous Soils

    Institute of Scientific and Technical Information of China (English)

    ZHUXIAO-PING; YINJIN-LAI; 等

    1993-01-01

    A thermostatic incubation experiment was carried out to estimate the effects of flooding periods,stalk application and P addition of Fe transformation and P availability in calcareous soils.Submergence increased amorphous Fe,especially in the case of stalk application.The newly formed amorphous Fe with a great surface area played an important role in Psorption;and submergence also stimulated the dissolution of inorganic P,thus increasing the availability of soil P in calcareous soils.Meanwhile,a part of soluble P was absorbed and fixed again on the surface of newly formed amorphous Fe,thus resulting in a decrease of P availability.Soil rapidly available P increased after 150-day incubation.There existed significantly negative correlations between soil amorphous Fe content and soil Fe-P and rapidly available P contents.Submerged conditions promoted the transformation of inorganic P added toward Fe-P in calcareous soils,especially in the case of stalk application.

  9. COMPARISON OF AL P AND OLSEN P TEST IN CALCAREOUS SOILS IN CROATIA

    OpenAIRE

    Brigita Popović; Miranda Šeput; Zdenko Lončarić; Milena Andrišić; Danijel Rašić; Krunoslav Karalić

    2010-01-01

    The purpose of this article was to compare soil P extraction by sodium bicarbonatesolution (Olsen P) and by ammonium lactate (AL P) in calcareous soils in Croatiaand to create a model for predicting AL P values using the correlation of these soiltests and common soil analysis data in Croatia. Soil samples were collected, nearOpuzen city, in the valley of the River Neretva, in 2005. The results of these studiesconfirmed significant correlation between soil P extracted by Olsen (NaHCO3) andby a...

  10. Repeated use of ion-exchange resin membranes in calcareous soils

    Science.gov (United States)

    Sherrod, S.K.; Belnap, Jayne; Miller, M.E.

    2003-01-01

    This study compared the consistency of nutrient extraction among repeated cycles of ion-exchange resin membrane use. Two sandy calcareous soils and different equilibration temperatures were tested. No single nutrient retained consistent values from cycle to cycle in all treatments, although both soil source and temperature conferred some influence. It was concluded that the most conservative use of resin membranes is single-use.

  11. Black carbon estimation in French calcareous soils using chemo-thermal oxidation method

    OpenAIRE

    Caria, G.; Arrouays, D.; Dubromel, E.; Jolivet, C.; Ratié, C.; Bernoux, MARTIAL,; Barthès, Bernard; Brunet, Didier; Grinand, Clovis

    2011-01-01

    We studied the black carbon (BC) content of ca. 405 samples from French topsoil and artificial soil and carbonate mixtures. Our protocol involved three main steps: (i) decarbonation by HCl, (ii) elimination of non-pyrogenic organic carbon in a furnace at 375 degrees C, and (iii) quantification of residual carbon by CHN analysis. BC content increased for calcareous soils according to their carbonates content. Subsequent analyses confirmed the existence of a methodological artefact for BC deter...

  12. Fate of Zinc Oxide Nanoparticles Coated onto Macronutrient Fertilizers in an Alkaline Calcareous Soil

    OpenAIRE

    Narges Milani; Ganga M Hettiarachchi; Kirby, Jason K.; Douglas G Beak; Stacey, Samuel P.; Mike J. McLaughlin

    2015-01-01

    Zinc oxide (ZnO) nanoparticles may provide a more soluble and plant available source of Zn in Zn fertilizers due to their greater reactivity compared to equivalent micron- or millimetre-sized (bulk) particles. However, the effect of soil on solubility, spatial distribution and speciation of ZnO nanoparticles has not yet been investigated. In this study, we examined the diffusion and solid phase speciation of Zn in an alkaline calcareous soil following application of nanoparticulate and bulk Z...

  13. Manure and nitrogen application enhances soil phosphorus mobility in calcareous soil in greenhouses.

    Science.gov (United States)

    Yan, Zhengjuan; Chen, Shuo; Li, Junliang; Alva, Ashok; Chen, Qing

    2016-10-01

    Over many years, high phosphorus (P) loading for intensive vegetable cropping in greenhouses of North China has contributed to excessive P accumulation, resulting in environmental risk. In this study, the influences of manure and nitrogen (N) application on the transformation and transport of soil P were investigated after nine years in a greenhouse tomato double cropping system (winter-spring and autumn-winter seasons). High loading of manure significantly increased the soil inorganic P (Pi), inositol hexakisphosphate (IHP), mobile P and P saturation ratio (PSR, >0.7 in 0-30 cm depth soil; PSR was estimated from P/(Fe + Al) in an oxalate extract of the soil). The high rate of N fertilizer application to the studied calcareous soil with heavy loading of manure increased the following: (i) mobile organic P (Po) and Pi fractions, as evidenced by the decrease in the ratio of monoesters to diesters and the proportion of stable Pi (i.e., HCl-Pi) in total P (Pt) in 0-30 cm depth soil; (ii) relative distribution of Po in the subsoil layer; and (iii) P leaching to soil depths below 90 cm and the proportion of Po in Pt in the leachate. More acidic soil due to excessive N application increased P mobility and leaching. The increase in Ox-Al (oxalate-extractable Al) and the proportion of microbe-associated Po related to N application at soil depths of 0-30 cm suggested decrease in the net Po mineralization, which may contribute to downward transport of Po in the soil profile. PMID:27300290

  14. The potential of willow for remediation of heavy metal polluted calcareous urban soils

    International Nuclear Information System (INIS)

    Growth performance and heavy metal uptake by willow (Salix viminalis) from strongly and moderately polluted calcareous soils were investigated in field and growth chamber trials to assess the suitability of willow for phytoremediation. Field uptakes were 2-10 times higher than growth chamber uptakes. Despite high concentrations of cadmium (≥80 mg/kg) and zinc (≥3000 mg/kg) in leaves of willow grown on strongly polluted soil with up to 18 mg Cd/kg, 1400 mg Cu/kg, 500 mg Pb/kg and 3300 mg Zn/kg, it is unsuited on strongly polluted soils because of poor growth. However, willow proved promising on moderately polluted soils (2.5 mg Cd/kg and 400 mg Zn/kg), where it extracted 0.13% of total Cd and 0.29% of the total Zn per year probably representing the most mobile fraction. Cu and Pb are strongly fixed in calcareous soils. - Willow is suited for remediation of moderately heavy metal polluted calcareous soils

  15. The potential of willow for remediation of heavy metal polluted calcareous urban soils

    Energy Technology Data Exchange (ETDEWEB)

    Jensen, Julie K. [Department of Basic Sciences and Environment, Faculty of Life Sciences, University of Copenhagen, Thorvaldsensvej 40, 1871 Frederiksberg C (Denmark); Copenhagen Recycling Center, Selinevej 2, DK-2300 Kobenhavn S (Denmark)], E-mail: jje@life.ku.dk; Holm, Peter E. [Department of Basic Sciences and Environment, Faculty of Life Sciences, University of Copenhagen, Thorvaldsensvej 40, 1871 Frederiksberg C (Denmark); Nejrup, Jens [Copenhagen Recycling Center, Selinevej 2, DK-2300 Kobenhavn S (Denmark); Larsen, Morten B. [Department of Environmental Engineering, Technical University of Denmark, DK-2800 Lyngby (Denmark); Borggaard, Ole K. [Department of Basic Sciences and Environment, Faculty of Life Sciences, University of Copenhagen, Thorvaldsensvej 40, 1871 Frederiksberg C (Denmark)

    2009-03-15

    Growth performance and heavy metal uptake by willow (Salix viminalis) from strongly and moderately polluted calcareous soils were investigated in field and growth chamber trials to assess the suitability of willow for phytoremediation. Field uptakes were 2-10 times higher than growth chamber uptakes. Despite high concentrations of cadmium ({>=}80 mg/kg) and zinc ({>=}3000 mg/kg) in leaves of willow grown on strongly polluted soil with up to 18 mg Cd/kg, 1400 mg Cu/kg, 500 mg Pb/kg and 3300 mg Zn/kg, it is unsuited on strongly polluted soils because of poor growth. However, willow proved promising on moderately polluted soils (2.5 mg Cd/kg and 400 mg Zn/kg), where it extracted 0.13% of total Cd and 0.29% of the total Zn per year probably representing the most mobile fraction. Cu and Pb are strongly fixed in calcareous soils. - Willow is suited for remediation of moderately heavy metal polluted calcareous soils.

  16. Uptake of 137Cs by Leafy Vegetables and Grains from Calcareous Soils

    Energy Technology Data Exchange (ETDEWEB)

    Robison, W; Hamilton, T; Conrado, C; Kehl, S

    2004-04-19

    Cesium-137 was deposited on Bikini Island at Bikini Atoll in 1954 as a result of nuclear testing and has been transported and cycled in the ecosystem ever since. Atoll soils are of marine origin and are almost pure CaCO{sub 3} with high concentrations of organic matter in the top 40 cm. Data from previous experiments with mature fruit trees show very high transfer factors (TF's), [Bq g{sup -1} plant/ Bq g{sup -1} soil, both in dry weight] into fruits from atoll calcareous soil. These TF's are much higher than reported for continental, silica-based soils. In this report TF's for 5 types of leafy vegetable crops and 2 types of grain crops are provided for use in predictive dose assessments and for comparison with other data from other investigators working with other types of soil in the IAEA CRP ''The Classification of Soil Systems on the Basis of Transfer Factors of Radionuclides from Soil to Reference Plants''. Transfer factors for plants grown on calcareous soil are again very high relative to clay-containing soils and range from 23 to 39 for grain crops and 21 to 113 for leafy vegetables. Results from these experiments, in this unique, high pH, high organic content, low potassium (K) soil, provide a boundary condition for models relating soil properties to TF.

  17. Effects of low-molecular-weight organic acids on phosphorus sorption characteristics in some calcareous soils

    OpenAIRE

    MORADI, Neda; SADAGHIANI, Mir Hassan RASOULI; SEPEHR, Ebrahim

    2012-01-01

    Understanding the role of organic acids in phosphorus sorption in soils is very important for economic and environmentally friendly management of soil P. Thus, calcareous surface soils (0-30 cm) from West Azerbaijan Province, Iran, were sampled to study the effect of different organic acids on P sorption. Soil samples (2.5 g) were equilibrated with 25 mL of 0.01 M CaCl2 solution containing 0-20 mg P L-1 and 5 mmol L-1 of different organic acids (citric, oxalic, and malic acid). The sorption d...

  18. Improving the relationship between soil characteristics and metal bioavailability by using reactive fractions of soil parameters in calcareous soils.

    Science.gov (United States)

    de Santiago-Martín, Ana; van Oort, Folkert; González, Concepción; Quintana, José R; Lafuente, Antonio L; Lamy, Isabelle

    2015-01-01

    The contribution of the nature instead of the total content of soil parameters relevant to metal bioavailability in lettuce was tested using a series of low-polluted Mediterranean agricultural calcareous soils offering natural gradients in the content and composition of carbonate, organic, and oxide fractions. Two datasets were compared by canonical ordination based on redundancy analysis: total concentrations (TC dataset) of main soil parameters (constituents, phases, or elements) involved in metal retention and bioavailability; and chemically defined reactive fractions of these parameters (RF dataset). The metal bioavailability patterns were satisfactorily explained only when the RF dataset was used, and the results showed that the proportion of crystalline Fe oxides, dissolved organic C, diethylene-triamine-pentaacetic acid (DTPA)-extractable Cu and Zn, and a labile organic pool accounted for 76% of the variance. In addition, 2 multipollution scenarios by metal spiking were tested that showed better relationships with the RF dataset than with the TC dataset (up to 17% more) and new reactive fractions involved. For Mediterranean calcareous soils, the use of reactive pools of soil parameters rather than their total contents improved the relationships between soil constituents and metal bioavailability. Such pool determinations should be systematically included in studies dealing with bioavailability or risk assessment. PMID:25318656

  19. Dried gamma-irradiated sewage solids use on calcareous soils: crop yields and heavy metals uptake

    International Nuclear Information System (INIS)

    The fertilizer values of gamma-irradiated digested sewage solids (RDSS) and gamma-irradiated undigested sewage solids (RUSS) have been examined on calcareous soils. Previously published data from Sandia Laboratories have shown that approximately 1 mega-rad of gamma-irradiation effectively destroys pathogenic bacteria, parasites and plant seeds in dried sewage solids. Greenhouse experiments directly comparing gamma-irradiated and non-irradiated undigested and digested dried sewage solids as fertilizers indicate little or no effect of 1 mega-rad gamma radiation treatment on plant yield or plant-nutrient uptake and demonstrated considerable benefit from using sewage solids on calcareous soils. Plant response to undigested sewage solids was considerably greater than to digested sewage solids when applied at levels that were isonitrogenous. The calcareous soils in New Mexico typically range in pH from 7.5 to 9.0, limiting the plant-availability of many elements, especially heavy metals. Soils irrigated with sewage-effluent for 40 years demonstrated beneficial use of supplied plant-nutrients with no apparent increase in plant-uptake of heavy metals. RDSS applied to a calcareous soil low in plant-available iron increased plant growth in the greenhouse considerably more than treatments with equal amounts of nitrogen, phosphorus and iron applied as common fertilizer materials. Plant tissue concentrations of Fe, Zn, Mn and Cu showed that RDSS was a good source of these nutrients. Results also indicated that the total soluble salt concentration of the RDSS was the factor most limiting plant growth. Chromium, Cd, Ni and Pd plant-tissue concentrations were apparently not increased by RDSS treatments. (Auth.)

  20. Effects of drought on cadmium accumulation in peanuts grown in a contaminated calcareous soil.

    Science.gov (United States)

    Xia, Shenglan; Wang, Xvming; Su, Genqiang; Shi, Gangrong

    2015-12-01

    This study aimed to investigate the effects of drought stress on cadmium (Cd) accumulation in peanut (Arachis hypogaea L.) grown in contaminated calcareous soils. Five peanut cultivars were grown in a calcareous soil spiked with 4 mg Cd kg(-1) soil (dry weight) under well-watered, mild drought, and severe drought conditions. The biomass production, gas exchange, spectral reflectance, and Cd accumulation in plant tissues were determined. The five cultivars significantly differed from each other in biomass production, gas exchange, spectral reflectance, and Cd accumulation. The effect of drought on Cd accumulation in peanuts varies with plant tissues, cultivars, and developmental stages. Drought decreased root Cd concentrations in seedlings of the two high Cd-accumulating cultivars (Haihua 1 and Zhenghong 3), which is associated with increasing leaf active Fe content. However, for the mature plants, drought stress caused an increase in Cd accumulation in roots, pod walls, and seeds depending on peanut cultivars. Negative correlations were found between seed Cd concentration and biomasses in both preflowering seedlings and mature plants. The seed Cd concentration in mature plants was also observed to be positively correlated with the shoot Cd concentration in preflowering seedlings. The increased Cd concentration in seeds of drought-stressed peanut plants grown in Cd-contaminated calcareous soils might be attributed to the drought-induced decrease of biomass production. PMID:26194243

  1. Preliminary validation of a sequential fractionation method to study phosphorus chemistry in a calcareous soil.

    Science.gov (United States)

    Audette, Yuki; O'Halloran, Ivan P; Evans, Les J; Voroney, R Paul

    2016-06-01

    A sequential fractionation method proposed by Jiang and Gu (1989) distinguished three types of calcium phosphates (Ca-P) according to their different plant availabilities. Three extractants, NaHCO3, NH4Ac, and H2SO4 were used to extract Ca2-P, Ca8-P, and Ca10-P types, respectively, from soil. This sequential fractionation method was tested and modified for analyzing the P chemistry of a calcareous soil. The solubility test and the model diagrams of the stability of the major Ca-P minerals showed that NaHCO3 was able to extract brushite (Ca2-P type), and NH4Ac extracted brushite and β-tricalcium P (Ca8-P type) as well as hydroxyapatite (Ca10-P type). Therefore the P forms targeted by extraction with NH4Ac should include both Ca8-and Ca10-P types. The sum of the P extracted by all extractants in the sequential fractionation method in the calcareous soil was in agreement with the total P measured by the perchloric acid digestion method. A proportion of organic P measured by the sequential fractionation method was in agreement with the result from solution (31)P NMR spectroscopy. This study showed that the modified sequential fractionation method and its target P forms would be useful for quantifying and characterizing inorganic and organic P in a calcareous soil, even though it should be used in combination with other techniques, such as solution (31)P NMR spectroscopy. PMID:26994430

  2. Carbon mineralization and nutrient availability in calcareous sandy soils amended with woody waste biochar.

    Science.gov (United States)

    El-Naggar, Ahmed H; Usman, Adel R A; Al-Omran, Abdulrasoul; Ok, Yong Sik; Ahmad, Mahtab; Al-Wabel, Mohammad I

    2015-11-01

    Many studies have reported the positive effect of biochar on soil carbon sequestration and soil fertility improvement in acidic soils. However, biochar may have different impacts on calcareous sandy soils. A 90-day incubation experiment was conducted to quantify the effects of woody waste biochar (10 g kg(-1)) on CO2-C emissions, K2SO4-extractable C and macro-(N, P and K) and micro-(Fe, Mn, Zn and Cu) nutrient availability in the presence or absence of poultry manure (5 g kg(-1) soil). The following six treatments were applied: (1) conocarpus (Conocarpus erectus L.) waste (CW), (2) conocarpus biochar (BC), (3) poultry manure (PM), (4) PM+CW, (5) PM+BC and (6) untreated soil (CK). Poultry manure increased CO2-C emissions and K2SO4-extractable C, and the highest increases in CO2-C emission rate and cumulative CO2-C and K2SO4-extractable C were observed for the PM+CW treatment. On the contrary, treatments with BC halted the CO2-C emission rate, indicating that the contribution of BC to CO2-C emissions is negligible compared with the soils amended with CW and PM. Furthermore, the combined addition of PM+BC increased available N, P and K compared with the PM or BC treatments. Overall, the incorporation of biochar into calcareous soils might have benefits in carbon sequestration and soil fertility improvement. PMID:26037818

  3. Uptake of caesium-137 by leafy vegetables and grains from calcareous soils

    International Nuclear Information System (INIS)

    137Cs was deposited on Bikini Island at Bikini Atoll in 1954 as a result of nuclear testing and has been transported and cycled in the ecosystem ever since. Atoll soils are of marine origin and are almost pure CaCO3 with high concentrations of organic matter in the top 40 cm. Data from previous experiments with mature fruit trees show very high transfer factors (TFs), [Bq kg-1 plant/Bq kg-1 soil, both in dry weight] into fruits from atoll calcareous soil. These TFs are much higher than reported for continental, silica-based soils. In this report TFs for five types of leafy vegetable crops and two types of grain crops are provided for use in predictive dose assessments and for comparison with other data from other investigators working with other types of soil in this CRP. Transfer factors for plants grown on calcareous soil are again very high relative to clay-containing soils and range from 2339 for grain crops and 21-113 for leafy vegetables. Results from these experiments, in this unique, high pH, high organic content, low potassium (K) soil, provide a boundary condition for models relating soil properties to TF. (author)

  4. Crop Yield and Soil Properties in the First 3 Years After Biochar Application to a Calcareous Soil

    Institute of Scientific and Technical Information of China (English)

    LIANG Feng; LI Gui-tong; LIN Qi-mei; ZHAO Xiao-rong

    2014-01-01

    It remains unclear whether biochar applications to calcareous soils can improve soil fertility and crop yield. A long-term ifeld experiment was established in 2009 so as to determine the effect of biochar on crop yield and soil properties in a calcareous soil. Five treatments were: 1) straw incorporation; 2) straw incorporation with inorganic fertilizer; 3), 4) and 5) straw incorporation with inorganic fertilizer, and biochar at 30, 60, and 90 t ha-1, respectively. The annual yield of either winter wheat or summer maize was not increased signiifcantly following biochar application, whereas the cumulative yield over the ifrst 4 growing seasons was signiifcantly increased. Soil pH, measured in situ, was increased by a maximum of 0.35 units after 2 yr following biochar application. After 3 yr, soil bulk density signiifcantly decreased while soil water holding capacity increased with adding biochar of 90 t ha-1. Alkaline hydrolysable N decreased but exchangeable K increased due to biochar addition. Olsen-P did not change compared to the treatment without biochar. The results suggested that biochar could be used in calcareous soils without yield loss or signiifcant impacts on nutrient availability.

  5. Wheat-Exuded Organic Acids Influence Zinc Release from Calcareous Soils

    Institute of Scientific and Technical Information of China (English)

    M. A. MAQSOOD; S. HUSSAIN; T. AZIZ; M. ASHRAF

    2011-01-01

    Rhizosphere drives plant uptake of sparingly soluble soil zinc (Zn).An investigation with three experiments was conducted to study organic acid exudation by two contrasting wheat genotypes (Sehar-06 and Vatan),Zn fractious in 10 different calcareous soils from Punjab,Pakistan,and release of different soil Zn fractions by organic acids.The two genotypes differed significantly in biomass production and Zn accumulation under deficient and optimum Zn levels in nutrient solution.At a deficient Zn level,Sehar-06 released more maleic acid in the rhizosphere than Vatan.Ten soils used in the present study had very different physicochemical properties; their total Zn and Zn distribution among different fractions varied significantly.Zinc release behaviour was determined by extracting the soils with 0.005 mol L-1 citric acid or maleic acid.The parabolic diffusion model best described Zn release as a function of time.Parabolic diffusion model fitting indicated more maleic acid-driven than citric acid-driven soil Zn mobility from different fractions.Cumulative Zn release in six consecutive extractions during 24 h ranged from 1.85 to 13.58 mg kg-1 using maleic acid and from 0.37 to 11.84 mg kg-1 using citric acid.In the selected calcareous soils,the results of stepwise linear regression indicated significant release of Fe-Mn oxide-bounded soil Zn by maleic acid and its availability to the Zn-efficient genotype.Hence,release of maleic acid by plants roots played an important role in phytoavailability of Zn from calcareous soils.

  6. Mutational reconstructed ferric chelate reductase confers enhanced tolerance in rice to iron deficiency in calcareous soil

    OpenAIRE

    Ishimaru, Yasuhiro; Kim, Suyeon; Tsukamoto, Takashi; Oki, Hiroyuki; Kobayashi, Takanori; Watanabe, Satoshi; Matsuhashi, Shinpei; Takahashi, Michiko; Nakanishi, Hiromi; Mori, Satoshi; Naoko K. Nishizawa

    2007-01-01

    Iron (Fe) deficiency is a worldwide agricultural problem on calcareous soils with low-Fe availability due to high soil pH. Rice plants use a well documented phytosiderophore-based system (Strategy II) to take up Fe from the soil and also possess a direct Fe2+ transport system. Rice plants are extremely susceptible to low-Fe supply, however, because of low phytosiderophore secretion and low Fe3+ reduction activity. A yeast Fe3+ chelate-reductase gene refre1/372, selected for better performance...

  7. Contribution of Iron Phosphate in Calcareous Paddy Soils to Phosphorus Nutrition of Rice Plant

    Institute of Scientific and Technical Information of China (English)

    GUOZHI-FEN; TUSHU-XIN; 等

    1995-01-01

    A study was carried out on contribution of iron phosphate to phosphorus nutrition of rice plant under waterlogged and moist conditions,respectively,by use of synthetic Fe32 PO4.nH2O,tagging directly the iron phophate in calcareous paddy soils.Results showed that under waterlogged condition,similar to iron phosphate in acidic paddy soils.that in clacareous paddy soils was an important source of phosphorus to rice plant ,and the amount of phosphorus originated from it generally constituted 30-65% of the total phosphorus absorbed by rice plant.

  8. Effect of Organic Fertilizers on Soil Chemical Properties on Vineyard Calcareous Soil

    Directory of Open Access Journals (Sweden)

    Tomislav Karažija

    2015-12-01

    Full Text Available Organic fertilizers are an important contribution of organic matter that modify the physical, chemical and microbiological characteristics of the soil. The aim of investigation was to determine the effect of different organic fertilization on soil chemical properties on vineyard calcareous soil. Two-year fertilization trial was carried out in the Plešivica wine-growing region, in a 10-year old vineyard, cv. Sauvignon White grafted on Kobber 5BB rootstock, planted on soil with quite high pH for grapevine growing. The trial was performed according to randomize complete block design with 6 treatments (unfertilized, farmyard manure 20 t ha-1 and 40 t ha-1, peat 20 000 L ha-1 and 40 000 L ha-1, NPK 5-20-30 500 kg ha-1+200 kg UREA ha-1 in 4 repetitions. Statistically significant differences in soil reaction (pH in plowing layer (0-30 cm were found among fertilization treatments in the second year of studies. In the plowing layer (0-30 cm in both years of the study significant differences between the values of average total nitrogen content and available phosphorus as well were found, while there were no significant differences in the subplowing layer (30-60cm. Regarding to average value of fertilization treatment, statistically significant difference in the content of available potassium in plowing layer were found in the both investigated years, while in subplowing layer statistical differences were found in the first year of investigation only. Therefore, fertilization with different organic fertilizers significantly influenced the most of studied chemical properties of the soil, especially in plowing layer (0-30 cm.

  9. Yield performance of cowpea plant introductions grown in calcareous soils

    Science.gov (United States)

    Cowpea or Southernpea [Vigna unguiculata (L.) Walp.] is an important legume crop used as a feed for livestock, as a green vegetable and for consumption of its dry beans which provide 22-25% protein. The crop is very sensitive to alkaline soil conditions. When grown at a soil pH of 7.5 or higher, co...

  10. Potential for breeding white lupin for calcareous rich soils in the Netherlands

    OpenAIRE

    Nuijten, E.; Prins, Udo

    2015-01-01

    White lupin (Lupinus albus) can be an interesting crop for both organic and conventional farmers who are looking for leguminous crops to broaden their crop rotation scheme. Lupin is also of interest for food processors as a guaranteed GMO-free protein source for the replacement of soy. However, the available varieties ripen too late in the Netherlands. Furthermore, the largest areas suitable for arable farming are calcareous rich clayey soils. So, there is a need for early maturing calcium to...

  11. Relationships of 137Cs inventory with magnetic measures of calcareous soils of hilly region in Iran

    International Nuclear Information System (INIS)

    Erosion is a natural process, but it has been dramatically increased by human activities; and this adversely influences soil productivity and environmental quality. For quantification of soil erosion, several techniques including the use of Cs-137 have been employed. This study was conducted to explore the relationships of Cs-137 inventory with magnetic properties in calcareous soils in western Iran. Ten transects were selected in the hilly region in Chelgerd district of Iran. Soil samples from 0 to 30 and 30–50 cm depths were collected from fifty points to determine Cs-137 inventory, magnetic measures and selected physico-chemical properties (in total there were 100 soil samples). The results showed that simple mass balance model (SMBM) estimated a gross erosion rate of 29.6 t ha−1 yr−1 and a net soil deposition of 21.8 t ha−1 yr−1; hence, a net soil loss of 9.6 t ha−1 yr−1 and a sediment delivery ratio of 31.4%. Simple linear regression and non-linear regression analysis showed that mass magnetic susceptibility (χlf) explained only 33.64% and 45% of variability in Cs-137 in the transects studied. The results of multiple linear regression analysis of 137Cs with magnetic parameters and physico-chemical properties indicated that extractable potassium and χlf explained approximately 61% of the total variability in 137Cs in the area studied. Overall, the results suggest that further research is needed for the use of magnetic characteristics as an alternative technique in place Cs-137 methodology for calcareous soils. - Highlights: ► Simple linear regression mass magnetic susceptibility (χL) explained only 33.64 % of Cs-137 variability. ► Non-linear regression model explained 45% of variability in Cs-137 in the transects studied. ► Magnetic Susceptibility measures could not directly be used in calcareous soils to evaluate soil redistribution. ► Magnetic characteristics as an alternative technique instead of Cs-137 in calcareous soils should be

  12. Effect of Additional Carbonates on CO2 Emission from Calcareous Soil During the Closed-Jar Incubation

    Institute of Scientific and Technical Information of China (English)

    DONG Yan-Jie; CAI Miao; LIANG Bin; ZHOU Jian-Bin

    2013-01-01

    The closed-jar incubation method is widely used to estimate the mineralization of soil organic C.There are two C pools (i.e.,organic and inorganic C) in calcareous soil.To evaluate the effect of additional carbonates on CO2 emission from calcareous soil during closed-jar incubation,three incubation experiments were conducted by adding different types (CaCO3 and MgCO3) and amounts of carbonate to the soil.The addition of carbonates significantly increased CO2 emission from the soil; the increase ranged from 12.0% in the CaCO3 amended soil to 460% in the MgCO3 amended soil during a 100-d incubation.Cumulative CO2 production at the end of the incubation was three times greater in the MgCO3 amended soil compared to the CaCO3 amended one.The CO2 emission increased with the amount of CaCO3 added to the soil.In contrast,CO2 emission decreased as the amount of MgCO3 added to the soil increased.Our results confirmed that the closed-jar incubation method could lead to an overestimate of organic C mineralization in calcareous soils.Because of its effect on soil pH and the dissolution of carbonates,HgC12 should not be used to sterilize calcareous soil if the experiment includes the measurement of soil CO2 production.

  13. The chemical characteristics of soil which determine phosphorus partitioning in highly calcareous soils

    Directory of Open Access Journals (Sweden)

    ANA TOPALOVIC

    2006-11-01

    Full Text Available Phosphorus fractions from three highly calcareous soils (average, 24.9 ± 4.8 %CO32- from sampling sites with aMediterranean climate were isolated by sequential extraction. In order to provide a more reliable basis for the definition of the obtained P-fractions, principal component analysis was applied and from the chemical characteristics of the 14 investigated soils, those characteristics which define the content and association features of the P-fractions were assessed. The soils are characterized by a relatively high pH (8.0 – 8.2 and by significantly differing contents of organic mater, acid-soluble Mg and total P. These differences affected the various association features of the P-fraction with the soil constituents. The NH4F–P fraction (isolated with 0.5 M NH4F, pH 8.2 is defined by the contents of the main metals of the oxide–hydroxide–clay associations (Al, Fe,Mn or by the the redox potential (Eh of Mn. The accumulation of NaOH–phosphorus (extractable with 0.1M NaOH depended on the constituents of the oxide–hydroxide–clay association, the humic substances and Eh-related factors. In those soils in whichNaOH–Pis defined by the oxide–hydroxide–clay assoiation, the participation of Fe as a bridge-forming metal is proposed. The main part of total P, i.e., DP = TP – (NH4F–P + NaOH–P is defined by the status of Mn– and Fe–humic complexes or by the concentration of hydroxyl-ions.

  14. Organic Carbon Stabilization of Soils Formed on Acidic and Calcareous Bedrocks in Neotropical Alpine Grassland, Peru

    Science.gov (United States)

    Yang, Songyu; Cammeraat, Erik; Jansen, Boris; Cerli, Chiara; Kalbitz, Karsten

    2016-04-01

    Increasing evidence shows that Neotropical alpine ecosystems are vulnerable to global change. Since soils in the alpine grasslands of the Peruvian Andean region have large soil organic carbon (SOC) stocks, profound understanding of soil organic matter (OM) stabilization mechanisms will improve the prediction of the feedback between SOC stocks and global change. It is well documented that poor-crystalline minerals and organo-metallic complexes significantly contribute to the OM stabilization in volcanic ash soils, including those in the Andean region. However, limited research has focused on non-ash soils that also express significant SOC accumulation. A pilot study of Peruvian Andean grassland soils suggests that lithology is a prominent factor for such carbon accumulation. As a consequence of contrasting mineral composition and pedogenic processes in soils formed on different non-volcanic parent materials, differences in OM stabilization mechanisms may be profound and consequently may respond differently to global change. Therefore, our study aims at a further understanding of carbon stocks and OM stabilization mechanisms in soils formed on contrasting bedrocks in the Peruvian Andes. The main objective is to identify and compare the roles that organo-mineral associations and aggregations play in OM stabilization, by a combination of selective extraction methods and fractionations based on density, particle size and aggregates size. Soil samples were collected from igneous acidic and calcareous sedimentary bedrocks in alpine grassland near Cajamarca, Peru (7.17°S, 78.63°W), at around 3700m altitude. Samples were taken from 3 plots per bedrock type by sampling distinguishable horizons until the C horizons were reached. Outcomes confirmed that both types of soil accumulate large amounts of carbon: 405.3±41.7 t/ha of calcareous bedrock soil and 226.0±5.6 t/ha of acidic bedrock soil respectively. In addition, extremely high carbon contents exceeding 90g carbon per

  15. Isolation and identification of ferric reducing bacteria and evaluation of their roles in iron availability in two calcareous soils

    Science.gov (United States)

    Ghorbanzadeh, N.; Lakzian, A.; Haghnia, G. H.; Karimi, A. R.

    2014-12-01

    Iron is an essential element for all organisms which plays a crucial role in important biochemical processes such as respiration and photosynthesis. Iron deficiency seems to be an important problem in many calcareous soils. Biological dissimilatory Fe(III) reduction increases iron availability through reduction of Fe(III) to Fe(II). The aim of this study was to isolate, identify and evaluate some bacterial isolates for their abilities to reduce Fe(III) in two calcareous soils. Three bacterial isolates were selected and identified from paddy soils by using 16S rRNA amplification and then inoculated to sterilized and non-sterilized calcareous soils in the presence and absence of glucose. The results showed that all isolates belonged to Bacillus genus and were capable of reducing Fe(III) to Fe(II) in vitro condition. The amount of Fe(III) reduction in sterilized calcareous soils was significantly higher when inoculated with PS23 isolate and Shewanella putrefaciens ( S. putrefaciens) (as positive control) compared to PS16 and PS11 isolates. No significant difference was observed between PS11 and PS16 isolates in the presence of indigenous microbial community. The results also revealed that glucose had a significant effect on Fe(III) reduction in the examined calcareous soil samples. The amount of Fe(III) reduction increased two-fold when soil samples were treated with glucose and inoculated by S. putrefaciens and PS23 in non-sterilized soils.

  16. Adsorption and co-adsorption of diclofenac and Cu(II) on calcareous soils.

    Science.gov (United States)

    Graouer-Bacart, Mareen; Sayen, Stéphanie; Guillon, Emmanuel

    2016-02-01

    Pharmaceuticals are emerging contaminants and their presence in different compartments of the environment has been detected in many countries. In this study, laboratory batch experiments were conducted to characterize the adsorption of diclofenac, a widely used non-steroidal anti-inflammatory drug, on six calcareous soils. The adsorption of diclofenac was relatively low, which may lead to a risk of groundwater contamination and plant uptake. A correlation between the soil-water distribution coefficient Kd and soil characteristics has been highlighted. Indeed, diclofenac adsorption as a function of soil organic matter content (% OM) and Rt=% CaCO3/% OM was successfully described through a simple empirical model, indicating the importance of considering the inhibiting effect of CaCO3 on OM retention properties for a better assessment of diclofenac fate in the specific case of calcareous soils. The simultaneous co-adsorption of diclofenac and copper - a ubiquitous pollutant in the environment - at the water/soil interface, was also investigated. It appeared quite unexpectedly that copper did not have a significant influence on diclofenac retention. PMID:26599281

  17. Characterization of commercial iron chelates and their behavior in an alkaline and calcareous soil.

    Science.gov (United States)

    Cantera, Rodrigo G; Zamarreño, Angel M; García-Mina, José M

    2002-12-18

    Iron deficiency is a common problem for many plants grown in alkaline and calcareous soils. To correct this problem, iron is supplied to plants as chelates. Several iron chelates are sold under diverse trademarks with different characteristics. This work evaluated 18 commercial products containing the most representative chelated iron sources used in agricultural practice in Spain when the study was done, namely the ferric chelates of EDDHA, EDDHMA, EDDCHA, EDDHSA, EDTA, and DTPA. The chelates were comprehensively characterized and quantitated by several techniques, including several chromatographic methods. Iron and chelate dynamics in soil were also studied in a model alkaline and calcareous soil. Results indicate that, in this model soil, among the different iron compounds studied only FeEDDHA and analogues have the capacity to maintain soluble iron in soil solution over time. These results are in agreement with general experience under field conditions. Furthermore, among the different ortho-ortho isomers of FeEDDHA's, FeEDDHSA and FeEDDCHA showed greater capacity than FeEDDHA and FeEDDHMA to maintain the chelated iron in soil solution over time. PMID:12475278

  18. Kinetics of addition of nitrogen-15 labelled nitrates to organic matter in a calcareous soil

    International Nuclear Information System (INIS)

    In a calcareous soil the transformation of added nitrates with or without wheat straw was studied. By using 15N it was possible to compare the net and real nitrification of the organic soil nitrogen, the mineral nitrogen organization and the denitrification losses. The observed priming effect was interpreted as a result of some modifications of nitrification-organization kinetics due to the high nitrate fertilization. The net nitrification is about three times less than the primary nitrification which is likely to be found even in a period of high organization. Finally the losses by denitrification appear even with a straw which immobilizes the nitrate nitrogen

  19. Net transformation of phosphorus forms applied as inorganic and organic amendments to a calcareous soil

    Science.gov (United States)

    Audette, Yuki; O'Halloran, Ivan; Voroney, Paul

    2016-04-01

    The forms of phosphorus (P) in animal manure composts are different from that of synthetic P fertilizers, and this could affect how soil P chemistry will be altered when they are used as P amendments. The objective of this study was to analyze the net changes in the nature and dynamics of plant available P forms applied either as inorganic P (KH2PO4) or turkey litter compost (TLC) in calcareous soil with and without plant growth. Forms of TLC-P were characterized by x-ray diffraction and solution 31P NMR spectroscopy techniques. The amounts of various P forms in soils were measured by a sequential fractionation method after 4, 8, 12 and 16 weeks incubation. Brushite (Ca-P) and newberyite (Mg-P) were the major forms of inorganic P, and phosphate monoester was the major form of organic P present in TLC. The addition of inorganic P fertilizer increased the labile/moderately labile P, whereas the compost increased the moderately labile P extractable with weak acid (pH 4.2). Even though the amount of the labile P fraction in the compost-treated soil was smaller than that in the fertilizer-treated soils, ryegrass growth and plant P uptake were greater. The net transformation of the labile/moderately labile P was slower in the compost-treated soil without plant growth, however it was faster with plant growth. This study showed that P applied either as an inorganic or an organic amendment was recovered in different P fractions in a calcareous soil, and therefore it is expected that the P source would affect soil P chemistry. A weak acid extractable inorganic P fraction should be considered as plant available P especially in the compost-treated soil, that is converted into plant available P through direct and/or indirect root-induced acidification in the rhizosphere.

  20. Optimizing Available Phosphorus in Calcareous Soils Fertilized with Diammonium Phosphate and Phosphoric Acid Using Freundlich Adsorption Isotherm

    OpenAIRE

    Asif Naeem; Muhammad Akhtar; Waqar Ahmad

    2013-01-01

    In calcareous soils, phosphorus (P) retention and immobilization take place due to precipitation and adsorption. Since soil pH is considered a major soil variable affecting the P sorption, an acidic P fertilizer could result in low P adsorption compared to alkaline one. Therefore, P adsorption from DAP and phosphoric acid (PA) required to produce desired soil solution P concentration was estimated using Freundlich sorption isotherms. Two soils from Faisalabad and T. T. Singh districts were sp...

  1. Effect of lemon waste on soil ph and availability of micronutrient in calcareous soils of fars province, Southern Iran

    OpenAIRE

    Gharaie, Hossienali

    2008-01-01

    Most of soils of Iran are calcareous in nature. The orchard trees are widespread in south of Iran. Sour lemon is one product of the area and is processed for lemon juice. To evaluate the effect of lemon waste on soil pH and availability of micronutrients, composite soil samples were collected from 0-40 Cm of the area and analyzed for physico- chemical properties. Lemon waste was gathered from processing factory, dried at 70 c and crushed to 1-2 mm size. A statistical complete r...

  2. Biochar and manure affect calcareous soil and corn silage nutrient concentrations and uptake.

    Science.gov (United States)

    Lentz, R D; Ippolito, J A

    2012-01-01

    Carbon-rich biochar derived from the pyrolysis of biomass can sequester atmospheric CO, mitigate climate change, and potentially increase crop productivity. However, research is needed to confirm the suitability and sustainability of biochar application to different soils. To an irrigated calcareous soil, we applied stockpiled dairy manure (42 Mg ha dry wt) and hardwood-derived biochar (22.4 Mg ha), singly and in combination with manure, along with a control, yielding four treatments. Nitrogen fertilizer was applied when needed (based on preseason soil test N and crop requirements) in all plots and years, with N mineralized from added manure included in this determination. Available soil nutrients (NH-N; NO-N; Olsen P; and diethylenetriaminepentaacetic acid-extractable K, Mg, Na, Cu, Mn, Zn, and Fe), total C (TC), total N (TN), total organic C (TOC), and pH were evaluated annually, and silage corn nutrient concentration, yield, and uptake were measured over two growing seasons. Biochar treatment resulted in a 1.5-fold increase in available soil Mn and a 1.4-fold increase in TC and TOC, whereas manure produced a 1.2- to 1.7-fold increase in available nutrients (except Fe), compared with controls. In 2009 biochar increased corn silage B concentration but produced no yield increase; in 2010 biochar decreased corn silage TN (33%), S (7%) concentrations, and yield (36%) relative to controls. Manure produced a 1.3-fold increase in corn silage Cu, Mn, S, Mg, K, and TN concentrations and yield compared with the control in 2010. The combined biochar-manure effects were not synergistic except in the case of available soil Mn. In these calcareous soils, biochar did not alter pH or availability of P and cations, as is typically observed for acidic soils. If the second year results are representative, they suggest that biochar applications to calcareous soils may lead to reduced N availability, requiring additional soil N inputs to maintain yield targets. PMID:22751045

  3. Phosphorus retention in calcareous soils and the effect of organic matter on its mobility

    Directory of Open Access Journals (Sweden)

    von Wandruszka Ray

    2006-06-01

    Full Text Available Abstract A survey of the interactions between phosphorus (P species and the components of calcareous soils shows that both surface reactions and precipitation take place, especially in the presence of calcite and limestone. The principal products of these reactions are dicalcium phosphate and octacalcium phosphate, which may interconvert after formation. The role of calcium carbonate in P retention by calcareous soils is, however, significant only at relatively high P concentrations – non-carbonate clays play a more important part at lower concentrations. In the presence of iron oxide particles, occlusion of P frequently occurs in these bodies, especially with forms of the element that are pedogenic in origin. Progressive mineralization and immobilization, often biological in nature, are generally observed when P is added as a fertilizer. Manure serves both as a source of subsurface P and an effective mobilizing agent. Blockage of P sorption sites by organic acids, as well as complexation of exchangeable Al and Fe in the soil, are potential causes of this mobilization. Swine and chicken manure are especially rich P sources, largely due the practice of adding the element to the feed of nonruminants. Humic materials, both native and added, appear to increase recovery of Olsen P. In the presence of metal cations, strong complexes between inorganic P and humates are formed. The influence of humic soil amendments on P mobility warrants further investigation.

  4. Dried gamma-irradiated sewage solids use on calcareous soils: crop yeilds and heavy metals uptake

    International Nuclear Information System (INIS)

    Experiments designed to examine gamma-radiation effects on extractable and plant-available sludge elements and to examine the response of crops to sludge applications on two typical, calcareous soils in New Mexico are summarized. Information has been given indicating that the radiation process of reducing pathogens in sewage products being developed by Sandia Laboratories, does not significantly increase the chemical extractability and plant uptake of a broad range of nutrients and heavy metals. However, radiation treatment greatly facilitates handling sewage for experimentation, because pathogen contamination precautions are eliminated and weed seeds killed. Studies on the effects of sludge irradiation on plant nutrient uptake revealed no concentration increases, agreeing with results presented herein. Sewage products may have special potential for use on calcareous soils, such as in New Mexico. For instance, in New Mexico the lack of potassium in sewage products is not a problem and the naturally high pH of New Mexico soil greatly reduces plant availability of many problem heavy metals. Dramatic increases in yield are typified by the greenhouse and field results presented herein, especially for the known micronutrient deficient soils of New Mexico. Results indicate that sewage sludge is an excellent Zn and Fe fertilizer. More research needs to be done before the economics of sludge application can be calculated and more field information is needed before irradiated sewage products are used indiscriminately

  5. Dried gamma-irradiated sewage solids use on calcareous soils: crop yeilds and heavy metals uptake

    Energy Technology Data Exchange (ETDEWEB)

    McCaslin, B.D.; Sivinski, J.S.

    1979-01-01

    Experiments designed to examine gamma-radiation effects on extractable and plant-available sludge elements and to examine the response of crops to sludge applications on two typical, calcareous soils in New Mexico are summarized. Information has been given indicating that the radiation process of reducing pathogens in sewage products being developed by Sandia Laboratories, does not significantly increase the chemical extractability and plant uptake of a broad range of nutrients and heavy metals. However, radiation treatment greatly facilitates handling sewage for experimentation, because pathogen contamination precautions are eliminated and weed seeds killed. Studies on the effects of sludge irradiation on plant nutrient uptake revealed no concentration increases, agreeing with results presented herein. Sewage products may have special potential for use on calcareous soils, such as in New Mexico. For instance, in New Mexico the lack of potassium in sewage products is not a problem and the naturally high pH of New Mexico soil greatly reduces plant availability of many problem heavy metals. Dramatic increases in yield are typified by the greenhouse and field results presented herein, especially for the known micronutrient deficient soils of New Mexico. Results indicate that sewage sludge is an excellent Zn and Fe fertilizer. More research needs to be done before the economics of sludge application can be calculated and more field information is needed before irradiated sewage products are used indiscriminately. (ERB)

  6. Adsorption of enrofloxacin in presence of Zn(II) on a calcareous soil.

    Science.gov (United States)

    Graouer-Bacart, Mareen; Sayen, Stéphanie; Guillon, Emmanuel

    2015-12-01

    As a result of their consumption, excretion, disposal and persistence, antibiotics enter the soil environment and may be transported to surface and ground waters. During their transfer through soils, retention processes play a key role in their mobility. Antibiotics often coexist with heavy metals in soils due to agricultural practices and other sources of inputs. In this context, this study deals with the co-adsorption of Zn(II) and enrofloxacin (ENR), a widely-used veterinary antibiotic, on a calcareous soil using batch retention experiments and X-ray Absorption Near Edge Structure (XANES) spectroscopy. To improve our understanding of the interaction of this emerging organic contaminant with metal cations at the water-soil interface, the ternary system containing ENR, Zn(II) and a selected calcareous soil was investigated over a pH range between 7 and 10, at different solid-solution contact times and ENR concentrations. The presence of Zn(II) slightly influenced the retention of the antibiotic, leading to an increase of the adsorbed ENR amounts. The distribution coefficient Kd value increased from 0.66 Lg(-1) for single ENR adsorption to 1.04 Lg(-1) in presence of Zn(II) at a 1/2 ENR/Zn(II) ratio. The combination of adsorption isotherm data, solution speciation diagrams and XANES spectra evidenced a small proportion of Zn(II)-ENR complexes at soil pH leading to the slight increase of ENR adsorption in presence of zinc. These results suggest that it is necessary to consider the interaction between ENR and metal cations when assessing the mobility of ENR in soils. PMID:26408826

  7. Fate of phosphorus added with urban compost to a calcareous soil

    OpenAIRE

    Cabrera, Francisco; Murillo Carpio, José Manuel; López Núñez, Rafael; Hernández Reina, José Manuel

    1991-01-01

    The effect of successive applications of urban compost (up to 150 and 400 t ha-1 during eight years) on the status of phosphorus in a calcareous soil (20%) was tested in a greenhouse experiment. An 8-15-15 complex fertiliser was also applied for comparison. Five years of ryegrass and three of horticultural plants (tomato and eggplant) were successively cropped during the experiment. Increases of total- and available-P were observed with both organic and inorganic fertilisation. Total-P increa...

  8. Effect of phosphate fertilization on the bioavailability of iron in calcareous soils

    Science.gov (United States)

    Sánchez-Rodríguez, A. R.; del Campillo, M. C.; Barrón, V.; Torrent, J.

    2012-04-01

    Iron (Fe) chlorosis is the most important nutritional problem in sensitive plant species cultivated in calcareous soils, its main symptoms being interveinal yellowing in the younger leaves due to lack of chlorophyll and reduced growth. Fe chlorosis has been related to the content of poorly crystalline Fe oxides in soil. The effect of other nutrients, especially phosphorus (P), is, however, a matter of debate. In this work we examined whether fertilization with P alters the availability of Fe to sensitive plants growing in two different Fe chlorosis-inducing calcareous soils. Phosphate at rates of 0 (control), 25, 50, 100 and 200 mg P kg-1 soil was applied to pots where six-months-old olive trees cv. Arbequina were grown. The experiment lasted three years and took place in a shaded house. Chlorophyll concentration in the young leaves was estimated with the SPAD value (using a Minolta apparatus) three-four times per year. Furthermore, shoot length, dry weight of annual pruning and mineral element concentration were measured at the end of each year. In one of the soils, SPAD and leaf Fe concentration decreased with increasing P dose. However in the other soil, SPAD was not correlated with the rate of applied P. In both soils, potassium and zinc concentrations in plants fertilized with P were lower than those in the control plants. This work was funded by the Spanish Ministry of Science and Innovation, Projects: AGL 2005-06691-C02-01 and AGL 2008-05053-C02-02, and the European Regional Development Funds. ARSR acknowledges the finnancial support from the Spanish Ministry of Education as a fellow of the program "Training of University Teachers" (Formación del Profesorado Universitario, AP2008-04716)

  9. Differences in the Zinc Efficiency Among and Within Maize Cultivars in a Calcareous Soil

    Directory of Open Access Journals (Sweden)

    A. Chaab

    2011-01-01

    Full Text Available Low availability of Zn in calcareous soils is one of the widest ranging abiotic stresses in world agriculture. Greenhouse experiment were carried out with Four cultivars of maize (301 Single Grass (A, 302 Single Grass (B, 307 Single Grass (C, 400 Single Grass (D, Zea mays L. were used to study the influence of varied zinc (Zn supply on Zn efficiency, shoot dry matter production, Zn uptake, Chlorophyll content, Leaf Area Index (LAI and Relative Growth Rate (RG R. Plants were grown in a Zn-deficient calcareous soil under greenhouse conditions with (+Zn = 10 mg/ kg soil and without (-Zn Zn supply. Plants were harvested after 40 and 80 days. Zinc efficiency, expressed as the percentage of shoot dry weight produced under conditions of Zn deficiency compared to Zn supply, ranged between 62.3 and 75.5% in first stage and between 63.5 and 81.2% in second stage. Application of Zinc caused increase in shoot dry weight in all cultivars. Zn uptake enhanced with application of zinc and ranged from 100.80 to 231.91 :g/pot in first stage and 458.01 to 858.83 :g/pot among cultivars. Zinc application increased the Chlorophyll content, Leaf Area Index and Relative Growth Rate. Zn efficiency had high and positive relation with Shoot dry weight and Zn uptake in different cultivars.

  10. Bacteria transport and retention in intact calcareous soil columns under saturated flow conditions

    Directory of Open Access Journals (Sweden)

    Farrokhian Firouzi Ahmad

    2015-06-01

    Full Text Available Study of bacterial transport and retention in soil is important for various environmental applications such as groundwater contamination and bioremediation of soil and water. The main objective of this research was to quantitatively assess bacterial transport and deposition under saturated conditions in calcareous soil. A series of leaching experiments was conducted on two undisturbed soil columns. Breakthrough curves of Pseudomonas fluorescens and Cl were measured. After the leaching experiment, spatial distribution of bacteria retention in the soil columns was determined. The HYDRUS-1D one- and two-site kinetic models were used to predict the transport and deposition of bacteria in soil. The results indicated that the two-site model fits the observed data better than one-site kinetic model. Bacteria interaction with the soil of kinetic site 1 revealed relatively fast attachment and slow detachment, whereas attachment to and detachment of bacteria from kinetic site 2 was fast. Fast attachment and slow detachment of site 1 can be attributed to soil calcium carbonate that has favorable attachment sites for bacteria. The detachment rate was less than 0.02 of the attachment rate, indicating irreversible attachment of bacteria. High reduction rate of bacteria was also attributed to soil calcium carbonate.

  11. Fate of Zinc Oxide Nanoparticles Coated onto Macronutrient Fertilizers in an Alkaline Calcareous Soil.

    Directory of Open Access Journals (Sweden)

    Narges Milani

    Full Text Available Zinc oxide (ZnO nanoparticles may provide a more soluble and plant available source of Zn in Zn fertilizers due to their greater reactivity compared to equivalent micron- or millimetre-sized (bulk particles. However, the effect of soil on solubility, spatial distribution and speciation of ZnO nanoparticles has not yet been investigated. In this study, we examined the diffusion and solid phase speciation of Zn in an alkaline calcareous soil following application of nanoparticulate and bulk ZnO coated fertilizer products (monoammonium phosphate (MAP and urea using laboratory-based x-ray techniques and synchrotron-based μ-x-ray fluorescence (μ-XRF mapping and absorption fine structure spectroscopy (μ-XAFS. Mapping of the soil-fertilizer reaction zones revealed that most of the applied Zn for all treatments remained on the coated fertilizer granule or close to the point of application after five weeks of incubation in soil. Zinc precipitated mainly as scholzite (CaZn2(PO42.2H2O and zinc ammonium phosphate (Zn(NH4PO4 species at the surface of MAP granules. These reactions reduced dissolution and diffusion of Zn from the MAP granules. Although Zn remained as zincite (ZnO at the surface of urea granules, limited diffusion of Zn from ZnO-coated urea granules was also observed for both bulk and nanoparticulate ZnO treatments. This might be due to either the high pH of urea granules, which reduced solubility of Zn, or aggregation (due to high ionic strength of released ZnO nanoparticles around the granule/point of application. The relative proportion of Zn(OH2 and ZnCO3 species increased for all Zn treatments with increasing distance from coated MAP and urea granules in the calcareous soil. When coated on macronutrient fertilizers, Zn from ZnO nanoparticles (without surface modifiers was not more mobile or diffusible compared to bulk forms of ZnO. The results also suggest that risk associated with the presence of ZnO NPs in calcareous soils would be

  12. Fate of Zinc Oxide Nanoparticles Coated onto Macronutrient Fertilizers in an Alkaline Calcareous Soil.

    Science.gov (United States)

    Milani, Narges; Hettiarachchi, Ganga M; Kirby, Jason K; Beak, Douglas G; Stacey, Samuel P; McLaughlin, Mike J

    2015-01-01

    Zinc oxide (ZnO) nanoparticles may provide a more soluble and plant available source of Zn in Zn fertilizers due to their greater reactivity compared to equivalent micron- or millimetre-sized (bulk) particles. However, the effect of soil on solubility, spatial distribution and speciation of ZnO nanoparticles has not yet been investigated. In this study, we examined the diffusion and solid phase speciation of Zn in an alkaline calcareous soil following application of nanoparticulate and bulk ZnO coated fertilizer products (monoammonium phosphate (MAP) and urea) using laboratory-based x-ray techniques and synchrotron-based μ-x-ray fluorescence (μ-XRF) mapping and absorption fine structure spectroscopy (μ-XAFS). Mapping of the soil-fertilizer reaction zones revealed that most of the applied Zn for all treatments remained on the coated fertilizer granule or close to the point of application after five weeks of incubation in soil. Zinc precipitated mainly as scholzite (CaZn2(PO4)2.2H2O) and zinc ammonium phosphate (Zn(NH4)PO4) species at the surface of MAP granules. These reactions reduced dissolution and diffusion of Zn from the MAP granules. Although Zn remained as zincite (ZnO) at the surface of urea granules, limited diffusion of Zn from ZnO-coated urea granules was also observed for both bulk and nanoparticulate ZnO treatments. This might be due to either the high pH of urea granules, which reduced solubility of Zn, or aggregation (due to high ionic strength) of released ZnO nanoparticles around the granule/point of application. The relative proportion of Zn(OH)2 and ZnCO3 species increased for all Zn treatments with increasing distance from coated MAP and urea granules in the calcareous soil. When coated on macronutrient fertilizers, Zn from ZnO nanoparticles (without surface modifiers) was not more mobile or diffusible compared to bulk forms of ZnO. The results also suggest that risk associated with the presence of ZnO NPs in calcareous soils would be the same

  13. LEAF MINERAL CONCENTRATION OF FIVE OLIVE CULTIVARS GROWN ON CALCAREOUS SOIL

    Directory of Open Access Journals (Sweden)

    Igor Pasković

    2013-12-01

    Full Text Available There are limited numbers of scientific publication regarding genotypic differences which exist among olive cultivars concerning nutrient uptake and translocation. For that purpose, the object of our study was to determine possible differences between leaf mineral content of five selected olive cultivars since leaf nutrient analysis is consider being the best method for diagnosing olive tree nutritional status. Plant material was obtained from an olive collection, grown on calcareous soil maintained at Institute of Adriatic Crops and Karst Reclamation, Split, Croatia. The study was conducted with two Croatian autochthonous olive cultivars (“Istarska bjelica”, “Lastovka”, two Italian cultivars (“Pendolino”, “Leccino” and one Spanish cultivar (“Hojiblanca”. Completely randomized design was applied. This study has shown questionably low Mg concentration in all olive cultivars with exception for “Hojiblanca” cultivar. Also, only Croatian cultivars “Istarska bjelica” and “Lastovka” as well as Spanish cultivar “Hojiblanca” recorded sufficient levels of iron leaf mineral content. Regarding other elements studied (P, K, Ca, Zn, Mn, Cu all cultivars were above literature cited thresholds for possible deficiencies. Selected olive cultivars in our experiment demonstrated different nutrient leaf concentration, which is of particular importance for fertilization requirements and fertilization practice in Croatian orchards grown on calcareous soil.

  14. Are Fe and P availabilities involved in determining the occurrence and distribution of Calluna vulgaris (L.) Hull in semi-arid grasslands on calcareous soils?

    OpenAIRE

    Fühner, Christoph; Runge, Michael

    2008-01-01

    Calluna vulgaris (L.) Hull is primarily found on acid soils and is generally classified as a calcifuge species. Therefore, its occasional growth in semi-arid grassland on shallow calcareous soils gave rise to the question as to whether special soil conditions, deviating from the typical conditions in calcareous soils, enable this unusual occurrence. In an attempt to answer this question, we analysed selected soil factors, comparing plots where C. vulgaris was growing besides calcicole species...

  15. Free Oxide Distribution in Poorly and Well Drained Soils Developed on Calcareous Alluvial Deposits

    Institute of Scientific and Technical Information of China (English)

    N. K. MOUSTAKAS; P. E. BAROUCHAS

    2003-01-01

    A study on the distribution of free iron and manganese oxides was conducted in soils developed on calcareous alluvial deposits under subhumid climatic conditions, in Western Greece. Soil samples from two well drained soils and from two poorly drained soils, classified as Alfisols, were collected and used in this study. After certification of soil homogeneity the acid ammonium oxalate and dithionite-citrate-bicarbonate methods were used to extract free iron and manganese oxides from the samples. Iron oxides extracted by the dithionite-citrate-bicarbonate method (Fed) were significantly higher than the iron oxides extracted by the ammonium oxalate method (Feo), indicating that a considerable fraction is present in crystalline forms,independent of drainage status. A confirmation of free iron oxides and fine clay was detected. The ratios Feo/Fed and (Fed-Feo)/total Fe (Fet) could not be used to distinguish the well drained soils from the poorly drained soils. Manganese movement in a soluble form is independent of the fine clay.

  16. REMEDIATION OF POLLUTED SOILS BY UTILIZING HYDROTHERMALLY TREATED CALCAREOUS FLY ASHES

    Institute of Scientific and Technical Information of China (English)

    A. Moutsatsou; V. Protonotarios

    2006-01-01

    This paper investigates a treated fly ash to act as a synthetic zeolite to remediate soils polluted with heavy metals and metalloids (As, Pb, Cu, Zn, Fe, Cd and Mn). Four types of such 'zeolites' were synthesized by hydrothermal treatment of a calcareous fly ash derived from Greek lignite-fired power plants: two with excess of sodium hydroxide in a a former mining site at Lavrion, Greece. Mobilization and transfer of metals to the retention agents was effected by using HCl aq 1M, with satisfactory results with respect to As, Pb, Cu, Mn and Cd. The great variety of metal complexes in soil was found to be of major importance for the effectiveness of the overall process. The final products were solidified either on their own, or by using additives such as lime and cement.

  17. Transformation of nitrogenous fertilizers of surface and deep application in calcareous soil

    International Nuclear Information System (INIS)

    The transformations of 15N labelled fertilizer N in calcareous soil were studied under greennhouse conditions. The experimental results indicate that the ratio of fixed ammonium is closely related to the methods of fertilizer application to the soil. When fertilizer N applied as deep dressing the fixation of nitrogen by clay minerals and microorganisms may markedly reduce the losses of nitrogen, but the amount of nitrogen fixed by the clay minerals and that by microorganisms showed negative correlation (r = -0.9185**). The more the amount of fixed nitrogen by clay minerals, the less by microorganisms. No obvious interrelation between the residual utilization of urea, ammonium bicarbonate, ammonium sulfate and the ammount of nitrogen fixed by organisms can be observed, but the residual utilization of these fertilizers by the succeeding crop has been related to the total amount of mineral nitrogen

  18. Am-241 remobilization in a calcareous soil under simplified rhizospheric conditions studied by column experiments

    International Nuclear Information System (INIS)

    The effects of simplified rhizospheric conditions on the leaching of 241Am from a calcareous soil, freshly contaminated, were investigated in batch and column experiments. Glucose and/or citrate were used as artificial exudate solutions at concentrations ranging from 10-4 to 10-2 mol dm-3. Am desorption, expressed in terms of distribution coefficients, varied from Kd > 104 dm3 kg-1 corresponding to a majority of experimental conditions, to Kd ≤ 102 dm3 kg-1 when citrate combined or not with glucose was used at ≥10-2 mol dm-3. Soil columns revealed successive steady states coupled with transitory episodes, the latter represented up to 90% of the total Am release. 241Am fractions with different behaviours were thus highlighted in columns whereas batch only accounted for highest Am mobile fractions. The implications of the different processes are discussed in terms of modelling approach and risk assessment

  19. A preliminary spatial-temporal study of some soil characteristics in the calcareous massif of Sicó, Portugal.

    Science.gov (United States)

    Torres, Maria Odete; Neves, Maria Manuela

    2016-01-01

    The mountainous massif of Sicó, in the centre of Portugal, is an extensive area composed of calcareous Jurassic formations. Hillside calcareous soils, with high pH, present chemical restrictions to support plant growth and are subjected to important erosion processes leading to their degradation if not protected by vegetation. In a first year of study some soil physicochemical characteristics have been measured in some geo-referenced locations of a larger design experiment and an exploratory spatial analysis has been performed. The objective of this study was to present some suggestions in order to give sustainable phosphorus fertiliser recommendations aiming to establish pastures in these soils and thus support traditional livestock activity. Ten years apart, those soil characteristics have been measured again in the same locations and comparisions have been made. The objective was to understand the variability of the soil properties under study in order to better adequate the fertiliser soil management regarding the area restoration. PMID:27087036

  20. Phytoavailability of Copper, Zinc and Cadmium in Sewage Sludge-Amended Calcareous Soils

    Institute of Scientific and Technical Information of China (English)

    LI Qiong; GUO Xue-Yan; XU Xing-Hua; ZUO Yu-Bao; WEI Dong-Pu; MA Yi-Bing

    2012-01-01

    The toxicity of trace elements (TEs),such as copper (Cu),zinc (Zn),and cadmium (Cd),often restrict land application of sewage sludge (SS) and there was little information about soil-plant transfer of TEs in SS from field experiments in China.In this study pot and field experiments were carried out for 2 years to investigate the phytoavailability of TEs in calcareous soils amended with SS.The results of the pot experiment showed that the phytoavailability of Zn and Cu in the SS was equal to 53.4%-80.9% and 54.8%-91.1% of corresponding water-soluble metal salts,respectively.The results from the field experiment showed that the contents of total Zn,Cu,and Cd in the soils increased linearly with SS application rates.With increasing SS application rates,the contents of Zn and Cu in the wheat grains initially increased and then reached a plateau,while there was no significant change of Cd content in the maize grains.The bioconcentration factors of the metals in the grains of wheat and maize were found to be in the order of Zn > Cu > Cd,but for the straw the order was Cd > Cu > Zn.It was also found that wheat grains could accumulate more metals compared with maize grains.The results will be helpful in developing the critical loads of sewage sludge applied to calcareous soils.

  1. Iron biofortification of wheat grains through integrated use of organic and chemical fertilizers in pH affected calcareous soil.

    Science.gov (United States)

    Ramzani, Pia Muhammad Adnan; Khalid, Muhammad; Naveed, Muhammad; Ahmad, Rashid; Shahid, Muhammad

    2016-07-01

    Incidence of iron (Fe) deficiency in human populations is an emerging global challenge. This study was conducted to evaluate the potential of iron sulphate combined with biochar and poultry manure for Fe biofortification of wheat grains in pH affected calcareous soil. In first two incubation studies, rates of sulfur (S) and Fe combined with various organic amendments for lowering pH and Fe availability in calcareous soil were optimized. In pot experiment, best rate of Fe along with biochar (BC) and poultry manure (PM) was evaluated for Fe biofortification of wheat in normal and S treated low pH calcareous soil. Fe applied with BC provided fair increase in root-shoot biomass and photosynthesis up to 79, 53 and 67%, respectively in S treated low pH soil than control. Grain Fe and ferritin concentration was increased up to 1.4 and 1.2 fold, respectively while phytate and polyphenol was decreased 35 and 44%, respectively than control in treatment where Fe was applied with BC and S. In conclusion, combined use of Fe and BC could be an effective approach to improve growth and grain Fe biofortification of wheat in pH affected calcareous soil. PMID:27179316

  2. Movement of Phosphorus in a Calcareous Soil as Affected by Humic Acid

    Institute of Scientific and Technical Information of China (English)

    DU Zhen-Yu; WANG Qing-Hua; LIU Fang-Chun; MA Hai-Lin; MA Bing-Yao; S.S.MALHI

    2013-01-01

    When humic acid (HA) and phosphorus (P) fertilizer are simultaneously applied to soil,HA may affect the movement of P.A laboratory incubation experiment was conducted to quantify the effects of a commercial HA product co-applied with monocalcium phosphate (MCP) on the distance of P movement and the concentration of P in various forms at different distances from the P fertilizer application site in a calcareous soil from northern China.Fertilizer MCP (at a rate equivalent to 26.6 kg P ha-1) was applied alone or in combination with HA (at 254.8 kg HA ha-1) to the surface of soil packed in cylinders (150 mm high and 50 mm internal diameter),and then incubated at 320 g kg-1 moisture content for 7 and 28 d periods.Extraction and analysis of each 2 mm soil layer in columns showed that the addition of HA to MCP increased the distance of P movement and the concentrations of water-extractable P,acid-extractable P and Olsen P in soil.The addition of HA to MCP could enhance P availability by increasing the distance of P movement and the concentration of extractable P in soil surrounding the P fertilizer.

  3. Natural Enrichment of Trace Elements in Surface Horizons of Calcareous Soils (La Mancha, Spain

    Directory of Open Access Journals (Sweden)

    Sandra Bravo Martín-Consuegra

    2015-01-01

    Full Text Available The study of five soil profiles developed on carbonatic sediments of Tertiary Miocene origin has been carried out. The topography of the area was basically flat and the traditional uses of the soils are the cultivation of dry cereals and grapevine. The geochemical characterization of the aforementioned profiles involves a study of the contents of major and trace elements among other pedologic aspects (texture, pH, organic matter, etc.. The results of this study also indicate a superficial enrichment of trace elements due to the leaching of Ca and moderate biological and anthropic activity. We can consider strontium, Sr, as the trace element that characterizes these limy soils (435 mg/kg average content in total soil and 708 mg/kg in the original rock. These contents are similar to the average value in Castilla-La Mancha of 380 mg/kg and are higher than the average in world soils of about 200 mg/kg. High levels of dangerous or pollutant elements (Cd, Hg, Pb, Cu, Zn, or Ni were not detected. The majority of trace element anomalies are related to calcareous material and the leaching of calcium carbonate (Ca, while the influence of the anthropogenic factor is secondary. Soil quality does not indicate toxicity although surficial enrichment suggests a weak threat from consuming crops.

  4. Effects of moisture and carbonate additions on CO2 emission from calcareous soil during closed-jar incubation

    Institute of Scientific and Technical Information of China (English)

    YanJie DONG; Miao CAI; JianBin ZHOU

    2014-01-01

    Calcareous soil contains organic and inorganic carbon (C) pools, which both contribute to CO2 emission during closed-jar incubation. The mineralization of organic C and dissolution of inorganic C are both related to soil moisture, but the exact effect of water content on CO2 emission from calcareous soil is unclear. The objective of this experiment was to determine the effect of soil water content (air-dried, 30%, 70%, and 100%water-holding capacity (WHC)), carbonate type (CaCO3 or MgCO3), and carbonate amount (0.0, 1.0%, and 2.0%) on CO2 emission from calcareous soil during closed-jar incubation. Soil CO2 emission increased significantly as the water content in-creased to 70%WHC, regardless of whether or not the soil was amended with carbonates. Soil CO2 emission re-mained the same or increased slowly as the soil water content increased from 70%WHC to 100%WHC. When the water content was≤30%WHC, soil CO2 emission from soil amended with 1.0%inorganic C was greater than that from unamended soil. When the soil water content was 70%or 100%WHC, CO2 emission from CaCO3 amended soil was greater than that from the control. Furthermore, CO2 emission from soil amended with 2.0%CaCO3 was greater than that from soil amended with 1.0%CaCO3. Soil CO2 emission was higher in the MgCO3 amended soil than from the unamended soil. Soil CO2 emission decreased as the MgCO3 content increased. Cumulative CO2 emission was 3-6 times higher from MgCO3 amended soil than from CaCO3 amended soil. There was significant interaction effect between soil moisture and carbonates on CO2 emission. Soil moisture plays an important role in CO2 emission from calcareous soil because it affects both biotic and abiotic processes during the closed-jar incu-bation.

  5. Effects of moisture and carbonate additions on CO2 emission from calcareous soil during closed–jar incubation

    Institute of Scientific and Technical Information of China (English)

    YanJie; DONG; Miao; CAI; JianBin; ZHOU

    2014-01-01

    Calcareous soil contains organic and inorganic carbon(C) pools,which both contribute to CO2 emission during closed-jar incubation. The mineralization of organic C and dissolution of inorganic C are both related to soil moisture,but the exact effect of water content on CO2 emission from calcareous soil is unclear. The objective of this experiment was to determine the effect of soil water content(air-dried,30%,70%,and 100% water-holding capacity(WHC)),carbonate type(CaCO3 or MgCO3),and carbonate amount(0.0,1.0%,and 2.0%) on CO2 emission from calcareous soil during closed-jar incubation. Soil CO2 emission increased significantly as the water content increased to 70% WHC,regardless of whether or not the soil was amended with carbonates. Soil CO2 emission remained the same or increased slowly as the soil water content increased from 70% WHC to 100% WHC. When the water content was ≤30% WHC,soil CO2 emission from soil amended with 1.0% inorganic C was greater than that from unamended soil. When the soil water content was 70% or 100% WHC,CO2 emission from CaCO3 amended soil was greater than that from the control. Furthermore,CO2 emission from soil amended with 2.0% CaCO3 was greater than that from soil amended with 1.0% CaCO3. Soil CO2 emission was higher in the MgCO3 amended soil than from the unamended soil. Soil CO2 emission decreased as the MgCO3 content increased. Cumulative CO2 emission was 3-6 times higher from MgCO3 amended soil than from CaCO3 amended soil. There was significant interaction effect between soil moisture and carbonates on CO2 emission. Soil moisture plays an important role in CO2 emission from calcareous soil because it affects both biotic and abiotic processes during the closed-jar incubation.

  6. Field Evidence of Cadmium Phytoavailability Decreased Effectively by Rape Straw and/or Red Mud with Zinc Sulphate in a Cd-Contaminated Calcareous Soil

    OpenAIRE

    Bo Li; Junxing Yang; Dongpu Wei; Shibao Chen; Jumei Li; Yibing Ma

    2014-01-01

    To reduce Cd phytoavailability in calcareous soils, the effects of soil amendments of red mud, rape straw, and corn straw in combination with zinc fertilization on Cd extractability and phytoavailability to spinach, tomato, Chinese cabbage and radish were investigated in a calcareous soil with added Cd at 1.5 mg kg-1. The results showed that water soluble and exchangeable Cd in soils was significantly decreased by the amendments themselves from 26% to 70%, which resulted in marked decrease by...

  7. Field Evidence of Cadmium Phytoavailability Decreased Effectively by Rape Straw and/or Red Mud with Zinc Sulphate in a Cd-Contaminated Calcareous Soil

    OpenAIRE

    Li, Bo; Yang, Junxing; Wei, Dongpu; Chen, Shibao; Li, Jumei; MA, YIBING

    2014-01-01

    To reduce Cd phytoavailability in calcareous soils, the effects of soil amendments of red mud, rape straw, and corn straw in combination with zinc fertilization on Cd extractability and phytoavailability to spinach, tomato, Chinese cabbage and radish were investigated in a calcareous soil with added Cd at 1.5 mg kg−1. The results showed that water soluble and exchangeable Cd in soils was significantly decreased by the amendments themselves from 26% to 70%, which resulted in marked decrease by...

  8. Dryland, calcareous soils store (and lose) significant quantities of near-surface organic carbon

    Science.gov (United States)

    Cunliffe, Andrew M.; Puttock, Alan K.; Turnbull, Laura; Wainwright, John; Brazier, Richard E.

    2016-04-01

    Semiarid ecosystems are susceptible to changes in dominant vegetation which may have significant implications for terrestrial carbon dynamics. The present study examines the distribution of organic carbon (OC) between particle size fractions in near-surface (0-0.05 m) soil and the water erosion-induced redistribution of particle-associated OC over a grass-shrub ecotone, in a semiarid landscape, subject to land degradation. Coarse (>2 mm) particles have comparable average OC concentrations to the fine (soil. This may be due to aggregate stabilization by precipitated calcium carbonate in these calcareous arid soils. Critically, standard protocols assuming that coarse fraction particles contain no OC are likely to underestimate soil OC stocks substantially, especially in soils with strongly stabilized aggregates. Sediment eroded from four hillslope scale (10 × 30 m) sites during rainstorm events was monitored over four annual monsoon seasons. Eroded sediment was significantly enriched in OC; enrichment increased significantly across the grass-shrub ecotone and appears to be an enduring phenomenon probably sustained through the dynamic replacement of preferentially removed organic matter. The average erosion-induced OC event yield increased sixfold across the ecotone from grass-dominated to shrub-dominated ecosystems, due to both greater erosion and greater OC enrichment. This erosional pathway is rarely considered when comparing the carbon budgets of grasslands and shrublands, yet this accelerated efflux of OC may be important for long-term carbon storage potentials of dryland ecosystems.

  9. Effects of organic acids on cadmium and copper sorption and desorption by two calcareous soils.

    Science.gov (United States)

    Najafi, Sarvenaz; Jalali, Mohsen

    2015-09-01

    Low molecular weight organic acids (LMWOAs) present in soil alter equilibrium pH of soil, and consequently, affect heavy metal sorption and desorption on soil constitutes. This study was conducted to investigate the effects of different concentrations (0.1, 1, 2.5, 5, 10, 30, 40, 50, 70, and 100 mM) of citric, malic, and oxalic acids on sorption and desorption of cadmium (Cd) and copper (Cu) in two calcareous soils. Increasing the concentrations of three LMWOAs decreased the equilibrium pH of soil solutions. The results indicated that increase in organic acids concentrations generally reduced Cd and Cu sorption in soils. Increase concentrations of LMWOAs generally promoted Cd and Cu desorption from soils. A valley-like curve was observed for desorption of Cu after the citric acid concentration increment in soil 2. Increasing the concentrations of three LMWOAs caused a marked decrease in Kd(sorp) values of Cd and Cu in soils. In general, citric acid was the most effective organic acid in reducing sorption and increasing desorption of both metals, and oxalic acid had the minimal impact. The results indicated that LMWOAs had a greater impact on Cu sorption and desorption than Cd, which can be attributed to higher stability constants of organic acids complexes with Cu compared to Cd. It can be concluded that by selecting suitable type and concentration of LMWOAs, mobility, and hence, bioavailability of heavy metals can be changed. So, environmental implications concerning heavy metals mobility might be derived from these findings. PMID:26298186

  10. Zinc solubility and fractionation in cultivated calcareous soils irrigated with wastewater

    Energy Technology Data Exchange (ETDEWEB)

    Nazif, W. [Division of Agricultural and Environmental Sciences, School of Biosciences, University of Nottingham, Sutton Bonington, Leicestershire LE12 5RD (United Kingdom); Marzouk, E.R. [Division of Soil and Water Sciences, Faculty of Environmental Agricultural Sciences, Suez Canal University, North Sinai 45516 (Egypt); Perveen, S. [Department of Soil and Environmental Sciences, Khyber Pakhtunkhwa Agricultural University, Peshawar (Pakistan); Crout, N.M.J. [Division of Agricultural and Environmental Sciences, School of Biosciences, University of Nottingham, Sutton Bonington, Leicestershire LE12 5RD (United Kingdom); Young, S.D., E-mail: scott.young@nottingham.ac.uk [Division of Agricultural and Environmental Sciences, School of Biosciences, University of Nottingham, Sutton Bonington, Leicestershire LE12 5RD (United Kingdom)

    2015-06-15

    The solubility, lability and fractionation of zinc in a range of calcareous soils from Peshawar, Pakistan were studied (18 topsoils and 18 subsoils). The lability (E-value) of Zn was assessed as the fraction isotopically exchangeable with {sup 70}Zn{sup 2+}; comparative extractions included 0.005 M DTPA, 0.43 M HNO{sub 3} and a Tessier-style sequential extraction procedure (SEP). Because of the extremely low concentration of labile Zn the E-value was determined in soils suspended in 0.0001 M Na{sub 2}-EDTA which provided reliable analytical conditions in which approximately 20% of the labile Zn was dissolved. On average, only 2.4% of soil Zn was isotopically exchangeable. This corresponded closely to Zn solubilised by extraction with 0.005 DTPA and by the carbonate extraction step (F1 + F2) of the Tessier-style SEP. Crucially, although the majority of the soil CaCO{sub 3} was dissolved in F2 of the SEP, the DTPA dissolved only a very small proportion of the soil CaCO{sub 3}. This suggests a superficial carbonate-bound form of labile Zn, accessible to extraction with DTPA and to isotopic exchange. Zinc solubility from soil suspended in 0.01 M Ca(NO{sub 3}){sub 2} (PCO{sub 2} controlled at 0.03) was measured over three days. Following solution speciation using WHAM(VII) two simple solubility models were parameterised: a pH dependent ‘adsorption’ model based on the labile (isotopically exchangeable) Zn distribution coefficient (Kd) and an apparent solubility product (Ks) for ZnCO{sub 3}. The distribution coefficient showed no pH-dependence and the solubility model provided the best fit to the free ion activity (Zn{sup 2+}) data, although the apparent value of log{sub 10} Ks (5.1) was 2.8 log units lower than that of the mineral smithsonite (ZnCO{sub 3}). - Highlights: • Isotopically exchangeable Zn in the calcareous soils of Peshawar is extremely low. • There is no evidence of topsoil enrichment from the use of wastewater for irrigation. • Solubility

  11. Zinc solubility and fractionation in cultivated calcareous soils irrigated with wastewater

    International Nuclear Information System (INIS)

    The solubility, lability and fractionation of zinc in a range of calcareous soils from Peshawar, Pakistan were studied (18 topsoils and 18 subsoils). The lability (E-value) of Zn was assessed as the fraction isotopically exchangeable with 70Zn2+; comparative extractions included 0.005 M DTPA, 0.43 M HNO3 and a Tessier-style sequential extraction procedure (SEP). Because of the extremely low concentration of labile Zn the E-value was determined in soils suspended in 0.0001 M Na2-EDTA which provided reliable analytical conditions in which approximately 20% of the labile Zn was dissolved. On average, only 2.4% of soil Zn was isotopically exchangeable. This corresponded closely to Zn solubilised by extraction with 0.005 DTPA and by the carbonate extraction step (F1 + F2) of the Tessier-style SEP. Crucially, although the majority of the soil CaCO3 was dissolved in F2 of the SEP, the DTPA dissolved only a very small proportion of the soil CaCO3. This suggests a superficial carbonate-bound form of labile Zn, accessible to extraction with DTPA and to isotopic exchange. Zinc solubility from soil suspended in 0.01 M Ca(NO3)2 (PCO2 controlled at 0.03) was measured over three days. Following solution speciation using WHAM(VII) two simple solubility models were parameterised: a pH dependent ‘adsorption’ model based on the labile (isotopically exchangeable) Zn distribution coefficient (Kd) and an apparent solubility product (Ks) for ZnCO3. The distribution coefficient showed no pH-dependence and the solubility model provided the best fit to the free ion activity (Zn2+) data, although the apparent value of log10 Ks (5.1) was 2.8 log units lower than that of the mineral smithsonite (ZnCO3). - Highlights: • Isotopically exchangeable Zn in the calcareous soils of Peshawar is extremely low. • There is no evidence of topsoil enrichment from the use of wastewater for irrigation. • Solubility products for smithsonite and hydrozincite fail to describe Zn2+ activity. • A p

  12. Time-Dependent Zinc Desorption in Some Calcareous Soils of Iran

    Institute of Scientific and Technical Information of China (English)

    M.BARANIMOTLAGH; M.GHOLAMI

    2013-01-01

    Desorption of zinc (Zn) from soil is an important factor governing Zn concentration in the soil solution and Zn availability to plants.Batch experiments were performed to study the kinetics of Zn desorption by diethylenetriaminepentaacetic acid (DTPA) from 15 calcareous soil samples taken from Golestan Province in northern Iran.Soils were equilibrated with 0.005 mol L-1 DTPA solutions for 0.25 to 192 h.The results showed that the extraction process consisted of rapid extraction in the first 2 h followed by much slower extraction for the remainder of the experiment.Desorption kinetic data was fitted to pseudo-first-order kinetic model.The experimental data were found to deviate from the straight line of the pseudo-first-order plots after 2 h.The model of two first-order reactions was fitted to the kinetic data and allowed to distinguish two pools for Zn:a labile fraction (Q1),quickly extracted with a rate constant k1,and a slowly labile fraction (Q2),more slowly extracted with a rate constant k2.The applicability of pseudo-second-order model in describing the kinetic data of Zn desorption was also evaluated.

  13. Self-diffusion of calcium-45 into certain carbonates and calcareous soils

    International Nuclear Information System (INIS)

    The investigations described in this paper were prompted by the lack of a reliable and accurate method for measuring exchangeable calcium in calcareous soils. A large group of arid-zone soils contains calcium carbonate and is under irrigation or planned to be irrigated in the future. For the purpose of predicting and measuring the influence of various types of irrigation water on these soils, especially the degree of alkalinization to be expected, an exact determination of exchangeable calcium is necessary. In the various stripping procedures used for the determination of exchangeable cations, the amount of calcium found depends on the solubility of calcium carbonate in the stripping solution and thus on the solution-soil ratio employed. Therefore, the use of an isotopic dilution method of 45Ca seemed most advantageous, also in view of the favourable characteristics of this isotope and its relatively low price. An accurate and easy counting technique employing an ordinary end-window G-M counter and dried-down samples had been developed, overcoming the disadvantage of the low-energy level of the beta-radiation of the isotope and placing its use within the reach even of small laboratories

  14. Floodwater properties, nitrogen utilization, and nitrogen-15 balance in a calcareous lowland rice soil

    International Nuclear Information System (INIS)

    Large areas of lowland rice (Oryza sativa L.) soils in South and Southeast Asia are calcareous. Field studies in the 1983 dry and wet seasons evaluated the effects of N source and application method on N loss and N utilization in a calcareous clay loam soil using the 15N-balance technique. In the 1983 wet season and the 1984 dry season, crop recovery of the residual 15N remaining after the first crop was determined. When urea supergranules (USG) were deep point-placed, the partial pressure of ammonia (pNH3) in the flood-water was negligible. High flood-water pNH3 was calculated with split application of fertilizer. Farmers' split of prilled urea (PU) gave the highest pNH3 (0.44 Pa in the wet season). pNH3 in the flood-water peaked on the third day and dropped to negligible thereafter. Deep placement (10 cm) of USG had the highest grain yield in the dry season. Ammonium sulfate produced a yield similar to that of urea. The highest 15N recovery by the crop was 78% in the dry season and 64% in the wet season with deep point placement of USG. Nitrogen-15-balance data showed that with point placement of USG, 3% N was not accounted for after harvest in the dry season and 10% in the wet season. In contrast, when urea or ammonium sulfate was split-applied using improved timing and water management, 26 to 28% of applied N was not recovered at harvest in the dry season and 36 to 41% in the wet season

  15. Phosphorus Changes and Sorption Characteristics in a Calcareous Soil Under Long-Term Fertilization

    Institute of Scientific and Technical Information of China (English)

    GUO Sheng-Li; DANG Ting-Hui; HAO Ming-De

    2008-01-01

    Knowledge of phosphorus (P) behavior in long-term fertilized soils is essential for programming fertilization practices and for sustaining environmental quality.The long-term (1984-1997) effects of various fertilization treatments on P changes and sorption isotherms as well as the relationship of soil properties to P sorption and P forms were evaluated in an Ustic Isohumisol,a calcareous soil,on the Loess Plateau,China.Compared to 1984,after 13 years of crop production,total soil P in the no-P treatments (control and N treatment) decreased by 5%-7%,but in the phosphorus fertilizer alone (P),nitrogen and phosphorus fertilizers in combination (NP),manure alone (M),and nitrogen and phosphorus fertilizers and manure in combination (NPM) treatments,it increased by 22%,19%,28%,and 58%,respectively.Residual fertilizer P was found mainly in NH4Ac-soluble P (Cas-P),followed by NaHCO3-sohible P (NaHCO3-P),and NH4F-soluble P (Al-P).Phosphorus sorption in the soils with different fertilization practices fit the Langmuir equations.Phosphorus sorption capacity in the no-P treatments increased,whereas it decreased in the P-included treatments (P,NP,and NPM treatments).Phosphorus sorption maximum (Qm) was significantly and negatively correlated to inorganic P including Na4CO3-P,Cas-P,NaOH-Na2CO3-soluble P (Fe-P),and AI-P (P ≤ 0.01).Moreover,long-term fertilization increased soil organic carbon in the NP,M,and NPM treatments and decreased pH in the NP and NPM treatments.Thus,the ability of the soil to release sorbed P to the environment increased under long-term P fertilization.

  16. The Content of Mg, K and Ca Ions in Vine Leaf under Foliar Application of Magnesium on Calcareous Soils

    OpenAIRE

    David Gluhić; Mirjana Herak Ćustić; Marko Petek; Lepomir Čoga; Sanja Slunjski; Marijan Sinčić

    2009-01-01

    Chlorosis frequently occurs in vine production on calcareous soils, which is usually attributed to high calcium concentrations in soil. If symptoms appear on older leaves, it is taken that chlorosis is caused by a deficit of Mg2+ ions. A method of preventing chlorosis is foliar application of magnesium; however, uncontrolled application can lead to imbalance with potassium and calcium ions. The research objective was to find out whether foliar application of magnesium could solve the problem ...

  17. Potassium Exchange Isotherms as a Plant Availability Index in Selected Calcareous Soils of Western Azarbaijan Province, Iran

    OpenAIRE

    Samadi, Abbas

    2006-01-01

    Potassium (K) exchange isotherms (quantity-intensity technique, Q/I) and K values derived from the Q-I relationship provide information about soil K availability. This investigation was conducted to study the relationships among K Q/I parameters, available K extracted by 1 N NH4AOc (exchangeable K plus solution K), potassium saturation percentage (K-index, %), and the properties of 6 different calcareous agricultural soils. In addition, the relationship of tomato plant yield response to the K...

  18. Effect of Arbuscular Mycorrhizae on zinc nutrition of maize grow in calcareous soil amended with different phosphorus sources

    International Nuclear Information System (INIS)

    Arbuscular mycorrhizal fungi (AMF) are known to improve P nutrition of plants. The information of AMF effects on corn Zn nutrition under P fertilization in calcareous soil is limited. A greenhouse experiment was carried out using calcareous soil and two P-sources i.e single superphosphate and rock phosphate (with full and one third of recommended dose). to evaluate the ability of AMF on improving Zn nutrition in maize plants. Labelled 65 ZnSo4 was added at rates of 0.10 and 20 mg Zn Kg-1 soil. Zinc uptake and dry mater of corn shoots were improved as a result of AMF inoculation. The maximum improvement was recorded with super-P fertilizer in combination with 10 or 20 mg Zn Kg-1 soil for non-inoculated and AMF inoculated plants. respectively. The amount of Zn in non-inoculated and AMF inoculated plants. respectively. The amount of ZnSo4 utilized plant derived from fertilizer.(Zndff) and the percent of ZnSo4 utilization by corn plants were increased when ZnSo4 was added at rate of 10 mg Zn Kg-1 soil in the presence of super-P fertilizer. Inoculated plants with AMF had higher Zndff content and U% than non-inoculated ones and the greater Zndff and superphosphate fertilizer. It could be concluded that. AMF is useful method utilization by corn plants grown in calcareous soil

  19. Assessment of several extractants for determination of copper bioavailability to wheat (Triticum aestivum L.) in sewage sludge-treated calcareous soils

    OpenAIRE

    H.R. Motaghian; A. R. Hosseinpour; F. Raeisi; J.Mohammadi

    2013-01-01

    Copper (Cu) is an essential micronutrient for plants. However, determination of a suitable extractant of Cu in sewage sludge-amended calcareous soils has seldom been attended. The aim of this research was evaluating several extractants to predict available Cu in 10 untreated and sewage sludge-treated calcareous soils in greenhouse under wheat cultivation. After 1 month incubation, available Cu of soils was determined using 7 chemical procedures (DTPA-TEA, AB-DTPA, Mehlich 1, Mehlich 2, Mehlic...

  20. Arbuscular mycorrhizal fungi in soil and roots respond differently to phosphorus inputs in an intensively managed calcareous agricultural soil.

    Science.gov (United States)

    Liu, Wei; Zhang, Yunlong; Jiang, Shanshan; Deng, Yan; Christie, Peter; Murray, Philip J; Li, Xiaolin; Zhang, Junling

    2016-01-01

    Understanding the diversity and community structure of arbuscular mycorrhizal fungi (AMF) is important for potentially optimizing their role in mining phosphorus (P) in agricultural ecosystems. Here, we conduct a comprehensive study to investigate the vertical distribution of AMF in a calcareous field and their temporal structure in maize-roots with fertilizer P application over a three-year period. The results showed that soil available-P response to P fertilization but maize yields did not. Phosphorus fertilization had no-significant effect on richness of AMF except at greater soil-depths. High P-supply reduced root colonization while optimum-P tended to increase colonization and fungal richness on all sampling occasions. Crop phenology might override P-supply in determining the community composition of active root inhabiting fungi. Significant differences in the community structure of soil AMF were observed between the controls and P treatments in surface soil and the community shift was attributable mainly to available-P, N/P and pH. Vertical distribution was related mainly to soil electrical conductivity and Na content. Our results indicate that the structure of AMF community assemblages is correlated with P fertilization, soil depth and crop phenology. Importantly, phosphorus management must be integrated with other agricultural-practices to ensure the sustainability of agricultural production in salinized soils. PMID:27102357

  1. Physical and microbiological properties of alluvial calcareous Çumra province soils (Central Anatolia, Turkey

    Directory of Open Access Journals (Sweden)

    Ahmet Sami Erol

    2015-04-01

    Full Text Available Alluvial calcareous soils in Central Anatolia (Konya province, Çumra district has a heavy granulometric composition (average clay, low organic carbon content (less than 1%, but stable pore space structure and favorable agrophysical properties. Studies of the water regime in drip irrigation confirm favorable hydrological properties of these soils. It is assumed that the favorable structure of the pore space due to vigorous activity a large and diverse soil biota. Four phyla dominate in soil biota, among which predominate Actinobacteria. The higher (Streptomyces, and lower (three species Rhodococcus actinobacteria are predominant in large amounts as a part of this phyla. Large biodiversity at a sufficiently high bacteria richness formed the structure of the microbial community that contribute to the balanced production of specific metabolites, including gases (CO2, N2, which allows the soil to function actively, preventing compaction of the pore space and maintaining optimal density, porosity, hydrologic properties of the studied silty clay soils. m the uppermost soil horizons. Analyses of heavy mineral fraction show presence of metamorphic and igneous minerals which indicate participation of weathering products from other rock types in the nearby area. The types of heavy minerals in soils depend more on composition of parent rocks and geomorphic position than on climate type. Soils from Nova Lovcha show similar composition, but the quantity of goethite and hematite significantly increase in soil from plain. Typical high-metamorphic minerals as andalusite, kyanite and sillimanite present only in Nova Lovcha, while garnet dominates in Petrovo and opaque minerals - in Dobrostan. Red soils, formed on slopes, where erosion prevails over accumulation, contain more illite, smectite and vermiculite-smectite, and very few or no kaolinite, whereas the kaolinite is dominant in soils formed on plain. The mineralogical composition of clays in different

  2. Hardwood biochar and manure co-application to a calcareous soil.

    Science.gov (United States)

    Ippolito, J A; Stromberger, M E; Lentz, R D; Dungan, R S

    2016-01-01

    Biochar may affect the mineralization rate of labile organic C sources such as manures via microbial community shifts, and subsequently affect nutrient release. In order to ascertain the positive or negative priming effect of biochar on manure, dairy manure (2% by wt.) and a hardwood-based, fast pyrolysis biochar were applied (0%, 1%, 2%, and 10% by wt.) to a calcareous soil. Destructive sampling occurred at 1, 2, 3, 4, 6 and 12 months to monitor for changes in soil chemistry, water content, microbial respiration, bacterial populations, and microbial community structure. Overall results showed that increasing biochar application rate improved the soil water content, which may be beneficial in limited irrigation or rainfall areas. Biochar application increased soil organic C content and plant-available Fe and Mn, while a synergistic biochar-manure effect increased plant-available Zn. Compared to the other rates, the 10% biochar application lowered concentrations of NO3-N; effects appeared masked at lower biochar rates due to manure application. Over time, soil NO3-N increased likely due to manure N mineralization, yet soil NO3-N in the 10% biochar rate remained lower as compared to other treatments. In the presence of manure, only the 10% biochar application caused subtle microbial community structure shifts by increasing the relative amounts of two fatty acids associated with Gram-negative bacteria and decreasing Gram-positive bacterial fatty acids, each by ∼1%. Our previous findings with biochar alone suggested an overall negative priming effect with increasing biochar application rates, yet when co-applied with manure the negative priming effect was eliminated. PMID:26009473

  3. Zinc solubility and fractionation in cultivated calcareous soils irrigated with wastewater.

    Science.gov (United States)

    Nazif, W; Marzouk, E R; Perveen, S; Crout, N M J; Young, S D

    2015-06-15

    The solubility, lability and fractionation of zinc in a range of calcareous soils from Peshawar, Pakistan were studied (18 topsoils and 18 subsoils). The lability (E-value) of Zn was assessed as the fraction isotopically exchangeable with (70)Zn(2+); comparative extractions included 0.005 M DTPA, 0.43 M HNO3 and a Tessier-style sequential extraction procedure (SEP). Because of the extremely low concentration of labile Zn the E-value was determined in soils suspended in 0.0001 M Na2-EDTA which provided reliable analytical conditions in which approximately 20% of the labile Zn was dissolved. On average, only 2.4% of soil Zn was isotopically exchangeable. This corresponded closely to Zn solubilised by extraction with 0.005 DTPA and by the carbonate extraction step (F1+F2) of the Tessier-style SEP. Crucially, although the majority of the soil CaCO3 was dissolved in F2 of the SEP, the DTPA dissolved only a very small proportion of the soil CaCO3. This suggests a superficial carbonate-bound form of labile Zn, accessible to extraction with DTPA and to isotopic exchange. Zinc solubility from soil suspended in 0.01 M Ca(NO3)2 (PCO2 controlled at 0.03) was measured over three days. Following solution speciation using WHAM(VII) two simple solubility models were parameterised: a pH dependent 'adsorption' model based on the labile (isotopically exchangeable) Zn distribution coefficient (Kd) and an apparent solubility product (Ks) for ZnCO3. The distribution coefficient showed no pH-dependence and the solubility model provided the best fit to the free ion activity (Zn(2+)) data, although the apparent value of log10 Ks (5.1) was 2.8 log units lower than that of the mineral smithsonite (ZnCO3). PMID:25770943

  4. The impact of oscillating redox conditions: Arsenic immobilisation in contaminated calcareous floodplain soils

    International Nuclear Information System (INIS)

    Arsenic contamination of floodplain soils is extensive and additional fresh arsenic inputs to the pedosphere from human activities are ongoing. We investigate the cumulative effects of repetitive soil redox cycles, which occur naturally during flooding and draining, on a calcareous fluvisol, the native microbial community and arsenic mobility following a simulated contamination event. We show through bioreactor experiments, spectroscopic techniques and modelling that repetitive redox cycling can decrease arsenic mobility during reducing conditions by up to 45%. Phylogenetic and functional analyses of the microbial community indicate that iron cycling is a key driver of observed changes to solution chemistry. We discuss probable mechanisms responsible for the arsenic immobilisation observed in-situ. The proposed mechanisms include, decreased heterotrophic iron reduction due to the depletion of labile particulate organic matter (POM), increases to the proportion of co-precipitated vs. aqueous or sorbed arsenic with α-FeOOH/Fe(OH)3 and potential precipitation of amorphous ferric arsenate. Highlights: •Oscillating redox conditions and heterotrophic metabolism are implemented in PHREEQC. •Depletion of labile organic matter limits iron reduction and arsenic release. •Amorphous FeAsO4∙2H2O precipitation potentially limits arsenic mobility during redox cycling. •Water fluctuating zones may naturally attenuate arsenic liberation during flooding. -- We demonstrate through batch experiments, spectroscopy and modelling that repetitive cycles of oxidation and reduction decrease arsenic mobility in soils during subsequent reducing conditions

  5. Effect of rhizosphere on release rate of zinc in selected calcareous soils of Chaharmahal-va-Bakhtiari province

    OpenAIRE

    H.R. Motaghian; A. R. Hosseinpur

    2015-01-01

    Rhizosphere is a small zone with different biological and chemical properties from bulk soil. In this research, kinetics of zinc (Zn) release was compared in wheat (Rowshan Back Cross) rhizosphere and bulk soil in 10 calcareous soils by using rhizobox at greenhouse conditions. The rhizosphere and bulk soil samples were extracted with DTPA-TEA for 1 to 504 h at 25±1 0C. In addition, available Zn was evaluated by chemical extractions (DTPA-TEA, AB-DTPA and Mehlich 3). Results showed that the am...

  6. Reactivity and effectiveness of traditional and novel ligands for multi-micronutrient fertilization in a calcareous soil.

    Science.gov (United States)

    López-Rayo, Sandra; Nadal, Paloma; Lucena, Juan J

    2015-01-01

    This study compares the effectiveness of multi-micronutrient formulations containing iron (Fe), manganese (Mn), and zinc (Zn) with traditional (EDTA, DTPA, HEEDTA, and EDDHAm) or novel chelates (o,p-EDDHA, S,S-EDDS, and IDHA) and natural complexing agents (gluconate and lignosulfonate). The stability and reactivity of the formulations were studied on batch experiments with calcareous soil and by speciation modeling. Formulations containing traditional ligands maintained higher Mn but lower Zn concentration in soil solution than the novel ligands. The gluconate and lignosulfonate maintained low concentrations of both Mn and Zn in soil solution. Selected formulations were applied into calcareous soil and their efficacy was evaluated in a pot experiment with soybean. The formulation containing DTPA led to the highest Zn concentration in plants, as well as the formulation containing S,S-EDDS in the short-term, which correlated with its biodegradability. The application of traditional or novel ligands in formulations did not result in sufficient plant Mn concentrations, which was related to the low Mn stability observed for all formulations under moderate oxidation conditions. The results highlight the need to consider the effect of metals and ligands interactions in multi-nutrient fertilization and the potential of S,S-EDDS to be used for Zn fertilization. Furthermore, it is necessary to explore new sources of Mn fertilization for calcareous soils that have greater stability and efficiency, or instead to use foliar fertilization. PMID:26442065

  7. Response of Tomato on Calcareous Soils to Different Seedbed Phosphorus Application Rates

    Institute of Scientific and Technical Information of China (English)

    ZHANG Xiao-Sheng; LIAO Hong; CHEN Qing; P. CHRISTIE; LI Xiao-Lin; ZHANG Fu-Suo

    2007-01-01

    Field experiments were conducted with five rates (0, 75, 150, 225, and 450 kg P2O5 ha-1) of seedbed P fertilizer application to investigate the yield of tomato in response to fertilizer P rate on calcareous soils with widely different levels of Olsen P (13-142 mg kg-1) at 15 sites in some suburban counties of Beijing in 1999. Under the condition of no P fertilizer application, tomato yield generally increased with an increase in soil test P levels, and the agronomic level for soil testing P measured with Olsen method was 50 or 82 mg kg-1 soil to achieve 85% or 95% of maximum tomato yield, respectively. With regard to marketable yield, in the fields where Olsen-P levels were < 50 mg kg-1, noticeable responses to applied P were observed. On the basis of a linear plateau regression, the optimum seedbed P application rate in the P-insufficient fields was 125 kg P2O5 ha-1 or about 1.5-2 times the P removal from harvested tomato plants. In contrast, in fields with moderate (50 < Olsen P < 90 mg kg-1) or high (Olsen P > 90 mg kg-1) available P, there was no marked effect on tomato fruit yield. Field survey data indicated that in most fields with conventional P management, a P surplus typically occurred. Thus, once the soil test P level reached the optimum for crop yield, it was recommended that P fertilizer application be restricted or eliminated to minimize negative environmental effects.

  8. The effect of chemical and organic amendments on sodium exchange equilibria in a calcareous sodic soil.

    Science.gov (United States)

    Ranjbar, Faranak; Jalali, Mohsen

    2015-11-01

    In this study, the reclamation of a calcareous sodic soil with the exchangeable sodium percentage (ESP) value of 26.6% was investigated using the cheap and readily available chemical and organic materials including natural bentonite and zeolite saturated with calcium (Ca2+), waste calcite, three metal oxide nanoparticles functionalized with an acidic extract of potato residues, and potato residues. Chemical amendments were added to the soil at a rate of 2%, while potato residues were applied at the rates of 2 and 4% by weight. The ESP in the amended soils was reduced in the range of 0.9-4.9% compared to the control soil, and the smallest and the largest decline was respectively observed in treatments containing waste calcite and 4% of potato residues. Despite the reduction in ESP, the values of this parameter were not below 15% at the end of a 40-day incubation period. So, the effect of solutions of varying sodium adsorption ratio (SAR) values of 0, 5, 10, 20, 30, 40, and 50 on sodium (Na+) exchange equilibria was evaluated in batch systems. The empirical models (simple linear, Temkin, and Dubinin-Radushkevich) fitted well to experimental data. The relations of quantity to intensity (Q/I) revealed that the potential buffering capacity for Na+ (PBCNa) varied from 0.275 to 0.337 ((cmolc kg(-1)) (mmol L(-1))(-1/2)) in the control soil and amended soils. The relationship between exchangeable sodium ratio (ESR) and SAR was individually determined for the control soil and amended soils. The values of Gapon selectivity coefficient (KG) of Na+ differed from the value suggested by U.S. Salinity Laboratory (USSL). The PHREEQC, a geochemical computer program, was applied to simulate Na+ exchange isotherms by using the mechanistic cation exchange model (CEM) along with Gaines-Thomas selectivity coefficients. The simulation results indicated that Na+ exchange isotherms and Q/I and ESR-SAR relations were influenced by the type of counter anions. The values of K G increased in

  9. Efficacy of crushed ore colemanite as boron fertilizer for rice grown under calcareous soil conditions

    International Nuclear Information System (INIS)

    Boron (B) deficiencies occur over a wider range of soils and crops in the world. Different sources of fertilizers are used to supply sufficient amounts of B for healthier plant growth. The effectiveness of crushed ore colemanite as B source for rice crop under flooded calcareous soil was evaluated in a glass house study. We studied the effects of powder colemanite (PC) and granular colemanite (GC) at the rates of 0, 1, 2, and 3 kg B ha-1 on growth and yield parameters of rice crop. Powder colemanite application at 2 and 3 kg B ha-1 significantly increased plant height, number of tillers and panicles plant-1, number of grains panicle-1, weight of 1000 grains and B concentration in grain compared to those observed due to application of 0 and 1 kg B ha-1. Rice crop applied B at 3 kg ha-1 in the form of PC produced significantly (18% increase over control) higher grain yield than 0 kg B ha-1 treatment. The effectiveness of PC was higher in terms of yield and yield parameters of rice than the GC, The B source of PC was very effective in supplying B to rice crop, however GC applied pots produced significantly lower yields because of its larger particle size which was the controlling factor in B release from the fertilizer. (author)

  10. Effects of Common Ions on Zn Sorption in Some Calcareous Soils of Western Iran

    Institute of Scientific and Technical Information of China (English)

    M. JALALI; N. AHMADI MOHAMMAD ZINLI

    2012-01-01

    Zinc (Zn) is essential to plant growth and relatively mobile in soils.This study was conducted to assess the effect of common ions (Ca2+,K+,Na+,NH4+,Cl-,NO3-,and H2PO4-) on sorption of Zn in surface samples of ten calcareous soils from western Iran using 10 mmol L-1 KCl,KNO3,KH2PO4,Ca(NO3)2,NaNO3,and NH4NO3 solutions as background electrolytes.The results indicated that both NH4+,K+,and Ca2+ equally decreased Zn sorption as compared to Na+.Zinc sorption was decreased by H2PO4- as compared to NO3- and Cl-.The Langmuir and Freundlich equations fitted closely to the sorption data of all ions.The Langmuir maximum,bonding energy constant,and Freundlich distribution coefficient for Zn sorption differed among the various ionic background electrolytes.Langmuir sorption parameters showed that the presence of H2PO4- decreased the maximum Zn adsorbed,but increased the bonding energy.Although K+ and NH4+ equally influenced maximum Zn adsorbed,they differed in their effect on the distribution coefficient of Zn in soils.Values of saturation index calculated using Visual MINTEQ indicated that at the low Zn concentration,Zn solubility was controlled by sorption reactions and at the high Zn concentration,it was mainly controlled by sorption and mineral precipitation reactions,such as precipitation of Zn3 (PO4)2·4H2O,Zn5(OH)6(CO3)2,and ZnCO3.For most ionic background electrolytes,soil pH,CaCO3,and cation exchange capacity (CEC) were significantly correlated with sorption parameters.

  11. Influence of Compost and Compost Leachate on Growth and Chemical Composition of Barley and Bioavailability of Some Nutrients in Calcareous Clay Loam Soil and Sandy Soil

    OpenAIRE

    Z. Hatam; A. Ronaghi

    2012-01-01

    Application of compost and compost leachate as organic fertilizers can improve plant growth, nutrients uptake and increase phytoavailability of nutrients in soil. A factorial experiment (4×4×2) was conducted in a completely randomized design to evaluate the effect of compost and compost leachate on growth and chemical composition of barley and bioavailability of some nutrients in calcareous clay loam soil and sandy soil under greenhouse conditions. Treatments consisted of four levels of compo...

  12. Sorption and mobility of Sb(V) in calcareous soils of Catalonia (NE Spain): Batch and column experiments

    OpenAIRE

    Martínez Lladó, Xavier; Valderrama Angel, César Alberto; Rovira Boixaderas, Miquel; Martí Gregorio, Vicenç; Giménez Izquierdo, Francisco Javier; Pablo Ribas, Joan de

    2011-01-01

    The sorption of Sb(V) onto natural calcareous soils was studied in batch and column experiments as a function of physicochemical properties of the soil, namely: organic matter, the active fraction of Fe and Al and the pH of the soils. Batch experiments were performed in order to determine the sorption capacity and the kinetic rate of the sorption. Freundlich isotherm described properly the equilibrium experimental data and the kinetic results show that the sorption was very slow in all the so...

  13. RESPONSE OF SOYBEANS AND WHEAT TO PHOSPHORUS FERTILIZATION ON CALCAREOUS ALLUVIAL SOIL OF SAVA VALLEY AREA IN BOSNIA AND HERZEGOVINA

    OpenAIRE

    JOVIC, Jurica; Antunovic, Manda; Rastija, Mirta; Varga, Ivana

    2015-01-01

    The stationary field experiment of increasing rates of phosphorus (P) fertilization started in spring 2011 on calcareous alluvial soil of Posavian Canton in Federation of Bosnia and Herzegovina (B&H). The level of plant available P was found to be low by previous soil tests carried on with ammonium-lactate-method (7.06 pH in 1 M KCl; 4.17% organic matter; 3.79% CaCO3; 5.4 mg P2O5 in 100 g of soil). Five rates of P fertilizers (monoammonium phosphate: 13% N + 53 % P2O5) were applied as fol...

  14. Influence of flooding and metal immobilising soil amendments on availability of metals for willows and earthworms in calcareous dredged sediment-derived soils

    International Nuclear Information System (INIS)

    Soil amendments previously shown to be effective in reducing metal bioavailability and/or mobility in calcareous metal-polluted soils were tested on a calcareous dredged sediment-derived soil with 26 mg Cd/kg dry soil, 2200 mg Cr/kg dry soil, 220 mg Pb/kg dry soil, and 3000 mg Zn/kg dry soil. The amendments were 5% modified aluminosilicate (AS), 10% w/w lignin, 1% w/w diammonium phosphate (DAP, (NH4)2HPO4), 1% w/w MnO, and 5% w/w CaSO4. In an additional treatment, the contaminated soil was submerged. Endpoints were metal uptake in Salix cinerea and Lumbricus terrestris, and effect on oxidation-reduction potential (ORP) in submerged soils. Results illustrated that the selected soil amendments were not effective in reducing ecological risk to vegetation or soil inhabiting invertebrates, as metal uptake in willows and earthworms did not significantly decrease following their application. Flooding the polluted soil resulted in metal uptake in S. cinerea comparable with concentrations for an uncontaminated soil. - Some soil amendments resulted in higher metal uptake by earthworms and willows than when the polluted soil was not amended but submersion of the polluted soil resulted in reduced Cd and Zn uptake in Salix cinerea.

  15. Pile foundation engineering in calcareous soils%钙质砂土中的桩基础工程综述

    Institute of Scientific and Technical Information of China (English)

    周杨; 刘晓宇; 李世海

    2013-01-01

    桩基础广泛应用于钙质砂土这类高压缩性地基中。在总结钙质砂土的成因、分布特点、基本物理性质和力学特性的基础上,认为在钙质砂土地基中传统打入桩提供的承载力不能满足工程要求,并针对传统打入桩失败原因进行了分析。详细介绍了两种新型桩结构形式、施工方法、承载力特性及存在的问题,对两种新型桩进行了比较。总结了两种新型桩的优缺点,提出对新型桩形式的可能的改进方案。在总结已有研究的基础上,建议引入数值模拟方法配合试验研究的新思路。%Pile foundations are widely used in compressible soils such as calcareous sediments. Based on an introduction of the origin, distribution, basic physical properties and mechanical properties of calcareous soils, it is concluded that traditional driven piles are ineffective in calcareous soils and the reasons for it are analyzed. A review of the published literature pertaining to pile foundations in calcareous soils is summarized, and two new types of piles are described, along with their structural types, construction methods, bearing capacity characters, existing problems and comparison between them. Each method has its own advantages and disadvantages. Some improved schemes are proposed and new research approaches combing experiments with numerical simulation are suggested.

  16. Reactivity and effectiveness of traditional and novel ligands for multi-micronutrient fertilization in a calcareous soil

    OpenAIRE

    López-Rayo, Sandra; Nadal, Paloma; Lucena, Juan J.

    2015-01-01

    This study compares the effectiveness of multi-micronutrient formulations containing iron (Fe), manganese (Mn), and zinc (Zn) with traditional (EDTA, DTPA, HEEDTA, and EDDHAm) or novel chelates (o,p-EDDHA, S,S-EDDS, and IDHA) and natural complexing agents (gluconate and lignosulfonate). The stability and reactivity of the formulations were studied on batch experiments with calcareous soil and by speciation modeling. Formulations containing traditional ligands maintained higher Mn but lower Zn...

  17. Soil-Plant Nutrient Interactions on Manure-Enriched Calcareous Soils

    Science.gov (United States)

    Nutrient accumulations on heavily manured soils can trigger soil and plant nutrient interactions. The goal of the study was to determine the current impact of dairy manure applications on nutrient concentrations in soil and tissue for irrigated corn silage crops grown in Southern Idaho. At harvest,...

  18. COMPARISON OF SOIL TEST METHODS FOR AVAILABLE PHOSPHORUS IN COMMON CALCAREOUS BLACK SOIL

    Directory of Open Access Journals (Sweden)

    Biryukova O. A.

    2014-11-01

    Full Text Available The article presents a comparative analysis of the results on available phosphorus measurements in common black soils using the Machigin and Olsen methods. The relationships between maize productivity and soil available phosphorus and also between phosphorus concentrations in the above-ground plant parts and soil available phosphorus were identified at various stages of crop development

  19. COMPARISON OF SOIL TEST METHODS FOR AVAILABLE PHOSPHORUS IN COMMON CALCAREOUS BLACK SOIL

    OpenAIRE

    Biryukova O. A.; Bozhkov D. V.; Nosov V. V.

    2014-01-01

    The article presents a comparative analysis of the results on available phosphorus measurements in common black soils using the Machigin and Olsen methods. The relationships between maize productivity and soil available phosphorus and also between phosphorus concentrations in the above-ground plant parts and soil available phosphorus were identified at various stages of crop development

  20. Assessing different agricultural managements with the use of soil quality indices in a Mediteranean calcareous soil

    Science.gov (United States)

    Morugán-Coronado, Alicia; García-Orenes, Fuensanta; Mataix-Solera, Jorge; Arcenegui, Vicky; Cerdà, Artemi

    2013-04-01

    Soil erosion is a major problem in the Mediterranean region due to the arid conditions and torrential rainfalls, which contribute to the degradation of agricultural land. New strategies must be developed to reduce soil losses and recover or maintain soil functionality in order to achieve a sustainable agriculture. An experiment was designed to evaluate the effect of different agricultural management on soil properties and soil quality. Ten different treatments (contact herbicide, systemic herbicide, ploughing, Oat mulch non-plough, Oats mulch plough, leguminous plant, straw rice mulch, chipped pruned branches, residual-herbicide and agro geo-textile, and three control plots including no tillage or control and long agricultural abandonment (shrub on marls and shrub on limestone) were established in 'El Teularet experimental station' located in the Sierra de Enguera (Valencia, Spain). The soil is a Typic Xerorthent developed over Cretaceous marls in an old agricultural terrace. The agricultural management can modify the soil equilibrium and affect its quality. In this work two soil quality indices (models) developed by Zornoza et al. (2007) are used to evaluate the effects of the different agricultural management along 4 years. The models were developed studying different soil properties in undisturbed forest soils in SE Spain, and the relationships between soil parameters were established using multiple linear regressions. Model 1, that explained 92% of the variance in soil organic carbon (SOC) showed that the SOC can be calculated by the linear combination of 6 physical, chemical and biochemical properties (acid phosphatase, water holding capacity (WHC), electrical conductivity (EC), available phosphorus (P), cation exchange capacity (CEC) and aggregate stability (AS). Model 2 explains 89% of the SOC variance, which can be calculated by means of 7 chemical and biochemical properties (urease, phosphatase, and ß-glucosidase activities, pH, EC, P and CEC). We use the

  1. Assessing the Mobility of Lead, Copper and Cadmium in a Calcareous Soil of Port-au-Prince, Haiti

    OpenAIRE

    Urbain Fifi; Thierry Winiarski; Evens Emmanuel

    2013-01-01

    The presence of heavy metals in the environment constitutes a potential source of both soil and groundwater pollution. This study has focused on the reactivity of lead (Pb), copper (Cu) and Cadmium (Cd) during their transfer in a calcareous soil of Port-au-Prince (Haiti). Kinetic, monometal and competitive batch tests were carried out at pH 6.0. Two simplified models including pseudo-first-order and pseudo-second-order were used to fit the experimental data from kinetics adsorption batch test...

  2. INTEGRATED NITROGEN AND BORON FERTILIZATION IMPROVES THE PRODUCTIVITY AND OIL QUALITY OF SUNFLOWER GROWN IN A CALCAREOUS SOIL

    OpenAIRE

    SHEHZAD, Muhammad Asif; Maqsood, Muhammad

    2015-01-01

    Among biotic and abiotic factors, imbalanced plant nutrition is more indispensable for low sunflower productivity. To assess the interaction behavior of nitrogen with boron on sunflower growth, yield and its oil quality in alkaline-calcareous soils, a field experiment was conducted for two consecutive growing seasons of 2011 and 2012. Sunflower hybrid (Helianthus annuus ‘Hysun-33’) was grown on sandy clay loam soil that was amended with diverse boron rates of 0, 2, 4, and 6 kg ha-1 under vari...

  3. Dynamics of phosphorus fractions in the rhizosphere of fababean (Phaseolus vulgaris L.) and maize (Zea mays L.) grown in calcareous and acid soils

    NARCIS (Netherlands)

    Li, G.; Li, Haigang; Leffelaar, P.A.; Shen, J.; Zhang, F.

    2015-01-01

    The dynamics of soil phosphorus (P) fractions were investigated, in the rhizosphere of fababean (Vicia faba L.) and maize (Zea mays L.) grown in calcareous and acid soils. Plants were grown in a mini-rhizotron with a thin (3 mm) soil layer, which was in contact with the root-mat, and considered as r

  4. Development of soils on calcareous quarry detritus of open-pit oil shale mining during three decades

    International Nuclear Information System (INIS)

    Primary pedogenesis on quarry detritus under planted stands was studied in six experimental areas at Kohtla and Viivikonna, North-East Estonia. During 29-35 years, natural differentiated soil sections have formed. These were classified as Calcaric Regosols and Calcaric Arenosols. Both represent an output of a highly intensive production process. Besides the root system, ground forest litter of the Moder and/or Mull-like Moder type was the main pedogenetic agent there. Although some residues of kukersite could humify and participate in the formation of the epipedon close to mollic, the composition of humus demonstrates the crucial role of plant remains in the humification processes during the progress of soils. Humus formations from humic-fulvic to humic are rich in organic carbon, but poor in nitrogen and free fulvic acids, and are mainly bound with mobile sesquioxides. Humus is characterized by a large proportion of insoluble residue. Therefore, pedogenetic argillization was extremely weak and humus colloids were prevalent in the soil exchange complex. Exchangeable hydrogen was completely lacking, soil reaction was alkaline. Changes in iron relationships reveal a slight formation of cambic properties in some soil sections. (author)

  5. CaCO3 and SrCO3 bioprecipitation by fungi isolated from calcareous soil.

    Science.gov (United States)

    Li, Qianwei; Csetenyi, Laszlo; Paton, Graeme Iain; Gadd, Geoffrey Michael

    2015-08-01

    The urease-positive fungi Pestalotiopsis sp. and Myrothecium gramineum, isolated from calcareous soil, were examined for their properties of CaCO3 and SrCO3 biomineralization. After incubation in media amended with urea and CaCl2 and/or SrCl2 , calcite (CaCO3 ), strontianite (SrCO3 ), vaterite in different forms [CaCO3 , (Cax Sr1-x )CO3 ] and olekminskite [Sr(Sr,Ca)(CO3 )2 ] were precipitated, and fungal 'footprints' were observed on mineral surfaces. The amorphous precipitate mediated by Pestalotiopsis sp. grown with urea and equivalent concentrations of CaCl2 and SrCl2 was identified as hydrated Ca and Sr carbonates by Fourier transform infrared spectroscopy. Liquid media experiments showed M. gramineum possessed the highest Sr(2+) removal ability, and ∼ 49% of supplied Sr(2+) was removed from solution when grown in media amended with urea and 50 mM SrCl2 . Furthermore, this organism could also precipitate 56% of the available Ca(2+) and 28% of the Sr(2+) in the form of CaCO3 , SrCO3 and (Cax Sr1-x )CO3 when incubated in urea-amended media and equivalent CaCl2 and SrCl2 concentrations. This is the first report of biomineralization of olekminskite and coprecipitation of Sr into vaterite mediated by fungi. These findings suggest that urease-positive fungi could play an important role in the environmental fate, bioremediation or biorecovery of Sr or other metals and radionuclides that form insoluble carbonates. PMID:26119362

  6. Point estimation of soil water infiltration process using Artificial Neural Networks for some calcareous soils

    Science.gov (United States)

    Parchami-Araghi, Farzin; Mirlatifi, Seyed Majid; Ghorbani Dashtaki, Shoja; Mahdian, Mohmmad Hossein

    2013-02-01

    SummaryInfiltration process is one of the most important components of the hydrological cycle. The direct measurement of infiltration is laborious, time consuming, expensive, and often involves large spatial and temporal variability. Thus, any indirect estimation of this process is quite helpful. The main objective of this study was to predict the cumulative infiltration at specific time steps, using readily available soil data and Artificial Neural Networks (ANNs). 210 double ring infiltration data were collected from different regions of Iran. Basic soil properties of the two upper pedogenic layers (A and B horizons) including initial soil water content, soil water contents at field capacity (-33 kPa) and permanent wilting point (-1500 kPa), bulk density, particle-size distributions, organic carbon, gravel content (>2 mm size), and CaCO3 content were determined. The feedforward multilayer perceptron ANN model was used to predict the cumulative infiltration at 5, 10, 15, 20, 30, 45, 60, 90, 120, 150, 180, 210, 240, and 270 min after the start of the infiltration experiment and at the time of the basic infiltration rate. The developed ANN models were categorized to type I and type II ANN models. The basic soil properties of the first upper soil horizon were hierarchically used as inputs to develop type I ANN models. In contrast, the type II ANN models were developed while the available soil properties of the two upper soil horizons were implemented as inputs using principal component analysis technique. Results of the reliability test for the developed ANN models indicated that type I ANN models with a RMSE of 1.136-9.312 cm had the best performance in estimating the cumulative infiltration. Type I ANN models with the mean RMSD of 6.307 cm had the best performance in estimating the cumulative infiltration curve (CIC). Results indicated that at the 1% probability level, ANNs-derived CIC can be accepted as one of the replications of a reliable infiltration experiment

  7. Optimizing Available Phosphorus in Calcareous Soils Fertilized with Diammonium Phosphate and Phosphoric Acid Using Freundlich Adsorption Isotherm

    Directory of Open Access Journals (Sweden)

    Asif Naeem

    2013-01-01

    Full Text Available In calcareous soils, phosphorus (P retention and immobilization take place due to precipitation and adsorption. Since soil pH is considered a major soil variable affecting the P sorption, an acidic P fertilizer could result in low P adsorption compared to alkaline one. Therefore, P adsorption from DAP and phosphoric acid (PA required to produce desired soil solution P concentration was estimated using Freundlich sorption isotherms. Two soils from Faisalabad and T. T. Singh districts were spiked with 0, 10, and 20 % for 15 days. Freundlich adsorption isotherms ( were constructed, and theoretical doses of PA and DAP to develop a desired soil solution P level (i.e., 0.20 mg L−1 were calculated. It was observed that P adsorption in soil increased with . Moreover, at all the levels of , P adsorption from PA was lower compared to that from DAP in both the soils. Consequently, lesser quantity of PA was required to produce desired solution P, 0.2 mg L−1, compared to DAP. However, extrapolating the developed relationship between soil contents and quantity of fertilizer to other similar textured soils needs confirmation.

  8. Aspects of land application of sewage solids and gamma-irradiated dried sewage solids on calcareous soils

    International Nuclear Information System (INIS)

    One of the cheapest and generally most convenient methods of disposing of sewage sludge is by land application. The greatest risks of land application are potential contamination of the environment by heavy metals, other toxicants, and pathogens. Irradiation of sewage sludge has been shown to have little or no effect on sludge elements available to plants, and can remove the potential pathogen problem. Work at New Mexico State University has shown that, with little risk, gamma-irradiated sewage sludge can be used to great advantage for crop production, especially on highly calcareous soils low in heavy metals essential for plant growth

  9. Non-cellulosic polysaccharides help to reveal the history of thick organic surface layers on calcareous Alpine soils

    Science.gov (United States)

    Prietzel, Jörg; Spielvogel, Sandra

    2015-04-01

    We investigated the potential of non-cellulosic polysaccharides (NCP) as biomarkers to identify the plant types that dominate present and past litter input into organic surface covers on calcareous Alpine soils and to reveal historic vegetation changes. At two sites in the Alps, NCP monomers were quantified in different organs of site-dominating plants, the Oa horizon of four Folic Leptosols, and different sections of thick organic surface layers of four Folic Histosols on calcareous bedrock. The dominating plant types at our study sites differ markedly in their NCP composition and (galactose + mannose)/(arabinose + xylose) [GM/AX] ratio (grasses and sedges: 0.2; dicots Fagus and Vaccinium: 0.2-0.6; conifers Abies, Picea, Pinus: 0.7-2.4; mosses: 5). For all except one soil, the NCP signature of the uppermost Oa horizon reflects the present vegetation. For all Histosol O horizons, NCP signatures indicate a dominance of conifer litter throughout their development (up to 1,500 years). Different NCP and GM/AX depth profiles reflect specific patterns of O layer genesis. From those results we conclude that NCP and GM/AX depth profiles in organic surface covers of soils provide important information about dominating litter sources in the past and can be valuable tools to reveal historic vegetation and/ or land use changes.

  10. Evaluation of chemical indices of soil Pb availability in calcareous soils

    Energy Technology Data Exchange (ETDEWEB)

    Al-Afifi, M.A. [Dept. of Plant Production, Coll. of Agricultural Science, United Arab Emirates Univ., Al Ain (United Arab Emirates)

    1994-12-31

    The objective of this study was to compure six soil test (1 M KNO{sub 3}, 1 M NH{sub 4}OAC, 0.005 M DTPA, 0.1 M EDTA, 1 M HNO{sub 3} and 0.025 M Ca DTPA B{sub 4}O{sub 7}) as extractants for soil Pb and as predictors of plant available Pb for wheat (Triticum aestivum L.) in the greenhouse. The soils received 0, 200 and 400 mg Pb kg{sup -1} as Pb(NO{sub 3}){sub 2} and are referred to as Pb{sub 0}, Pb{sub 1} and Pb{sub 2} treatments respectively. Of the six soil extractants, 1 M HNO{sub 3} was the most effective extractant for Pb from Pb{sub 0} treatment whereas 0.1 M EDTA and 0.025 M Ca DTPA-B{sub 4}O{sub 7} were the best and equally effective in their ability to extract Pb from Pb{sub 1} and Pb{sub 2} treatments. Regression analysis was used to develop two variable models for predicting Pb uptake by wheat as a function of extractable Pb and selected soil properties. The 0.025 M Ca DTPA-B{sub 4}O{sub 7} extractant was the best in predicting uptake by wheat in Pb{sub 0} (r=0.791*** significant at p=0.001) and Pb{sub 1} (r=0.726***) and Pb{sub 2} (r=0.942***) treatments. (orig.) [Deutsch] Ziel der Untersuchung war der Vergleich von 6 Methoden (a) 1 M KNO{sub 3}, (b) 1 M NH{sub 4} OAC, (c) 0.25 M Ca DTPA-B{sub 4}O{sub 7}, (d) 0.005 M DTPA, (e) 0.1 M EDTA, (f) 1 M HNO{sub 3} zur Charakterisierung des fuer Pflanzen verfuegbaren Boden-Pb. Proben (0-15 cm) von 22 kalkhaltigen Boeden wurden mit 0 (=Pb{sub 0}), 200 (=Pb{sub 1}), bzw. 400 (=Pb{sub 2}) mg Pb kg{sup -1} als Pb (NO{sub 3}){sub 2} versetzt und im Gefaessversuch mit Weizen kultiviert. Methode (f) extrahierte am meisten aus Pb{sub 0}, (c) und (e) brachten mehr aus Pb{sub 1} und Pb{sub 2}, (c) korrelierte am besten mit dem Pflanzenentzug (Pb{sub 0} r=0,791*** bei p=0.001; Pb{sub 1} 0.726***, Pb{sub 2} 0.942***). (orig.)

  11. Integrated use of boiler ash as organic fertilizer and soil conditioner with NPK in calcareous soil

    OpenAIRE

    Muhammad Jamil Khan; Muhammad Qasim

    2008-01-01

    characteristics and provide a reasonable economic means to recycle these wastes in an environmentally friendly manner. To achieve this objective, sugar industry boiler ash was applied to wheat crop in pots having 20 kg soil @ 3, 12, 25,50, 125 and 250 t ha-1 respectively, compared to the control. Same doses of boiler ash were also applied to wheat crop in the field experiment. A basal dose of NPK, 120, 90, and 60 kg ha-1 respectively, was also applied with boiler ash before sowingof wheat cro...

  12. Movement of manganese-54 in calcareous soils as affected by leaching solution, lime content, salinization, and sterilization

    International Nuclear Information System (INIS)

    Movement of 54Mn was investigated in calcareous soil columns leached with 0.05 mol CaCl2 L-1 followed by 0.03 mol EDTA L-1. Manganese was monitored along the soil columns using gamma spectrometry and measured in the effluent during the leaching course. Results indicated that the leaching with CaCl2 for 45 d left 63, 32, and 10% of the applied Mn in the upper 0.5 cm of the silty clay, loam, and loamy sand soils, respectively, with no Mn detected below 5.0 cm. Conversely, leaching with EDTA for 4 d resulted in a nearly uniform distribution of Mn in the 20-cm soil columns. The various soil treatments caused a reduction in the retention capacity of the three soils for Mn with the maximum reduction occurring in the soils with partially depleted line. In most cases, leaching with CaCl2 for 45 d produced no Mn in the column effluent except negligible amounts of Mn that were displaced from the sterilized and 50 g lime kg-1 columns. On the other hand, Mn emerged in the effluent immediately after EDTA application and continued until the end of the leaching course. The shape and the position of the breakthrough curves varied depending on the specific soil treatment

  13. Soil water repellency patterns following long-term irrigation with waste water in a sandy calcareous soil, SE Spain

    Science.gov (United States)

    Mataix-Solera, J.; García-Irles, L.; Morugán, A.; Doerr, S. H.; García-Orenes, F.; Atanassova, I.; Navarro, M. A.; Ayguadé, H.

    2009-04-01

    One of the consequences of long-term irrigation with waste water can be the development of soil water repellency (WR). Its emergence can affect soil-water balance, irrigation efficiency and crop yield. Water repellency development has been suggested to be controlled by parameters such as organic matter quantity and type present in the waste water, soil properties (particularly the texture), and the overall time period of irrigation. Here we examine the effect of long-term (~20 years) irrigation with low quality waste-water on soil wettability under a Populus alba tree stand used as a "green filter". The plot exhibited considerable micro-topography (ridges and furrows) and consisted of sandy calcareous soil (Xerofluvent). Water repellency and organic carbon content (OC) were studied in 160 samples taken from the plot and from an adjacent area used as control (no irrigated). From the control area 40 samples were taken from the first 5 cm of mineral soil (C samples). From the irrigated plot a total of 120 samples were collected. To account for the micro-topography of the terrain, 40 samples each were taken from ridges (R samples; 0-5 cm depth), furrows (F samples; 0-5 cm depth), and from furrows at depth (FD samples, 5-10 cm depth). Soil WR was assessed in the laboratory for all air dry samples using the water drop penetration time test (WDPT Test). Samples with WDPT ? 5 seconds were classified as non-repellent. Organic carbon content (OC) was analyzed in all samples by potassium dichromate oxidation method. We also carried out a detailed chemical characterisation of the organic matter in two furrow samples that exhibited contrasting wettability, but no major difference in OC content (F10: WDPT 9960s, OC 6.7%; F31: WDPT 10s, OC 7.5%). Following accelerated solvent extraction with Dichloro-methane/MeOH (95:5), the extract was analysed by GC-MS. All samples from the control area (C) were wettable (mean WDPT=1s). In the irrigated plot, water repellency was present for 48

  14. A study on zinc distribution in calcareous soils for cowpea (Vigna Unguiculata L.) and barely ( Hordeum Vulgare L.)

    Science.gov (United States)

    Boroomand, Naser; Maleki, Mohammad Reza

    2010-05-01

    Compared to other cereals, such as wheat and barley cultivars which have low sensitivity to Zn deficiency, cowpea is sensitive to zinc (Zn) deficiency, however it extensively grows even in soils with deficient in Zn. A 8-week greenhouse experiment was conducted to study the response of cowpea and barely to Zn in calcareous soils with different DTPA- Zn. The soil samples were taken from soil surface up to 0.3 m in which their DTPA- Zn ranged from 0.5 to 3.5 mg kg-1. Shoot dry matter, concentration and uptake of Zn were found to be significantly correlated with soil DTPA- Zn in cowpea and barely. Critical deficiency level of Zn in cowpea was 1.3 mg kg-1 in soil and 28.5 mg kg-1 in shoot dry matter, however, to barely symptoms of Zn deficiency was not observed and concentration of Zn was higher than the critical level reported in literatures. Organic carbon (OC), calcium carbonate equivalent (CCE), pH and field capacity soil moisture content(FC) were significantly correlated with plant responses to Zn which were the most influenced characteristics to Zn uptake by plants.

  15. Direct and residual effect of hazara rock phosphate (hrp) on wheat and succeeding maize in alkaline calcareous soils

    International Nuclear Information System (INIS)

    The potential of Hazara rock phosphate (HRP) containing 18 % acid soluble P/sub 2/O/sub 5/ as cheaper substitute for costly commercial fertilizer for crop production, was evaluated. Field experiments were conducted on silty clay loam, calcareous (16 % CaCO/sub 3/), high pH (8.6) soil where 0, 250, 500, 1000 and 1500 kg HRP ha-1 was added to wheat (Triticum aestivum L.), cv Serin with three replications in RCB arrangement. Recommended doses of N and K were applied to all plots. Maize (Zea mays L.) cv Babar was grown as a succeeding crop for evaluating the residual effect of HRP as a source of P. Addition of HRP produced significant increase in wheat grain and biomass yield over control. HRP demonstrated a significant residual effect on grain and biomass yield over control. Similar increases were registered in the number of grains, grains spike-1 of wheat and cobs weight and grain weight cob-1 of maize. The variations induced by levels of HRP were mostly similar while the residual levels showed better results for higher doses compared to lower for maize yield and yield components. The soil analysis performed for the growth stages revealed significant water soluble P concentrations with HRP treatments over control suggesting sustained supply of P into the soil solution for crop growth and development. The total P uptake by both wheat and maize closely followed the pattern of WSP, which corroborated the yield data. It was concluded that HRP offer promise as alternate source of P, however, to ensure optimum crop production on high pH calcareous soil, some acidification after careful standardization will be advisable. (author)

  16. Assessing the Mobility of Lead, Copper and Cadmium in a Calcareous Soil of Port-au-Prince, Haiti

    Directory of Open Access Journals (Sweden)

    Urbain Fifi

    2013-11-01

    Full Text Available The presence of heavy metals in the environment constitutes a potential source of both soil and groundwater pollution. This study has focused on the reactivity of lead (Pb, copper (Cu and Cadmium (Cd during their transfer in a calcareous soil of Port-au-Prince (Haiti. Kinetic, monometal and competitive batch tests were carried out at pH 6.0. Two simplified models including pseudo-first-order and pseudo-second-order were used to fit the experimental data from kinetics adsorption batch tests. A good fit of these data was found with pseudo-second-order kinetic model which indicates the applicability of this model to describe the adsorption rates of these metals on the soil. Monometal batch tests indicated that both Langmuir and Freundlich models allowed a good fit for experimental data. On the basis of the maximum adsorption capacity (qmax, the order affinity of Pb, Cu and Cd for the studied soil was Pb2+ > Cu2+ > Cd2+. Competitive sorption has proved that the competition between two or several cations on soils for the same active sites can decrease their qmax. These results show that, at high metal concentrations, Cd may pose more threat in soils and groundwater of Port-au-Prince than Pb and Cu.

  17. Effect of Long-Term Fertilization on Organic Nitrogen Forms in a Calcareous Alluvial Soil on the North China Plain

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    In order to illustrate the change of nitrogen (N) supply capacity after long-term application of manure and chemical fertilizer, as well as to properly manage soil fertility through fertilizer application under the soil-climatic conditions of the North China Plain, organic N forms were quantified in the topsoil with different manure and chemical fertilizer treatments in a 15-year fertilizer experiment in a Chinese calcareous alluvial soil Soil total N (TN) and various organic N forms were significantly influenced by long-term application of chemical fertilizer and manure. TN, total hydrolysable N, acid-insoluble N, amino acid N and ammonium N in the soil increased significantly (P < 0.05) with increasing manure and fertilizer N rates, but were not influenced by increasing P rates. Also, application of manure or N fertilizer or P fertilizer did not significantly influence either the quantity of amino sugar N or its proportion of TN. Application of manure significantly increased (P < 0.05) hydrolysable unknown N, but adding N or P did not. In addition, application of manure or N fertilizer or P fertilizer did not significantly influence the proportions of different soil organic N forms.

  18. Development and validation of a terrestrial biotic ligand model for Ni toxicity to barley root elongation for non-calcareous soils.

    Science.gov (United States)

    Lin, Yanqing; Di Toro, Dominic M; Allen, Herbert E

    2015-07-01

    A Terrestrial Biotic Ligand Model (TBLM) for Ni toxicity to barley root elongation (RE) developed from experiments conducted in sand culture was used to predict toxicity in non-calcareous soils. Ca(2+) and Mg(2+) concentrations and pH in sand solution were varied individually and TBLM parameters were computed. EC50 increased as Mg(2+) increased, whereas the effect of Ca(2+) was insignificant. TBLM parameters developed from sand culture were validated by toxicity tests in eight Ni-amended, non-calcareous soils. Additional to Ni(2+) toxicity, toxicity from all solution ions was modelled independently as an osmotic effect and needed to be included for soil culture results. The EC50s and EC10s in soil culture were predicted within twofold of measured results. These are close to the results obtained using parameters estimated from the soil culture data itself. PMID:25800936

  19. Phosphate solubilization and promotion of maize growth in a calcareous soil by Penicillium oxalicum P4 and Aspergillus niger P85

    Science.gov (United States)

    Alternative tactics for improving phosphorus nutrition in crop production are needed in China and elsewhere as the over-application of phosphatic fertilizers can adversely impact agricultural sustainability. Penicillium oxalicum P4 and Aspergillus niger P85 were isolated from a calcareous soil in C...

  20. Evolution of the soil humus status on the calcareous Neogene clay dumps of the Sokolov quarry complex in the Czech Republic

    Czech Academy of Sciences Publication Activity Database

    Abakumov, E.V.; Frouz, Jan

    2009-01-01

    Roč. 42, č. 7 (2009), s. 718-724. ISSN 1064-2293 Grant ostatní: Russian Foundation for Basic Research(XE) 08-04-01128 Institutional research plan: CEZ:AV0Z60660521 Keywords : soil humus status * calcareous Neogene clay dumps * Sokolov quarry complex Subject RIV: EH - Ecology, Behaviour Impact factor: 0.222, year: 2009

  1. Soil pH management by calcareous and siliceous minerals: effect on N2O yield in nitrification and denitrification

    Science.gov (United States)

    Nadeem, Shahid; Bakken, Lars; Dörsch, Peter

    2016-04-01

    Amelioration of soil pH by liming is necessary and common practice in vast areas of crop production. It is well known that pH is one of the most pervasive factors controlling rates and product stoichiometries in microbially mediated N transformations, including N2O emissions. While liming of acid soils appears to increase N2O reductase activity in denitrification (resulting in less N2O relative to N2), sudden pH raise may boost nitrification and hence N2O emission from ammonia oxidation. Thus, the net effect of liming on N2O emissions is not straightforward, which probably explains why soil pH management has not been embraced as a strategy for mitigating N2O emissions so far. Here we report laboratory incubations in which we determined potential rates and N2O yields in soils from an ongoing field experiment, comparing traditional calcareous limes (calcite, dolomite) with mafic minerals (olivine, different types of plagioclase). The experiment is in its second year, and shows strong pH increase (0.7-1.5, units) in plots with calcareous limes, a weak pH increase (~ 0.2 unit) in the olivine treatment and no measurable pH increase with the plagioclases. Potential nitrification rates correlated positively with effective soil pH as did the N2O yield, measured as N2O accumulation rate over NO2- + NO3- accumulation rate. The N2O yield increased in the order, control soils. Overall, the N2O yield from nitrification was quite low (0.09 - 0.17%). Potential denitrifications rates showed little response to pH increase (no C source added) but significantly lower N2O product ratios (N2O/(N2O + N2) with increasing pH in the order, calcite < dolomite < olivine < plagioclase < control. Given the overall low N2O yield of nitrification as compared to that of denitrification (10 - 100%), the observed increases in N2O yields of nitrification are unlikely to override a significant reduction in N2O production by denitrification under fluctuating oxic-anoxic conditions. The results will be

  2. Behavior of zinc from six organic fertilizers applied to a navy bean crop grown in a calcareous soil.

    Science.gov (United States)

    Gonzalez, D; Obrador, A; Alvarez, J M

    2007-08-22

    The objective of this study was to compare the mobility, leaching, availability, and relative effectiveness of Zn from Zn-polyhydroxyphenylcarboxilate (Zn-PHP), Zn-HEDTA (Zn-N-2-hydroxyethyl-ethylenediaminetriacetate), Zn-EDDHSA [Zn-ethylenediamine-di-(2-hydroxy-5-sulfophenylacetate)], Zn-EDTA (Zn-ethylenediaminetetraacetate), Zn-S,S-EDDS (Zn-ethylenediaminedisuccinate), and Zn-EDTA-HEDTA sources by applying different Zn rates (5 and 10 mg kg(-1)) to a calcareous soil under greenhouse conditions. A lysimeter experiment was carried out for 60 days and using navy bean (Phaseolus vulgaris L.) as an indicator plant. The Zn available to the plant and easily leachable Zn were determined in soil by different single extractions, while the distribution of Zn in the soil was assessed by sequential speciation. The utilization of applied Zn by the navy bean was greatest when the Zn treatments were Zn-EDTA, Zn-EDTA-HEDTA, Zn-HEDTA, and Zn-EDDHSA. Both total Zn in the plants and soluble Zn in the plant dry matter (extracted with 1 mM 2-morpholino-ethanesulfonic acid) were positive and significantly correlated with the following: the amounts of Zn extracted with the three single extractions used to estimate soil available Zn and the amounts of Zn in the water soluble plus exchangeable and organically complexed fractions. The Zn-HEDTA, Zn-EDDHSA, Zn-EDTA-HEDTA, Zn-S,S-EDDS, and Zn-EDTA sources significantly increased the mobility of micronutrients through the soil with respect to the control and Zn-PHP source. The maximum Zn concentration obtained in the leachate fractions was 65 mg L(-1) (13% of Zn applied) for the Zn-S,S-EDDS chelate applied at a rate of 10 mg Zn kg(-1) soil. In the course of the crop, the soil pH + pe parameter increased significantly with experimental time. PMID:17663567

  3. Comparison of ion-exchange resin counterions in the nutrient measurement of calcareous soils: Implications for correlative studies of plant-soil relationships

    Science.gov (United States)

    Sherrod, S.K.; Belnap, J.; Miller, M.E.

    2003-01-01

    For more than 40 years, ion-exchange resins have been used to characterize nutrient bioavailability in terrestrial and aquatic ecosystems. To date, however, no standardized methodology has been developed, particularly with respect to the counterions that initially occupy resin exchange sites. To determine whether different resin counterions yield different measures of soil nutrients and rank soils differently with respect to their measured nutrient bioavailability, we compared nutrient measurements by three common counterion combinations (HCl, HOH, and NaHCO3). Five sandy calcareous soils were chosen to represent a range of soil characteristics at Canyonlands National Park, Utah, and resin capsules charged with the different counterions equilibrated in saturated pastes of these soils for one week. Data were converted to proportions of total ions of corresponding charge for ANOVA. Results from the different methods were not comparable with respect to any nutrient. Of eleven nutrients measured, all but iron (Fe2+), manganese (Mn2+), and zinc (Zn2+) differed significantly (p ??? 0.05) as a function of soil x counterion interactions; Fe2+ and Zn2+ varied as functions of counterion alone. Of the counterion combinations, HCl-resins yielded the most net ion exchange with all measured nutrients except Na+, NH4+, and HPO42-, the three of which desorbed in the greatest quantities from HOH-resins. Conventional chemical extractions using ammonium acetate generally yielded high proportional values of Ca2+, K+, and Na+. Further, among-soil rankings of nutrient bioavailability varied widely among methods. This study highlights the fact that various ion-exchange resin techniques for measuring soil nutrients may have differential effects on the soil-resin environment and yield data that should not be compared nor considered interchangeable. The most appropriate methods for characterizing soil-nutrient bioavailability depends on soil characteristics and likely on the physiological

  4. Sorption, desorption, and speciation of Cd, Ni, and Fe by four calcareous soils as affected by pH.

    Science.gov (United States)

    Tahervand, Samaneh; Jalali, Mohsen

    2016-06-01

    The sorption, desorption, and speciation of cadmium (Cd), nickel (Ni), and iron (Fe) in four calcareous soils were investigated at the pH range of 2-9. The results indicated that sorption of Fe by four soils was higher than 80 % at pH 2, while in the case of Cd and Ni was less than 30 %. The most common sequence of metal sorption at pH 2-9 for four soils was in the order of Fe ≫ Ni > Cd. Cadmium and Ni sorption as a function of pH showed the predictable trend of increasing metal sorption with increase in equilibrium pH, while the Fe sorption trend was different and characterized by three phases. With regard to the order of Cd, Ni, and Fe sorption on soils, Cd and Ni showed high affinity for organic matter (OM), whereas Fe had high tendency for calcium carbonate (CaCO3). Results of metal desorption using 0.01 M NaCl demonstrated that metal sorption on soils containing high amounts of CaCO3 was less reversible in comparison to soils containing high OM. In general, Cd and Ni desorption curves were characterized by three phases; (1) the greatest desorption at pH 2, (2) the low desorption at pH 3-7, and (3) the least desorption at pH > 7. The MINTEQ speciation solubility program showed that the percentage of free metals declined markedly with increase of pH, while the percentage of carbonate and hydroxyl species increased. Furthermore, MINTEQ predicted that saturation index (SI) of metals increased with increasing pH. PMID:27147235

  5. Aging effect on Zn retention on a calcareous soil: Column experiments and synchrotron X-ray micro-spectroscopic investigation

    Energy Technology Data Exchange (ETDEWEB)

    Sayen, Stéphanie, E-mail: stephanie.sayen@univ-reims.fr; Guillon, Emmanuel

    2014-07-01

    In this study, a combination of column experiments and micro-analytical techniques exploiting synchrotron generated X-rays was used to assess the effect of aging time on Zn retention and mobility in the specific case of calcareous soils (high pH value, ≈ 8). The samples were subjected to aging for 2, 6, 17, and 63 days. Freshly added Zn mainly existed as an exchangeable form, and this metal fraction decreased over time due to Zn redistribution to stronger binding sites. Thus, after aging for 63 days, 45% of Zn is remobilized from exchangeable sites to stronger binding sites. μ-XRF maps were used to find correlations among elements in the sample, and μ-XANES spectra were recorded to precise Zn speciation. These analyses evidenced an increasing partitioning of Zn from organic matter to iron oxy(hydr)oxides over time. The occurrence of hydrozincite is evidenced in all samples. - Highlights: • Zinc retention on soil column induced a calcium release. • Increasing soil aging time enhanced its zinc retention capacity. • Zinc decreasing mobility over time is evidenced by leaching experiments. • Zn redistribution occurred from exchangeable sites to stronger binding sites. • Zn redistribution occurred from organic matter to primarily iron oxy(hydr)oxides.

  6. Formation of Zn-rich phyllosilicate, Zn-layered double hydroxide and hydrozincite in contaminated calcareous soils

    Energy Technology Data Exchange (ETDEWEB)

    Jacquat, Olivier; Voegelin, Andreas; Villard, Andre; Marcus, Matthew A.; Kretzschmar, Ruben

    2007-10-15

    Recent studies demonstrated that Zn-phyllosilicate- and Zn-layered double hydroxide-type (Zn-LDH) precipitates may form in contaminated soils. However, the influence of soil properties and Zn content on the quantity and type of precipitate forming has not been studied in detail so far. In this work, we determined the speciation of Zn in six carbonate-rich surface soils (pH 6.2 to 7.5) contaminated by aqueous Zn in the runoff from galvanized power line towers (1322 to 30090 mg/kg Zn). Based on 12 bulk and 23 microfocused extended X-ray absorption fine structure (EXAFS) spectra, the number, type and proportion of Zn species were derived using principal component analysis, target testing, and linear combination fitting. Nearly pure Zn-rich phyllosilicate and Zn-LDH were identified at different locations within a single soil horizon, suggesting that the local availabilities of Al and Si controlled the type of precipitate forming. Hydrozincite was identified on the surfaces of limestone particles that were not in direct contact with the soil clay matrix. With increasing Zn loading of the soils, the percentage of precipitated Zn increased from {approx}20% to {approx}80%, while the precipitate type shifted from Zn-phyllosilicate and/or Zn-LDH at the lowest studied soil Zn contents over predominantly Zn-LDH at intermediate loadings to hydrozincite in extremely contaminated soils. These trends were in agreement with the solubility of Zn in equilibrium with these phases. Sequential extractions showed that large fractions of soil Zn ({approx}30% to {approx}80%) as well as of synthetic Zn-kerolite, Zn-LDH, and hydrozincite spiked into uncontaminated soil were readily extracted by 1 M NH{sub 4}NO{sub 3} followed by 1 M NH{sub 4}-acetate at pH 6.0. Even though the formation of Zn precipitates allows for the retention of Zn in excess to the adsorption capacity of calcareous soils, the long-term immobilization potential of these precipitates is limited.

  7. The influences of selected soil properties on Pb availability and its transfer to wheat (Triticum aestivum L.) in a polluted calcareous soil.

    Science.gov (United States)

    Safari, Yaser; Delavar, Mohammad-Amir; Zhang, Chaosheng; Esfandiarpour-Boroujeni, Isa; Owliaie, Hamid-Reza

    2015-12-01

    Accumulated anthropogenic heavy metals in the surface layer of agricultural soils may be transferred through the food chain via plant uptake processes. The objectives of this study were to assess the spatial distribution of lead (Pb) in the soils and wheat plants and to determine the soil properties which may affect the Pb transferring from soil to wheat plants in Zanjan Zinc Town area, northwestern Iran. A total of 110 topsoil samples (0-20 cm) were systematically collected from an agricultural area near a large metallurgical factory for the analyses of physico-chemical properties and total and bioavailable Pb concentrations. Furthermore, a total of 65 wheat samples collected at the same soil sampling locations were analyzed for Pb concentration in different plant parts. The results showed that elevated Pb concentrations were mostly found in soils located surrounding the industrial source of pollution. The bioavailable Pb concentration in the studied soils was up to 128.4 mg kg(-1), which was relatively high considering the observed soil alkalinity. 24.6% of the wheat grain samples exceeded the FAO/WHO maximum permitted concentration of Pb in wheat grain (0.2 mg kg(-1)). Correlation analyses revealed that soil organic matter, soil pH, and clay content showed insignificant correlation with Pb concentration in the soil and wheat grains, whereas calcium carbonate content showed significantly negative correlations with both total and bioavailable Pb in the soil, and Pb content in wheat grains, demonstrating the strong influences of calcium carbonate on Pb bioavailability in the polluted calcareous soils. PMID:26612564

  8. The Content of Mg, K and Ca Ions in Vine Leaf under Foliar Application of Magnesium on Calcareous Soils

    Directory of Open Access Journals (Sweden)

    David Gluhić

    2009-06-01

    Full Text Available Chlorosis frequently occurs in vine production on calcareous soils, which is usually attributed to high calcium concentrations in soil. If symptoms appear on older leaves, it is taken that chlorosis is caused by a deficit of Mg2+ ions. A method of preventing chlorosis is foliar application of magnesium; however, uncontrolled application can lead to imbalance with potassium and calcium ions. The research objective was to find out whether foliar application of magnesium could solve the problem of chlorosis, and whether magnesium affects ion interactions with potassium and calcium. The fertilizing trial was set up in vineyards, on anthropogenized rigosols, with different contents of available lime in soil (< 20, 25 and 30 % CaO. Fertilizer was applied three times during the growing period, in a total amount of 2500 g Mg/ha. According to the results, foliar application of magnesium can solve the problem of chlorosis only on soils with a lower lime content (< 20 % CaO. Magnesium concentrations in dry leaf ranged from 0.25 % (beginning of growing period to 0.64 % (post harvest, which is in agreement with literature data. On soils with a high lime content, negative correlation was determined between Mg and K ions in the leaf (r = -0.78. Although correlation between Mg and Ca in plant was positive (r = +0.61 to +0.90 during whole grape vine vegetative period, determined high ratios between Ca and Mg, especially during summer (12.4, indicated that Ca was dominant ion in plant disturbing K and Mg physiological roles.

  9. Distribution and indexation of plant available nutrients of rainfed calcareous soils of Pakistan

    OpenAIRE

    Rizwan Khalid; Tariq Mahmood2, Riffat Bibi; Muhammad Tariq Siddique; Sarosh Alvi and Shahid Yaqub Naz

    2012-01-01

    Soil characteristics of Chakwal district were evaluated through physical and chemical analyses. Representative soil samples received/collected from farmers fields were analyzed for texture, electrical conductivity (EC), pH, organic matter (SOM), available phosphorus (P) and potassium (K) contents. Texture of the soils varied from sandy loam to loam. About 97% soils had EC values within the normal range (< 4 dS m-1). The pH values of 64% soils ranged from 7.0 to 8.7 with an average of 7.9 and ...

  10. Vesicular Arbuscular Mycorrhizae—Mediated Uptake and Translocation of P and Zn by Wheat in Calcareous Soil

    Institute of Scientific and Technical Information of China (English)

    TUSHIHUA; T.B.GOH; 等

    1997-01-01

    Vesicular-arbuscular mycorrhizal(VMA) fungi have been credited with improving the growth and mineral nutritons of many host plants but these effects are moderated by soil factors and nutrient balance.The combined effects of VAM,Zn and P application on the growth and translocation of nutrients in wheat were investigated using a calcareous soil marginal in P and Zn concentrations.Wheat was grown in a growth chamber under various combinations of VAM,P and Zn with measurements done at heading stage and maturity,Vegetative dry matter accumlation was increased by P application and reduced by VAM treatments.Both P and VAM increased grain yield.Zince oncentration and uptake were generally reduced by P addition and VAM infection,There were no antagonistic effects of Zn on P acquisition in the plant,The role of VAM in enhancing the translocation of Zn and P from root to grain would be beneficial to seed setting and yield.

  11. Use of Clay Deposits in Water Management of Calcareous Sandy Soils Under-surface and Sub-surface Drip Irrigation

    International Nuclear Information System (INIS)

    The objective of this study was to investigate the effect of irrigation (levels and methods) and type of clay deposits on lettuce yield, water use efficiency WUE and the distributions of soil moisture and salts in the root zone of sandy calcareous soils. A field experiment was conducted at the college experimental station in 2002-2003. It consists of three clay deposits, three rates (0, 1.0 and 2.0%), and four total irrigation applied water levels, 360 mm (T1), 520 mm (T2), 635 mm (T3) and 822 mm (T4), using surface and subsurface drip irrigation. Results indicated that yield was significantly increased with the increase of irrigation level, whereas WUE significantly decreased with increase of irrigation level. The average yield increased by 9.30% in a high irrigation level compared to a moderate irrigation level, and decreased by 14.2% at the more stressed irrigation level. WUE decreased by 49.0% at a moderate irrigation level and yield was significantly affected by amendment rates. The difference between surface and subsurface drip on yields and WUE were also significant. Results indicated that the moisture content of the subsurface treated layer increased dramatically, while salts were accumulated at the surface and away from the emitters in subsurface drip irrigation. The advantages of surface drip irrigation were related to the relative decrease in salt accumulation in the root zone area where the plant roots were active and the water content was relatively high. (author)

  12. Evaluation of factors influencing root-induced changes of copper fractionation in rhizosphere of a calcareous soil

    International Nuclear Information System (INIS)

    Major factors influencing the root-induced copper fractionation changes within the rhizosphere of maize, wheat, pea, and soybean seedlings were evaluated using a contaminated calcareous soil. The effects of acidification, alkalization, and introduction of root exudates were investigated by addition of acid, alkaline and root exudates from solution cultures, prior to incubation and copper fractionation. Raw and sterilized soils were compared for changes of copper fractionation in the rhizosphere using rhizoboxes with maize, wheat, pea and soybean seedlings. The results indicated that the general trend in considerable changes was similar among the plant species studied. The rhizosphere experienced a depletion of carbonate associated and organic bound copper along with an accumulation of exchangeable and Fe-Mn oxide bound copper. The resulting significant influence of root exudates on copper fractionation appears to have been produced through complexation rather than acidification or alkalization. The increase in exchangeable copper in rhizosphere was strengthened by microorganisms. - Influence of root exudates on copper fractionation appeared to be due to complexation, rather than acidification or alkalisation

  13. Field application of mycorrhizal bio-inoculants affects the mineral uptake of a forage legume (Hedysarum coronarium L.) on a highly calcareous soil.

    Science.gov (United States)

    Labidi, S; Jeddi, F Ben; Tisserant, B; Yousfi, M; Sanaa, M; Dalpé, Y; Sahraoui, A Lounès-Hadj

    2015-05-01

    The efficiency of two mycorrhizal bio-inoculants on the mineral uptake during the growth stages of a Mediterranean forage legume sulla (Hedysarum coronarium L.) was studied in the field on a highly calcareous soil. The first inoculum (Mm) was made up of a mixture of native arbuscular mycorrhizal fungi (AMF) isolated from calcareous soils: Septoglomus constrictum, Funneliformis geosporum, Glomus fuegianum, Rhizophagus irregularis and Glomus sp. The second was a commercial inoculum (Mi) containing one AMF species: R. irregularis. Both mycorrhizal inoculants increased total and arbuscular colonization of sulla roots. Inoculation with Mm showed a positive effect on sulla shoot dry weight (SDW) when compared to Mi and non-inoculated plants (control). Mineral contents (P, Mg, Mn, Fe) were higher in the shoots of sulla plants cultivated on mycorrhiza-inoculated plots compared to non-inoculated ones. This enhancement was observed during the flowering stage for P, Mg and Mn and during the rosette stage for Fe. An increase in P content of 50 % in plants inoculated with Mm compared to non-inoculated ones may be explained by the induction of root alkaline and acid phosphatase activities. Higher efficiency of native AMF species adapted to calcareous soils opens the way towards the development of mycorrhiza bio-fertilizers targeted to improve sustainable fertilization management in such soils. PMID:25323044

  14. Sorption of Aldicarb Sulfoxide by Samples of Some Calcareous Soils From Turkey

    OpenAIRE

    GÜLÜT, Kemal Y.; SAYIN, Mahmut

    1998-01-01

    Sorption of aldicarb and aldicarb sulfoxide was investigated spectrophotometrically on 16 soil samples. Ten of them were from the Çukurova region. The results showed that organic matter is the single soil property to give correlation with sorption of aldicarb. Clay minerals are also important in sorption but their effect is masked by fine carbonates and organic matter. CaCO 3 sorbs aldicarb weakly. Aldicarb sulfoxide was also sorbed by soil constituents very weakly.

  15. Role of Fe-oxides for predicting phosphorus sorption in calcareous soils

    OpenAIRE

    Memon, Mehruinsa

    2008-01-01

    Agronomic efficiency and management of environmental P inputs can be improved by understanding soil-phosphorus interaction. Iron oxides and other clay minerals, P forms, and P sorption in young alluvial and weathered residual soils were determined. Phosphorus retention related to crystallinity and phase distribution of iron oxides. CBD and oxalate extractable iron and aluminum and smectite and kaolinite explained 90% variation while soil CaCO3 role was only insignificant in explaining P sorpt...

  16. Deep weathering of calcareous sedimentary rock and the redistribution of iron and manganese in soil and saprolite

    International Nuclear Information System (INIS)

    Iron and Mn redistribute in soil and saprolite during weathering. The geological weathering fronts of calcareous sedimentary rock were investigated by examining the bulk density, porosity, and distribution of Ca, Fe, and Mn. Core samples were taken of soil, saprolite, and bedrock material from both summit (HHMS-4B) and sideslope (HHMS-5A) positions on an interbedded Nolichucky shale and Maryville limestone landform in Solid Waste Storage Area 6 (SWSA-6). This is a low-level radioactive solids waste disposal site on the Dept. of Energy (DOE) Oak Ridge Reservation in Roane County Tennessee. This work was initiated because data about the properties of highly weathered sedimentary rock on this site were limited. The core samples were analyzed for pH, calcium carbonate equivalence (CCE), hydroxylamine-extractable (HA) Mn, and dithionite-citrate (CBD)-extractable Fe and Mn. Low pH values occurred from the soil surface down to the depth of the oxidized and leached saprolite in both cores. The CCE and HA-extractable Mn results were also influenced by the weathering that has occurred in these zones. Extractable Mn oxide was higher at a lower depth in the oxidized and leached saprolite compared with the Fe oxide, which was higher in the overlying soil solum. Amounts of Mn oxides were higher in the sideslope core (HHMS-5A) than in the summit core (HHMS-4B). Iron was more abundant in the deeper weathered summit core, but the highest value, 39.4 g kg-1, was found at 1.8 to 2.4 m in the sideslope core. The zone encompassing the oxidized and partially leached saprolite down to the unoxidized and unleached bedrock had higher densities and larger quantities of CaCO3 than the soil solum and oxidized and leached saprolite. The overlying soil and oxidized and leached saprolite had lower pH and CCE values and were higher in Fe and Mn oxides than the oxidized and unleached saprolite. The distribution of Fe and Mn is important when evaluating soil and saprolite for hazardous waste

  17. Foliar potassium fertilization of muskmelons on calcareous soils in south Texas: Effects on yield and quality

    Science.gov (United States)

    Among the essential plant nutrients, potassium (K) has the strongest influence on crop quality parameters. However, many soil and plant factors often limit adequate soil K uptake to satisfy plant requirements during fruit development stages. The objectives of this multiyear field study were to det...

  18. Impact of fertilizer phosphorus application on phosphorus release kinetics in some calcareous soils

    Science.gov (United States)

    Hosseinpur, A. R.; Biabanaki, F. S.

    2009-01-01

    Phosphate reactions and retention in the soil are of paramount importance from the perspective of plant nutrition and fertilizer use efficiency. The objective of this work was to study the kinetics of phosphorus (P) desorption in different soils of Hamadan in fertilized and unfertilized soils. Soils were fertilized with 200 mg P kg-1. Fertilized and unfertilized soils were incubated at 25 ± 1°C for 6 months. After that, release of P was studied by successive extraction with 0.5 M NaHCO3 over a period of 1,752 h. The results showed that phosphorus desorption from the fertilized and unfertilized soils began with a fast initial reaction, followed by a slow secondary reaction. The amount of P released after 1,752 h in fertilized and unfertilized soils ranged from 457 to 762.4 and 309.6 to 586.7 mg kg-1, respectively. The kinetics of cumulative P release was evaluated using the five kinetic equations. Phosphorus desorption kinetics were best described by parabolic diffusion law, first order, and power function equations. Rate constants of these equations were higher in fertilized than unfertilized soils. Results from this study indicate that release rate of P plays a significant role in supplying available P and released P in runoff.

  19. Modeling of Nitrogen Dynamics in an Austrian Alpine Forest Ecosystem on Calcareous Soils: A Scenario-Based Risk Assessment under Changing Environmental Conditions

    OpenAIRE

    Friedl Herman; Stefan Smidt; Klaus Butterbach-Bahl; Michael Englisch; Ernst Gebetsroither; Robert Jandl; Klaus Katzensteiner; Manfred Lexer; Friederike Strebl; Sophie Zechmeister-Boltenstern

    2007-01-01

    We modeled the behavior of an Austrian alpine forest ecosystem on calcareous soils under changing climate and atmospheric nitrogen deposition scenarios. The change of nitrate leaching, emission rates of nitrogen compounds, and forest productivity were calculated using four process-oriented models for the periods 1998–2002 and 2048–2052. Each model reflects with high detail a segment of the ecosystem: PnET-N-DNDC (photosynthesis-evapotranspiration-nitrification-denitrification-decomposition; s...

  20. Comparison of chemical fertilizer and sewage sludge application on some nutrients’ bioavailability in three textural classes of a calcareous soil after harvesting spinach (Spinacia oleracea L.)

    OpenAIRE

    Boostani, H. R; A. Ronaghi

    2012-01-01

    Sewage sludge (SS) as a source of macro- and micro nutrients has been utilized in many countries for crop and vegetable production. To compare the influence of SS with chemical fertilizer on macro- and micro nutrients bioavailability in three textural classes of a calcareous soil after harvesting spinach (Spinacia oleracea L.), a factorial experiment was carried out in a completely randomized design with two factors and three replications under glasshouse conditions. The first factor was SS l...

  1. Phosphate solubilization and promotion of maize growth by Penicillium oxalicum P4 and Aspergillus niger P85 in a calcareous soil.

    Science.gov (United States)

    Yin, Zhongwei; Shi, Fachao; Jiang, Hongmei; Roberts, Daniel P; Chen, Sanfeng; Fan, Bingquan

    2015-12-01

    Alternative tactics for improving phosphorus nutrition in crop production are needed in China and elsewhere, as the overapplication of phosphatic fertilizers can adversely impact agricultural sustainability. Penicillium oxalicum P4 and Aspergillus niger P85 were isolated from a calcareous soil in China that had been exposed to excessive application of phosphatic fertilizer for decades. Each isolate excreted a number of organic acids into, acidified, and solubilized phosphorus in a synthetic broth containing insoluble tricalcium phosphate or rock phosphate. Isolate P4, applied as a seed treatment, increased maize fresh mass per plant when rock phosphate was added to the calcareous soil in greenhouse pot studies. Isolate P85 did not increase maize fresh mass per plant but did significantly increase total phosphorus per plant when rock phosphate was added. Significant increases in 7 and 4 organic acids were detected in soil in association with isolates P4 and P85, respectively, relative to the soil-only control. The quantity and (or) number of organic acids produced by these isolates increased when rock phosphate was added to the soil. Both isolates also significantly increased available phosphorus in soil in the presence of added rock phosphate and effectively colonized the maize rhizosphere. Studies reported here indicate that isolate P4 is adapted to and capable of promoting maize growth in a calcareous soil. Plant-growth promotion by this isolate is likely due, at least in part, to increased phosphorus availability resulting from the excretion of organic acids into, and the resulting acidification of, this soil. PMID:26469739

  2. Distribution, age and genesis of cohesive soil containing calcareous nodules in Huaibei Plain of Anhui Province%安徽淮北平原钙质结核土分布及成因年代研究

    Institute of Scientific and Technical Information of China (English)

    吴道祥; 曹亚娟; 钟轩民; 施国军; 徐东生; 刘秋燕; 王国强

    2009-01-01

    After proposing the concept of "cohesive soil containing calcareous nodules", the distribution law, genesis, age and types of calcareous nodules of cohesive soil containing calcareous nodules in Huaibei Plain of Anhui Province are studied in detail. Based on field geology studies, tests, exploration and extensive reference to engineering geological exploration reports and professional literature data, the burial and distribution law of cohesive soil containing calcareous nodules are analyzed; and the plane distribution map and typical strata section maps of cohesive soil containing calcareous nodules are drawn. Cohesive soil containing calcareous nodules mainly distributes in the block between rivers, depression and the Yellow River Flood Plain in Huaibei Plain. The change law of the elevation of the roof of cohesive soil containing calcareous nodules and the ground elevation is basically identical. Calcareous concretions can generally be divided into three forms: embryonic calcareous concretions, mature calcareous concretions and calcareous hard pan. It is pointed out that there are embryonic calcareous, mature calcareous and calcareous hard pan from up to down on profile, the particle size and number of calcareous concretions increase gradually with depth and calcareous hard pan comes to being around the perennial groundwater level. In addition, the radiocarbon ages of embryonic calcareous, mature calcareous and calcareous hard pan gradually increase on profile.%提出了钙质结核土的概念,并详细研究了安徽淮北平原钙质结核土的分布规律、成因年代以及钙质结核的类型.通过地质调查、试验和勘探,并参阅工程勘察报告和文献资料,分析了安徽淮北平原钙质结核土的埋藏和分布规律,绘制了淮北平原钙质结核土平面分布图及典型地层剖面图.钙质结核土分布在淮北平原河间地块、洼地及黄泛平地上,结核层的埋藏标高与地面标高变化基本一致.在剖面

  3. Cardoon (Cynara cardunculus L.) biomass production in a calcareous soil amended with sewage sludge compost and irrigated with sewage water

    Science.gov (United States)

    Lag, A.; Gomez, I.; Navarro-Pedreño, J.; Melendez, I.; Perez Gimeno, A.; Soriano-Disla, J. M.

    2010-05-01

    Energy use is one of the most important current global issues. Traditional energetic resources are limited and its use generates environmental problems, i.e. Global Warming, thus it is necessary to find alternative ways to produce energy. Energy crops represent one step towards sustainability but it must be coupled with appropriate land use and management adapted to local conditions. Moreover, positive effects like soil conservation; economical improvement of rural areas and CO2 storage could be achieved. Treated sewage water and sewage sludge compost were used as low-cost inputs for nutrition and irrigation, to cultivate cardoon (Cynara cardunculus L.) a perennial Mediterranean crop. The aim of the present field experiment was to ascertain the optimum dose of compost application to obtain maximum biomass production. Four compost treatments were applied by triplicate (D1=0; D2=30; D3=50; D4=70 ton/ha) and forty eight cardoon plants were placed in each plot, 12 per treatment, in a calcareous soil (CLfv; WRB, 2006) plot, located in the South East of Spain, in semi-arid conditions. The experiment was developed for one cardoon productive cycle (one year); soil was sampled three times (October, April and July). Soil, compost and treated sewage irrigation water were analyzed (physical and chemical properties). Stalk, capitula and leave weight as well as height and total biomass production were the parameters determined for cardoon samples. Analyses of variance (ANOVA) at p=0,05 significance level were performed to detect differences among treatments for each sampling/plot and to study soil parameters evolution and biomass production for each plot/dose. Several statistical differences in soil were found between treatments for extractable zinc, magnesium and phosphorus; as well as Kjeldahl nitrogen and organic carbon due to compost application, showing a gradual increase of nutrients from D1 to D4. However, considering the evolution of soil parameters along time, pH was

  4. Legacy phosphorus in calcareous soils: Effects of long-term poultry litter application

    Science.gov (United States)

    The effect of manure application on soil phosphorus has been intensively studied with modifications of the Hedley sequential fractionation procedure, X ray absorption near edge structure spectroscopy, and 31P nuclear magnetic resonance. Modern sequential fractionation techniques, coupled with phosph...

  5. Natural Enrichment of Trace Elements in Surface Horizons of Calcareous Soils (La Mancha, Spain)

    OpenAIRE

    Sandra Bravo Martín-Consuegra; Amorós Ortíz-Villajos, Jose A.; Caridad Pérez-de-los-Reyes; García Navarro, Francisco J.; Rolando Ruedas Luna; Raimundo Jiménez Ballesta

    2015-01-01

    The study of five soil profiles developed on carbonatic sediments of Tertiary Miocene origin has been carried out. The topography of the area was basically flat and the traditional uses of the soils are the cultivation of dry cereals and grapevine. The geochemical characterization of the aforementioned profiles involves a study of the contents of major and trace elements among other pedologic aspects (texture, pH, organic matter, etc.). The results of this study also indicate a superficial en...

  6. Phosphorus Accumulation and Sorption in Calcareous Soil under Long-Term Fertilization.

    Directory of Open Access Journals (Sweden)

    Rui Wang

    Full Text Available Application of phosphorus (P fertilizers to P-deficient soils can also result in P accumulation. In this study, soil P status and P uptake by apple trees were investigated in 5-, 10-, and 15-year-old orchards in the semi-arid Loess Plateau, China, and subset soils with different soil P statuses (14-90 Olsen-P mg kg(-1 were selected to evaluate the characteristic P adsorption. Due to the low P-use efficiency (4-6%, total soil P increased from 540 mg kg(-1 to 904 mg kg(-1, Olsen-P ranged from 3.4 mg kg(-1 to 30.7 mg kg(-1, and CaCl2-P increased from less than 0.1 mg kg(-1 to 0.66 mg kg(-1 under continuous P fertilization. The P sorption isotherms for each apple orchard were found to fit the Langmuir isotherm model (R2 = 0.91-0.98. K (binding energy and Qm (P sorption maximum decreased, whereas DPS (degree of phosphorus sorption increased with increasing P concentration. CaCl2-P increased significantly with the increase of Olsen-P, especially above the change point of 46.1 mg kg(-1. Application of surplus P could result in P enrichment in P-deficient soil which has high P fixation capacity, thus posing a significant environmental risk.

  7. Effects of soil water conditions and organic and chemical fertilizers on growth characteristics and water use efficiency of rice in an alkaline non-calcareous soil

    Directory of Open Access Journals (Sweden)

    M. Abbasi

    2012-12-01

    Full Text Available In a greenhouse research, the effects of soil water conditions, sewage sludge and chemical fertilizers on growth characteristics and water use efficiency of rice (Oryza sativa L. cv. Ali Kazemi were studied in a loamy sand alkaline non-calcareous soil. The study was performed as a factorial experiment in a randomized complete blocks design including soil water conditions in three levels (continuous submergence, alternate submergence and alternate saturation and source and amount of organic and chemical fertilizers in 10 levels [control, 100% chemical fertilizers (434.8 mg urea, 66.1 mg KH2PO4, 40 mg KCl, 50 mg FeSO4.7H2O, 38.5 mg FeSO4.7H2O, 21.3 mg ZnSO4.7H2O and 7.9 mg CuSO4.5H2O per kg of soil, 20 g sewage sludge per kg of soil with and without 50% of chemical fertilizers, 40 g sewage sludge per kg of soil with and without 50% of chemical fertilizers, 20 g poultry manure per kg of soil with and without 50% of chemical fertilizers and 40 g poultry manure per kg of soil with and without 50% of chemical fertilizers] with three replications. At the end of growth period, tiller and leaf number per plant, length and diameter of stem, length and volume of roots, and shoot and root dry matter were measured and water use efficiency (WUE was calculated. The results showed that application of 20 and 40 g poultry manure per kg of soil prevented the growth of rice due to increase of soil salinity. Application of 20 and 40 g sewage sludge per kg of soil increased significantly tiller and leaf number per plant, length and diameter of stem, length and volume of roots, shoot and root dry matter and WUE compared to control and 100% chemical fertilizers treatments. Addition of 50% chemical fertilizers to 40 g sewage sludge per kg of soil did not significantly affect tiller and leaf number per plant, stem length, volume of roots, shoot dry matter and WUE of rice. The highest tiller number per plant, stem diameter, root length and the ratio of shoot dry matter to

  8. Losses of Urea—Nitrogen Applied to Maize Grown on a Calcareous Fluvo—Aquic Soil in North China Plain

    Institute of Scientific and Technical Information of China (English)

    ZHANGSHAO-LIN; ZHUZHAO-LIANG; 等

    1992-01-01

    Field experiments were conducted in a maize (Zea mays L.)field of a calcareous fluvo-aquic soil in North China Plain for studying the fate and ammonia loss of urea-N applied at seedling stage,as well as the effectiveness of coated calcium carbide(CCC) in reducing N loss and in improving the yield efficiency of urea.Results show that:(1) For the surface-broadcast treatment ammonia volatilization (measured with micro-meteorological technique)took place quickly,reached the peak 20-26hr after application,and then declined gradually;the cumulative ammonia loss approached the maximum 188hr after application (30% of the N applied),and increased only to 32% 284 hr after application;the latter accounted for 71% of the total loss (45% of applied N).(2) In the case of point placement at a depth of 5-10 cm,ammonia loss 188hr after application was only 12% of the N applied,accounting for 40% of the total loss.(3) There was no difference in total loss between the application depths of 6cm and 10 cm,the loss of them was 30% and 29%,respectively.(4) Total loss of N applied at lower rate (40kg N/ha)with point deep placement at 6cm depth was found only 4% of the N applied,it rose up to 30% when the rate of application increased to 80kg N/ ha.(5) The nitrification inhibitor,CCC,seemed to enhance N loss of urea rather than reduce it,and did not show any benefit effect in improving the yield efficiency of urea,which is presumably due to the high potential of ammonia volatilization in the soil and climatic conditions under investigation.

  9. Elemental sulfur improves growth and phytoremediative ability of wheat grown in lead-contaminated calcareous soil.

    Science.gov (United States)

    Saifullah; Khan, Muhammad Naeem; Iqbal, Muhammad; Naeem, Asif; Bibi, Sadia; Waraich, Ejaz Ahmad; Dahlawi, Saad

    2016-10-01

    Little is known about the effect of elemental sulfur on lead uptake and its toxicity in wheat. A pot experiment was conducted with the purpose to examine the impact of sulfur on improving Pb solubility in soil, and uptake and accumulation in wheat plants. The effect of three levels of lead (0, 50, and 100 mg/kg soil) and sulfur (0, 150, and 300 mmol/kg soil) was tested in all possible combinations. Root dry matter, straw, and grain yields, and the photosynthetic and transpiration rates decreased significantly with increase in the concentration of Pb in the soil. However, sulfur fertilization in the presence of Pb improved the photosynthetic and transpiration rates and consequently increased the straw and grain yields of wheat. It also enhanced Pb accumulation in roots, its translocation from roots to shoot, and accumulation in grain. S and Zn contents of different plant parts were also enhanced. Thus, by mitigating the toxic effect of Pb and improving wheat growth, sulfur enhances Pb accumulation by the aboveground plant parts and hence the phytoextraction capacity of wheat. However, total accumulation of Pb shows that wheat plant cannot be considered as a suitable candidate for phytoremediation. PMID:26852881

  10. Legacy phosphorus in calcareous soils: effects of long-term poultry litter application

    Science.gov (United States)

    Sequential fractionation techniques, coupled with phosphatase hydrolysis, have allowed for greater understanding of manure/litter effects on soil P distribution. We evaluated the effect of long-term (greater than 10 years) poultry litter (broiler and turkey litter) application at annual rates of 4.5...

  11. Bioavailability of zinc and phosphorus in calcareous soils as affected by citrate exudation

    NARCIS (Netherlands)

    Duffner, A.; Hoffland, E.; Temminghoff, E.J.M.

    2012-01-01

    Aims Zinc (Zn) and phosphorus (P) deficiency often occurs at the same time and limits crop production in many soils. It has been suggested that citrate root exudation is a response of plants to both deficiencies. We used white lupin (Lupinus albus L.) as a model plant to clarify if citrate exuded by

  12. Possible positive-feedback mechanisms : plants change abiotic soil parameters in wet calcareous dune slacks

    NARCIS (Netherlands)

    Adema, EB; Grootjans, AP; Adema, Erwin B.; Grootjans, Ab P.

    2003-01-01

    In this paper the results are presented from a mesocosm study of the effects of typical dune slack plants on the soil solution nutrient contents. In dune slack succession, early successional species often show radial oxygen loss (ROL) whereas their successor species do not show ROL. ROL has impact o

  13. Transfer of heavy metals to biota after remediation of contaminated soils with calcareous residues.

    Science.gov (United States)

    Pérez-Sirvent, Carmen; Martínez-Sánchez, Maria Jose; Agudo, Ines; Gonzalez, Eva; Perez-Espinosa, Victor; Belen Martínez, Lucia; Hernández, Carmen; García-Fernandez, Antonio Juan; Bech, Jaime

    2013-04-01

    A study was carried out to evaluate the assimilation of heavy metals by three types of horticultural plants (broccoli, lettuce and leek), different parts of which are destined for human and farm animals consumption (leaves, roots, fruits). Five consecutive crops of each vegetable were obtained in greenhouse. In a second stage, experiments were carried out with rabbits fed with such vegetables. The plants were cultivated in four types of soil. The first one was contaminated by heavy metals (S1), the second was a uncontaminated soil (blank soil) (S2), the third was the material obtained by mixing S1 with residues coming from demolition and construction activities (S3); while the fourth was the result of remediating S1 with lime residues coming from quarries (S4). The total metal content (As, Pb, Cd and Zn) of the soil samples, rizosphere, leached water and vegetable samples, were measured, and both the translocation and bioconcentration factors (TF and BCF, respectively) were calculated. In the second stage, the effect caused in rabbits fed with the vegetables was monitorized using both external observation and the analysis of blood, urine, and the levels of metals in muscles, liver and kidney. The statistical analysis of the results obtained showed that there were no significant differences in the heavy metal levels for the vegetables cultivated in S2, S3 and S4. The results for soil sample S1 did not have a normal distribution since the growing of the vegetables were not homogeneous and also strongly dependent on the type of vegetal. As regards the effect caused in rabbits, significant differences were observed for the animals fed with plants cultivated in S1 compared with the others.

  14. [Screening, identification and phosphate-solubilizing characteristics of Rahnella sp. phosphate-solubilizing bacteria in calcareous soil].

    Science.gov (United States)

    Qiao, Zhi-wei; Hong, Jian-ping; Xie, Ying-he; Li, Lin-xuan

    2013-08-01

    Several strains of phosphate-solubilizing bacteria were isolated and screened from the crop rhizosphere of calcareous soil in Shanxi Province of China. After repeated isolation and purification, the strain W25 with strong phosphate-solubilizing activity was obtained, and identified as Rahnella sp., based on the morphological, physiological and biochemical properties and the analysis of 16S rRNA gene sequence. Further studies on the W25 showed that the maximum phosphate-solubilizing capability of the W25 on tricalium phosphate, aluminum phosphate and ferric phosphate reached 385.5, 110.4 and 216.6 mg x L(-1), respectively. In the liquid culture with aluminum phosphate and ferric phosphate, the solubilized phosphorous by the W25 was significantly negatively correlated with the liquid pH, with the correlation coefficient being 0.56 and 0.81, respectively. Among the carbon and nitrogen sources, glucose and ammonium nitrate were the optimum for the solubilization of tricalium phosphate by W25. The utilization of carbon source was in the order of glucose > lactose > sucrose > mannitose > starch, and that of nitrogen source was in the order of ammonium nitrate > ammonium chloride > ammonium sulfate > potassium nitrate > sodium nitrate. Different nitrogen sources had greater effects on the production of organic acids by W25. Formic acid and acetic acid would be produced when the nitrogen source was NH4+, oxalic acid and succinic acid would be produced when the nitrogen source was NO3(-), and citric acid would be extra produced when the ammonium nitrate was used as the nitrogen source. PMID:24380351

  15. Ground cover and tree growth on calcareous minesoils: Greater influence of soil surface than nitrogen rate or seed mix

    International Nuclear Information System (INIS)

    Growth of ground cover and trees was evaluated for five growing seasons on calcareous coal minesoil surfaces (standard graded topsoil, graded and ripped topsoil, graded gray cast overburden) in southeastern Ohio. Soil surface plots were seeded in September 1987 with either a standard herbaceous seed mix [orchardgrass (Dactylis glomerata L.), timothy (Phleum pratense L.), perennial ryegrass (Lolium perenne L.), Kentucky bluegrass (Poa pratensis L.), Ranger alfalfa (Medicago sativa L.), Mammoth red clover (Trifolium pratense L.), Empire birdsfoot trefoil (Lotus corniculatus L.), and wheat (Triticum aestivum L.)], or a modified mix using no alfalfa and half the rate of orchardgrass. Nitrogen (45, 90, or 135 kg ha/N) was applied as ammonium nitrate in September 1987 and April 1989. White ash (Fraxinus americana L.), silver maple (Acer saccharinum L.), northern red oak (Quercus rubra L.), and eastern white pine (Pinus strobus L.) were planted in spring 1989 into 0.8 m-wide strips sprayed with glyphosate herbicide at 2.24 kg/ha in October 1988. Total cover and total biomass were highest in July 1989, following the last application of nitrogen fertilizer in April 1989. Total cover ranged from 44% to 56%, and total biomass ranged from 102 to 162 g/0.5 m2 from 1990 to 1993. Total cover and total biomass were lower at the lowest nitrogen rate in 1989 only. Type of herbaceous seed mix did not affect growth of ground cover or trees. Overall tree survival was 82.0% the first year but declined to 40.6% after 5 yr. Survival varied significantly among all tree species (3.5% for pine, 22.2% for oak, 38.5% for maple, 98.1% for ash)

  16. Effects of different Fe levels from Fe-nano-chelate and Fe-EDDHA sources on growth and some nutrients concentrations in cowpea in a calcareous soil

    Directory of Open Access Journals (Sweden)

    L. Jokar

    2015-08-01

    Full Text Available To evaluate the effects of different levels of iron (Fe (from Fe-nano-chelate and Fe-EDDHA sources on growth parameters, concentration and absorption of Fe and some nutrients in cowpea (Vigna unguiculata in a calcareous soil, a greenhouse experiment was conducted based on completely randomized design with three replications. Treatments consisted of four levels of Fe (0, 0.135, 0.270 and 0.405 mg Fe per kg soil as Fe-nano-chelate or Fe-EDDHA. The studied soil (Fine-loamy, carbonatic, thermic, Typic Calcixerepts had a loam texture with low available Fe content. Results showed that application of both Fe fertilizers increased shoot dry-matter yield, root dry matter yield, number of pods per plant, weight of pods and seeds per plant, grain weight per pot, shoot Fe concentration and Fe uptake by cowpea as compared to control treatment. Some of the evaluated growth parameters at all levels of Fe from Fe-nano-chelate source were higher than the Fe-EDDHA source and some were the same and had no significant difference. Application of both Fe-nano-chelate and Fe-EDDHA decreased phosphorus and manganese concentrations in shoots as compared to control treatment. Concentration of zinc and cooper in shoots was not significantly affected by the Fe level. In conclusion, lower rates of Fe-nano-chelate were required, as compared to Fe-EDDHA, to alleviate iron deficiency in cowpea grown in calcareous soils.

  17. Impact of Humic Acid on Yield and Quality of Sugar Beet (Beta vulgaris L.) Grown on Calcareous Soil

    OpenAIRE

    Ghorbanali RASSAM; Alireza DADKHAH; Asghar KHOSHNOOD YAZDI; Maryam DASHTI

    2015-01-01

    A field experiment was performed to determine the effects of using humic acid with irrigation on quantitative and qualitative yield traits of sugar beet grown on calcareous soils in Esfaraen, located in the North-East of Iran. Treatments consisted of three levels of humic acid concentration (zero or control, 2.5 and 5 L ha-1) and the number of applications (once 45 days after planting; twice, 45 and 75 days after planting; three times, respectively 45, 75 and 105 days after planting). The eff...

  18. Modeling of Nitrogen Dynamics in an Austrian Alpine Forest Ecosystem on Calcareous Soils: A Scenario-Based Risk Assessment under Changing Environmental Conditions

    Directory of Open Access Journals (Sweden)

    Friedl Herman

    2007-01-01

    Full Text Available We modeled the behavior of an Austrian alpine forest ecosystem on calcareous soils under changing climate and atmospheric nitrogen deposition scenarios. The change of nitrate leaching, emission rates of nitrogen compounds, and forest productivity were calculated using four process-oriented models for the periods 1998–2002 and 2048–2052. Each model reflects with high detail a segment of the ecosystem: PnET-N-DNDC (photosynthesis-evapotranspiration-nitrification-denitrification-decomposition; shortterm nitrogen cycling, BROOK90 (water balance for small and homogenous forest watersheds, HYDRUS (water flux in complex and heterogenous soils, and PICUS v1.3 (forest productivity. The nitrogen balance model (NBM combines the individual results into a comprehensive picture and extends the specific values beyond the limits of the individual models. The evaluation of the findings was outlined with TRACE, a model enabling a long-term prognosis of nitrogen cycling in annual time steps.

  19. Comparison of chemical fertilizer and sewage sludge application on some nutrients’ bioavailability in three textural classes of a calcareous soil after harvesting spinach (Spinacia oleracea L.

    Directory of Open Access Journals (Sweden)

    H.R Boostani

    2012-12-01

    Full Text Available Sewage sludge (SS as a source of macro- and micro nutrients has been utilized in many countries for crop and vegetable production. To compare the influence of SS with chemical fertilizer on macro- and micro nutrients bioavailability in three textural classes of a calcareous soil after harvesting spinach (Spinacia oleracea L., a factorial experiment was carried out in a completely randomized design with two factors and three replications under glasshouse conditions. The first factor was SS levels (0, 10, 20, 40, and 80 mg per kg soil and the second factor was soil textural classes (sandy, sandy loam, and clay loam. A chemical fertilizer treatment was used for comparison with the applied SS treatments. Results indicated that total nitrogen (N and available phosphorus (P was significantly higher in SS amended soils compared to fertilizer treatment. Effect of increasing soil potassium (K due to addition of SS was less than P and N, which is probably due to low content of K in SS. Soil DTPA extractable iron, zinc, copper, and manganese were significantly increased in SS treatments in all soil textures and were higher than fertilizer treatment. Based on nutrients’ bioavailability in soil after harvesting spinach, especially at high rates of SS, addition of most nutrients is not necessary for the next crop. Concentration of DTPA extractable cadmium (Cd and lead (Pb was not detectable in all treatments. Therefore, because of low contents of Cd and Pb in the utilized SS, reaching to a toxic level of these elements in soil is unexpected. However, if high levels of SS are applied frequently, soil test is recommended for monitoring heavy metals concentration in amended soils. Prior to any SS recommendation, the results of this research need to be verified under field conditions.

  20. Land use effects on soil organic carbon sequestration in calcareous Leptosols in former pastureland - a case study from the Tatra Mountains (Poland)

    Science.gov (United States)

    Wasak, K.; Drewnik, M.

    2015-10-01

    The purpose of the paper is to describe soil organic carbon (SOC) sequestration rates in calcareous shallow soils in reforested areas in the Tatra Mountains with a particular focus on different forms of organic matter (OM) storage. Three plant communities creating a mosaic on the slopes of the studied valley were taken into account. Fifty years since the conversion of pastureland to unused grassland, dwarf pine shrub and larch forest have emerged in the study area, along with the development of genetic soil horizons as well as SOC sequestration in the soil despite the steepness of slopes. SOC stock was measured to be the highest in soils under larch forest (63.5 Mg ha-1), while in soil under grassland and under dwarf pine shrub, this value was found to be smaller (47.5 and 42.9 Mg ha-1, respectively). The highest amount of mineral-associated OM inside stable microaggregates (MOM FF3) was found in grassland soil (21.9-27.1 % of SOC) and less under dwarf pine shrub (16.3-19.3 % of SOC) and larch forest (15.3-17.7 % of SOC). A pool of mineral-associated OM inside transitional macroaggregates (MOM FF2) was found in soil under dwarf pine shrub (39.2-59.2 % of SOC), with less under larch forest (43.8-44.7 % of SOC) and the least in grassland soil (37.9-41.6 % of SOC). The highest amount of the free light particulate fraction (POM LF1) was found in soil under dwarf pine shrub (6.6-10.3 % of SOC), with less under larch forest (2.6-6.2 % of SOC) and the least in grassland soil (1.7-4.8 % of SOC).

  1. Effects of nitrogen and phosphorus fertilizer on crop yields in a field pea-spring wheat-potato rotation system with calcareous soil in semi-arid environments

    Directory of Open Access Journals (Sweden)

    Chang-An Liu

    2016-06-01

    Full Text Available The object of the present study was to investigate the yield-affecting mechanisms influenced by N and P applications in rainfed areas with calcareous soil. The experimental treatments were as follows: NF (no fertilizer, N (nitrogen, P (phosphorus, and NP (nitrogen plus phosphorus in a field pea-spring wheat-potato cropping system. This study was conducted over six years (2003-2008 on China’s semi-arid Loess Plateau. The fertilizer treatments were found to decrease the soil water content more than the NF treatment in each of the growing seasons. The annual average yields of the field pea crops during the entire experimental period were 635, 677, 858, and 1117 kg/ha for the NF, N, P, and NP treatments, respectively. The annual average yields were 673, 547, 966, and 1056 kg/ha for the spring wheat crops for the NF, N, P, and NP treatments, respectively. Also, the annual average yields were 1476, 2120, 1480, and 2424 kg/ha for the potato crops for the NF, N, P, and NP treatments, respectively. In the second cycle of the three-year rotation, the pea and spring wheat yields in the P treatment were 1.2 and 2.8 times higher than that in the N treatment, respectively. Meanwhile, the potato crop yield in the N treatment was 3.1 times higher than that in the P treatment. In conclusion, the P fertilizer was found to increase the yields of the field pea and wheat crops, and the N fertilizer increased the potato crop yield in rainfed areas with calcareous soil.

  2. A field study of soil-to-plant transfer of strontium-90 and caesium-137 based on a calcaric cambisol in sub-tropical southwest China

    International Nuclear Information System (INIS)

    Root uptake is one of the most important pathways of radionuclide transfer from a contaminated environment to the terrestrial food chain. For this pathway Bv, which is defined as 'Concentration of radionuclide per unit weight of plant organ' divided by 'Concentration of radionuclide per unit weight of dry soil', is necessary for dose assessment models. In China assessment generally uses Bv values derived from American or European countries. In 1994, IAEA published the Handbook of Parameter Values for the Prediction of Radionuclide Transfer in Temperate Environments. The data are mostly drawn from North America and Europe, much of which was compiled through projects of IUR and CEC. However, there are only limited data for crops cultivated in Asian countries, especially in China. Since Bv changes with factors such as soil properties, crop species, and climatic characteristics, it is necessary to obtain TF data on radionuclides for major agriculture crops grown in typical soils in different regions or countries. In this study the transfer of 90Sr (half-life:28.78y) and 137Cs (half-life:30.07y) from soil to wheat, maize, broad bean, spinach, Chinese cabbage, potato, radish, tomato and lettuce were investigated in field conditions in Sichuan Province from 1999 to 2002. The soil involved is a Calcaric Cambisol which was contaminated artificially with 90Sr and 137Cs in 1999. Each Bv (soil to plant transfer factor) was determined from 5 replicates of crop and related soil samples taken at harvest time. Soil characteristics are analysed and other parameters important to the experiments are provided. The variability of the 90Sr and 137Cs Bv is rather wide. The year to year variations suggest climatic factors may be important. For both radionuclides, the Bv to cereals were close to, or below, the bottom of the range predicted on the basis of the data of IUR and IAEA. There was no clear trend for Bv to change with time for both. (authors)

  3. Evaluation of alkaline phosphatase activity and availability of various P fractions for bean (Phaseolus vulgaris in some calcareous soils amended with municipal sewage sludge

    Directory of Open Access Journals (Sweden)

    T. Raeisi

    2014-07-01

    Full Text Available To evaluate the relationship of various P fractions and alkaline phosphatase activity with bean indices growing in 10 calcareous soils, amended with municipal sewage sludge from Chaharmahal-Va-Bakhtiari province, a greenhouse research was carried out. Soil samples were incubated for one month with sludge at a rate equivalent to 1% (w/w. Then, the P fractions, including P adsorbed by Fe and Al oxides (]NaOH+CB]-P, occluded P (CBD-P and P absorbed by Ca (HCl-P, were determined by Olsen and Summers' sequential fractionation procedure. Furthermore, total P, organic P and residual P were determined. Also, alkaline phosphatase activity was measured. A pot experiment in a completely randomized design with three replications in the ten soils was done to evaluate the bean plant indices. The results showed that the amount of P fractions decreased in the following order: HCl-P>residual-P>]NaOH+CB]-P > OP>CBD-P. The results also indicated that alkaline phosphatase activity was significantly correlated with CBD-P fraction, organic P and total P. In addition, significant correlations were found between ([NaOH+CB]-P and HCl-P and plant shoots. In general, the results of this research showed that P fractionation method appears to be a powerful tool to identify the P status and availability in the soils amended with sewage sludge.

  4. Comparison of sewage sludge and chemical fertilizer application on yield and concentration of some nutrients in spinach (Spinosa olerace L. in three textural classes of a calcareous soil

    Directory of Open Access Journals (Sweden)

    A. Ronaghi

    2011-07-01

    Full Text Available Addition of sewage sludge (SS in soil causes increasing soil organic matter, which in turn improves soil physical properties, and could supply part of the nutrients required by plants. For comparison of SS application and chemical fertilizer treatment (CFT on yield and concentration of some macro and micro nutrients in spinach, a greenhouse factorial experiment, arranged in a completely randomized design (CRD, was conducted with three replications. The first factor included SS levels (0, 10, 20, 40 and 80 gr kg-1 and the second factor was soil textural classes (clay loam, sandy loam and sandy. A CFT was also used to compare its affect with that of SS levels. Results showed that addition of all levels of SS caused significant increase in the weight of spinach shoots in three soil textures. Application of all SS levels caused significant increase of nitrogen (N, phosphorous (P, iron (Fe, zinc (Zn, copper (Cu and manganese (Mn concentration in spinach shoots. With SS application, none of the nutrients’ concentration in spinach reached the toxic level. The amounts of cadmium (Cd and lead (Pb were not detectable in shoots. However, in frequent application of SS, especially at high levels, it is necessary to measure and detect these elements in plants. Effect of fertilizer in increasing yield and concentration of nutrients was less than the 40 and 80 gr kg-1 SS treatments. Considering the Fe and Zn deficiency in calcareous soils, application of SS can be effective for combating this deficiency. Prior to any recommendation of SS application, the results of this research need to be verified under field conditions.

  5. CO2 emission and structural characteristics of two calcareous soils amended with municipal solid waste and plant residue

    Directory of Open Access Journals (Sweden)

    N. Yazdanpanah

    2015-11-01

    Full Text Available This investigation examines the effect of different amendments on selected soil physical and biological properties over a twenty four month period in two cropland fields. Urban municipal solid waste (MSW compost and alfalfa residue (AR were used as different organic amendments at the rates of 0 (control, 10 and 30 Mg ha−1 to a clay loam soil and a loamy sand soil in a semiarid region. Result showed that the soil improvement was controlled by the application rate and decomposability of amendments and soil type. The addition of organic amendments to the soils improved aggregate stability and consequently enhanced total porosity, especially macro pores fraction. The increased soil organic carbon (SOC and total porosity values as compared to the control treatment were greater in the loamy sand soil than in the clay loam soil. Moreover, compared to the microbial respiration of control plots, the application of MSW resulted in higher values of microbial respiration in the clay loam soil than in the loamy sand soil, whereas the reverse order was found for AR. Linear and power functions were provided for the relationships between microbial respiration and SOC in the loamy sand and clay loam soils, respectively. Also, CO2 emission was stimulated significantly as power functions of the total porosity and the ratio of macro to micro pores. However, the soil microbial respiration and carbon storage improved aggregate stability and pore size distribution, as a response, soil porosity especially macro pores fraction controlled CO2 flux.

  6. CO2 emission and structural characteristics of two calcareous soils amended with municipal solid waste and plant residue

    Science.gov (United States)

    Yazdanpanah, N.

    2016-01-01

    This investigation examines the effect of different amendments on selected soil physical and biological properties over a 24-month period in two cropland fields. Urban municipal solid waste (MSW) compost and alfalfa residue (AR) were used as different organic amendments at the rates of 0 (control), 10 and 30 Mg ha-1 to a clay loam soil and a loamy sand soil in a semiarid region. Results showed that the soil improvement was controlled by the application rate and decomposability of amendments and soil type. The addition of organic amendments to the soils improved aggregate stability and consequently enhanced total porosity, especially macropore fraction. The increased soil organic carbon (SOC) and total porosity values as compared to the control treatment were greater in the loamy sand soil than in the clay loam soil. Moreover, compared to the microbial respiration of control plots, the application of MSW resulted in higher values of microbial respiration in the clay loam soil than in the loamy sand soil, whereas the reverse was found for AR. Linear and power functions were provided for the relationships between microbial respiration and SOC in the loamy sand and clay loam soils, respectively. Also, CO2 emission was stimulated significantly as power functions of the total porosity and the ratio of macroporosity to microporosity. However, the soil microbial respiration and carbon storage improved aggregate stability and pore size distribution, and as a response, soil porosity, especially the macropore fraction, controlled CO2 flux.

  7. Phosphorus Sorption Characteristics of Calcareous Soils and Their Relationship with the Soil Properties%石灰性土壤吸磷差异及其与土壤性质的关系

    Institute of Scientific and Technical Information of China (English)

    梁美英; 卜玉山; 张广峰; 郭淑红

    2011-01-01

    采用等温吸附法研究了24个农田石灰性土壤和4个石灰性生土的磷吸附能力及其与土壤基本理化性质的关系,进而采用通径分析和多元逐步回归分析确定了影响供试石灰性土壤吸附固磷能力的主要土壤性质.研究结果表明:28个供试石灰性土壤的磷等温吸附曲线都很好地拟合了Langmuir等温吸附方程,最大吸磷量(Xm)以4个石灰性生土最大;其次为7个大田褐土性土,9个大田石灰性褐土;8个蔬菜大棚石灰性褐土最小.土壤pH值、CaCO3、活性钙、活性镁、活性铝和小于0.002mm的土粒均与最大吸磷量呈显著或极显著正相关,而土壤有机质、全氮、速效磷、速效钾和0.2~2.0 mm的土粒均与最大吸磷量呈极显著负相关.经通径分析和反向逐步回归分析可知,影响供试石灰性土壤吸附固磷能力的主要因素为有机质,其次为速效磷和活性钙,土壤有机质、速效磷、活性钙和小于0.002 mm土粒共同决定了供试石灰性土壤95%的最大吸磷量.供试土壤中,8个蔬菜大棚石灰性褐土有机质、全氮、速效磷、速效钾含量相对较高,而吸附固磷能力相对较弱.连年大量有机和无机肥料的投入不仅导致磷在土壤中大量积累,而且由于土壤肥力的逐步提高,其吸附固磷能力下降,土壤中累积的磷素迁移性增强,造成水环境污染的风险增加.%The P-adsorption characteristics of 28 agricultural calcareous soils and 4 immature calcareous soils and their relationship with the soil physic-chemical properties were studied by isotherm-adsorption method, and the major soil properties affecting P-adsorbing maximum (Xm) of the experimental calcareous soils were determined by path and stepwise multiple regression analyses. The results indicated that the phosphorus isothermal adsorption curves of the 28 experimental calcareous soils all properly fitted the Langmuir adsorption equation. The sequence of Xm was 4 immature

  8. Processes and factors controlling N2O production in an intensively managed low carbon calcareous soil under sub-humid monsoon conditions

    International Nuclear Information System (INIS)

    An automated system for continuous measurement of N2O fluxes on an hourly basis was employed to study N2O emissions in an intensively managed low carbon calcareous soil under sub-humid temperate monsoon conditions. N2O emissions occurred mainly within two weeks of application of NH4+-based fertilizer and total N2O emissions in wheat (average 0.35 or 0.21 kg N ha-1 season-1) and maize (average 1.47 or 0.49 kg N ha-1 season-1) under conventional and optimum N fertilization (300 and 50-122 kg N ha-1, respectively) were lower than previously reported from low frequency measurements. Results from closed static chamber showed that N2O was produced mainly from nitrification of NH4+-based fertilizer, with little denitrification occurring due to limited readily oxidizable carbon and low soil moisture despite consistently high soil nitrate-N concentrations. Significant reductions in N2O emissions can be achieved by optimizing fertilizer N rates, using nitrification inhibitors, or changing from NH4+- to NO3--based fertilizers. - Research highlights: → N2O was produced mainly from nitrification of NH4+ based fertilizers. → Denitrification played minor role on N2O emission due to C and soil moisture limitation. → Using NO3- base fertilizer or NI is an effective way to reduce N2O emission. - Nitrification of NH4+-based fertilizer is the main N2O production process with little denitrification due to limited readily oxidizable carbon and low soil moisture.

  9. Processes and factors controlling N{sub 2}O production in an intensively managed low carbon calcareous soil under sub-humid monsoon conditions

    Energy Technology Data Exchange (ETDEWEB)

    Ju Xiaotang; Lu Xing [Key Laboratory of Plant Nutrition, Chinese Ministry of Agriculture, and College of Resources and Environmental Sciences, China Agricultural University, 2 Yuanmingyuan West Road, Beijing 100193 (China); Gao Zhiling [College of Agricultural Resources and Environmental Sciences, Hebei Agricultural University, Baoding 071001 (China); Chen Xinping; Su Fang [Key Laboratory of Plant Nutrition, Chinese Ministry of Agriculture, and College of Resources and Environmental Sciences, China Agricultural University, 2 Yuanmingyuan West Road, Beijing 100193 (China); Kogge, Martin; Roemheld, Volker [Institute for Plant Nutrition, University of Hohenheim, Stuttgart 70599 (Germany); Christie, Peter [Key Laboratory of Plant Nutrition, Chinese Ministry of Agriculture, and College of Resources and Environmental Sciences, China Agricultural University, 2 Yuanmingyuan West Road, Beijing 100193 (China); Agri-Environment Branch, Agri-Food and Biosciences Institute, BelfastBT9 5PX (United Kingdom); Zhang Fusuo, E-mail: zhangfs@cau.edu.cn [Key Laboratory of Plant Nutrition, Chinese Ministry of Agriculture, and College of Resources and Environmental Sciences, China Agricultural University, 2 Yuanmingyuan West Road, Beijing 100193 (China)

    2011-04-15

    An automated system for continuous measurement of N{sub 2}O fluxes on an hourly basis was employed to study N{sub 2}O emissions in an intensively managed low carbon calcareous soil under sub-humid temperate monsoon conditions. N{sub 2}O emissions occurred mainly within two weeks of application of NH{sub 4}{sup +}-based fertilizer and total N{sub 2}O emissions in wheat (average 0.35 or 0.21 kg N ha{sup -1} season{sup -1}) and maize (average 1.47 or 0.49 kg N ha{sup -1} season{sup -1}) under conventional and optimum N fertilization (300 and 50-122 kg N ha{sup -1}, respectively) were lower than previously reported from low frequency measurements. Results from closed static chamber showed that N{sub 2}O was produced mainly from nitrification of NH{sub 4}{sup +}-based fertilizer, with little denitrification occurring due to limited readily oxidizable carbon and low soil moisture despite consistently high soil nitrate-N concentrations. Significant reductions in N{sub 2}O emissions can be achieved by optimizing fertilizer N rates, using nitrification inhibitors, or changing from NH{sub 4}{sup +}- to NO{sub 3}{sup -}-based fertilizers. - Research highlights: > N{sub 2}O was produced mainly from nitrification of NH{sub 4}{sup +} based fertilizers. > Denitrification played minor role on N{sub 2}O emission due to C and soil moisture limitation. > Using NO{sub 3}{sup -} base fertilizer or NI is an effective way to reduce N{sub 2}O emission. - Nitrification of NH{sub 4}{sup +}-based fertilizer is the main N{sub 2}O production process with little denitrification due to limited readily oxidizable carbon and low soil moisture.

  10. CO2 emission and structural characteristics of two calcareous soils amended with municipal solid waste and plant residue

    OpenAIRE

    Yazdanpanah, N.

    2016-01-01

    This investigation examines the effect of different amendments on selected soil physical and biological properties over a 24-month period in two cropland fields. Urban municipal solid waste (MSW) compost and alfalfa residue (AR) were used as different organic amendments at the rates of 0 (control), 10 and 30 Mg ha−1 to a clay loam soil and a loamy sand soil in a semiarid region. Results showed that the soil improvement was controlled by the application rate and decomposabili...

  11. Function and composition of the soil microbial community in calcareous grassland exposed to elevated atmospheric carbon dioxide

    OpenAIRE

    Ebersberger, Diana

    2003-01-01

    Terrestrial ecosystems generally respond to rising atmospheric carbon dioxide (CO2) concentrations with increased net primary productivity and increased water use efficiency. This may change the amount and quality of organic substances entering the soil and fuelling microbial metabolism. Soil microorganisms and their activity might also be affected by increased soil moisture at elevated CO2. This thesis was designed to analyse the response of the soil microbial community in a species-rich cal...

  12. Organic Carbon Storage and Decomposition Rate of Three Subcategories of Calcareous Soil in Karst Area%桂林毛村岩溶区三种亚类石灰土有机碳矿化研究

    Institute of Scientific and Technical Information of China (English)

    严毅萍; 曹建华; 梁毅; 王培; 玉宏

    2012-01-01

    three sub-categories are following the order: black calcareous soilbrown calcareous soilred calcareous soil,the black calcareous soil mineralization rate is much greater than that of brown and red calcareous soils,in which the differences in 0~20 cm soil layer are largest.Mineralization rate of SOC and SOC contents displayed a positive correlattion.Black calcareous soil has the highest fraction of cumulative CO2-C released by SOC mineralization,and reached 3.33%.Secondly the fraction of the red calcareous soil is 2.92%.The Brown calcareous soil of cultivated land has the lowest fraction of cumulative CO2-C released by SOC mineralization by 1.90%,indicating that the stability of black calcareous soil and Red calcareous soil were weakly than Brown calcareous soil.The Brown calcareous soil of cultivated land has a strong capability to fix organic carbon.

  13. Influence of organic amendments on diuron leaching through an acidic and a calcareous vineyard soil using undisturbed lysimeters

    International Nuclear Information System (INIS)

    The influence of different organic amendments on diuron leaching was studied through undisturbed vineyard soil columns. Two composts (A and D), the second at two stages of maturity, and two soils (VR and Bj) were sampled. After 1 year, the amount of residues (diuron + metabolites) in the leachates of the VR soil (0.19-0.71%) was lower than in the Bj soil (4.27-8.23%), which could be explained by stronger diuron adsorption on VR. An increase in the amount of diuron leached through the amended soil columns, compared to the blank, was observed for the Bj soil only. This result may be explained by the formation of mobile complexes between diuron and water-extractable organic matter (WEOM) through the Bj soil, or by competition between diuron and WEOM for the adsorption sites in the soil. For both soils, the nature of the composts and their degree of maturity did not significantly influence diuron leaching. - The application of organic amendments increased diuron leaching through a sandy-loam soil, in contrast to a clay-loam soil

  14. 干旱区绿洲灌漠土和灰钙土Cu,Ni的吸附解吸特征%Sorption and desorption of copper and nickel in the irrigated desert soil and gray calcareous soil in the arid regions oasis

    Institute of Scientific and Technical Information of China (English)

    王胜利; 南忠仁; 赵转军; 胡小娜; 黄璜; 晋王强; 赵翠翠; 刘姣; 范登耀

    2009-01-01

    利用热力学吸附平衡法研究了干旱区绿洲灌漠土和灰钙土Cu,Ni的吸附解吸行为.结果表明:Henry方程,Freundlich方程可以较好地模拟Cu,Ni在灌漠土和灰钙土中的等温吸附特征;灌漠土和灰钙土对Cu,Ni吸附选择顺序都为Cu>Ni,灰钙土Cu,Ni之间的竞争作用大于灌漠土中的;灌漠土和灰钙土Cu的解吸率都远远小于Ni的,两种土壤Cu的吸附滞后作用都比Ni的强.%Laboratory batch experiments were carried out to study the sorption and desorption of Cu and Ni in the irrigated desert soil and gray calcareous soil from the oasis in the arid regions of northwest China. The results show that, under the coexistence of Cu and Ni, adsorption of Cu and Ni in the irrigated desert soil and the gray calcareous soil is well described by both Henry and Preundlich equations; the selectivity sequence of Cu and Ni sorption in irrigated desert soil and gray calcareous soil is Cu>Ni, and the competitive interaction between Cu and Ni in gray calcareous soil is more significant than that in irrigated desert soil; percentage of Cu and Ni desorption in irrigated desert soil and gray calcareous soil is Cu>Ni, and sorption hysteresis of Cu and Ni in both soils is also Cu>Ni.

  15. 石灰性旱地土壤对酸性矿山废水污染的酸缓冲能力与作用%Acid Buffer Performance of Calcareous Dry Land Soil Against Continuing AMD Pol lution

    Institute of Scientific and Technical Information of China (English)

    刘桂华; 吴永贵; 付天岭; 杨少博; 张春辉; 王虎

    2014-01-01

    The acid buffer performance and functional mechanism of calcareous soil against continuing AMD pollution were evaluated by analyzing characteristic changes of pH,acidity,alkalinity and karst components of calcareous soil under the continuing AMD pollution to study the effect of continuing AMD pollution on calcareous soil in Karst areas of Guizhou.The calcareous soil in Karst area has of better buffer performance against AMD because when AMD usage amount is 10 times that of soil quality,the acid buffer capacity of calcareous soil against AMD is to 77.266g/kg (taking CaCO3 as the calculation unit)and pH of calcareous soil still maintain above 6.65.The acid buffer performance of the air drying and fresh calcareous soil is 151.027 1.03 g/kg and 93.285 4.32 g/kg respectively.With increase of adding AMD proportion, the Ca content of calcareous soil decreases significantly under the low pollution concentration and increases slightly under the higher pollution concentration. Meanwhile Mg leaching loss and CO2 emission (p<0.01 )of calcareous soil increased significantly.The correlation analysis showed that there is no obvious correlation between soil pH and AMD amount (rpH=-0.473,ppH=0.237;rCa=-0.416,pCa=0.305)but there are very significant correlation between AMD amount and Ca content,Mg content,CO2 emission amount of the calcareous soil in Karst area(rCa=-0.955**,pCa=0.000;rMg=-0.994**,pMg=0.000;rCO2=0.991**,pCO2=0.000),which indicates that the calcareous soil in Karst area has the better buffer performance against continuing AMD pollution, and CO3 2-, Ca and Mg components play an important role in AMD acid buffer of the calcareous soil in Karst area.%为探索酸性矿山废水(AMD)持续污染的影响程度,以贵州喀斯特岩溶区石灰性旱地土壤为研究对象,通过模拟分析AMD持续污染下石灰性旱地土壤 p H、岩溶组分等特性的变化,评价石灰性旱地土壤对AMD持续污染的酸缓冲性能及其作用机理。结果表明

  16. Foliar potassium fertilization improves fruit quality of field-grown muskmelon on calcareous soils in south Texas

    Science.gov (United States)

    Among plant nutrients, potassium (K) has the strongest influence on crop quality parameters that determine consumer preference. However, many soil plant factors often limit adequate soil K uptake to satisfy plant requirements during fruit development stages. The objectives of this multiyear field ...

  17. Comparison of methods for nutrient measurement in calcareous soils: Ion-exchange resin bag, capsule, membrane, and chemical extractions

    Science.gov (United States)

    Sherrod, S.K.; Belnap, J.; Miller, M.E.

    2002-01-01

    Four methods for measuring quantities of 12 plant-available nutrients were compared using three sandy soils in a series of three experiments. Three of the methods use different ion-exchange resin forms-bags, capsules, and membranes-and the fourth was conventional chemical extraction. The first experiment compared nutrient extraction data from a medium of sand saturated with a nutrient solution. The second and third experiments used Nakai and Sheppard series soils from Canyonlands National Park, which are relatively high in soil carbonates. The second experiment compared nutrient extraction data provided by the four methods from soils equilibrated at two temperatures, "warm" and "cold." The third experiment extracted nutrients from the same soils in a field equilibration. Our results show that the four extraction techniques are not comparable. This conclusion is due to differences among the methods in the net quantities of nutrients extracted from equivalent soil volumes, in the proportional representation of nutrients within similar soils and treatments, in the measurement of nutrients that were added in known quantities, and even in the order of nutrients ranked by net abundance. We attribute the disparities in nutrient measurement among the different resin forms to interacting effects of the inherent differences in resin exchange capacity, differences among nutrients in their resin affinities, and possibly the relatively short equilibration time for laboratory trials. One constraint for measuring carbonate-related nutrients in high-carbonate soils is the conventional ammonium acetate extraction method, which we suspect of dissolving fine CaCO3 particles that are more abundant in Nakai series soils, resulting in erroneously high Ca2+ estimates. For study of plant-available nutrients, it is important to identify the nutrients of foremost interest and understand differences in their resin sorption dynamics to determine the most appropriate extraction method.

  18. Prospects of damaged calcareous spring systems in temperate Europe : Can we restore travertine-marl deposition?

    NARCIS (Netherlands)

    Grootjans, Ab; Bulte, Marc; Wolejko, Leslaw; Pakalne, Mara; Dullo, Bikila; Eck, Nelly; Fritz, Christian

    2015-01-01

    Calcareous mires are peat forming systems fed by calcareous groundwater that regularly deposit travertine (CaCO3) on the soil surface or in small pools that are present in such mires. At present almost all calcareous mires in Poland are degraded, most often by land use, which has led to disturbances

  19. Wheat phytotoxicity from arsenic and cadmium separately and together in solution culture and in a calcareous soil

    International Nuclear Information System (INIS)

    The toxicity of two toxic elements, arsenic (As) and cadmium (Cd) (individually or in combination) on root elongation of wheat seedlings (Triticum aestivum, L.) were investigated both in hydroponics and in soils freshly spiked with the toxic elements. Median effective concentration (EC50) and non-observed effect concentration (NOEC) were used to investigate the toxic thresholds and potencies of the two elements. The EC50 for As was 0.97 μM in hydroponics and 196 mg kg-1 in soil, and 4.32 μM and 449 mg kg-1 for Cd, respectively. Toxic unit (TU) and additive index (AI) concepts were introduced to determine the combined outcomes, and different behaviors were obtained: synergism in solution culture (EC50mix = 0.36TUmix and AI: 1.76) and antagonism in soil experiments (EC50mix = 1.49TUmix and AI: -0.33). Furthermore, the data of soil bioavailable As and Cd cannot explain the discrepancy between the results derived from soil and hydroponics experiments

  20. Wheat phytotoxicity from arsenic and cadmium separately and together in solution culture and in a calcareous soil

    Energy Technology Data Exchange (ETDEWEB)

    Cao Qing [Research Center for Eco-environmental Sciences, Chinese Academy of Sciences, Beijing 100085 (China); Hu Qinhong [Lawrence Livermore National Laboratory, University of California, Livermore, CA 94550 (United States); Khan, Sardan [Research Center for Eco-environmental Sciences, Chinese Academy of Sciences, Beijing 100085 (China); Department of Environmental Sciences, University of Peshawar, 25120 Peshawar (Pakistan); Wang Zijian [Research Center for Eco-environmental Sciences, Chinese Academy of Sciences, Beijing 100085 (China); Lin Aijun [College of Chemical Engineering, Beijing University of Chemical Technology, Beijing 100029 (China); Du Xin [Research Center for Eco-environmental Sciences, Chinese Academy of Sciences, Beijing 100085 (China); Zhu Yongguan [Research Center for Eco-environmental Sciences, Chinese Academy of Sciences, Beijing 100085 (China)], E-mail: ygzhu@rcees.ac.cn

    2007-09-05

    The toxicity of two toxic elements, arsenic (As) and cadmium (Cd) (individually or in combination) on root elongation of wheat seedlings (Triticum aestivum, L.) were investigated both in hydroponics and in soils freshly spiked with the toxic elements. Median effective concentration (EC{sub 50}) and non-observed effect concentration (NOEC) were used to investigate the toxic thresholds and potencies of the two elements. The EC{sub 50} for As was 0.97 {mu}M in hydroponics and 196 mg kg{sup -1} in soil, and 4.32 {mu}M and 449 mg kg{sup -1} for Cd, respectively. Toxic unit (TU) and additive index (AI) concepts were introduced to determine the combined outcomes, and different behaviors were obtained: synergism in solution culture (EC{sub 50mix} = 0.36TU{sub mix} and AI: 1.76) and antagonism in soil experiments (EC{sub 50mix} = 1.49TU{sub mix} and AI: -0.33). Furthermore, the data of soil bioavailable As and Cd cannot explain the discrepancy between the results derived from soil and hydroponics experiments.

  1. Wheat phytotoxicity from arsenic and cadmium separately and together in solution culture and in a calcareous soil

    Energy Technology Data Exchange (ETDEWEB)

    Cao, Q; Hu, Q; Khan, S; Wang, Z; Lin, A; Du, X; Zhu, Y

    2007-03-05

    The toxicity effect of two deleterious elements of arsenic (As) and cadmium (Cd) (individually or in combination) on root elongation of wheat seedlings (Triticum aestivum, L.) were investigated both in hydroponics and in soils freshly spiked with the toxic elements. Median effective concentration (EC{sub 50}) and non-observed effect concentration (NOEC) were used to investigate the toxic thresholds and potencies of the two elements. The EC{sub 50} for As was 0.97 {mu}M in hydroponics and 196 mg {center_dot} kg{sup -1} in soil, and 4.32 {mu}M and 449 mg {center_dot} kg{sup -1} for Cd, respectively. Toxic unit (TU) and additive index (AI) concepts were introduced to determine the combined outcomes, and different behaviors were obtained: synergism in solution culture (EC{sub 50mix} = 0.36 TU{sub mix} and AI: 1.76) and antagonism in soil experiments (EC{sub 50mix} = 1.49 TU{sub mix} and AI: -0.33). Furthermore, the data of soil bioavailable As and Cd can not explain the discrepancy between the results derived from soil and hydroponics experiments.

  2. 饱和钙质砂爆炸密实动力特性试验研究%Experimental study of dynamic characteristics of saturated calcareous soil explosion compaction

    Institute of Scientific and Technical Information of China (English)

    徐学勇; 汪稔; 胡明鉴; 孟庆山

    2012-01-01

    开展饱和钙质砂爆炸密实动力特性试验研究,探索饱和钙质砂爆炸密实机制和密实效果,对钙质砂地层中进行的工程建设有重要的理论意义和工程实用价值.通过控制爆炸参数,测试不同参数作用时钙质砂爆炸前后声波特性和表面沉降规律,揭示饱和钙质砂爆炸密实动力特性.试验结果表明:钙质砂高孔隙比和颗粒破碎特性对爆炸密实效果有重要影响.爆炸密实作用后,在爆炸近区,钙质砂颗粒受到较强爆炸冲击作用,导致钙质砂颗粒破碎而形成破碎区和压缩区,压缩区随着时间的推移有松弛的趋势,钙质砂颗粒结构重新固结过程在爆炸后2h内基本完成.%Exploring saturated calcareous soil explosion compacting mechanism and effect through the experimental study have great theoretical and practical significance on engineering construction in calcareous soil area. First, longitudinal wave velocity and surface settlement are tested at different moments before and after explosion under different explosive parameters through indoor mini-explosive compacting experiment. And then, wave velocity characteristics and settlement rules are studied to reveal dynamic characteristics of saturated calcareous soil explosion compaction through analyzing and contrasting the test results. It is suggested that high void ratio and particle breakage characteristics of calcareous soil have great impact on compacting effect. After explosion, breakage and compression cavity are formed in the neighborhood of explosion because of calcareous soil particle breakage resulted from the heavy shock of explosion, compression cavity would relax along with time lapse, the explosion compaction process is completed within two hours.

  3. Role of Carbon Substrates Added in the Transformation of Surplus Nitrate to Organic Nitrogen in a Calcareous Soil

    Institute of Scientific and Technical Information of China (English)

    QIU Shao-Jun; JU Xiao-Tang; J.INGWERSEN; GUO Zi-De; C.F.STANGE; R.BISHARAT; T.STRECK

    2013-01-01

    Excessive amounts of nitrate have accumulated in many soils on the North China Plain due to the large amounts of chemical N fertilizers or manures used in combination with low carbon inputs.We investigated the potential of different carbon substrates added to transform soil nitrate into soil organic N (SON).A 56-d laboratory incubation experiment using the 15N tracer (K15NO3)technique was carried out to elucidate the proportion of SON derived from accumulated soil nitrate following amendment with glucose or maize straw at controlled soil temperature and moisture.The dynamics and isotopic abundance of mineral N (NO3-and NH4+) and SON and greenhouse gas (N2O and CO2) emissions during the incubation were investigated.Although carbon amendments markedly stimulated transformation of nitrate to newly formed SON,this was only a substitution effect of the newly formed SON with native SON because SON at the end of the incubation period was not significantly different (P > 0.05) from that in control soil without added C.At the end of the incubation period,amendment with glucose,a readily available C source,increased nitrate immobilization by 2.65 times and total N2O-N emission by 33.7 times,as compared with maize straw amendment.Moreover,the differences in SON and total N2O-N emission between the treatments with glucose and maize straw were significant (P < 0.05).However,the total N2O-N emission in the straw treatment was not significantly (P > 0.05) greater than that in the control.Straw amendment may be a potential option in agricultural practice for transformation of nitrate N to SON and minimization of N2O emitted as well as restriction of NO3-N leaching.

  4. Legacy phosphorus in calcareous soils: effects of long-term poultry litter application on phosphorus distribution in Texas Blackland Vertisol

    Science.gov (United States)

    Sequential fractionation techniques, coupled with phosphatase hydrolysis, have allowed for greater understanding of manure/litter effects on soil phosphorus (P) distribution. We evaluated the effect of long-term (> 10 years) poultry litter (broiler and turkey litter) application at rates of 4.5, 6.7...

  5. Theoretical and experimental study of the bio-geochemical behaviour of americium 241 in simplified rhizosphere conditions. Application to a calcareous agricultural soil

    International Nuclear Information System (INIS)

    Americium 241, is one of the most radio-toxic contaminant produced during the nuclear fuel cycle. It can be found in all environmental compartments, in particular the soils. The main goals of this study are to identify, quantify and model the effect of the main factors controlling the mobility of 241Am in the rhizosphere and the agricultural soils. The physico-chemical parameters of the soil and of the soil solution, the potential role of microorganisms on the sorption-desorption processes, and the speciation of americium in solution have been more particularly studied. 241Am remobilization has been studied at the laboratory using leaching experiments performed in controlled conditions on reworked calcareous soils artificially contaminated with 241Am. The soil samples have been washed out in different hydrodynamic conditions by solutions with various compositions. The eluted solution has been analyzed (pH, conductivity, ionic composition, Fetot, organic acids, 241Am) and its bacterial biomass content too. The overall results indicate that 241Am remobilization is contrasted and strongly linked with the condition under study (pH, ionic strength, glucose and/or citrate concentration). Therefore, a solution in equilibrium with the soil or containing small exudate concentrations (10-4 M) re-mobilizes only a very small part of the americium fixed on the solid phase. The desorption of 241Am corresponds to a solid/liquid coefficient of partition (Kd) of about 105 L.kg-1. A significant addition of glucose induces an important dissolution of soil carbonates by the indirect action of microorganisms, but does not significantly favor the 241Am remobilization. On the other hand, the presence of strong citrate concentrations (≥ 10-2 M) allows 300 to 10000 time greater re-mobilizations by the complexing of 241Am released after the dissolution of the carrying phases. Finally, the colloidal transport of 241Am has been systematically observed in a limited but significant extend and

  6. Spatial Distribution of Magnetic Properties and Selected Heavy Metals in Calcareous Soils as Affected by Land Use in the Isfahan Region, Central Iran

    Institute of Scientific and Technical Information of China (English)

    Z. DANKOUB; S. AYOUBI; H. KHADEMI; LU Sheng-Gao

    2012-01-01

    Anthropogenic activities have caused the accumulation of heavy metals in the soil environment.Pollution of the soils significantly reduces environmental quality and affects human health. In many recent studies,magnetic susceptibility measurements have been used for pollution monitoring.The objective of this research was to determine the spatial variability of magnetic properties and selected heavy metals and the effect of land use on their variability in the surface soils of the Isfahan region,Central Iran.A total of 158 composite surface (0-5 cm) samples of calcareous soils were collected from an area of about 700 km2,located along a cross-border transect from Isfahan City to a steel plant,covering urban,industrial,agricultural,and uncultivated land uses. Concentrations of copper (Cu),zinc (Zn),lead (Pb),manganese (Mn),iron (Fe),nickel (Ni),chromium (Cr),and cobalt (Co) and magnetic parameters,magnetic susceptibility at low frequency (xlf),natural remanent magnetization (NRM),saturation isothermal remanent magnetization (SIRM),and isothermal remanent magnetization at the field of 100 mT (IRM100mT) and the backfield of 100 mT (IRM-100mT),were measured in all the soil samples.Results showed that magnetic susceptibility in the urban and industrial land topsoils (0-5 cm) samples was significantly higher than that in the agricultural and uncultivated land soils in the study area.Concentrations of Cu,Zn,Pb,Mn,and Fe were positively correlated with magnetic properties (xlf,IRM100mT,SIRM,IRM-100mT,and NRM),which could be attributed to their inputs from traffic emissions and industrial activities at the study sites.Ni and Cr concentrations showed significant negative correlations with magnetic properties.No significant correlation was found between Co concentration and magnetic parameters.The Tomlinson pollution load index (PLI) showed significant correlation with the magnetic properties (xlf,IRM100mT,SIRM,IRM-100mT,and NRM).The spatial distribution of the selected heavy

  7. Regulating mineralization rates of Tithonia diversifolia and Lantana camara prunings to improve phosphorus availability in calcareous soils

    Directory of Open Access Journals (Sweden)

    Y. Nuraini

    2014-01-01

    Full Text Available The effect of mixing of Tithonia diversifolia and Lantana camara prunings to improve synchronization between P released from the prunings with crop demand for P was studied in a laboratory and in a glasshouse. Tithonia diversifolia prunings (Td, Lantana camara prunings (Lc, and farmyard manure (Pk were thoroughly mixed with the proportion (% of dry weight of; 25Td +75 Lc ; 50Td +50 Lc ; 75Td +25 Lc ; 90Lc +10 Pk ; 45Td +45 +10 Lc Pk ; 100Td and 100Lc, and then mixed with 100 g of air-dried soil with a rate equivalent to 100 kg P / ha. Results of the study showed that the pruning mixtures decomposed and mineralized faster than that of Lantana camara pruning only, but slower than that of Tithonia diversifolia pruning only. The amount of P released from the pruning mixtures increased with increasing proportion of Tithonia diversifolia pruning in the mixtures. Increasing proportion of Tithonia diversifolia pruning in the mixture applied to the soil increased the amount of P taken up by maize.

  8. Chemistry of atmospheric precipitation in the north-central united states: Influence of sulfate, nitrate, ammonia and calcareous soil particulates

    Science.gov (United States)

    Munger, James William

    The supply of alkaline soil dust and gaseous NH 3 available to neutralize anthropogenic acids in the atmosphere controls the acidity of precipitation in the north-central United States. Major ions and trace metals were determined in precipitation-event and snow-core samples from sites along a 600 km transect from the North Dakota prairie to the forests of northeastern Minnesota, collected during the period April 1978-June 1979. Acidity increased 4-fold from west to east as the effect of alkaline dust and NH 3 decreased with increasing distance from the cultivated prairie; calcium and Mg 2+ decreased 2 to 3-fold across the transect. However, minimum concentrations of NH 4+ and SO 42- were observed at Itasca, the central site. Natural emissions of these elements were important in the west, while anthropogenic emissions were responsible for the higher concentrations in the east. Wet deposition of H + decreased 8-fold and deposition of NO 3- and SO 42- decreased 1.5 to 2-fold from Hovland in the east to Tewaukon in the west. Wet deposition of the metal cations increased from Hovland to Tewaukon. Dry deposition followed a similar trend. Winter snow cover and freezing temperatures, which decreased airborne soil dust and the evolution of NH 3 from the prairie soils, led to an increase in precipitation acidity at all sites. The acid increase was accompanied by a decrease in alkaline metal cations, especially Ca 2+, and in NH 4+. At Hovland SO 42- and NO 3- also increased during the winter. The occurrence of snow events at Tewaukon that were appreciably more acid than the snowpack accumulated there indicates that snow was neutralized after it fell by alkaline dust entrained in resuspended snow, or deposited separately. Winter inputs of acid are especially important because they are released during a short period in the spring. Over half of the acid input at Hovland occurred during the winter. Precipitation inputs of P and N probably benefit nutrient-poor ecosystems in the

  9. Effect of salinity and vermicompost application on nutrients concentration and yield of spinach cv. Virofly in a calcareous soil

    Directory of Open Access Journals (Sweden)

    J. Sheikhi

    2013-04-01

    Full Text Available To evaluate the effect of salinity (S and vermicompost (V on yield and concentration of nitrogen (N, phosphorus (P, potassium (K, iron (Fe, manganese (Mn, zinc (Zn, copper (Cu, calcium (Ca, magnesium (Mg, sodium (Na and chlorine (Cl of spinach shoots cv. Virofly, a pot experiment was conducted in greenhouse, and arranged as factorial in a completely randomized design with three replications. Treatments included three V levels (0, 1 and 2%, w/w and four S levels (0, 1, 2 and 3 g NaCl per kg soil. Electrical conductivity of the soil for these four S levels was 0.7, 4.5, 8 and 11.5 dS/m, respectively. Results showed that the highest yield of spinach shoots was obtained in 10% V treatment. Application of sodium chloride (NaCl had no significant effect on shoot yield. Therefore, under the present experimental conditions, S threshold level for "Viroflay" cultivar was at least 11.5 dS/m, which is much higher than the level reported in literature for spinach (2 dS/m. Application of V increased concentration of N, P, K, Fe and Mg in spinach shoots, but decreased concentration of Mn, Zn, Cu, Ca, Na and Cl. Application of NaCl had no significant effect on the concentration of P, Fe, Mn, Ca and Mg. But, with the addition of NaCl, concentration of N, Zn, Cu, Na and Cl was increased in spinach shoots. In the absence of NaCl, application of V had no significant effect on Na concentration, but increased Cl concentration. Whereas, at 3 g NaCl level, application of V significantly decreased Na and Cl concentrations of shoots, compared to the application of NaCl alone. Therefore, application of V not only can increase plant growth, but also could be an effective solution to mitigate the negative effects of high concentrations of Na and Cl on growth of spinach, cv. Virofly, in saline soils.

  10. The influence of coniferous canopies on understorey vegetation and soils in mountain forests of the northern Calcareous Alps

    International Nuclear Information System (INIS)

    Compositional and edaphic gradients were studied in montane forests of the Bavarian Alps (Germany), in which natural mixed deciduous-coniferous tree layers have been altered by past management in favour of Picea abies. Data on species composition and ecological factors were collected in a stratified random sample of 84 quadrats comprising a gradient from pure Picea to pure Fagus sylvatica stands. Data about the understorey composition were subjected to indirect (DCA) and direct gradient analysis (RDA) with the proportion of Picea in the canopy as a constraining variable. Three principal components of a matrix containing seven descriptors of mineral soil, relief and tree layer cover were included as covariables describing the variability of primary ecological factors. Gradients of organic topsoil morphology and chemistry were extracted correspondingly. Responses of individual species, species group and topsoil attributes were studied by simple and partial correlation analysis. Mosses were significantly more abundant and diverse under Picea stands. Few graminoid and herb species were partially associated with Picea, and total understorey richness and cover did not differ systematically by stand type. No relationship between tree layer and understorey diversity was detected at the studied scale. Juvenile Fagus sylvatica was the only woody species significantly less abundant under Picea. In the topsoil lower base saturation, lower pH and larger C/N ratios in the litter layer were partially attributable to the proportion of Picea, only for base saturation a relationship was detected in greater soil depth also. The frequency of broad humus form types did not differ by tree species, nor was overall depth of organic forest floor attributable to canopy composition

  11. State-of-the-art review of developments of laboratory tests on cemented calcareous soils%胶结钙质土的室内试验研究进展

    Institute of Scientific and Technical Information of China (English)

    朱长歧; 周斌; 刘海峰

    2015-01-01

    The naturally cemented calcareous soil is a carbonate soil or rock cemented by high-magnesium calcite or aragonite. It usually contains a large portion of coral and other tropical marine organism. Its unique engineering properties often result in troubles and difficulties in the geotechnical design and foundation construction. Its characteristics also attract research and experimental interests of many researchers. This paper presents state-of-the-art review of developments of the laboratory tests on both naturally and artificially cemented calcareous soils as well as the sample preparation techniques of artificially cemented soils. The general stress-strain behaviors of the cemented calcareous samples and factors that might affect its characteristics, such as confining pressure, initial sample density, and degree of cementation, are also summarized. The research work that could be improved is also proposed with an objective of providing a research guideline for the further studies of cemented calcareous soils.%天然胶结钙质土是广泛分布于热带及亚热带海洋中由生物碎屑经碳酸钙胶结或固结而形成的碳酸盐岩类。其独特的工程性质常常给岩土工程设计与施工带来麻烦,也正因此引起了研究者的兴趣并对其开展了较为全面的试验研究工作。针对天然胶结钙质土、人工胶结钙质土的室内试验以及人工胶结钙质土试样的制备等3方面取得的研究进展进行总结回顾,汇总了胶结钙质土的基本应力-应变行为以及围压、初始密度及胶结度等主要参数的影响规律,指出了研究中尚存在的问题,并对胶结钙质土的进一步的研究工作进行了展望。该工作必将对此领域的研究具有借鉴和指导意义。

  12. Effects of soil amendments at a heavy loading rate associated with cover crops as green manures on the leaching of nutrients and heavy metals from a calcareous soil

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Q.R.; Li, Y.C.; Klassen, W. [University of Florida, Homestead, FL (USA). Center of Tropical Research & Education

    2003-07-01

    The potential risk of groundwater contamination by the excessive leaching of N, P and heavy metals from soils amended at heavy loading rates of biosolids, coal ash, N-viro soil (1:1 mixture of coal ash and biosolids), yard waste compost and co-compost (3:7 mixture of biosolids to yard wastes), and by soil incorporation of green manures of sunn hemp (Crotalaria juncea) and sorghum sudangrass (Sorghum bicolorXS. bicolor var. sudanense) was studied by collecting and analyzing leachates from pots of Krome gravelly loam soil subjected to these treatments. A subtropical vegetable crop, okra (Abelmoschus esculentus L.), was grown after the soil amendments or cover crops had been incorporated into the soil. The results showed that the concentration of NO{sub 3}-N in leachate from biosolids was significantly higher than in leachate from other treatments. The levels of heavy metals found in the leachates from all amended soils were so low, as to suggest these amendments may be used without risk of leaching dangerous amounts of these toxic elements. Nevertheless the level of heavy metals in leachate from coal ash amended soil was substantially greater than in leachates from the other treatments.

  13. Effect of Different Fertilizer Treatments on Quantity of Soil Microbes and Structure of Ammonium Oxidizing Bacterial Community in a Calcareous Purple Paddy Soil

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The quantity of soil microbes and the structure of ammonium oxidizing bacterial (AOB) community were analyzed using the dilution plate counting and most probable number method (MPN), and denaturing gradient gel electrophoresis (DGGE), respectively. Fertilizer application tended to increase the number of soil microbes and alter the AOB community compared to the control with no fertilizer application (CK). Among the eight fertilizer treatments, soil samples from the treatments of mineral fertilizers (e.g., N, P, K) in combination with farmyard manure (M) had greater numbers of soil microbes and more complex structure of AOB community than those receiving mineral fertilizers alone. The principal component analyses (PCA) for ammonium oxidizing bacterial community structure showed that the eight fertilizer treatments could be divided into two PCA groups (PCA1 and PCA2). For the soil sampled after rice harvest, PCA1 included NP, NM, NPM and NPKM fertilizer treatments, while PCA2 was consisted of CK, N, M and NPK fertilizer treatments. For soil samples collected after wheat harvest, PCA1 was consisted of M, NM, NPM and NPKM fertilizer treatments, while PCA2 was composed of CK, N, NP and NPK fertilizer treatments. For a given rotation, the richness of AOB community in PCA1 was greater than that in PCA2. In addition, AOB community structure was more complex in the soil after rice harvest than that after wheat harvest. The results indicated that different fertilizer treatments resulted in substantial changes of soil microbe number and AOB community. Furthermore, mineral fertilizers (N, NP, NPK) combined with farmyard manure were effective for increasing the quantity of soil microbes, enriching AOB community, and improving the soil biofertility.

  14. Short-term effects of treated waste water irrigation on soil. Two years of a study monitoring a Mediterranean calcareous soil

    Science.gov (United States)

    Morugán, A.; García-Orenes, F.; Mataix-Solera, J.; Gómez, I.; Arcenegui, V.; Navarro, M. A.; Mataix-Beneyto, J.

    2009-04-01

    Shortage of water and soil degradation are the most important environmental problems in the Mediterranean areas due, in many cases, to inadequate agricultural management of irrigation to which organic matter is not correctly added, and the use of low quality waters for irrigation. For this reason strategies for saving water and for the restoration of the mean properties of soil are necessary. The use of treated waste water for the irrigation of agricultural land is a good solution to these problems, because it reduces the utilization of fresh water and potentially could improve key soil parameters, thus influencing crop production in a positive way by increasing soil nutrients and organic matter content. In this work we are studying the short-term effects of irrigation with waste waters on several soil properties related to fertility, in an agricultural area located at Biar (Alicante, SE of Spain), with a crop of grape (Vitis labrusca). Three treatments are being used in the irrigation of the soil: fresh water (control), and treated waste waters from secondary and tertiary treatment. A soil sampling was carried out every four months. We show here the results after two years of irrigation treatments. Results confirm a slight decrease of organic carbon and nitrogen contents in plots irrigated with water from secondary treatment, in these plots an increase of the electrical conductivity (EC) has also been observed. Laboratory analyses also show an increase in P available, pH and Na on plots with waste water application. At the moment, the changes found between treatments do not imply quantitatively great changes in soil properties and negative impacts into the soil with the exception of EC, which must be monitored to control their values. Although we show here partial results of a long-term experiment, the conclusion is positive since treated waste waters are not producing notable changes on soil parameters in comparison with plots treated with fresh water.

  15. Changes in soil test phosphorus and phosphorus in runoff from calcareous soils receiving manure, compost, and fertilizer application with and without alum

    Science.gov (United States)

    Intensification of the dairy industry in southern Idaho had led to the over-application of manures and a buildup of soil phosphorus (P) which is a potential threat to water quality in the region. As the use of alum has been shown to reduce both soluble manure P and runoff P from alum treated manure...

  16. On Surface Charge Properties of Red,Yellow and Calcareous Purplish Soils%红壤黄壤及紫色土表面电荷性质的研究

    Institute of Scientific and Technical Information of China (English)

    余正洪; 刘新敏; 李航

    2013-01-01

    运用带电颗粒表面性质联合分析法,测定了不同pH值条件下(pH7和4.5)下红壤、黄壤和石灰性紫色土的表面电荷性质.结果表明:在相同pH值条件下,石灰性紫色土比可变电荷土壤有较高的表面电位、表面电场强度、表面电荷数量和比表面积,且3种土壤的表面电场强度都可达108V/m的数量级;随着pH值的降低,3种土壤的表面电荷数量和表面电荷密度显著减小;pH值为4.5时,红壤和黄壤的表面电位和表面电荷数量接近.%The surface properties of red, yellow and calcareous purplish soils have been determined based on the combined method for surface properties determination to discuss its application to soils with variable charges (red earth and yellow soil) and constant charges under different pH (pH 7 and 4. 5) values. The results show that the surface potential, electrostatic field strength at surface, surface charge number and surface charge density of calcareous purplish soil are higher than that of variable soils under the same pH value, and the surface electrostatic field strength of all the three soils are more than 108V/m. With the decrease of pH, the surface charge number and surface charge density of the three soils dramatically decreased. When the pH is 4. 5, the surface potential and surface charge number of red soil are almost equal to that of the yellow soil.

  17. Implications of Cadmium Forms and Risk Assessment of Calcareous Soil in Karst Area:A Case Study of Maocun in Guilin,China%岩溶区典型石灰土Cd形态指示意义及风险评价以桂林毛村为例

    Institute of Scientific and Technical Information of China (English)

    周长松; 邹胜章; 李录娟; 朱丹尼; 卢海平; 夏日元

    2016-01-01

    In order to grasp the forms and accumulation of cadmium in the soils of karst area ,three calcareous soil samples collected from Maocun ,Guilin ,were analyzed .Their cadmium concentration was tested by an atomic spectrometer ,and the cadmium was tested by an improved .Tessier assay ,for its different existing status as it is in the five forms of EXC (exchangeable ) ,CAB (carbonate combined ) , OXI(Fe Mn oxide combined) ,ORG(organic combined) and RES(residual) .Moreover ,its risk to the environment and implications were analyzed and evaluated . The results showed that the relative cadmium contents of the three calcareous soil are :Black calcareous soil >Brow n calcareous soil> Red calcareous soil ;Cadmium in Black calcareous soil and Brow n calcareous soil present mainly in Fe Mn oxide combined form ,and the chance to find it in other forms is reduced by the order of OXI > RES>EXC>CAB > ORG .In Red calcareous soil ,the relative contents of cadmium in different chemical forms reduced in the order of RES > OXI> EXC> CAB> ORG .The results of RSP and RAC showed that cadmium contents of the three calcareous soil are :Black calcareous soil >Brow n calcareous soil> Red calcareous soil . The ecological and health risks of cadmium of the three calcareous soil are :Black calcareous soil > Brown calcareous soil > Red calcareous soil . The results provide basic data for remediation and control of cadmium in karst area .%为了了解岩溶区石灰土中重金属Cd形态分配特征及富集情况,在桂林毛村采集了3种处于不同发育阶段的黑色、棕色和红色石灰土进行研究。通过原子光谱仪测试了 Cd质量分数,运用改进的Tessier分析法测定了3种石灰土中Cd的可交换态(EXC)、碳酸盐结合态(CAB)、铁锰氧化物结合态(OXI)、有机结合态(ORG)、残渣态(RES)5种形态,并对其指示意义及风险进行了分析与评价,结果表明,3种石灰土中Cd质量分数从大到小依次为早

  18. Electrodialytic Soil Remediation. Improved conditions and acceleration of the process by addition of desorbing agents to the soil

    DEFF Research Database (Denmark)

    Ottosen, Lisbeth M.; Hansen, Henrik; Hansen, Lene;

    1998-01-01

    The principel of electrodialytic soil remediation was improved when ammonia was added to a calcareous copper polluted soil......The principel of electrodialytic soil remediation was improved when ammonia was added to a calcareous copper polluted soil...

  19. Electrodialytic Soil Remediation. Improved conditions and acceleration of the process by addition of desorbing agents to the soil

    DEFF Research Database (Denmark)

    Ottosen, Lisbeth M.; Hansen, Henrik; Hansen, Lene; Bech-Nielsen, Gregers; Pettersen, Berit W; Villumsen, Arne

    The principel of electrodialytic soil remediation was improved when ammonia was added to a calcareous copper polluted soil......The principel of electrodialytic soil remediation was improved when ammonia was added to a calcareous copper polluted soil...

  20. The efficiency of applying phosphate on rice and utilization rate in calcareous fluvo-aquic soil%石灰性灰潮土水稻施磷效应及利用率

    Institute of Scientific and Technical Information of China (English)

    姜剑平; 刘伯芹

    2012-01-01

    The effects of different phosphorus fertilization level on soil rapid available phosphorus and rice yield are studied in calcareous fluvo-aquic soil of Tongzhou area, the utilization rate of phosphate fertilizer is determined in different phosphorus fertilization level. The results show: the phosphate fertilizer coefficient of calcareous fluvo-aquic soil is 1.72 in middle containing phosphorus soil, the critical value is 6.0 mg/kg; the reasonable applying phosphate fertilizer can significantly increase the yield of rice, and the yield is increased with the increasing of applying phosphate amount below a certain phosphorus fertilization level, the best phosphorus fertilization amount is 3.8 kg, and the phosphorus fertilization amount of the highest yield is 9.4 kg. The phosphate utilization rate is decreased with the increasing of applying phosphate amount, the averaKe utilization rate is 8.5%.%以通州区石灰性灰潮土为供试土壤,研究了不同施磷水平对土壤速效磷含量及水稻产量的影响,测定了水稻不同施磷水平下磷肥的利用率。结果表明,在中等含磷的土壤上,石灰性灰潮土的磷肥系数为1.72,磷肥临界值为6.0mg/kg;水稻合理施用磷肥能显著增产,但产量只在一定的施磷水平下随着施磷量的增加而增加,其667m。最经济施磷量为3.8kg,最高产量施磷量为9.4kg。磷肥利用率则随施磷量的增加而逐渐下降,平均利用率为8.5%。

  1. Calcareous Fens - Source Feature Points

    Data.gov (United States)

    Minnesota Department of Natural Resources — Pursuant to the provisions of Minnesota Statutes, section 103G.223, this database contains points that represent calcareous fens as defined in Minnesota Rules, part...

  2. CO2 emission and structural characteristics of two calcareous soils amended with municipal solid waste and plant residue

    OpenAIRE

    Yazdanpanah, N.

    2015-01-01

    This investigation examines the effect of different amendments on selected soil physical and biological properties over a twenty four month period in two cropland fields. Urban municipal solid waste (MSW) compost and alfalfa residue (AR) were used as different organic amendments at the rates of 0 (control), 10 and 30 Mg ha−1 to a clay loam soil and a loamy sand soil in a semiarid region. Result showed that the soil improvement was controlled by the app...

  3. Reducing the infectivity and richness of ectomycorrhizal fungi in a calcareous Quercus ilex forest through soil preparations for truffle plantation establishment: A bioassay study.

    Science.gov (United States)

    Garcia-Barreda, Sergi; Molina-Grau, Sara; Reyna, Santiago

    2015-11-01

    In the early years of a black truffle plantation, the field proliferation of the nursery-inoculated fungi can be hampered by native ectomycorrhizal fungi colonising the seedling roots. Reducing the soil ectomycorrhizal infectivity in the planting hole before introducing the inoculated seedling could be an effective strategy to reduce this problem. Three bioassays were conducted to evaluate the impact of several soil preparations on the ectomycorrhizal infectivity and richness of a Quercus ilex soil in a truffle-producing region. Microwaves, quicklime, and acetic acid significantly decreased the percent root colonisation and morphotype richness of the native ectomycorrhizal fungi. However, they also decreased seedling survival or growth. Peracetic acid, hydrogen peroxide, and sodium hypochlorite did not show a significant negative effect on the soil ectomycorrhizal community. The results support the potential of soil preparation for reducing the ectomycorrhizal infectivity of forest soils, thus being a promising strategy to reduce the early colonisation by native fungi in truffle plantations. However, the indications of damage to the seedling development must be addressed. PMID:26466886

  4. The use of natural abundance carbon-13 to identify and quantify sources of emitted carbon dioxide in a calcareous southern Ontario Luvisolic soil

    Science.gov (United States)

    Wilton, Meaghan

    Three studies Were conducted at the Elora Research Station (ERS) on a Luvisolic soil to investigate the soil inorganic carbon (SIC) and soil organic carbon (SOC) components contributing to the CO2 flux (FC) using natural 13C abundance. SIC contributed to the FC in intact soil incubations. Soil disruption exacerbated the release of CO2 from both pedogenic and lithogenic carbonates. Field and laboratory techniques to obtain the delta13C of respired CO2 (delta13CR) were compared. Short-term deployment of non flow-through non steady-state chambers and the use of the simple two-ended mass balance approach to derive delta 13CR were found acceptable to apply to the ERS site. The delta13CR from a corn field at ERS with a history of multiple C4 and C3 crop rotations was partitioned into SIC and SOC components using two approaches. Root respiration contributed 2% - 64% and carbonates contribute up to 20% to the FC.

  5. Zinc Availability and Its Influencing Factors of Xinjiang Calcareous Soil%新疆石灰性土壤锌有效性及其影响因素

    Institute of Scientific and Technical Information of China (English)

    王金鑫; 危常州; 王肖娟; 李美宁; 朱齐超; 王娟

    2012-01-01

    This paper studied Zn contents and its fractal components by 3 typical types of soils in southern and northern in Xinjiang. The results showed. The average available Zn was aquic soil(0.69 mg/kg) 〉brown desert soil(0.57 mg/kg) 〉grey desert soil(0.51 mg/kg), the coefficient of variation was grey desert soil 〉 aquic soil 〉brown desert soil. In the Zn fractal content, the components contents of SBO, CARB, OxMn, WBO and AOFe were aquic soil 〉brown desert soil 〉grey desert soil. The background value of soil Zn were different, total zinc content of southern soils was higher than that of northern soils, which were more variability. The contents of CaCO3 and physical clay were highly relevant to the percentages of WBO, CARB and SBO. The relative percentages were significantly or very significantly positive in physical clay content and WBO, CARB, SBO. The content of WBO remarkably influenced the content of Exc. There was significant positive correlation between WBO and CARB. The content of available Zn was remarkably influenced by WBO, CARB, which could be forecasted by the equation. Y=0.306+0.123WBO+0.116CARB(F=20.095,r2=0.801**).%为探讨新疆石灰性土壤锌的组分分布特征及锌有效性的影响因素,对南北疆3种最主要土壤类型农田土壤锌及其组分含量进行研究。结果表明:新疆石灰性土壤有效锌平均含量为潮土(0.69mg/kg)〉棕漠土(0.57mg/kg)〉灰漠土(0.51mg/kg),变异系数为灰漠土〉潮土〉棕漠土。在土壤锌组分中,松结有机态锌(WBO)、碳酸盐结合态锌(CARB)、氧化锰结合态锌(OxMn)、紧结有机态锌(SBO)、无定形铁结合态锌(AOFe)平均含量均为潮土〉棕壤土〉灰漠土。南北疆土壤锌背景值不同,南疆土壤全锌含量高于北疆土壤,而北疆土壤全锌变异较大。土壤碳酸钙含量和物理性粘粒含量与松结有机态、碳酸盐结合态、紧结有机态锌分配率高度相关。松结有机

  6. The Influence of Mineral Fertilizer Combined With a Nitrification Inhibitor on Microbial Populations and Activities in Calcareous Uzbekistanian Soil Under Cotton Cultivation

    Directory of Open Access Journals (Sweden)

    Dilfuza Egamberdiyeva

    2001-01-01

    Full Text Available Application of fertilizers combined with nitrification inhibitors affects soil microbial biomass and activity. The objective of this research was to determine the effects of fertilizer application combined with the nitrification inhibitor potassium oxalate (PO on soil microbial population and activities in nitrogen-poor soil under cotton cultivation in Uzbekistan. Fertilizer treatments were N as urea, P as ammophos, and K as potassium chloride. The nitrification inhibitor PO was added to urea and ammophos at the rate of 2%. Three treatments—N200P140K60 (T1, N200 P140 POK60 (T2, and N200 P140 POK60 (T3 mg kg-1 soil—were applied for this study. The control (C was without fertilizer and PO. The populations of oligotrophic bacteria, ammonifying bacteria, nitrifying bacteria, denitrifying bacteria, mineral assimilating bacteria, oligonitrophilic bacteria, and bacteria group Azotobacter were determined by the most probable number method. The treatments T2 and T3 increased the number of oligonitrophilic bacteria and utilization mineral forms of nitrogen on the background of reducing number of ammonifying bacteria. T2 and T3 also decreased the number of nitrifying bacteria, denitrifying bacteria, and net nitrification. In conclusion, our experiments showed that PO combined with mineral fertilizer is one of the most promising compounds for inhibiting nitrification rate, which was reflected in the increased availability and efficiency of fertilizer nitrogen to the cotton plants. PO combined with mineral fertilizer has no negative effects on nitrogen-fixing bacteria Azotobacter and oligo-nitrophilic bacteria.

  7. The influence of wine-distillery waste compost on nitrogen and phosphorus dynamics and uptake by a melon crop in a shallow calcareous soil

    Science.gov (United States)

    Requejo, M. I.; Villena, R.; Ribas, F.; Castellanos, M. T.; Cabello, M. J.; Arce, A.; Cartagena, M. C.

    2012-04-01

    In Mediterranean countries, the large quantity of organic wastes generated by the winery industry constitutes a serious environmental concern, due to its low pH and high content of phenolic compounds. This is accompanied by a seasonal production that makes their management difficult. Winery wastes are characterized by high organic matter contents, low electrical conductivity values and notable contents in macronutrients, so their use as organic amendments is a good management option for improving soil fertility. However, a composting treatment is necessary to convert these organic wastes into more stable, hygienic and humic-rich materials. The aim of this work was to evaluate the effects of the application of exhausted grape marc compost (composed of dealcoholized pulp, skins and stems) as fertilizer in soil nitrogen and phosphorus availability and uptake by a melon crop (Cucumis melo L.). This experiment was carried out from May to September 2011 in Ciudad Real (Spain). This area was designated "vulnerable zone" by the "Nitrates Directive" 91/676/CEE. The soil was a shallow sandy-loam (Alfisol Xeralf Petrocalcic Palexeralfs) with a depth of 0.60 m and a discontinuous petrocalcic horizon between 0.60 and 0.70 m, slightly basic (pH 7.9), poor in organic matter (0.20%), rich in potassium (407 ppm) and with a medium level of phosphorus (19.4 ppm). The experiment had a randomised complete block design, with four treatments consisted of four compost doses: 0 (D0), 6.7 (D1), 13.3 (D2) and 20 T compost ha-1 (D3), in order to determine the optimum dose to ensure nutrient demand, maximizing yield and minimizing nutrient losses. Acknowledgements This project has been supported by INIA-RTA2010-00110-C03-01.

  8. Effects of acid atmospheric deposition on the chemical composition of loess, clay and peat soils under forest in the Netherlands

    NARCIS (Netherlands)

    Klap, J.M.; Vries, de W.; Leeters, E.E.J.M.

    1999-01-01

    In addition to a survey of the soils under 150 forest stands on non-calcareous sandy soils, the chemical composition of the soils under 40 stands on non-calcareous loess soil, 30 stands on non-calcareous clay soils and 30 stands on oligotrophous peat soils have been examined, to assess the current s

  9. Effects of water additions, chemical amendments, and plants on in situ measures of nutrient bioavailability in calcareous soils of southeastern Utah, USA

    Science.gov (United States)

    Miller, M.E.; Belnap, J.; Beatty, S.W.; Webb, B.L.

    2006-01-01

    We used ion-exchange resin bags to investigate effects of water additions, chemical amendments, and plant presence on in situ measures of nutrient bioavailability in conjunction with a study examining soil controls of ecosystem invasion by the exotic annual grass Bromus tectorum L. At five dryland sites in southeastern Utah, USA, resin bags were buried in experimental plots randomly assigned to combinations of two watering treatments (wet and dry), four chemical-amendment treatments (KCl, MgO, CaO, and no amendment), and four plant treatments (B. tectorum alone, the perennial bunchgrass Stipa hymenoides R. & S. alone, B. tectorum and S. hymenoides together, and no plants). Resin bags were initially buried in September 1997; replaced in January, April, and June 1998; and removed at the end of the study in October 1998. When averaged across watering treatments, plots receiving KCl applications had lower resin-bag NO 3- than plots receiving no chemical amendments during three of four measurement periods-probably due to NO 3- displacement from resin bags by Cl- ions. During the January-April period, KCl application in wet plots (but not dry plots) decreased resin-bag NH 4+ and increased resin-bag NO 3- . This interaction effect likely resulted from displacement of NH 4+ from resins by K+ ions, followed by nitrification and enhanced NO 3- capture by resin bags. In plots not receiving KCl applications, resin-bag NH 4+ was higher in wet plots than in dry plots during the same period. During the January-April period, resin-bag measures for carbonate-related ions HPO 42- , Ca2+, and Mn2+ tended to be greater in the presence of B. tectorum than in the absence of B. tectorum. This trend was evident only in wet plots where B. tectorum densities were much higher than in dry plots. We attribute this pattern to the mobilization of carbonate-associated ions by root exudates of B. tectorum. These findings indicate the importance of considering potential indirect effects of soil

  10. Effects of grain size distribution on the initial strain shear modulus of calcareous sand

    OpenAIRE

    Pham, Huu Ha Giang; Van Impe, PO; Van Impe, William; Mengé, P; Haegeman, Wim

    2015-01-01

    The soil’s small strain shear modulus, Gmax or G0, is applied in dynamic behavior analyses and is correlated to other soil properties (density and void ratio) for predicting soil dynamic behavior under seismic loadings such as earthquakes, machinery or traffic vibrations. However, for calcareous sands, selecting representative samples for the field conditions is difficult; therefore, almost all measured soil parameters (post-seismic properties) do not reflect exactly the soil state before sei...

  11. 低分子量有机酸对石灰性土壤有机磷组成及有效性的影响%Effect of Low Molecular Weigh Organic Acid on Organic Phosphorus Fraction and Availability in Calcareous Soil

    Institute of Scientific and Technical Information of China (English)

    杨绍琼; 党廷辉; 戚瑞生; 马瑞萍

    2012-01-01

    To explore the effective way to improve soil phosphorus availability, indoor incubation experiments were conducted. So, the effect of low molecular weight(LMW) organic acids on organic phosphorus fraction and its availability in calcareous soil was investigated. The results showed that the LMW organic acids could significantly stimulate the soil available phosphorus. For calcareous soil, the ability of oxalic acid in mobili- zing soil available phosphorus was higher than that of malic or citric acid~ citric and malic acid could signifi- cantly restrained soil available phosphorus activity in calcareous soil. The content of soil available phosphorus decreased with the lengthened of the incubation time. Moreover, with the increase of oxalic acid concentra- tion, or the decrease of citric and malic acid concentrations, the content of soil available phosphorus increased. After disposed by LMW organic acids, the contents of liable organic phosphorus(L-OP), moderate liable organic phosphorus(ML-OP), and moderate stable organic phosphorus(MS-OP) increased, while the content of high stable organic phosphorus(HS-OP) decreased in calcareous soil. As a conclusion, LMW organic acids can improve the soil phosphorus availability by affecting the organic phosphorus fractions.%为探索提高土壤磷素有效性的途径,采用室内培养的方法,研究不同有机酸对土壤速效磷含量及有机磷组分的影响。结果表明,添加有机酸后土壤速效磷含量发生显著变化,其中草酸处理下土壤速效磷含量显著高于其他处理,而柠檬酸和苹果酸对土壤速效磷含量具有抑制作用,其活化量为负值;随着培养时间的延长,速效磷含量缓慢降低。速效磷含量随着草酸浓度的升高而升高,随着苹果酸、柠檬酸浓度的升高而降低;有机酸处理后,土壤活性、中活性、中稳性有机磷升高,高稳性有机磷降低,这说明有机酸能促进土壤有机磷由有效性低的

  12. Calcareous tubeworms of the Phanerozoic

    Directory of Open Access Journals (Sweden)

    Vinn, Olev

    2009-12-01

    Full Text Available Morphological similarities indicate that Palaeozoic problematic tubeworms, e.g. tentaculitids, cornulitids, microconchids, trypanoporids, Anticalyptraea, and Tymbochoos, form a monophyletic group. This group may also include hederelloids. Members of this group share affinities with lophophorates and their evolution could have partly been driven by predation. The extinction of Palaeozoic tubeworms in the Middle Jurassic was possibly at least partly caused by the ecological pressure by serpulid and sabellid polychaetes. The input of Palaeozoic tubeworms to the general ocean biocalcification system may have been smaller in the Ordovician to Jurassic than that of calcareous polychaetes in the Late Triassic to Recent. There seems to have been some correlation between the aragonite–calcite seas and the skeletal mineralogy of Triassic–Recent polychaete tubeworms.

  13. 玉米秸秆还田对石灰性土壤Zn形态及其有效性的影响%Effects of returning maize straw into field on the Zn forms and their availability in a calcareous soil

    Institute of Scientific and Technical Information of China (English)

    崔娟; 田霄鸿; 陆欣春; 任思潮; 代二战

    2011-01-01

    Maize straws were put into nylon mash bags and buried in a calcareous soil to study the effects of returning maize straw into field on the calcareous soil Zn forms and their availability. Compared with Zn fertilization, returning maize straw into field had little contribution to the soil total Zn content. Both Zn fertilization and straw returning increased the soil DTPA-Zn content significantly , and the increment was larger under Zn fertilization. As compared to that in low Zn concentration straw, the Zn released from high Zn concentration straw after returned into soil was more easily transformed into soil DTPA-Zn, with the transformation rate reached 49.0%. The transformation rate of soil DTPA-Zn had a trend of decreasing first and increasing then after straw returned into soil, but had little change under Zn fertilization. The soil exchangeable Zn (Ex-Zn) , carbonate bound Zn ( Carb-Zn ) , manganese oxide bound Zn ( OxMn-Zn) , tightly organic bound Zn ( SboZn) , and mineral Zn (Min-Zn) contents had no significant differences among the treatments, but the soil weakly organic bound Zn ( Wbo-Zn) content was significantly higher under Zn fertilization, compared with the treatments control and straw addition alone. It was considered that the Zn in maize straw could be easily transformed into soil DTPA-Zn, though the Zn concentration in straw was rather low. Therefore, Zn fertilization combined with returning maize straw into filed could be an effective way to improve the Zn supply capacity of calcareous soil.%采用尼龙网袋田间填埋的方法,研究了玉米秸秆还田对石灰性土壤Zn形态及其生物有效性的影响.结果表明:与施用Zn肥相比,秸秆还田对提高土壤全Zn含量贡献较小;施Zn肥和添加秸秆处理均显著增加土壤有效Zn( DTPA -Zn)含量,且施Zn肥处理增加的幅度更大;高锌秸秆还田后释放的Zn更易转化为土壤DTPA -Zn,转化率达49.0%,秸秆还田后土壤DTPA-Zn转化率呈先减小后

  14. Activity and diversity of methane-oxidizing bacteria in glacier forefields on siliceous and calcareous bedrock

    Directory of Open Access Journals (Sweden)

    P. A. Nauer

    2012-06-01

    Full Text Available The global methane (CH4 cycle is largely driven by methanogenic archaea and methane-oxidizing bacteria (MOB, but little is known about their activity and diversity in pioneer ecosystems. We conducted a field survey in forefields of 13 receding Swiss glaciers on both siliceous and calcareous bedrock to investigate and quantify CH4 turnover based on soil-gas CH4 concentration profiles, and to characterize the MOB community by sequencing and terminal restriction fragment length polymorphism (T-RFLP analysis of pmoA. Methane turnover was fundamentally different in the two bedrock categories. Of the 36 CH4 concentration profiles from siliceous locations, 11 showed atmospheric CH4 consumption at concentrations of ~1–2 μL L−1 with soil-atmosphere CH4 fluxes of –0.14 to –1.1 mg m−2 d−1. Another 11 profiles showed no apparent activity, while the remaining 14 exhibited slightly increased CH4 concentrations of ~2–10 μL L−1 , most likely due to microsite methanogenesis. In contrast, all profiles from calcareous sites suggested a substantial, yet unknown CH4 source below our sampling zone, with soil-gas CH4 concentrations reaching up to 1400 μL L−1. Remarkably, most soils oxidized ~90 % of the deep-soil CH4, resulting in soil-atmosphere fluxes of 0.12 to 31 mg m−2 d−1. MOB showed limited diversity in both siliceous and calcareous forefields: all identified pmoA sequences formed only 5 operational taxonomic units (OTUs at the species level and, with one exception, could be assigned to either Methylocystis or the as-yet-uncultivated Upland Soil Cluster γ (USCγ. The latter dominated T-RFLP patterns of all siliceous and most calcareous samples, while Methylocystis dominated in 4 calcareous samples. Members of Upland Soil

  15. Activity and diversity of methane-oxidizing bacteria in glacier forefields on siliceous and calcareous bedrock

    Directory of Open Access Journals (Sweden)

    P. A. Nauer

    2012-01-01

    Full Text Available The global methane (CH4 cycle is largely driven by methanogenic archaea and methane-oxidizing bacteria (MOB, but little is known about their activity and diversity in pioneer ecosystems. We conducted a field survey in forefields of 13 receding Swiss glaciers on both siliceous and calcareous bedrock to investigate and quantify CH4 turnover based on soil-gas CH4 concentration profiles, and to characterize MOB communities using pmoA sequencing and T-RFLP. Methane turnover was fundamentally different in the two bedrock categories. Of the 36 CH4 concentration profiles from siliceous locations, 11 showed atmospheric CH4 consumption at concentrations of ∼1–2 μl l−1 with soil-atmosphere CH4 fluxes of −0.14 to −1.1 mg m−2 d−1. Another 11 profiles showed no apparent activity, while the remaining 14 exhibited slightly increased CH4 concentrations of ∼2–10 μl l−1, most likely due to microsite methanogenesis. In contrast, all profiles from calcareous sites suggested a substantial, yet unknown CH4 source below our sampling zone, with soil-gas CH4 concentrations reaching up to 1400 μl l−1. Remarkably, most soils oxidized ∼90% of the deep-soil CH4, resulting in soil-atmosphere fluxes of 0.12 to 31 mg m−2 d−1. MOB showed limited diversity in both siliceous and calcareous forefields: all identified pmoA sequences formed only 5 OTUs and, with one exception, could be assigned to either Methylocystis or the as-yet-uncultivated Upland Soil Cluster γ (USCγ. The latter dominated T-RFLP patterns of all siliceous and most calcareous samples, while Methylocystis dominated in 4 calcareous samples. As Type I MOB are widespread in cold climate habitats with elevated CH4 concentrations, USCγ might be the corresponding

  16. Patellar calcar: MRI appearance of a previously undescribed anatomical entity

    International Nuclear Information System (INIS)

    The femoral calcar is a constant anatomical structure within the proximal femur representing a condensation of bone trabeculae. It is our impression that a similar structure is present within the patella. The purpose of this retrospective study was to define the prevalence, appearance, location, and configuration of the patellar calcar on MRI examinations. One hundred consecutive unenhanced knee MRIs were retrospectively reviewed by two readers who were blinded to the clinical indication. The patellar calcar was defined as a dark signaling, linear or curvilinear structure subjacent to the patellar articular surface. If present, the patellar calcar was assigned to a ''well seen,'' ''moderately well seen,'' or ''faintly seen'' category. Location of the calcar within the patella, orientation, configuration, and thickness were recorded. Confounding variables, such as marrow edema, patellar chondromalacia, bipartite patella, or postoperative changes were also recorded. The patellar calcar was visualized in 81 out of 100 (81 %) MRIs. When detected, the calcar was well seen in 20 out of 81 (25 %), moderately well seen in 35 out of 81 (43 %), and faintly seen in 26 out of 81 (32 %). The anteroposterior width of the calcar measured at its thickest segment was: 1 mm in 10 out of 81 (12 %). The patellar calcar was seen in the majority of knee MRIs and had a consistent imaging appearance. The calcar may be obscured by degenerative arthrosis of the patella and rarely may mimic patellar stress fracture or osteochondritis dissecans. Radiologists and clinicians should be familiar with this normal anatomical structure. (orig.)

  17. Kaolinite influence on calcareous deposit formation

    International Nuclear Information System (INIS)

    This study investigate the influence of kaolinite, introduced in electrolytes solutions, on the calcareous deposit formation, which is monitored by chronoamperometric measurements coupled with chemical impedance spectroscopy analyses. The deposits formed are observed by scanning electron microscopy and analysed by Raman spectroscopy and X-ray diffraction analyses. In presence of Mg2+ ions, kaolinite delay the deposit formation, preventing the reduction of energy required for an efficient cathodic protection. Whereas no influence of this clay was noticed on the CaCO3 deposit when the electrolyte was totally exempt of Mg2+.

  18. Patellar calcar: MRI appearance of a previously undescribed anatomical entity

    Energy Technology Data Exchange (ETDEWEB)

    Collins, Mark S.; Tiegs-Heiden, Christin A. [Department of Radiology, Mayo Clinic, Rochester, Minnesota (United States); Stuart, Michael J. [Department of Orthopedic Surgery, Mayo Clinic, Rochester, Minnesota (United States)

    2014-02-15

    The femoral calcar is a constant anatomical structure within the proximal femur representing a condensation of bone trabeculae. It is our impression that a similar structure is present within the patella. The purpose of this retrospective study was to define the prevalence, appearance, location, and configuration of the patellar calcar on MRI examinations. One hundred consecutive unenhanced knee MRIs were retrospectively reviewed by two readers who were blinded to the clinical indication. The patellar calcar was defined as a dark signaling, linear or curvilinear structure subjacent to the patellar articular surface. If present, the patellar calcar was assigned to a ''well seen,'' ''moderately well seen,'' or ''faintly seen'' category. Location of the calcar within the patella, orientation, configuration, and thickness were recorded. Confounding variables, such as marrow edema, patellar chondromalacia, bipartite patella, or postoperative changes were also recorded. The patellar calcar was visualized in 81 out of 100 (81 %) MRIs. When detected, the calcar was well seen in 20 out of 81 (25 %), moderately well seen in 35 out of 81 (43 %), and faintly seen in 26 out of 81 (32 %). The anteroposterior width of the calcar measured at its thickest segment was: < 1 mm in 43 out of 81 (53 %), 1 mm in 28 out of 81 (35 %), and >1 mm in 10 out of 81 (12 %). The patellar calcar was seen in the majority of knee MRIs and had a consistent imaging appearance. The calcar may be obscured by degenerative arthrosis of the patella and rarely may mimic patellar stress fracture or osteochondritis dissecans. Radiologists and clinicians should be familiar with this normal anatomical structure. (orig.)

  19. Transformation of Applied Phosphorus in a Calcareous Fluvisol

    Institute of Scientific and Technical Information of China (English)

    TUSHU-XIN; GUOZHI-FEN; 等

    1993-01-01

    A new inorganic phosphorus(IP) fractionation scheme developed by Jiang and Gu wasused in an incubation experiment to investigate the transformation of applied P in a calcareous fluvisol.The results show that after addition of common superphosphate (CSP),the Ca2-P in the soil decreased gradually and transformed largely to the less available Fe-P,Al-P and Ca8-P,rather than to the unavailable forms of Ca10-P and O-P.The different IP fractions ranked in the following order with respect to the increment by addition of CSP after 120 days of incubation:Fe-P>Al-P>Ca8-P>Ca2-P.After addition of pig manure,the content of Ca2-P in the soil increased rapidly at first and then decreased slowly,and the amount of different IP fractions accumulated after 120 days of incubation ranked in the following order:Ca2-P>Fe-P>Ca8-P>Al-P.Evidently,the variation in content of Ca2-P and the order of increase in different IP fractions in incubation induced by application of pig manure were quite different from that of CSP.The increase in IP fractions in the incubation of broad bean green manure (BBGM) for 120 days was in the rank of Fe-P>Ca2-P>Ca8-P;but because organic phosphorus(OP)of BBGM degraded relatively slowly,the increment in IP fractions was lower than that of pig manure.Wheat straw was difficult to mineralize and induced a strong biological fixation of soil P,resulting in a decrease of the content of Ca2-P,even Ca8-P,Fe-P and Al-P.

  20. Aggregate composition and stability of structural aggregates of non-calcareous rendzinas in Eastern Serbia

    Directory of Open Access Journals (Sweden)

    Gajić Boško

    2006-01-01

    Full Text Available The present study includes the results of comparative investigations of aggregate composition and water stability of structural aggregates in humus horizons of non-calcareous rendzina under native forest and pasture vegetations and the same rendzina utilized long-term as arable field. The results show that aggregate composition and water stability of structural aggregates in the cultivated non-calcareous rendzina are significantly impaired due to a long-term anthropogenization. In the cultivated rendzinas the content of agronomically most valuable aggregates (0.25-10 mm significantly decreased, while the percentage of cloddy aggregates (>10 mm was increased about 1.5 to 3.5 times in comparison with the rendzina under pasture and forest vegetations. The structure coefficient of cultivated soils was lower (2.61 than in forest (4.63 and pasture (10.47 rendzinas. The cultivated non-calcareous rendzina had lower (59.12% aggregate water stability than rendzina under pasture (82.66% and forest (91.92%. Mean weight diameters of water stable agregates was higher in forest (1.44 mm and pasture (1.20 mm than in cultivated (0.65 mm rendzina.

  1. Preliminary Investigation of Intercropping of Wheat with Cd Hyperaccumulator Sedum plumbizincicola on Calcareous, Lead Smelting Contaminated Soil%铅冶炼污染石灰性土壤上冬小麦间作伴矿景天的探讨

    Institute of Scientific and Technical Information of China (English)

    卢一富; 李真理; 阮心玲; 李会勇; 张红毅; 田会阳; 李立平

    2015-01-01

    The effect of intercropping wheat(Triticum aestivum)with Cd hyperaccumulator Sedum plumbizincicola was investigated in a field experiment on calcareous, lead smelting contaminated soils in Henan Province. Wheat varieties Bainong Aikang 58 and Zhengmai 7698 were either monocultured or intercropped with Sedum plumbizincicola in alternating rows. Intercropping resulted in non-significant lower or similar extractability of soil As, Cd and Pb compared to the monocultured soil. No significant difference was found in grain concen-trations of As, Cd and Pb between intercropped and monocultured wheat(P>0.05), grain Cd concentrations of all treatments exceeded the maximum permissible concentration set by national standard GB 2762—2012. Wheat variety had no influence on the Cd concentration of the hyperaccumulator, and mean shoot concentration of Cd was 23.4 mg·kg-1. Shoot accumulation of Cd of Sedum plumbizincicola was 2.12 g·hm-2. Availability of nitrogen(N)and phosphorus(P)in intercropped soil were 2.87%~42.0%higher than the monocultured soil, while the grain yields of the intercropped wheat were 0.578%~5.57%lower than the monocultured wheat. The results suggest that intercropping with alternating rows of wheat and Cd hyperaccumulator is not effective in reducing As, Cd and Pb concentrations in wheat grain, and the phytoextraction of Cd from the soil by the Sedum plumbizincicola is negligible.%通过田间试验探讨了在河南省某铅冶炼污染石灰性土壤上冬小麦与镉超积累植物伴矿景天(Sedum plumbizincicola)间作的可行性。研究采用百农矮抗58和郑麦7698两个小麦品种,设置小麦单作和小麦与伴矿景天间作两种种植方式。结果表明,与单作相比,间作后土壤砷、镉和铅有效性均略有下降或持平。小麦与伴矿景天间作后,籽粒砷、镉和铅含量未出现显著差异(P>0.05),试验条件下小麦籽粒镉含量超过国家标准GB 2762—2012限值。间作伴矿景天

  2. Environmental and climatic aspects of the early to mid Holocene calcareous tufa and land mollusc fauna in southern Sweden

    OpenAIRE

    Gedda, Björn

    2001-01-01

    Although deposition of freshwater calcium carbonates, tufa, has occurred in large areas with carbonate soil or bedrock in Sweden, no tufa formation has been observed in Sweden. To better understand the factors controlling tufa formation in southern Sweden, bio- and lithostratigraphical studies were carried out on (paludal) calcareous tufa deposits in the province of Skåne. The biostratigraphical methods include mollusc, pollen, plant macrofossil and insect analysis. These were supplemented by...

  3. Effects of acid atmospheric deposition on the chemical composition of loess, clay and peat soils under forest in the Netherlands

    OpenAIRE

    Klap, J.M.; Vries, de, H.J.C.; Leeters, E.E.J.M.

    1999-01-01

    In addition to a survey of the soils under 150 forest stands on non-calcareous sandy soils, the chemical composition of the soils under 40 stands on non-calcareous loess soil, 30 stands on non-calcareous clay soils and 30 stands on oligotrophous peat soils have been examined, to assess the current status with repect to acidification and eutrophication, and the provide data for further studies. Only the clay soils are not yet seriously affected by the atmospheric inputs. The loess soils are ge...

  4. Changes in nutrient availability from calcareous to acid wetland habitats with closely related brown moss species: Increase instead of decrease in N and P

    NARCIS (Netherlands)

    A. Kooijman; L. Hedenäs

    2009-01-01

    To test whether shifts in nutrient availability from calcareous to mineral-poor habitats could be a driving force in the evolution of seven closely related wetland brown mosses, we measured soil and vascular plant nutrients and conducted a laboratory incubation experiment with Swedish and some Dutch

  5. Speciation And Distribution Of Phosphorus In A Fertilized Soil: A Synchrotron-Based Investigation

    Science.gov (United States)

    Phosphorus availability is often a limiting factor for crop production around the world. The efficiency of P fertilizers in calcareous soils is limited by reactions that decrease P availability; however, fluid fertilizers have recently been shown, in highly calcareous soils of s...

  6. Production of Calcareous Nannofossil Ooze for Sedimentological Experiments

    DEFF Research Database (Denmark)

    Buls, Toms; Anderskouv, Kresten; Fabricius, Ida Lykke;

    2015-01-01

    subject. However, the use of modern calcareous nannofossil ooze as an analogue for Cretaceous ooze is associated with a number of disadvantages such as generally higher noncarbonate content and smaller coccolith size of modern oozes. Here, we document a preparation method for the production of calcareous......, laser diffraction granulometry, and smear slides. The Upper Cretaceous chalk chosen for disaggregation is highly friable due to delicate contact cement and has a low noncarbonate content (<2 wt %), a high porosity, friability, and good nannofossil and microfossil preservation. These characteristics...... validating the use of the freeze-thaw method for production of experimental ooze to model the basic depositional behavior of Cretaceous chalk....

  7. Assessment of calcareous alga Corallina pilulifera as elemental provider

    International Nuclear Information System (INIS)

    Calcareous algae such as Corallina pilulifera Postels et Ruprecht can be one of the most potential candidates to be used in biological carbon dioxide assimilation to reduce greenhouse effect because of its calcification capacity as well as photosynthesis if utilized extensively and properly. The major elemental composition of C. pilulifera is as follows: sodium 0.13%, chloride 1.75%, magnesium 4.37%, calcium 18.4%, iron 0.31%, and carbonate 28.5%. Calcareous algae can be used as elemental provider for livestock or agriculture. (author)

  8. Effect of Microbial and Chemical,Organic Fertilizer on Different Nitrogen in Calcareous Cinnamon Soil%菌肥与有机无机肥配施对石灰性土壤不同形态氮素的影响

    Institute of Scientific and Technical Information of China (English)

    梁利宝; 李维宏; 许剑敏

    2012-01-01

    The experiment was conducted to investigate the influence of different application fertilizers on different nitrogen and correlation of them in the calcareous cinnamon soil,in Jinzhong,Shanxi province.The results shows: When adding the same content of N and P2O5 in each treatment of application,NH+4-N,NO-3-N and SMB-N increased gradually,the effect of chemical+organic+microbial was obvious for NH+4-N,organic fertilizer separately application was the best for NO-3-N,the difference was not significant with the chemical+organic and chemical+organic+microbial;the effect of chemical+organic+microbial was remarkable,and there were the significant difference with the chemical+organic;there was a significant positive correlation between NO-3-N and NH+4-N,and there was not the correlation between SMB-N and NO-3-N,NH+4-N.Increasing the content of SMB-N was the best(10.09%) by microbial fertilizer,NH+4-N was the second(6.24%),NO-3-N was the least(2.05%),though microbial fertilizer was added,and the fact that chemical+organic+microbial was chemical+organic treatment still was not changed entirely.%利用不同施肥处理对山西省晋中市石灰性土壤几种不同形态氮素含量的变化及其相关性进行研究。结果表明:每个施肥处理施入等量的氮(N)、磷(P2O5),土壤的铵态氮、硝态氮及微生物氮含量都在逐年增加,其中有机肥+化肥+菌肥处理对提高土壤铵态氮作用明显;单施有机肥处理对提高土壤硝态氮效果显著,与有机肥+化肥+菌肥、有机肥+化肥处理效果差异性不显著;有机肥+化肥+菌肥处理对土壤微生物氮效果最明显,有机肥+化肥效果次之,两处理差异显著。土壤铵态氮和硝态氮含量呈显著正相关;微生物氮与铵态氮、硝态氮含量相关性都不好;菌肥与有机无机肥配施后,菌肥对于提高土壤微生物氮最显著(10.09%),铵态氮次之(6.24%

  9. Interaction of NPK Fertilizers During Their Transformation in Soils:I.Dynamic Changes of Soil pH

    Institute of Scientific and Technical Information of China (English)

    WANG HUOYAN; ZHOU JIANMIN; CHEN XIAOQIN; LI SHOUTIAN; DU CHANGWEN; DONG CAIXIA

    2003-01-01

    Dynamic changes of soil pH as influenced by ammonium sulfate (AS), monocalcium phosphate (MCP),potassium chloride (KCl) and their interaction in soils were evaluated in incubation experiments. Applyingthese fertilizers significantly reduced soil pH values in all cases and followed sequences of AS > MCP >KCl, MCP > KCl > AS and KCl > AS > MCP for the paddy, calcareous and red soils, respectively. TheAS-induced reduction of pH in the three soils followed the sequence of red soil > paddy soilcalcareous soil,while in MCP and KCl systems the reduction of pH followed the sequences of calcareous soil > paddy soil >red soil and red soilcalcareous soil > paddy soil, respectively. The interactions of the NPK fertilizers on pHwere significant. MCP plus KCl or MCP plus AS reduced pH values more than the fertilizers applied solelyin the paddy soil, but AS partly counteracted the effect of MCP on pH in the 1 d sample of the calcareoussoil. The effect of MCP on pH was trivial when MCP was applied in combination with KCl or AS in the redsoil. When applied in combination with AS, KCl did not affect soil pH initially, but suppressed the reductionof pH at the later incubation stage, which was related to inhibition of nitrification by KCl in the soils.

  10. Estimate of erosion risk on soils in the Vinodol Valley

    OpenAIRE

    Ivica Kisić; Ferdo Bašić; Milan Mesić; Anđelko Butorac

    2000-01-01

    Potential natural soil erosion by water was investigated on six soil units occurring in the studied area of the Vinodol valley. According to the overall depth to the parent rock, soils were classified into three groups: medium deep (1,2 m - Fluvisol, calcareous, gleyic; Gleys, hypogleyic and Gleys, amphigleyic). Tolerant soil...

  11. Evaluating of Efficiency of Three Halophyte Plants for Reduction of Soil Exchangeable Sodium (ESP) and Cadmium (Cd) and Lead (Pb) Contamination

    OpenAIRE

    R. Hamzenejad Taghlidabad; H. Khodaverdiloo; S Rezapour; SH. Manafi

    2012-01-01

    Soil contamination with heavy metals, including Cd and Pb, is of serious concern. The aim of this study was to investigate the efficiency of Atriplex verucifera, Salicornia europaea and Chenopodium album for simultaneous remediation of soil exchangeable sodium percentage and Cd and Pb contamination in two soils with different properties. Two soils, including a saline-sodic-calcareous (S1) and calcareous (S2) soil, were selected. Different concentrations of Pb and Cd were then added to the soi...

  12. Calcar Preservation Arthroplasty for Unstable Intertrochanteric Femoral Fractures in Elderly

    OpenAIRE

    Celiktas, Mustafa; Togrul, Emre; Kose, Ozkan

    2015-01-01

    Background The treatment of unstable intertrochanteric fractures in elderly is still controversial. The purpose of this study is to present treatment strategies for unstable intertrochanteric fractures with hemiarthroplasty using standard uncemented collared femoral stems and at the same time preserving the fractured calcar fragment. Methods Fifty-four patients aged 75 years or older with unstable intertrochanteric fractures were included in this prospective cohort study. All patients were tr...

  13. Calcar Preservation Arthroplasty for Unstable Intertrochanteric Femoral Fractures in Elderly

    Science.gov (United States)

    Togrul, Emre; Kose, Ozkan

    2015-01-01

    Background The treatment of unstable intertrochanteric fractures in elderly is still controversial. The purpose of this study is to present treatment strategies for unstable intertrochanteric fractures with hemiarthroplasty using standard uncemented collared femoral stems and at the same time preserving the fractured calcar fragment. Methods Fifty-four patients aged 75 years or older with unstable intertrochanteric fractures were included in this prospective cohort study. All patients were treated with calcar preserving hemiarthroplasty using cementless collored femoral stems. Fractured calcar fragment was stabilized either by compaction between the implant and femur or fixed with cable grip system. Follow-up evaluations were performed at least 24 months and later. Palmer and Parker mobility score and visual analogue scale (VAS) pain score were assessed. We also analyzed radiographs of the operated hip at each follow-up visit. Results The patients were 15 males and 39 females with a mean age of 81.3 years (range, 75 to 93 years). The average operative time was 86.6 minutes. The mean transfused blood units were 1.2 units. The average duration of hospital stay was 5.3 days. The preoperative mean mobility score was 6.20. This score was found to be 4.96 on postoperative third day and 5.90 at 24 months postoperatively. The results of the statistical analysis revealed significant increase in the mobility scores at each follow-up after three days. Radiological interpretation revealed no loosening in the cable-grip systems, and no significant subsidence (> 5 mm) of prosthesis was observed. Conclusions Calcar preservation arthroplasty is a good option for elderly patients with severe osteoporosis, frail constitution and the patients who are at higher risk for second operation due to unstable intertrochanteric fractures. PMID:26640625

  14. Fibrous Calcareous Concretions in the Capsules of Human Pineal Glands

    OpenAIRE

    Kodaka Tetsuo; Mori Ryoichi; Ezure Hiromitsu; Ito Junji; Otsuka Naruhito

    2013-01-01

    We examined calcareous concretions in the capsule of 15 human pineal glands containing a large amount of the concretions in the matrix. The capsule concretions, brown to blackish-brown in color and/or translucent, were smaller than the matrix concretions, which were yellowish-white. The matrix concretions showed the typical mulberry-shaped overall appearance with scallop-shaped concentric laminations of non-fibrous structures, but the capsule concretions, which also contained Ca and P, showed...

  15. Malacofauna of Holocene freshwater calcareous deposits of Lithuania

    Science.gov (United States)

    Sanko, Aleksander; Vainorius, Julius; Melešytė, Monika

    2010-12-01

    The malacofauna of freshwater calcareous deposits of Lithuania was studied. Sections of the Mūšos Tyrelis and Pabaliai peatbogs near the town of Šiauliai, as well as Dubičiai section (three sites) in SE Lithuania and Dūkštos in Central Lithuania were investigated. Freshwater calcareous deposits are attributed to three groups of facies - lacustrine, valley-hollow-peatbog and terrestrial. Each group of facies consists of sub-facies (freshwater lime, "gazha" (limno-calcite), peat-tufa, calcareous tufa, "mada") varying the formation conditions, composition and other characteristics. The mollusc fauna in the lacustrine facies group (Mūšos Tyrelis and Pabaliai sections) is represented by lacustrine species containing euryecological freshwater molluscs. Terrestrial and rheophilous species are rare or absent in the lacustrine group. Deposits of valley-hollow-peatbog facies contain shells of euryecological freshwater and lacustrine molluscs together with rheophyl shells, sometimes with abundant terrestrial shells, as was observed in the Dubičiai-4 section. A characteristic feature of the terrestrial facies group deposits is the occurrence of solely terrestrial mollusc shells (Dūkštos section).

  16. TL studies of calcareous rocks of Danta area, North Gujarat

    International Nuclear Information System (INIS)

    The lithounits exposed around Danta in Banaskantha district of North Gujarat belong to Ajabgarh Group, the upper division of the Delhi super group. These rocks are intruded by syn to late kinematic basic rocks and by Erinpura granites of post Delhi age. The Ajabgarh group consists of pelitic and calcareous components. Mineralogically the pelitic rocks comprise cordierite, almandine garnet, k-feldspar, sillimanite, quartz and mica in variable proportions. The calcareous rocks are seen to contain dominantly calcite, scapolite, forsterite, sphene, k-feldspar. These mineral assemblages correspond to upper Amphibolite to lower Granulite facies of regional metamorphism. The chemistry of the calcareous rocks show predominance of CaO over MgO. The glow curves obtained from virgin samples (NTL) as well as artificial beta irradiated indicate glow peaks at 140oC, 290oC, 310oC and 390oC. The TL glow peak temperatures are in general agreement with those reported by Borsi and Rinaldi and Medlin. The pronounced peak at 390oC and 290oC are suggestive of their high irradiation sensitivity and also probably reflect variation in the Mn content of the rocks. (author). 9 refs., 16 tabs., 2 figs

  17. Fertility Status of Bangladesh Soils -A Review

    OpenAIRE

    Moslehuddin, Abu Zofar Md.; Salma, Laizoo; Egashira, Kazuhiko

    1997-01-01

    Fertility status of Bangladesh soils was critically evaluated by reviewing the studies which have been carried out in universities and research institutes of Bangladesh. Almost all upland soils are low in organic matter and deficient in N. Availability of P to the crops is a problem mainly in calcareous soils of Ganges floodplain and acidic soils of terrace and hill areas. Status of K is not a great problem in floodplain areas, but terrace and Piedmont soils are not capable of supplying enoug...

  18. A first paleomagnetic and rock magnetic investigation of calcareous nodules from the Chinese Loess Plateau

    Science.gov (United States)

    Yang, T.; Hyodo, M.; Yang, Z.; Sun, Z.

    2005-01-01

    A detailed paleomagnetic and rock magnetic investigation was carried out on calcareous nodule layers embed-ded in the loess-paleosol sequences near Baoji city, southern Chinese Loess Plateau. The anisotropy of low-field magnetic susceptibility confirms that calcareous nodules retain the primary sedimentary fabric of original de-posits. Rock magnetic properties demonstrate that calcareous nodules have the same mineralogy and grain sizes as loess-paleosol deposits. Characteristic remanent magnetizations of calcareous nodules have directions consis-tent with those of adjacent loess and paleosol deposits. The Punaruu event, previously found from loess deposits in the upper part of loess unit L13 in Weinan, southern Chinese Loess Plateau, is observed at the corresponding stratigraphic level in the calcareous nodule layer. These observations indicate that the calcareous nodule layers preserve primary remanent magnetizations of original deposits before calcification, and that they can contribute to paleomagnetic studies in the Chinese Loess Plateau.

  19. Changes in ph, ec and concentration of phosphorus in soil solution during submergence and rice growth period in some paddy soils of north of Iran

    OpenAIRE

    Nosratollah NAJAFI; Towfighi, Hassan

    2008-01-01

    Changes in pH, EC and concentration of phosphorus in soil solution during submergence and rice growth period were studied in three paddy soils of North of Iran (one acid and two alkaline-calcareous soils). Also, changes in pH, EC and concentration of phosphorus in soil solution of an alkaline-calcareous soil after addition of 40 mg P/ kg of soil during submergence and rice growth period were studied. The experiment was performed in a set of specially fabricated pots equipped with ...

  20. Effects of naturally acidified seawater on seagrass calcareous epibionts

    OpenAIRE

    Martin, Sophie; Rodolfo-Metalpa, Riccardo; Ransome, Emma; Rowley, Sonia; Buia, Maria-Christina; Gattuso, Jean-Pierre; Hall-Spencer, Jason

    2008-01-01

    Surface ocean pH is likely to decrease by up to 0.4 units by 2100 due to the uptake of anthropogenic CO2 from the atmosphere. Short-term experiments have revealed that this degree of seawater acidification can alter calcification rates in certain planktonic and benthic organisms, although the effects recorded may be shock responses and the long-term ecological effects are unknown. Here, we show the response of calcareous seagrass epibionts to elevated CO2 partial pressure in aquaria and at a ...

  1. Red and lateritic soils : world scenario

    OpenAIRE

    Volkoff, Boris

    1998-01-01

    Calcareous, neutral and acid red soils, red lateritic soils, latosols and lateritic soils sensu lato are defined on the basis of their mineralogical composition and profile development. Their geographical distribution is discussed. Their origin is interpreted, considering successively palaeoclimates and continental drifts, tectonic movements and land-form development since the Early Tertiary period and the soil transformation during the Quaternary period. Finally, it is shown that in the trop...

  2. Interrelationships between soil cover and plant cover depending on land use

    OpenAIRE

    Tiina Köster; Raimo Kõlli

    2013-01-01

    Interrelationships between soil cover and plant cover of normally developed (or postlithogenic) mineral soils are analysed on the basis of four sampling soil groups. The four-link pedo-ecological sequence of analysed soils, rendzinas → brown soils → pseudopodzolic soils → gley-podzols, forms a representative cross section in relation to the normal mineral soils of Estonia. All groups differ substantially from each other in terms of soil properties (calcareousness...

  3. Cylinders and Seances: Elise van Calcar and the Spirit of Froebel

    Science.gov (United States)

    Bakker, Nelleke

    2013-01-01

    This essay discusses the life and work of Elise van Calcar (1822-1904), a writer and maternal feminist who introduced Froebel's kindergarten in the Netherlands. Van Calcar also was the leader of a Christian branch of spiritualism. The focus is pointed at parallels between her reading of Froebel and of "messages" from spirits in the "other world"…

  4. Hippocampus minor, calcar avis, and the Huxley-Owen debate.

    Science.gov (United States)

    Owen, Christopher M; Howard, Allyson; Binder, Devin K

    2009-12-01

    On the bicentennial of Darwin's birth, we describe the origin of the calcar avis and summarize the debate around this structure, which played a central role in the evolution debate in the mid-19th century. We performed a comprehensive review of relevant neuroanatomic literature, bibliographic sources, and 19th century primary sources. Once known as the hippocampus minor, the structure now known as the calcar avis is an involution of the ventricular wall produced by the calcarine fissure. A heated debate raged between 2 prominent scientific theorists, Sir Richard Owen and Thomas Henry Huxley, over the presence of the hippocampus minor in apes versus humans. Owen put forward the lack of an identifiable hippocampus minor in humans as part of an attempt to debunk evolution. A bitter personal and academic rivalry ensued, as Huxley conducted his own dissections to refute Owen's claims. Huxley ultimately dismantled Owen's premises, securing the epithet "Darwin's bulldog" for his defense of the theory of evolution. Thus, this relatively obscure neuroanatomic landmark served as a pivotal point of contention in the most popularized and acrimonious evolutionary debate of the 19th century. PMID:19934969

  5. Computational Visual Stress Level Analysis of Calcareous Algae Exposed to Sedimentation.

    Science.gov (United States)

    Osterloff, Jonas; Nilssen, Ingunn; Eide, Ingvar; de Oliveira Figueiredo, Marcia Abreu; de Souza Tâmega, Frederico Tapajós; Nattkemper, Tim W

    2016-01-01

    This paper presents a machine learning based approach for analyses of photos collected from laboratory experiments conducted to assess the potential impact of water-based drill cuttings on deep-water rhodolith-forming calcareous algae. This pilot study uses imaging technology to quantify and monitor the stress levels of the calcareous algae Mesophyllum engelhartii (Foslie) Adey caused by various degrees of light exposure, flow intensity and amount of sediment. A machine learning based algorithm was applied to assess the temporal variation of the calcareous algae size (∼ mass) and color automatically. Measured size and color were correlated to the photosynthetic efficiency (maximum quantum yield of charge separation in photosystem II, [Formula: see text]) and degree of sediment coverage using multivariate regression. The multivariate regression showed correlations between time and calcareous algae sizes, as well as correlations between fluorescence and calcareous algae colors. PMID:27285611

  6. Soils

    International Nuclear Information System (INIS)

    For Austria there exists a comprehensive soil data collection, integrated in a GIS (geographical information system). The content values of pollutants (cadmium, mercury, lead, copper, mercury, radio-cesium) are given in geographical charts and in tables by regions and by type of soil (forests, agriculture, greenland, others) for the whole area of Austria. Erosion effects are studied for the Austrian region. Legal regulations and measures for an effective soil protection, reduction of soil degradation and sustainable development in Austria and the European Union are discussed. (a.n.)

  7. Process of phase formation in calcareous hydromica-containing clays

    International Nuclear Information System (INIS)

    Illite type hydromica-containing clays as raw materials of highly heat-insulating materials are investigated. Secondary crystalline phases of anorthite, gehlenite, hematite, mullite and diopside are formed in the process of high-temperature firing. In the clays with high content of dolomite akermanite, monticellite and calcium ferrite are formed in the thermal process. 1000-1-2- deg C is an optimal firing temperature for these heat-insulating materials. Finally we have obtained the following characteristics for the calcareous hydromica-containing firing ceramic body: density 1.30-1.20 g/cm3, bending strength 120-180 MPa, coefficient of thermal conductivity λ 0.19 W/m.K. (author)

  8. Lignite-Derived Humic Acid Effect on Growth of Wheat Plants in Different Soils

    Institute of Scientific and Technical Information of China (English)

    M.M.TAHIR; M.KHURSHID; M.Z.KHAN; M.K.ABBASI; M.H.KAZMI

    2011-01-01

    Humic acid (HA), a fairly stable product of decomposed organic matter that consequently accumulates in ecological systems,enhances plant growth by chelating unavailable nutrients and buffering pH.We examined the effect of HA derived from lignite on growth and macronutrient uptake of wheat (Triticum aestivum L.) grown in earthen pots under greenhouse conditions.The soils used in the pot experiment were a calcareous Haplustalf and a non-calcareous Haplustalf collected from Raisalpur and Guliana, respectively,in Punjab Province, Pakistan.The experiment consisted of four treatments with HA levels of 0 (control without HA), 30, 60, and 90 mg kg-1 soil designated as HA0, HA1, HA2, and HA3, respectively.In the treatment without HA (HA0), nitrogen (N), phosphorus (P), and potassium (K) were applied at 200, 100, and 125 mg kg-1 soil, respectively.Significant differences among HA levels were recorded for wheat growth (plant height and shoot weight) and N uptake.On an average of both soils, the largest increases in plant height and shoot fresh and dry weights were found with HA2 (60 mg kg-1 soil), being 10%, 25%, and 18%, respectively, as compared to the control without HA (HA0).Both soils responded positively towards HA application.The wheat growth and N uptake in the non-calcareous soil were higher than those of the calcareous soil The HA application significantly improved K concentration of the non-calcareous soil and P and NO3-N of the calcareous soil.The highest rate of HA (90 mg kg- 1 soil) had a negative effect on growth and nutrient uptake of wheat as well as nutrient accumulation in soil, whereas the medium dose of HA (60 mg kg-1 soil) was more efficient in promoting wheat growth.

  9. Late-Glacial and Holocene history of the Western Carpathian calcareous fens

    Czech Academy of Sciences Publication Activity Database

    Hájková, Petra; Horsák, M.; Hájek, Michal

    Zeist: KNNV Publishing, 2012 - (Grootjans, A.; Šefferová-Stanová, V.; Jansen, A.), s. 13-20 ISBN 9789050114417 Institutional support: RVO:67985939 Keywords : macrofossils * snails * relict species * calcareous fens Subject RIV: EF - Botanics

  10. Aggregate composition and stability of structural aggregates of non-calcareous rendzinas in Eastern Serbia

    OpenAIRE

    Gajić Boško; Živković Miodrag

    2006-01-01

    The present study includes the results of comparative investigations of aggregate composition and water stability of structural aggregates in humus horizons of non-calcareous rendzina under native forest and pasture vegetations and the same rendzina utilized long-term as arable field. The results show that aggregate composition and water stability of structural aggregates in the cultivated non-calcareous rendzina are significantly impaired due to a long-term anthropogenization. In the cultiva...

  11. Cementation processes of naturally aged Hawaiian calcarerous [i.e. calcareous] sands: a thesis …

    OpenAIRE

    McLemore, Thomas B.

    2002-01-01

    Researchers have studied cementation calcareous sands for decades. While cementation increases static and cyclic strengths, it also reduces skin friction on piles. Cementation sands in their own environment varies widely with many different factors. Obtaining undisturbed samples can be difficult and costly, and laboratory reproduction of samples has become an accepted method for testing calcareous materials. The focus of this research is on understanding the processes and effects of early cem...

  12. Impact of grazing on vegetation and on selected plant species of calcareous fens

    OpenAIRE

    Stammel, Barbara

    2005-01-01

    Calcareous fens are traditionally mown in autumn, which maintains species rich vegetation types (Caricion davallianae, Molinion caeruleae). Nowadays, abandonment due to changes in agriculture causes a decline of many characteristic plant species of fen meadows due to litter accumulation and dominance of few competitive species. The aim of this study is to evaluate grazing as an alternative management tool to mowing. The impact of grazing and mowing on the vegetation of calcareous fens in the ...

  13. Calcar femorale grafting in the hemiarthroplasty of the hip for unstable inter trochanteric fractures

    Directory of Open Access Journals (Sweden)

    Chandrashekar J Thakkar

    2015-01-01

    Full Text Available Background: The sliding screw-plate devices and cephalo-medullary nail devices have performed well in stable inter-trochanteric fractures in patients with reasonably good quality of bone. However, their suboptimal performance in comminuted fractures in the presence of osteoporotic bone has prompted many surgeons to consider bipolar hemiarthroplasty as the primary modality of management of comminuted inter-trochanteric fractures in elderly patients. However, long term stability of the hemiarthroplasty implant also may be compromised due to the presence of postero-medial bone loss at the area of the calcar. Materials and Methods: We have presented a simple and effective technique of calcar grafting by harvesting cortical bone strut from the neck of the fractured femur. A total of 34 patients with inter-trochanteric fractures of the femur were treated with calcar grafting. The mean age was 79.2 years. The graft was harvested from the calcar region of the head and neck fragment of the femur and wedged between the medial femoral cortex and medial edge of the prosthesis. The mean followup period was 54.5 months. Results: In 32 of 34 (94% patients in our series, the calcar graft healed well without dislodgement. There was graft resorption in two patients associated with subsidence of the implant and loosening. Conclusion: Calcar grafting using this technique provides stability to the implant in the presence of comminution and incorporates well in the majority of patients. Donor site morbidity of graft harvesting is also avoided.

  14. A comparison of corn residue and its biochar on soil C and plant growth

    Science.gov (United States)

    Biochar amendment can be beneficial to soils because it contains mostly recalcitrant forms of C, and biochar contributes base cations that can remedy nutrient deficiencies on acid soils. However, the benefits of biochars on neutral or calcareous soils needs to be assessed. In order to properly deter...

  15. Acidification of Forest Soil in Russia: 1893-Present

    OpenAIRE

    Lapenis, A. G.; Lawrence, G; Andreev, Andrei; A. A. Bobrov; M. S. Torn

    2004-01-01

    It is commonly believed that fine texture soils developed on carbonateparent material are well buffered from possible acidification. There areno data, however, documenting resistance of such soils to acidicdeposition exposure on a time scale longer than 30-40 years.In this paper we employed a rare opportunity of directly testinglong-term buffering capacity of 19th century forest soils developedon calcareous silt loam. A comparison of chemical analysis of archivedsoils with modern soils collec...

  16. Albian-Cenomanian Zonation (Foraminifers and Calcareous Aglae in the Northern Fars, Iran

    Directory of Open Access Journals (Sweden)

    Mahnaz P.N. Shirazi

    2009-01-01

    Full Text Available Problem statement: In the middle Cretaceous of Iran, fossil calcareous algae and zonation them with foraminifers are one of the less studied compared to others invertebrate groups such as foraminiferis, mollusks and others. Several stratigraphic units were analyzed in detail and a biostratigraphic zonation of the Albian-Cenomanian rocks of the Fars basin (Sw. Iran is proposed. Approach: All stratigraphic units were studied for the determination calcareous algae accompanying with foraminifers. Identification of planktonic, benthic foraminifers and calcareous algae was made from thin slides. After the identification of the microfossils assemblages, benthic, planktonic microfossil and calcareous algae biostratigraphy was recognized and a possible correlation with the other zonations was established. Results: The stratigraphic distribution of 21 genus of calcareous algae and benthic and planktonic foraminifers is used to characterize 4 ass. zone that in ascending order are: Or. aperta-Cuneolina ass. zone, Or. conica-Hemicyclammina ass. zone, Dicyclina-Orbitolina ass. zone and Alveolinids ass. zone. The top of Or. aperta-Cuneolina ass. zone is marked at the last appearance of the marker fossil. The Or. conica-Hemicyclammina ass. zone was defined with the last appearance of Or. conica and represented by an assemblage characterized by Cuneolina pavonia-Hemicyclammina sigali-Pseudochrysalidina sp. together with calcareous algae such as: Trinocladus tripolitanus-Permocalcus irenae. Overmost of the area, the transition from shallow-marine limestones up into pelagic facies occurs within the R. appenninica-Radiolaria ass. Zone. The Orbitolina-Dicyclina ass. zone is recognized in the Sarvak Formation and is represented by an assemblage characterized by Nezzazata simplex-Neoiraqia convexa-Hemicyclammina sigali together with Permocalculus irenea. Toward the central and western part of the area in shallow marine facies, this zone is changed to the Alveolinids

  17. Firing transformations of an argentinean calcareous commercial clay

    Directory of Open Access Journals (Sweden)

    M. F. Serra

    2013-06-01

    Full Text Available Mineralogical transformations caused by firing are usually studied by XRD methods only semi-quantitatively. In this work the original mineral disappearance and the neo-mineralization were evaluated quantitatively. Furthermore an indirect non crystalline phase quantification was performed under 1100 ºC was also carried out using the quartz content as internal standard. This study specifically discusses the behavior of an Argentinean white calcareous earthenware commercial when subjected to traditional ceramic firing, besides the technological importance of this particular material, it acts as a model for other clay based ceramic materials. Materials were subjected to thermal treatments between 700 ºC and 1100 ºC. A preliminary sintering characterization was carried out by contraction and porosity evolution. Simultaneous thermogravimetric and differential thermal analysis (TG-DTA was carried out to elucidate the actual temperature at which the chemical changes occur. Finally, a quantitative analysis based on the Rietveld refinement of the X-ray diffraction patterns was performed to characterize the crystalline phases present in both the clay and in the materials obtained after different thermal treatments. The actual chemical reactions are proposed. The phases identified after firing at traditional working temperature (1040 ºC are quartz, plagioclase, and the Spinel type alumino-silicate, accompanied by the non-diffracting un-reacted metakaolin and some amount of amorphous glassy phase. At intermediate temperatures (900 ºC the presence of gehlenite was also detected. The carbonates (calcite and dolomite presence and decomposition were also evaluated and demonstrated to determine the sintering characteristics of this material.

  18. Rock composition and origin of the Duwi Formation calcareous rocks, Upper Egypt

    Institute of Scientific and Technical Information of China (English)

    Baioumy H.M.; Attia A.M.; Boulis S.N.; Hassan M.S.; Helmy M.E.

    2005-01-01

    Upper Cretaceous phosphorite beds of the Duwi Formation, Upper Egypt, are intercalated with limestone, sandy limestone, marl, calcareous shales, and calcareous sandstone. Calcareous intercalations were subjected to field and detailed petrographic, mineralogical and geochemical investigations in order to constrain their rock composition and origin.Mineralogically, dolomite, calcite, quartz, francolite and feldspars are the non-clay minerals. Smectite, kaolinite and illite represent the clay minerals. Major and trace elements can be classified as the detrital and carbonate fractions based on their sources. The detrital fraction includes the elements that are derived from detrital sources, mainly clay minerals and quartz, such as Si, Al, Fe, Ti, K, Ba, V, Ni, Co, Cr, Zn, Cu, Zr, and Mo. The carbonate fraction includes the elements that are derived from carbonates, maily calcite and dolomite, such as Ca, Mg and Sr. Dolomite occurs as being dense, uniform, mosaic, very fine-to-fine, non-ferroan, and non-stoichiometrical suggesting its early diagenetic formation in a near-shore oxidizing shallow marine environment. The close association and positive correlation between dolomite and smectite indicates the role of clay minerals in the formation of dolomite as a source of Mg 2+-rich solutions.Calcareous rocks were deposited in marine, oxidizing and weakly alkaline conditions, marking a semi-arid climatic period. The calcareous/argillaceous alternations are due to oscillations in clay/carbonate ratio.

  19. Interaction of NPK Fertilizers During Their Transformation in Soils:III.Transformations of Monocalcium Phosphate

    Institute of Scientific and Technical Information of China (English)

    WANG Huo-Yan; ZHOU Jian-Min; CHEN Xiao-Qin; DU Chang-Wen

    2004-01-01

    Interactions of N, P and K fertilizers in soil-plant systems are widely recognized. This study focused on the transformations of monocalcium phosphate (Ca(H2PO4)2) (MCP) with co-application of ammonium and potassium fertilizers in three different soils. The results showed that after i d incubation a large portion of the MCP applied in the paddy,calcareous and red soils became the water-insoluble form and the recoveries of P applied as Olsen P varied greatly in these three soils. Application of ammonium sulfate ((NH4)2SO4) (AS) or potassium chloride (KC1) reduced WSP significantly in the soils with AS more effective than KC1 in the calcareous soil, while the reverse occurred in the red soil. Meanwhile, in the paddy soil, co-application of the two fertilizers reduced WSP more than when the fertilizers were applied individually. The co-application of AS with MCP in the paddy and calcareous soils significantly reduced Olsen P, but the opposite occurred in the red soil. The experiment on the effect of different accompanying anions showed that the ammonium fertilizers (PNC1 and PNS) reduced WSP more effectively than the corresponding potassium fertilizers (PKC1 and PKS) in the calcareous soil due to the difference of the cations, whereas in the red soil, the chlorides reduced WSP more effectively than the sulfates. Overall, co-application of ammonium or potassium fertilizers with MCP significantly decreased availability of P from MCP during its transformation in soils, especially when MCP was applied in combination with ammonium in the calcareous soil.

  20. Evaluation of Five Extraction Methods for Available Phosphorus in Intensively Fertilized Greenhouse Soils

    OpenAIRE

    Than, Aye Aye; Araki, Masato; Wada, Shin-ichiro

    2011-01-01

    Intensively fertilized lime receiving soils encased in greenhouses have complex nature. We collected 11 greenhouse soils and examined the chemical forms of inorganic phosphorus (P) by applying two kinds of sequential extraction methods. The results and the foregoing study on the same soils revealed that the method developed for calcareous soils is better suited for the greenhouse soils. Among the five availability testing methods including Truog method, Mehlich III method, Olsen method, water...

  1. Effect of Two Halophyte Plants Irrigated with Saline Water on Soil Salinization under Different Soil Type

    International Nuclear Information System (INIS)

    A lysimeter experiment was conducted to evaluate the impact of saline water irrigation at three levels namely, fresh water (0.3), 4 and 8 dS/m on salt accumulation and its effect on different soil types. The tested halophyte plants were Kallar grass and Atriplex (Salt bush). The tested soil types were sandy, calcareous and clayey soils. Irrigating the soil with saline water (either 4 or 8 dS/m) resulted in increasing salinity levels in soil profile with different orders of magnitude, depending on the soil type layer and the cultivated plant. Kallar grass seems limit the accumulation of salts in soil profile, compared to Atriplex at any tested soil. This may be attributed to its root effect on soil profile such as dispersed soil matrix and improved soil structure, which provide channels for solute movement through the profile under halophyte cultivation. Calculating the SAR average values for each irrigation treatment (18 values) showed significant increase in soil SAR values, especially under Kallar grass compared to Atriplex. The highest SAR values were observed in the case of clayey soil. However, the relevant SAR values under Atriplex cultivation were always lower. Values for SAR were always higher in the saline clayey > calcareous > sandy soils

  2. TRIASSIC AND JURASSIC CALCAREOUS NANNOFOSSILS OF THE PIZZO MONDELLO SECTION: A SEM STUDY

    Directory of Open Access Journals (Sweden)

    NEREO PRETO

    2012-03-01

    Full Text Available Pizzo Mondello is a ca. 500 m thick pelagic-hemipelagic succession cropping out in Sicily consisting of a nodular cherty limestone facies association of late Carnian to late Norian age. The uppermost portion was attributed to the Rhaetian and is represented by the plane-bedded Portella Gebbia Limestone. The section has been proposed as the stratotype for the base of the Norian stage. The calcareous nannofossil content of limestones was studied with Scanning Electron Microscope (SEM in two portions of the Pizzo Mondello section, one within 'La Cava' that encompasses all the proposed horizons for the base of the Norian, and one within the Portella Gebbia Limestone in the uppermost part of the section.Calcareous nannofossil assemblages of the first portion display low diversity, being constituted exclusively by calcispheres, that may constitute up to 40% of the sediment volume. Species richness increases in the upper portion. Initially, samples are dominated by Prinsiosphaera triassica, a nannolith of unknown taxonomic affinity. Rare calcareous dinocysts (Thoracosphaera cf. geometrica and coccoliths are present in few samples. Uppermost samples are still dominated by "calcispheres" comparable to Thoracosphaera, but also yield a variety of coccoliths and nannoliths.Calcareous nannofossil distribution was calibrated with conodont and radiolarian biostratigraphy. On the basis of this integrated work, specimens attributed to cf. Thoracosphaera, observed in the lower portion of the section, are late Carnian to early Norian, while samples dominated by Prinsiosphaera, with rare Thoracosphaera and coccoliths are Rhaetian. The calcareous nannofossil assemblage of the uppermost samples, along with radiolarians and the absence of conodonts, point to a Jurassic age (Pliensbachian for the uppermost Portella Gebbia Limestone at Pizzo Mondello. In conclusion, the age of the uppermost part of the Pizzo Mondello section is Jurassic, i.e., younger than previously

  3. Biostratigraphy of the Lower Cretaceous Schrambach Formation on the classical locality of Schrambachgraben (Northern Calcareous Alps, Salzburg Area)

    Czech Academy of Sciences Publication Activity Database

    Boorová, D.; Skupien, P.; Vašíček, Zdeněk

    2014-01-01

    Roč. 90, č. 1 (2014), s. 89-131. ISSN 1214-1119 Institutional support: RVO:68145535 Keywords : biostratigraphy * Schrambach and Rossfeld formations * Berriasian, Valanginian * calcareous and non-calcareous dinoflagellata * ammonites Subject RIV: DB - Geology ; Mineralogy Impact factor: 1.515, year: 2014 http://www. geology .cz/bulletin/fulltext/1479_Boorova_in_press.pdf

  4. [Form tendency and bio-availability dynamics of Cu and Zn in different farm soils after application of organic fertilizer of livestock and poultry manures].

    Science.gov (United States)

    Shang, He-ping; Li, Yang; Zhang, Tao; Su, De-chun

    2015-01-01

    Soil incubation experiments were conducted with different sources of manures containing heavy metals to evaluate the bioavailability of heavy metals (Cu and Zn) and their form transformation in different soils. This study may assist in developing strategies to ascertain the loads of heavy metals which entered into soils together with manures, and promote policies to evaluate the ecological risk in agriculture soils. The results showed that, during the six months of soil incubation, the pH value of acidic soil increased and the pH value of calcareous soil reduced. After adding chicken manures, the contents of available Cu in both calcareous and acid soils were significant lower than those in the equivalent inorganic salt treatments, but there was no significant difference between the treatments in the contents of available Zn in both calcareous and acid soils. Furthermore, there were also no significant differences between pig matures and the equivalent inorganic salt treatments in the contents of available Cu and Zn in both calcareous and acid soils. The results of form tendency showed that the main forms of Cu and Zn in both calcareous and acid soils, which entered into soils together with manures, were exchangeable, carbonate, Fe-Mn oxides, and organic. And the proportions of different heavy metals species in calcareous and acid soils were different with different manures sources. After six months of incubation, the contents of exchangeable and Fe-Mn oxides Cu, Zn were lower than those in the equivalent inorganic salt treatments, the contents of organics Cu and Zn were higher than those in the equivalent inorganic salt treatments, and other Cu and Zn forms in soils showed no difference with inorganic salt treatments. PMID:25898681

  5. Coniacian-maastrichtian calcareous nannofossil biostratigraphy and carbon-isotope stratigraphy in the Zagros Basin (Iran)

    DEFF Research Database (Denmark)

    Razmjooei, Mohammad Javad; Thibault, Nicolas; Kani, Anoshiravan;

    2014-01-01

    Calcareous nannofossil biostratigraphy and stable isotope stratigraphy have been investigated in the Shahneshin section of the Gurpi Formation from the Zagros Basin (Iran). The results show that the Gurpi Formation spans the late early Coniacian to late Thanetian. The age-model shows that the...... magnetostratigraphy in the Santonian-early Campanian interval. The δ13C correlation, supported by calcareous nannofossil biostratigraphy, brings insights into: (1) the position of the Coniacian/Santonian, Santonian/Campanian and Campanian/Maastrichtian boundaries with respect to carbon-isotope stratigraphy and...

  6. Physical and chemical protection of soil organic carbon in three agricultural soils with different contents of calcium carbonate

    International Nuclear Information System (INIS)

    The amount of organic carbon physically protected by entrapment within aggregates and through polyvalent cation organic matter bridging was determined on non-calcareous and calcareous soils. The composition of organic carbon in whole soils and 13C NMR analysis. High energy photo-oxidation was carried out on <53 μm fractions and results from the NMR spectra showed 17-40% of organic carbon was in a condensed aromatic form, most likely charcoal (char). The concept that organic material remaining after photo-oxidation may be physically protected within aggregates was investigated by treating soils with a mild acid prior to photo-oxidation. More organic material was protected in the calcareous than the non-calcareous soils, regardless of whether the calcium occurred naturally or was an amendment. Acid treatment indicated that the presence of exchangeable calcium reduced losses of organic material upon photo-oxidation by about 7% due to calcium bridging. These results have implications for N fertiliser recommendations based upon organic carbon content. Firstly, calcium does not impact upon degradability of organic material to an extent likely to affect N fertiliser recommendations. Secondly, standard assessment techniques overestimate active organic carbon content in soils with high char content. Copyright (2000) CSIRO Publishing

  7. Characterization of bacterial diversity associated with calcareous deposits and drip-waters, and isolation of calcifying bacteria from two Colombian mines.

    Science.gov (United States)

    García G, Mariandrea; Márquez G, Marco Antonio; Moreno H, Claudia Ximena

    2016-01-01

    Bacterial carbonate precipitation has implications in geological processes and important biotechnological applications. Bacteria capable of precipitating carbonates have been isolated from different calcium carbonate deposits (speleothems) in caves, soil, freshwater and seawater around the world. However, the diversity of bacteria from calcareous deposits in Colombia, and their ability to precipitate carbonates, remains unknown. In this study, conventional microbiological methods and molecular tools, such as temporal temperature gradient electrophoresis (TTGE), were used to assess the composition of bacterial communities associated with carbonate deposits and drip-waters from two Colombian mines. A genetic analysis of these bacterial communities revealed a similar level of diversity, based on the number of bands detected using TTGE. The dominant phylogenetic affiliations of the bacteria, determined using 16S rRNA gene sequencing, were grouped into two phyla: Proteobacteria and Firmicutes. Within these phyla, seven genera were capable of precipitating calcium carbonates: Lysinibacillus, Bacillus, Strenotophomonas, Brevibacillus, Methylobacterium, Aeromicrobium and Acinetobacter. FTIR and SEM/EDX were used to analyze calcium carbonate crystals produced by isolated Acinetobacter gyllenbergii. The results showed that rhombohedral and angular calcite crystals with sizes of 90μm were precipitated. This research provides information regarding the presence of complex bacterial communities in secondary carbonate deposits from mines and their ability to precipitate calcium carbonate from calcareous deposits of Colombian mines. PMID:26686610

  8. ECOLOGICAL PECULIARITIES OF COPPER CHEMICAL FORMS CONTENT IN THE ERODED SOILS

    OpenAIRE

    T. Leah

    2013-01-01

    The content of chemical forms of copper, the features of the distribution and transformation in eroded Gray soils and Calcareous chernozems are presented. Erosion process led to increase the chemical forms associated with clay minerals, carbonates, oxides, and reducing the mobile and humus organic forms. The losses of copper in different chemical forms consist 35% from humus horizon of eroded soils.

  9. ECOLOGICAL PECULIARITIES OF COPPER CHEMICAL FORMS CONTENT IN THE ERODED SOILS

    Directory of Open Access Journals (Sweden)

    T. Leah

    2013-06-01

    Full Text Available The content of chemical forms of copper, the features of the distribution and transformation in eroded Gray soils and Calcareous chernozems are presented. Erosion process led to increase the chemical forms associated with clay minerals, carbonates, oxides, and reducing the mobile and humus organic forms. The losses of copper in different chemical forms consist 35% from humus horizon of eroded soils.

  10. The influence of soil type at Cs-137-spreading in soil depth

    International Nuclear Information System (INIS)

    The distribution of Cs-137 in soil depth up to 15 cm was examined for four types of soil - leached black earth, calcareous black earth, brown forest soil and slightly leached humus-calcareous soil. The behaviour of Cs-137 before and after Chernobyl accident depending on soil type was determined using Cs-134. Accounting for halftime effect of Cs-134 it was possible to distinguish the penetration of the Chernobyl Cs-137 from that of the older one. The same degree of penetration has been achieved: for 30 years for the old Cs-137 and only for a year for the Chernobyl one probably due to its modification. The most expressed tendency to penetrate in depth has been observed at the calcareous black earth (from Kozloduy region, with highest pH value and basis content), the least - at the brown forest soil (from Smolyan region, lowest pH value and basis content). The mineral composition and organic matter content influence the penetration process. The humus matter absorbs Cs-137. Thus it is accessible to the plants, but its penetration is limited to 2.5 cm. 9 refs., 2 tabs. (author)

  11. Community structure and palaeoecological implications of calcareous encrusters on artificial substrates across a Mexican Caribbean reef

    Science.gov (United States)

    Hepburn, L. J.; Blanchon, P.; Murphy, G.; Cousins, L.; Perry, C. T.

    2015-03-01

    Calcareous encrusters stabilize and bind reef framework and contribute significantly to reef function and biodiversity. Their calcareous skeletons have good preservation potential which, together with well-constrained habitat preferences, makes them useful indicators of past environmental conditions. However, our knowledge of environmental tolerances and spatial distribution trends of encrusters remains limited. Here, we determine the distributional trends and environmental tolerances of calcareous encrusters and delineate the relevance of particular species/genera for palaeoecological reconstructions. Artificial microhabitats were created to mimic exposed, partially cryptic, and cryptic habitats in various orientations for periods of 1 and 2 yr. Calcareous encruster coverage was high, especially in cryptic habitats (95 %), and clear successional trends were observed over time. Total encruster carbonate production was intermediate (range 72.8-476.3 g m-2 yr-1). Encruster species and growth morphology exhibited a defined zonation in response to reef sub-environment, microhabitat, and environmental factors such as light and wave exposure. Linear regression identified three coralline algae genera, as well as Homotrema rubrum, Planorbulina spp., and cemented bivalves as those most likely to occur in particular habitats. Therefore, the presence of these species may be used with greater confidence in distinguishing palaeomicroenvironments.

  12. Biot's coefficient as an indicator of strength and porosity reduction: Calcareous sediments from Kerguelen Plateau

    DEFF Research Database (Denmark)

    Alam, Mohammad Monzurul; Borre, Mai Kirstine; Fabricius, Ida Lykke;

    2010-01-01

    Chalk develops as a result of diagenesis of pelagic calcareous ooze. In a newly deposited ooze sediment, porosity ranges from 60% to 80% but porosity reduces with burial. We studied how different porosity reduction mechanisms change the strength of these deep sea carbonate-rich sediments and effe...

  13. Laboratory Experiment Investigating the Impact of Ocean Acidification on Calcareous Organisms

    Science.gov (United States)

    Perera, Alokya P.; Bopegedera, A. M. R. P.

    2014-01-01

    The increase in ocean acidity since preindustrial times may have deleterious consequences for marine organisms, particularly those with calcareous structures. We present a laboratory experiment to investigate this impact with general, introductory, environmental, and nonmajors chemistry students. For simplicity and homogeneity, calcite was…

  14. Changes in the polysaccharide matrix of calcareous green algae during growth

    OpenAIRE

    Liebezeit, G.; Dawson, R.

    1981-01-01

    The organic matrix of three species of calcareous green algae (family Caulerpales, order Udoteaceae was analysed during different growth stages for its carbohydrate content. In all cases investigated a decrease with age in the relative content of structural polysaccharides paralleled by an increase in reserve polymers was observed. A dynamic carbonate deposition model is suggested based on consideration of the carbohydrate composition.

  15. Geochemistry of calcareous sediments from the SW Carlsberg Ridge: Evidence for deeper carbonate compensation depth

    Digital Repository Service at National Institute of Oceanography (India)

    Valsangkar, A.B.; Ambre, N.V.

    , Cu, Ni and Zn elements due to high surface biological (calcareous) productivity. Mn and Fe are hydrogenous and Al, K and Ti are either terrigenous or in situ due to alteration of basalts. Occurrence of deeper lysocline (4700 m) and deeper carbonate...

  16. EDTA retention and emissions from remediated soil.

    Science.gov (United States)

    Jez, Erika; Lestan, Domen

    2016-05-01

    EDTA-based remediation is reaching maturity but little information is available on the state of chelant in remediated soil. EDTA soil retention was examined after extracting 20 soil samples from Pb contaminated areas in Slovenia, Austria, Czech Republic and USA with 120 mM kg(-1) Na2H2EDTA, CaNa2EDTA and H4EDTA for 2 and 24 h. On average, 73% of Pb was removed from acidic and 71% from calcareous soils (24 h extractions). On average, 15% and up to 64% of applied EDTA was after remediation retained in acidic soils. Much less; in average 1% and up to the 22% of EDTA was retained in calcareous soils. The secondary emissions of EDTA retained in selected remediated soil increased with the acidity of the media: the TCLP (Toxicity Characteristic Leaching Procedure) solution (average pH end point 3.6) released up to 36% of EDTA applied in the soil (28.1 mmol kg(-1)). Extraction with deionised water (pH > 6.0) did not produce measurable EDTA emissions. Exposing soil to model abiotic (thawing/freezing cycles) and biotic (ingestion by earthworms Lumbricus rubellus) ageing factors did not induce additional secondary emissions of EDTA retained in remediated soil. PMID:26943741

  17. Use of calcareous algae and monensin in Nellore cattle subjected to an abrupt change in diet

    Directory of Open Access Journals (Sweden)

    Roberta Ferreira Carvalho

    2016-04-01

    Full Text Available ABSTRACT: Additives are used in high concentrate diets to prevent metabolic disorders in cattle. This study was designed to evaluate the effect of calcium sources and monensin on the control of ruminal acidosis in Nellore cattle that were abruptly shifted to a high (92.3% concentrate diet. Eight cannulated steers were randomly assigned to two contemporary 4x4 Latin square. Treatments involved the addition of a calcium source, either limestone (LI or a product derived from calcareous algae (CA, to the basic diet with or without the presence of monensin. Calcareous alga (Lithothamnium calcareum is a natural and renewable product and a source of calcium carbonate. The quantity of added limestone, calcareous algae and monensin was 7.1g kg-1, 7.4g kg-1 and 30mg kg-1 DM, respectively. There was no effect of calcium source (P=0.607 or monensin (P=0.294 on feed intake or on the concentration of short chain fatty acids. Treatments with calcareous algae resulted in a higher mean ruminal pH (P=0.039, a shorter amount of time with the ruminal pH under 5.2 (P<0.001 and a better control of blood pH (P=0.006. Treatments with monensin also resulted in a shorter amount of time with the ruminal pH below 5.2 (P=0.023. Calcareous algae were shown to be effective in controlling adverse changes in the rumen and in blood variables for Nellore cattle that were subjected to an abrupt change to a high concentrate diet.

  18. DESCRIPTION OF CERTAIN ASPECTS OF THE PRODUCTION POTENTIAL OF SOILS TAMAN PENINSULA

    OpenAIRE

    Lukyanov A. A.

    2015-01-01

    The work presents the results of the scientific research in the Taman Peninsula soil properties. We carry out the historic review of the studies in the Taman Peninsula soils, and its geological structure. We present morphological characteristics of the soil profile for the southern, calcareous, ultra heavy loam chernozem developed from the loessial loams and forming genetic horizons. The studies of the humus content in the soils show the associations between its percentage and the type and in...

  19. Speciation and Distribution of Phosphorus in a Fertilized Soil: A Synchrotron-Based Investigation

    Energy Technology Data Exchange (ETDEWEB)

    Lombi, E.; Scheckel, K.G.; Armstrong, R.D.; Forrester, S.; Cutler, J.N.; Paterson, D. (USEPA); (CSIRO/LW); (CLS); (DPI); (ANSTO)

    2008-06-09

    Phosphorus availability is often a limiting factor for crop production around the world. The efficiency of P fertilizers in calcareous soils is limited by reactions that decrease P availability; however, fluid fertilizers have recently been shown, in highly calcareous soils of southern Australia, to be more efficient for crop (wheat [Triticum aestivum L.]) P nutrition than granular products. To elucidate the mechanisms responsible for this differential response, an isotopic dilution technique (E value) coupled with a synchrotron-based spectroscopic investigation were used to assess the reaction products of a granular (monoammonium phosphate, MAP) and a fluid P (technical-grade monoammonium phosphate, TG-MAP) fertilizer in a highly calcareous soil. The isotopic exchangeability of P from the fluid fertilizer, measured with the E-value technique, was higher than that of the granular product. The spatially resolved spectroscopic investigation, performed using nano x-ray fluorescence and nano x-ray absorption near-edge structure (n-XANES), showed that P is heterogeneously distributed in soil and that, at least in this highly calcareous soil, it is invariably associated with Ca rather than Fe at the nanoscale. 'Bulk' XANES spectroscopy revealed that, in the soil surrounding fertilizer granules, P precipitation in the form of octacalcium phosphate and apatite-like compounds is the dominant mechanism responsible for decreases in P exchangeability. This process was less prominent when the fluid P fertilizer was applied to the soil.

  20. Irradiated sewage sludge for increased crop production - II. Effects on soil properties and tomato yields

    International Nuclear Information System (INIS)

    Irradiated and non-irradiated sewage sludge from El-Gabal El-Asfar Farm near Cairo, was applied to sandy and calcareous soils at rates of 20, 40, 60, and 80 t/ha. Treatments with and without a basal fertilizer dressing were included for comparison. Soil organic matter, water-holding capacity, cation-exchange capacity, electrical conductivity, and concentrations of available N, P, and K increased under sludge treatments. However, total carbonate, soil pH, and bulk density decreased with increasing application rates of sludge. The changes were higher in the sandy than in the calcareous soil. There was no significant difference between irradiated and nonirradiated sludge treatments in any of the measured soil properties. The concentrations of available N, P, and K were significantly correlated with organic matter content in both soils. Improved soil fertility due to sludge addition was reflected in higher yields of tomato and enhanced fruit quality. (author)

  1. Iron and Zinc Deficiencies in Selected Calcareous Soils of Southern Utah

    OpenAIRE

    Schnitzer, E. Frank

    1980-01-01

    The response of field corn to iron and zinc fertilization was studied using a split plot experimental design in Millard County, Utah, in cooperation with the Utah Stat e University Extension Agent and a local farmer. ~!ainp l ot treatment applications consisted, on an acre basis, of (1) 5 t ons of sulfuric acid, (2) 1 ton sulfuric acid, (3) 1.8 tons gypsum, (4) check plot. Subplot treatments were (1) Fe at 5 lbs/Ac, (2) Zn at 10 lbs/Ac, (3) Fe and Zn at 5 and 10 lb / Ac, respectively, (4) che...

  2. Medial calcar of proximal humeral fracture as landmark in restoration of humeral length in case of hemiarthroplasty

    Czech Academy of Sciences Publication Activity Database

    Hromádka, R.; Kuběna, Aleš Antonín; Šmíd, Martin; Popelka, S.

    2014-01-01

    Roč. 35, č. 5 (2014), s. 473-479. ISSN 0930-1038 Institutional support: RVO:67985556 Keywords : Fracture of proximal humerus * Calcar of humeral fracture * Reconstruction of proximal humerus * Reconstruction of humeral length * Shoulder arthroplasty * Shoulder hemiarthroplasty Subject RIV: FJ - Surgery incl. Transplants Impact factor: 1.047, year: 2014 http://library.utia.cas.cz/separaty/2013/E/smid-medial calcar of proximal humeral fracture as landmark in restoration of humeral length in case of hemiarthroplasty.pdf

  3. Calcareous nannoplankton and diatoms from the Eocene/Pliocene sediments, Fayoum depression, Egypt

    Science.gov (United States)

    Zalat, Abdelfattah A.

    1995-04-01

    Different assemblages of calcareous nannofossil and diatom taxa are detected in samples collected from sections at Shaqluf, Siela and Qaret El Faras in the Fayoum area. Five calcareous nannoplankton biozones are recorded: the Middle Eocene Discoaster tanii nodifer Zone, the Discoaster saipanensis Zone; the early, Late Eocene Chiasmolithus oamaruensis Zone; the Late Eocene Isthmolithus recurvus Zone and the Early Pliocene Reticulofenestra pseudoumbilicus Zone. Diatoms are recorded for the first time in the sections studied. The gradual changes in diatom composition from marine to brackish, ending with a well-developed, freshwater flora at the top of the Pliocene Shaqluf section, indicate changes in the palaeoecological conditions in the area during that time. In the Pliocene Siela and Qaret El Faras sections, all the identified diatom taxa belong to the freshwater assemblage together with some brackish water forms. The predominance of freshwater diatoms suggests that these taxa were introduced to the area with the sediments of the Palaeonile river during the Late Pliocene.

  4. CALCAREOUS NANNOFOSSIL BIOSTRATIGRAPHY OF PALEOCENE TO MIDDLE EOCENE SUCCESSIONS (TERTIARY FLYSCH AUCTT. OF THE NORTHERN APENNINES

    Directory of Open Access Journals (Sweden)

    RITA CATANZARITI

    2015-11-01

    Full Text Available An accurate biostratigraphic study of the Paleocene-middle Eocene calcareous nannofossils was performed on the turbiditic successions that characterize the Northern Apennines Mt. Caio, Farini d’Olmo, Mt. Sporno and Mt. Penice Units, belonging to the “Tertiary Flysch Auctt.” and referable to the External Ligurides. This geologic complex accumulated in a link key area, located between the oceanic Ligure-Piedmontese domain and the Adria continental margin. The reference biostratigraphic scheme used in the study is the recently published calcareous nannofossil biozonation proposed for the Paleogene by Agnini et al. (2014. The obtained biostratigraphic and chronostratigraphic data suggest that further investigation is needed to clarify the tectono-sedimentary evolution and to unravel the complex architecture of the External Ligurides.

  5. Occurrence of palygorskite in soils of Ecija (Spain)

    OpenAIRE

    Pérez Rodríguez, José Luis; Maqueda Porras, Celia; Morillo González, Esmeralda

    1990-01-01

    Palygorskite has been characterized in soils classified as typic argixerolls, located in an extensive Quaternary zone in the north of Seville (Spain), where the geological and climatic conditions suggest its genesis. The soils contain a Ck horizon which has different textural characteristics to the other horizons in the profiles. The presence of large white calcareous nodules and cristobalite is the principal difference between them. The formation of palygorsltite at textural discontinuities ...

  6. Root exudation of phytosiderophores from soil-grown wheat

    OpenAIRE

    Oburger, Eva; Gruber, Barbara; Schindlegger, Yvonne; Schenkeveld, Walter D C; Hann, Stephan; Kraemer, Stephan M; Wenzel, Walter W.; Puschenreiter, Markus

    2014-01-01

    For the first time, phytosiderophore (PS) release of wheat (Triticum aestivum cv Tamaro) grown on a calcareous soil was repeatedly and nondestructively sampled using rhizoboxes combined with a recently developed root exudate collecting tool. As in nutrient solution culture, we observed a distinct diurnal release rhythm; however, the measured PS efflux was c. 50 times lower than PS exudation from the same cultivar grown in zero iron (Fe)-hydroponic culture. Phytosiderophore rhizosphere soil so...

  7. Molecular phylogenetic evaluation of classification and scenarios of character evolution in calcareous sponges (Porifera, Class Calcarea).

    OpenAIRE

    Oliver Voigt; Eilika Wülfing; Gert Wörheide

    2012-01-01

    Calcareous sponges (Phylum Porifera, Class Calcarea) are known to be taxonomically difficult. Previous molecular studies have revealed many discrepancies between classically recognized taxa and the observed relationships at the order, family and genus levels; these inconsistencies question underlying hypotheses regarding the evolution of certain morphological characters. Therefore, we extended the available taxa and character set by sequencing the complete small subunit (SSU) rDNA and the alm...

  8. Calcareous nannofossil biostratigraphy and depositional history of the late Cretaceous to early Miocene sequence of Iraq

    OpenAIRE

    Starkie, S. P.

    1994-01-01

    This thesis presents a new calcareous nannofossil based zonation scheme for Iraq based upon the examination of 515 drill cutting, conventional core and bit samples from both southern and northern Iraq. This zonation consists of 13 zones and 7 subzones covering the Late Cretaceous to Early Miocene. To date no detailed nannofossil zonation scheme was available for Iraq and therefore the nannofossil zonation presented here breaks new ground. The new zonation scheme has also been successfully cor...

  9. TRIASSIC AND JURASSIC CALCAREOUS NANNOFOSSILS OF THE PIZZO MONDELLO SECTION: A SEM STUDY

    OpenAIRE

    NEREO PRETO; MANUEL RIGO; CLAUDIA AGNINI; ANGELA BERTINELLI; CHIARA GUAIUMI; STEFANO BORELLO; HILDEGARD WESTPHAL

    2012-01-01

    Pizzo Mondello is a ca. 500 m thick pelagic-hemipelagic succession cropping out in Sicily consisting of a nodular cherty limestone facies association of late Carnian to late Norian age. The uppermost portion was attributed to the Rhaetian and is represented by the plane-bedded Portella Gebbia Limestone. The section has been proposed as the stratotype for the base of the Norian stage. The calcareous nannofossil content of limestones was studied with Scanning Electron Microscope (SEM) in two po...

  10. Reformation of the surface oceanic circulation during Paleogene: Calcareous nannoplanktonic, foraminiferal and oxygen isotopic evidences

    OpenAIRE

    Ushakova, Maola; Blyum, Natalia

    1995-01-01

    [EN] Paleogene calcareous nannoplankton evolution with regard to morphotype changes was analysed. The^°0/1"0 ratio in planktonic foraminifera tests was studied. Conclusions about surface water temperature and salinity changes and about main features of surface circulation based on these data were arrived. Can be seen that the reformation from the mainly halinotypic circulation of the early Paleogene into halotherme one took place in the middle Eocene. In the same time the notable climatic zon...

  11. Sunlight-enhanced calcareous deposition on cathodic stainless steel in natural seawater

    Digital Repository Service at National Institute of Oceanography (India)

    Eashwar, M.; SathishKumar, P.; Ravishankar, R.; Subramanian, G.

    : Biofouling, vol.29(2); 2013; 185-193 Sunlight enhances calcareous deposition on cathodic stainless steel in natural seawater M. Eashwara,*, P. Sathish Kumara,b, R. Ravishankarb, G. Subramaniand aCSIR – Central Electrochemical Research Institute..., Corrosion Research Centre, Mandapam Camp - 623519, Tamil Nadu, India bCurrent Address: CSIR – National Institute of Oceanography, Marine Corrosion and Materials Research Division, Dona Paula, Goa - 403 004, India cCSIR – Central Electrochemical...

  12. Contrasting effects of ocean acidification on tropical fleshy and calcareous algae

    Directory of Open Access Journals (Sweden)

    Maggie Dorothy Johnson

    2014-05-01

    Full Text Available Despite the heightened awareness of ocean acidification (OA effects on marine organisms, few studies empirically juxtapose biological responses to CO2 manipulations across functionally distinct primary producers, particularly benthic algae. Algal responses to OA may vary because increasing CO2 has the potential to fertilize photosynthesis but impair biomineralization. Using a series of repeated experiments on Palmyra Atoll, simulated OA effects were tested across a suite of ecologically important coral reef algae, including five fleshy and six calcareous species. Growth, calcification and photophysiology were measured for each species independently and metrics were combined from each experiment using a meta-analysis to examine overall trends across functional groups categorized as fleshy, upright calcareous, and crustose coralline algae (CCA. The magnitude of the effect of OA on algal growth response varied by species, but the direction was consistent within functional groups. Exposure to OA conditions generally enhanced growth in fleshy macroalgae, reduced net calcification in upright calcareous algae, and caused net dissolution in CCA. Additionally, three of the five fleshy seaweeds tested became reproductive upon exposure to OA conditions. There was no consistent effect of OA on algal photophysiology. Our study provides experimental evidence to support the hypothesis that OA will reduce the ability of calcareous algae to biomineralize. Further, we show that CO2 enrichment either will stimulate population or somatic growth in some species of fleshy macroalgae. Thus, our results suggest that projected OA conditions may favor non-calcifying algae and influence the relative dominance of fleshy macroalgae on reefs, perpetuating or exacerbating existing shifts in reef community structure.

  13. Phosphorus sorption in subsurface constructed wetlands: investigations focused on calcareous materials and their chemical reactions

    OpenAIRE

    Molle, P.; Liénard, A.; Grasmick, A.; Iwema, A.

    2002-01-01

    Phosphorus removal from wastewater has been of growing interest for some decades to avoid eutrophication in surface water. In subsurface constructed wetlands precipitation and adsorption are the main mechanisms responsible of P uptake. The use of calcareous media is attractive because of p-ca interactions. Two media (calcite and recycled crushed concrete (rcc)) were examined in batch and continuous systems. They show attractive sorption capacities using batch experiments, however experiments ...

  14. Conservation of Sandy Calcareous Grassland: What Can Be Learned from the Land Use History?

    OpenAIRE

    Ödman, Anja Madelen; Olsson, Pål Axel

    2014-01-01

    Understanding the land use history has proven crucial for the conservation of biodiversity in the agricultural landscape. In southern Sweden, very small and fragmented areas of the disturbance-dependent habitat xeric sand calcareous grassland support a large number of threatened and rare plants and animals. In order to find out if historical land use could explain variation in present-day habitat quality, the land use on eight such sites was traced back to the 18th century and compared with k...

  15. Zanclean/Piacenzian transition on Cyprus (SE Mediterranean): calcareous nannofossil evidence of sapropel formation

    Science.gov (United States)

    Athanasiou, M.; Triantaphyllou, M. V.; Dimiza, M. D.; Gogou, A.; Τheodorou, G.

    2015-10-01

    Quantitative analyses of calcareous nannofossils in the sediments of Pissouri South section on the island of Cyprus have produced a paleoceanographic record reflecting the paleoclimatic conditions during the Zanclean/Piacenzian transition. Pissouri South cyclical lithological alternations between organic-rich laminated layers and grey marls reflect the Earth's orbital precession. According to the calcareous nannofossil biostratigraphy which has been performed, the studied section is correlated with MNN14/15 and MNN16 calcareous nannofossil biozones and is astronomically dated between 4.065 and 3.217 Ma. Intervals of increased organic carbon content, along with the positive values of Florisphaera profunda, Helicosphaera sellii, Discoaster spp. and the subsequent increase of stratification S-index, correspond to the sapropel deposition during periods of wetter climate and intense continental runoff, especially from the river Nile. These layers alternate with grey marly intervals, featured by the increased values of small placoliths of Reticulofenestra and Gephyrocapsa species, which are indicative of eutrophic conditions during intense surface-water mixing. Our data support the prevalence of a generally warm phase characterized by the absence of high-frequency climate variations in the southeastern Mediterranean during the Zanclean/Piacenzian (Early/Late Pliocene) transition.

  16. Cathodic behaviour of stainless steel in coastal Indian seawater: calcareous deposits overwhelm biofilms.

    Science.gov (United States)

    Eashwar, M; Subramanian, G; Palanichamy, S; Rajagopal, G; Madhu, S; Kamaraj, P

    2009-01-01

    Type-316 stainless steel (SS) was investigated as the cathode in galvanic couples in full-strength seawater from the Gulf of Mannar on the southeast coast of India. Tests were devised to examine the impact of SS cathodes on anode materials with or without the accrual of marine biofilms. Biofilmed SS cathodes significantly enhanced the rate of corrosion of nickel, causing noble shifts in the couple potentials. With mild steel and zinc as the anodes, calcareous deposits developed quite rapidly on the SS cathodes and led to a significant reduction of bacterial numbers. The calcareous deposits also caused substantial reduction of galvanic corrosion rates for mild steel, whereas there was no difference for zinc. The deposits were identified by XRD as essentially carbonates, oxides and hydroxides of calcium and magnesium. Potentiodynamic polarization performed on the actual couples after disconnection and equilibration provided reasonable interpretations of the galvanic corrosion trends. Data from this work suggest that a potential of about -0.70 V vs. saturated calomel electrode (SCE) should provide optimum protection of SS in warmer, full-strength seawater that supports the precipitation of calcareous deposits. The criterion commonly recommended for temperate conditions of lower water temperature and estuarine waters of lower alkalinity is -1.0 V (SCE). PMID:19169951

  17. Modelling trace metal background to evaluate anthropogenic contamination in arable soils of south-western France

    OpenAIRE

    Redon, Paul-Olivier; Bur, Thomas; Guiresse, Maritxu; Probst, Jean-Luc; Toiser, Aurore; Revel, Jean-Claude; Jolivet, Claudy; Probst, Anne

    2013-01-01

    International audience The trace metal (TM) content in arable soils has been monitored across a region of France characterised by a large proportion of calcareous soils. Within this particular geological context, the objectives were to first determine the natural levels of trace metals in the soils and secondly, to assess which sites were significantly contaminated. Because no universal contamination assessment method is currently available, four different methods were applied and compared...

  18. Comparison between organic and mineral fertilization for soil fertility levels, crop macronutrient concentrations and yield

    OpenAIRE

    Herencia, Juan F.; Ruiz Porras, J. C.; Melero Sánchez, Sebastiana; Morillo González, Esmeralda; Maqueda Porras, Celia

    2007-01-01

    Interest in soil organic fertilization has grown appreciably in recent years; however, few studies have been performed in greenhouses. A comparative study of organic vs. mineral fertilization in a greenhouse has been conducted for 9 yr in a calcareous loamy soil classified as Xerofluvent in the Guadalquivir River Valley, Seville, Spain. The nutrient availability in the soil, macronutrient concentration in the edible part of the plants, and yield were examined. The organic fertilizer used was ...

  19. Temperature Effect on Boron Adsorption—Desorption Kinetics in Soils

    Institute of Scientific and Technical Information of China (English)

    ZHUDUANWEI; SHILEI; 等

    1999-01-01

    The effect of temperature on the properties of boron adsorption-desorption in brown-red soil,yellowbrown soil and calcareous alluvial soil of Hubei Province was investigated with the mobile displacement technique.The experimental data of B adsorption-desorption amounts and reaction time at 25 and 40℃ were fitted by the zero-order,first-order and parabolic diffusion kinetic equations.The adsorption process was in conformity with the parabolic diffusion law at both the temperatures,and the values of rate constant of the parabolic diffusion equation in B adsorption were 0.138,0.124 and 0.105 mg kg-1 min-1/2 at 25℃,and 0.147,0.146and 0.135mg kg-1 min1/2 at 40℃ for the brown-red soil,yellow-brown soil,and calcareous alluvial soil,respectively,The relationship between amount of B desorption and reaction time could be well described by the first-order kinetic equation,and the corresponding values of rate constant were 0.0422,0.0563 and 0.0384min-1 at 25℃,and 0.0408,0.0423 and 0.0401min-1 at 40℃ for the brown-red soil,the yellow-brown soil and the calcareous alluvial soil,respectively.Therefore,the desorption process of B might be related to the amount of B adsorbed in soil,The higher th temperature,the lower the amount of B adsorption of the same soil in the same reaction time,The values of the apparent activation energy of B adsorption in the three soils calculated with the rate constants of parabolic diffusion equation were 3.27,8.44 and 12.99 kJ mol-1,respectively,based on the experimental data of B adsorption amounts and reaction time at and 40℃.

  20. The effects of soil amendments on heavy metal bioavailability in two contaminated Mediterranean soils

    Energy Technology Data Exchange (ETDEWEB)

    Walker, D.J.; Clemente, Rafael; Roig, Asuncion; Bernal, M.P

    2003-04-01

    The effects of organic amendments on metal bioavailability were not always related to their degree of humification. - Two heavy metal contaminated calcareous soils from the Mediterranean region of Spain were studied. One soil, from the province of Murcia, was characterised by very high total levels of Pb (1572 mg kg{sup -1}) and Zn (2602 mg kg{sup -1}), whilst the second, from Valencia, had elevated concentrations of Cu (72 mg kg{sup -1}) and Pb (190 mg kg{sup -1}). The effects of two contrasting organic amendments (fresh manure and mature compost) and the chelate ethylenediaminetetraacetic acid (EDTA) on soil fractionation of Cu, Fe, Mn, Pb and Zn, their uptake by plants and plant growth were determined. For Murcia soil, Brassica juncea (L.) Czern. was grown first, followed by radish (Raphanus sativus L.). For Valencia soil, Beta maritima L. was followed by radish. Bioavailability of metals was expressed in terms of concentrations extractable with 0.1 M CaCl{sub 2} or diethylenetriaminepentaacetic acid (DTPA). In the Murcia soil, heavy metal bioavailability was decreased more greatly by manure than by the highly-humified compost. EDTA (2 mmol kg{sup -1} soil) had only a limited effect on metal uptake by plants. The metal-solubilising effect of EDTA was shorter-lived in the less contaminated, more highly calcareous Valencia soil. When correlation coefficients were calculated for plant tissue and bioavailable metals, the clearest relationships were for Beta maritima and radish.

  1. The effects of soil amendments on heavy metal bioavailability in two contaminated Mediterranean soils

    International Nuclear Information System (INIS)

    The effects of organic amendments on metal bioavailability were not always related to their degree of humification. - Two heavy metal contaminated calcareous soils from the Mediterranean region of Spain were studied. One soil, from the province of Murcia, was characterised by very high total levels of Pb (1572 mg kg-1) and Zn (2602 mg kg-1), whilst the second, from Valencia, had elevated concentrations of Cu (72 mg kg-1) and Pb (190 mg kg-1). The effects of two contrasting organic amendments (fresh manure and mature compost) and the chelate ethylenediaminetetraacetic acid (EDTA) on soil fractionation of Cu, Fe, Mn, Pb and Zn, their uptake by plants and plant growth were determined. For Murcia soil, Brassica juncea (L.) Czern. was grown first, followed by radish (Raphanus sativus L.). For Valencia soil, Beta maritima L. was followed by radish. Bioavailability of metals was expressed in terms of concentrations extractable with 0.1 M CaCl2 or diethylenetriaminepentaacetic acid (DTPA). In the Murcia soil, heavy metal bioavailability was decreased more greatly by manure than by the highly-humified compost. EDTA (2 mmol kg-1 soil) had only a limited effect on metal uptake by plants. The metal-solubilising effect of EDTA was shorter-lived in the less contaminated, more highly calcareous Valencia soil. When correlation coefficients were calculated for plant tissue and bioavailable metals, the clearest relationships were for Beta maritima and radish

  2. Predicting cadmium adsorption on soils using WHAM VI

    OpenAIRE

    Shi, Zhenquing; Allen, Herbert E.; Di Toro, Dominic M.; Lee, Suen-Zone; Meza, Diego M. Flores; Lofts, Steve

    2007-01-01

    Cadmium (Cd) adsorption on 14 non-calcareous New Jersey soils was investigated with a batch method. Both adsorption edge and isotherm experiments were conducted covering a wide range of soil composition, e.g. soil organic carbon (SOC) concentration ranging from 0.18% to 7.15%, and varying Cd concentrations and solution pH. The SOC and solution pH were the most important parameters controlling Cd partition equilibrium between soils and solutions in our experimental conditions. The Windermer...

  3. Natural Nitrogen—15 Abundance of Ammonium Nitrogen and Fixed Ammonium in Soils

    Institute of Scientific and Technical Information of China (English)

    SHISHU-LIAN; XINGGUANG-XI; 等

    1992-01-01

    The present article deals with the natural nitrogen-15 abundance of ammonium nitrogen and fixed ammonium in different soils.Variations in the natural 15N abundance of ammonium nitrogen mineralized in soils under anaerobic incubation condition were related to soil pH.The δ 15N of mineralizable N in acid soils was lower but that in neutral and calcareous soils was higher compared with the δ 15N of total N in the soils.A variation tendence was also found in the δ 15N of amino-acid N in the hydrolysates of soils.The natural 15N abundance of fixed ammonium was higher than that of total N in most surface soils and other soil horizons,indicating that the increase of δ 15N in the soil borizons beneath subsurface horizon of some forest soils and acid paddy soils was related to the higher δ 15N value of fixed ammonium in the soil.

  4. Significance of Some Soil Amendments and Phosphate Dissolving Bacteria to Enhance the Availability of Phosphate in Calcareous Soil

    OpenAIRE

    Khalil, Ahmed A.

    2013-01-01

    A field experiment was carried-out on a private farm at the Salah El-Din village, El-Bostan district, Nobaria, El-Behera Governorate, Egypt. The aim of this study was to evaluate the best combination of rock phosphate (RP), sulphur (S), organic manure, and phosphate dissolving bacteria (PDB) inoculation to enhance the availability of phosphorous from rock phosphate and their effects on yield of broad bean plants (cv. Luz doe Otono L.). It was found that either sulphur application or PDB inocu...

  5. Chemical composition of the humus layer, mineral soil and soil solution of 200 forest stands in the Netherlands in 1995

    OpenAIRE

    Leeters, E.E.J.M.; De, Vries, J.A.

    2001-01-01

    A nationwide assessment of the chemical composition of the soil solid phase and the soil solution in the humus layer and two mineral layers (0-10 cm and 10-30 cm) was made for 200 forest stands in the year 1995. The stands were part of the national forest inventory on vitality, included seven tree species and were all located on non-calcareous sandy soils. The soils are nearly all characterized by high nitrogen and metal contents in the humus layer ans low pH and base saturation values in the...

  6. Adding a New Dimension to the Study of Calcareous Plankton Response to Ocean Acidification

    Science.gov (United States)

    Oakes, R. L.; Urbanski, J. M.; Bralower, T. J.

    2014-12-01

    Anthropogenic activities are increasing atmospheric carbon dioxide concentrations at unprecedented rates. This carbon dioxide dissolves in the ocean causing both the pH and the concentration of carbonate ions to decrease. These chemical changes make it less energetically viable for calcareous organisms to form shells. This study focuses on a particularly important group of organisms; calcareous plankton, namely planktonic foraminifera and pteropods. These organisms lie at low trophic levels and therefore their demise could cause the total collapse of the marine food chain as we know it. The Pleistocene is defined by glacial-interglacial cycles with lower atmospheric CO2 concentrations (180 ppm) during glacials and higher concentrations (280 ppm) during interglacials. These fluctuations provide an ancient experiment assessing the response of planktonic foraminifera and pteropods to changing ocean chemistry. Measurements of planktonic foraminiferal tests over glacial-interglacial cycles (e.g. Broecker et al., 2003) show that shell weight increases as atmospheric CO2 decreases. We take this investigation one step further by observing individual plankton shells in a nano-CT (computed tomography) scanner which provides extraordinarily detailed three-dimensional images. These images enable us to determine detailed variations in test wall thickness and test volume, as well as ontogenetic changes in shell morphology as a response to changing atmospheric carbon dioxide. One of the key aspects of our investigation is that pteropods and planktonic foraminifera are studied collectively. This allows us to assess the differential impact of ocean acidification on aragonite and calcite. In our presentation, we illustrate the CT technique and present preliminary results from a downhole investigation of the Pleistocene from Ocean Drilling Program Site 1002 in the Cariaco Basin. In the future the nano-CT scanning method can be used to evaluate the detailed morphological response of

  7. EARLY TO LATE OLIGOCENE CALCAREOUS NANNOFOSSIL BIOEVENTS IN THE MEDITERRANEAN (UMBRIA-MARCHE BASIN, CENTRAL ITALY

    Directory of Open Access Journals (Sweden)

    PATRIZIA MAIORANO

    2006-07-01

    Full Text Available Calcareous nannofossil assemblages have been investigated by means of quantitative analyses in three Oligocene pelagic sections located in the Umbria-Marche Apennines (Central Italy. The studied sections mainly consist of marly limestones and marls belonging to the Scaglia Cinerea Formation, and include the interval between NP23 and NP25 representing a time interval of about 3.5 Ma. Biostratigraphic resolution is extremely low and only two standard bioevents are known, which are the FO of Sphenolithus ciperoensis and the LO of Sphenolithus distentus. The distribution patterns of poorly known or recently described calcareous nannofossils provided a valuable tool for improving the current biostratigraphic framework. The studied interval is characterized by significant changes in the calcareous nannofossil assemblages and by several extinction events. The last occurrence (LO and/or the last common occurrence (LCO here proposed are: the LO of Sphenolithus akropodus, the LO of Reticulofenestra circus, the LCO of Helicosphaera ethologa, the LCO of Helicosphaera compactathe LO of Discoaster tanii nodifer. The reversal in abundance between Sphenolithus predistentus and S. distentus provided an additional biostratigraphic constraint at the NP23-NP24 transition. In addition biometric criteria enabled the recognition of the first common occurrence (FCO of Cyclicargolithus abisectus > 12 mm as potential bioevent within NP24. The quantitative distribution of Sphenolithus distentus suggests to rely on the LCO of the species rather than on the LO, for the identification of NP24-NP25 boundary. The identified bioevents is a first step towards the improvement of the present Mediterranean biostratigraphic framework of the Oligocene geological record. A preliminary correlation of the bioevents to the Geomagnetic Polarity Time Scale is presented.

  8. Potential use of calcareous mudstones in low hydraulic conductivity earthen barriers for environmental applications.

    Science.gov (United States)

    Musso, T B; Francisca, F M; Musso, T B; Musso, T B

    2013-01-01

    Earthen layers play a significant role in isolating contaminants in the subsurface, controlling the migration of contaminant plumes, and as landfill liners and covers. The physical, chemical and mineralogical properties of three calcareous mudstones from the Jagüel and Roca formations in North Patagonia, Argentina, are evaluated to determine their potential for the construction of liners. These mudstones were deposited in a marine environment in the Upper Cretaceous-Paleocene. The tested specimens mainly comprise silt and clay-sized particles, and their mineralogy is dominated by a smectite/illite mixed layer (70-90% Sm) and calcite in smaller proportion. Powdered mudstone samples have little viscosity and swelling potential when suspended in water. The hydraulic conductivity of compacted mudstones and sand-mudstone mixtures is very low (around 1-3 x 10(-10) m/s) and in good agreement with the expected hydraulic behaviour of compacted earthen layers. This behaviour can be attributed to the large amount of fine particles, high specific surface and the close packing of particles as confirmed by scanning electron microscope analysis. The tested materials also show a high cation exchange capacity (50-70 cmol/kg), indicating a high contaminant retardation capability. The calcareous mudstones show satisfactory mineralogical and chemical properties as well as an adequate hydraulic behaviour, demonstrating the potential use of these materials for the construction of compacted liners for the containment of leachate or as covers in landfills. These findings confirm the potential usage of marine calcareous mudstones as a low-cost geomaterial in environmental engineering projects. PMID:24527607

  9. Effect of Oxalic Acid on Potassium Release from Typical Chinese Soils and Minerals

    Institute of Scientific and Technical Information of China (English)

    TU Shu-Xin; GUO Zhi-Fen; SUN Jin-He

    2007-01-01

    Oxalic acid plays an important role in improving the bioavailability of soil nutrients. Batch experiments were employed to examine the influences of oxalic acid on extraction and release kinetics of potassium (K) from soils and minerals along with the adsorption and desorption of soil K+. The soils and minerals used were three typical Chinese soils, black soil (Mollisol), red soil (Ultisol), and calcareous alluvial soil (Entisol), and four K-bearing minerals, biotite, phlogopite, muscovite, and microcline. The results showed that soil K extracted using 0.2 mol L-1 oxalic acid was similar to that using 1 mol L-1 boiling HNO3. The relation between K release (y) and concentrations of oxalic acid (c) could be best described logarithmically as y=a+blogc, while the best-fit kinetic equation of K release was y=a +b√t, where a and b are the constants and t is the elapsed time. The K release for minerals was ranked as biotite> phlogopite>> muscovite> microcline and for soils it was in the order: black soil> calcareous alluvial soil> red soil. An oxalic acid solution with low pH was able to release more K from weathered minerals and alkaline soils. Oxalic acid decreased the soil K+ adsorption and increased the soil K+ desorption, the effect of which tended to be greater at lower solution pH, especially in the red soil.

  10. Alternative stable states in a wet calcareous dune slack in The Netherlands

    OpenAIRE

    Adema, EB; Grootjans, AP; J. Petersen; Grijpstra, J.

    2002-01-01

    Evidence is presented for the occurrence of alternative stable states in a wet calcareous dune slack on the Frisian island of Texel, The Netherlands. An early pioneer stage (0.5 kg m–2 total standing crop) and a more productive later successional stage (2.9 kg m–2) occur side by side, with sharp boundaries between them. The pioneer vegetation has been recorded at the site for more than 62 yr. These features indicate the occurrence of a positive-feedback mechanism that has led to alternative s...

  11. Mining and geologic characterization of calcareous resources for the cement industry in Uruguay

    International Nuclear Information System (INIS)

    The main objective of this work was the study of geological and mining potential that Uruguay has on limestone rocks rich in calcium and poor in magnesium and silica, which are considered primary requirements suitable for the manufacture of cement. The results obtained allow defining four major regions of the country that although do not include all occurrences of calcareous rocks, they do not constitute the most important areas concerning: rock quality, higher volumes and improved extraction possibilities. The areas are: Queguay, Minas, Carape and Treinta y tres

  12. Structure and evolution of a rocksalt-mudrock-tectonite: The haselgebirge in the Northern Calcareous Alps

    OpenAIRE

    Leitner, Christoph; Neubauer, Franz; Urai, János L.; Schoenherr, Johannes

    2011-01-01

    The Northern Calcareous Alps are part of the Eastern Alps in Austria and Germany. The Mesozoic units of this fold-and-thrust belt were detached, thrusted and stacked along the evaporitic Haselgebirge Formation. Exposed in salt mines, rocksalt and mudrock form a two component tectonite: The rock type “haselgebirge” consists of 10–70 wt % halite with silt- to gravel- or block-sized components within a halite matrix, and the “kerngebirge” with >70 wt % halite. All rock types studied are fault ro...

  13. The calcareous mires in South-East Poland are home to two rare Anthracoidea species

    Directory of Open Access Journals (Sweden)

    Marcin Piątek

    2013-12-01

    Full Text Available The new collections of Anthracoidea buxbaumii Kukkonen on Carex buxbaumii Wahlenb. and Anthracoidea hostianae B.Lindeb. ex Nannf. on Carex lepidocarpa Tausch recorded in the calcareous mires in South-East Poland are described, illustrated and discussed. The holotype of the latter smut is also re-examined, described and illustrated in detail. Anthracoidea buxbaumii is reported for the second time from Poland on a new host plant. Anthracoidea hostianae is new to Poland. The variability of spore sizes of both species is discussed. The conspecificity of Anthracoidea buxbaumii and A. hostianae suggested in the literature is analyzed.

  14. CALCAREOUS NANNOFOSSIL BIOSTRATIGRAPHY AND CHRONOSTRATIGRAPHY OF ODP HOLE 964D (EASTERN MEDITERRANEAN SEA

    Directory of Open Access Journals (Sweden)

    ENRICO DI STEFANO

    2008-07-01

    Full Text Available Quantitative analyses of calcareous nannofossil were carried out on sediments from ODP Hole 964D succession, recovered in the Ionian Sea, Eastern Mediterranean. Results show that the sedimentary sequence, spanning from about 3.5 Ma (Early Pliocene to the Present, has been investigated through an average sampling resolution of less than 30 kyr. The detailed subdivision into 11 biozones makes it possible to recognize chronostratigraphic the boundaries in the Early Pliocene-Middle Pleistocene interval. Finally, two sedimentary gaps, lasting at least 340 kyr and 120 kyr respectively, have been recognized between the Zanclean and Piacenzian and in the lower part of the Early Pleistocene. SHORT NOTE

  15. Technical Note: Disturbance of soil structure can lead to release of methane entrapped in glacier forefield soils

    Directory of Open Access Journals (Sweden)

    P. A. Nauer

    2013-09-01

    Full Text Available Investigations of sources and sinks of atmospheric CH4 are needed to understand the global CH4 cycle and climate-change mitigation options. Glaciated environments might play a critical role due to potential feedbacks with global glacial meltdown. In an emerging glacier forefield, an ecological shift occurs from an anoxic, potentially methanogenic subglacial sediment to an oxic proglacial soil, in which soil-microbial consumption of atmospheric CH4 is initiated. The development of this change in CH4 turnover can be quantified by soil-gas profile analysis. We found evidence for CH4 entrapped in glacier forefield soils when comparing two methods for the collection of soil-gas samples: a modified steel rod (SR designed for one-time sampling and rapid screening (samples collected ~ 1 min after hammering the SR into the soil, and a novel multi-level sampler (MLS for repetitive sampling through a previously installed access tube (samples collected weeks after access-tube installation. In glacier forefields on siliceous bedrock, sub-atmospheric CH4 concentrations were observed with both methods. Conversely, elevated soil-CH4 concentrations were observed in calcareous glacier forefields, but only in samples collected with the SR, while MLS samples all showed sub-atmospheric CH4 concentrations. Time-series SR soil-gas sampling (additional samples collected 2, 3, 5, and 7 min after hammering confirmed the transient nature of the elevated soil-CH4 concentrations, which were decreasing from ~ 100 μL L−1 towards background levels within minutes. This hints towards the existence of entrapped CH4 in calcareous glacier forefield soil that can be released when sampling soil-gas with the SR. Laboratory experiments with miniature soil cores collected from two glacier forefields confirmed CH4 entrapment in these soils. Treatment by sonication and acidification resulted in a massive release of CH4 from calcareous cores (on average 0.3–1.8 μg CH4 (g d.w.−1

  16. Speciation of plutonium and americium in the soils affected by Kraton-3 accidental underground nuclear explosion in Yakutia (Russia)

    International Nuclear Information System (INIS)

    In calcareous soils from Yakutia only 0.1 % or less 239Pu and 241Am exist in water-soluble form, i.e., the mobility of these radionuclides is relatively low. In the top humus-containing layer (0-4 cm) 239Pu and 241Am are distributed uniformly between organic and inorganic soil components. In the bottom soil layer (20-30 cm) the radionuclides are present mainly in inorganic soil components. The estimation of the radionuclide mobility demonstrates that 241Am is potentially a more mobile element than 239Pu. In the considered calcareous soils collected from the top layer 239Pu and 241Am exist both in humic and fulvic acids (FA). 241Am is much stronger bound to the group of mobile FA than 239Pu. In the bottom soil layer 239Pu and 241Am have been found mainly in FA. (author)

  17. Calcareous dinoflagellate cyst evolution and their response to the environmental changes related to the Messinian salinity crisis in the eastern (Cyprus) and central (Sicily) Mediterranean

    OpenAIRE

    Bison, Katarzyna-Maria

    2011-01-01

    Past climatic and environmental conditions can be reconstructed by the use of different types of microfossils as proxies. Calcareous cyst producing dinoflagellates (calcareous dinoflagellates) were shown to have a high proxy potential. They provide a good fossil record. Several studies on Quaternary sediments have confirmed their usability for environmental reconstructions. However, these studies mainly focused on Quaternary records derived from surface sediments. Palaeoenvironmental reconstr...

  18. Fragmentation, Fusion, and Genetic Homogeneity in a Calcareous Sponge (Porifera, Calcarea).

    Science.gov (United States)

    Padua, André; Leocorny, Pedro; Custódio, Márcio Reis; Klautau, Michelle

    2016-06-01

    Sessile marine invertebrates living on hard substrata usually present strategies such as size variations, longer life spans, fragmentation and fusion to occupy and compete for space. Calcareous sponges are usually small and short-lived, and some species are known to undergo frequent fragmentation and fusion events. However, whether fusion occurs only between genetically identical individuals remains unclear. We investigated the occurrence of chimaeras in the calcareous sponge Clathrina aurea by following the dynamics of fragmentation and fusion of 66 individuals in the field for up to 18 months and determined size variations and the life span of each individual. Microsatellites were used to determine whether fusion events occur among genetically different individuals. Growth and shrinkage of individuals were frequently observed, showing that size cannot be associated with age in C. aurea. The life span of the species ranged from 1 to 16 months (mean: 4.7 months). Short life spans and variable growth rates have been observed in other species of the class Calcarea. Fragmentation and fusion events were observed, but fusion events always occurred between genetically identical individuals, as has been suggested by graft experiments in adult Demospongiae and other Calcarea. These results suggest that at least C. aurea adults may have some mechanism to avoid chimaerism. PMID:27194182

  19. The effects of tropospheric ozone on the species dynamics of calcareous grassland

    International Nuclear Information System (INIS)

    Although ozone has been shown to reduce the growth of individual species and to alter the composition of simple species mixtures, there is little understanding of its long-term effects on species dynamics and composition in real communities. Intact turfs of calcareous grassland were exposed to four different ozone regimes in open-top chambers over three consecutive summers. Treatments provided a mean seasonal AOT40 ranging from approximately zero to 15 ppm h. Cumulative ozone exposure was a significant factor in compositional change, but only explained 4.6% of the variation. The dominant grass species (Festuca rubra) showed a consistent decline in cover in the high ozone treatment over time and the forb Campanula rotundifolia was lost from all three ozone treatments. The frequency of some species (Galium verum and Plantago lanceolata) increased with ozone exposure. Long-term effects of ozone on species composition in chalk grassland may be a function of both the sensitivity of individual species and the response of the dominant species. - Exposure of calcareous grassland turfs to ozone for three years resulted in small, but significant, changes in species composition

  20. The effects of tropospheric ozone on the species dynamics of calcareous grassland

    Energy Technology Data Exchange (ETDEWEB)

    Thwaites, R.H. [Department of Biology, Imperial College, Silwood Park, Ascot, Berkshire SL5 7PY (United Kingdom); Ashmore, M.R. [Environment Department, University of York, Heslington, York YO10 5DD (United Kingdom); Morton, A.J. [Department of Biology, Imperial College, Silwood Park, Ascot, Berkshire SL5 7PY (United Kingdom); Pakeman, R.J. [Ecology of Grazed Ecosystems, Macaulay Institute, Craigiebuckler, Aberdeen AB15 8QH (United Kingdom)]. E-mail: r.pakeman@macaulay.ac.uk

    2006-11-15

    Although ozone has been shown to reduce the growth of individual species and to alter the composition of simple species mixtures, there is little understanding of its long-term effects on species dynamics and composition in real communities. Intact turfs of calcareous grassland were exposed to four different ozone regimes in open-top chambers over three consecutive summers. Treatments provided a mean seasonal AOT40 ranging from approximately zero to 15 ppm h. Cumulative ozone exposure was a significant factor in compositional change, but only explained 4.6% of the variation. The dominant grass species (Festuca rubra) showed a consistent decline in cover in the high ozone treatment over time and the forb Campanula rotundifolia was lost from all three ozone treatments. The frequency of some species (Galium verum and Plantago lanceolata) increased with ozone exposure. Long-term effects of ozone on species composition in chalk grassland may be a function of both the sensitivity of individual species and the response of the dominant species. - Exposure of calcareous grassland turfs to ozone for three years resulted in small, but significant, changes in species composition.

  1. The siliceous-calcareous-argillaceous rock type uranium deposit in south subzone of Western Qinling

    International Nuclear Information System (INIS)

    The siliceous-calcareous-argillaceous rock type uranium deposit in south subzone of western Qinling is an inland found type deposit with specific mineralization and good potentiality. The mineralization distributes along definite horizons and occurs in siliceous layer and lenses of siliceous-calcareous rocks. Orebody presents in forms of stratoid, lenticular and irregular veins and controlled by factorial structures. Ore is identified as massive and sandy and each characterized by various mineral compositions and element associations. The study shows that the mineralizing materials are mainly derived from ore-bearing strata. The metallogenic environment has characteristics of middle-low temperature and supergene The metallogenesis underwent three stages: (1) Sedimentation-diagenesis of the ore-bearing strata led to preliminary concentration of uranium; (2) Polytectonic activities accompanied by underground hydrothermal process resulted in the industrial concentration of uranium; and (3) Orebody reworked by oxidation-denudation and leaching, locally has taken place secondary concentration. The deposit in origin attributes to polygenesis dominated by underground hydrothermal metallogenesis. Main metallogenic epoch happens during the periods of Late Yanshan and Himalayan. According to the geological-tectonic conditions the further prospecting direction in study area is proposed. (3 refs., 5 figs., 9 tabs.)

  2. Comparisons of late quaternary climatic development between the Arctic and Antarctic through calcareous nannofossils

    International Nuclear Information System (INIS)

    The content of calcareous nannofossils (remnants of microscopic planktonic algae) have been documented in numerous sediment cores from the Norwegian and Greenland Seas and in ODP Hole 704A from the subantarctic South Atlantic. Worldwide species extinctions, inceptions and distinct abundance variations have been used to correlate and date the studied cores, which comprise the last 500,000 years. The biostratigraphy has been correlated to oxygen isotope stratigraphy which shows that intervals rich in nannofossils represent interglacial time periods. The calcareous nannofossils indicate that during the time period studied, climatic fluctuations were similar in character and timing in both the subarctic and the subantarctic South Atlantic. Abundance patterns of warm water species suggest that surface waters were warmer than today only during oxygen isotope substage 5e (the last interglacial). The environment was interglacial also during isotope stages 9, 11, and 13, while stages 3 and 8 may have been characterized by intermediate glacial conditions. A significantly colder environment than at present prevailed in isotope stages 2, 4, 6, 10 and 12. Isotope stage 7 appears to have been fully interglacial in the subantarctic South Atlantic, but intermediate glacial in the Norwegian sea

  3. Dark gray soils on two-layered deposits in the north of Tambov Plain: Agroecology, properties, and diagnostics

    Science.gov (United States)

    Zaidelman, F. R.; Nikiforova, A. S.; Stepantsova, L. V.; Volokhina, V. P.

    2012-05-01

    Dark gray soils in the Tambov Plain are developed from the light-textured glaciofluvial deposits underlain by the calcareous loam. Their morphology, water regime, and productivity are determined by the depth of the slightly permeable calcareous loamy layer, relief, and the degree of gleyzation. The light texture of the upper layer is responsible for its weak structure, high density, the low content of productive moisture, and the low water-holding capacity. If the calcareous loam is at a depth of 100-130 cm, dark gray soils are formed; if it lies at a depth of 40-70 cm, temporary perched water appears in the profile, and dark gray contact-gleyed soils are formed. Their characteristic pedofeatures are skeletans in the upper layers, calcareous nodules in the loamy clay layer, and iron nodules in the podzolized humus and podzolic horizons. The appearance of Fe-Mn concretions is related to gleyzation. The high yield of winter cereals is shown to be produced on the dark gray soils; the yields of spring crops are less stable. Spring cereals should not be grown on the contact-gleyed dark gray soils.

  4. Influence of Irrigation Rate and Soil Type on the Vertical Migration of Iron and Manganese in the Soils of South-East Spain

    International Nuclear Information System (INIS)

    The citrus plantations in south-east Spain, situated largely on calcareous soils which are submitted to intensive cultivation, are investigating nutritional changes caused mainly by deficiencies of trace elements, especially iron and manganese, which result in a lower yield and premature exhaustion of the trees. The paper deals with a radioactive tracer study of the behaviour of these ions in soils and with the factors influencing their migration to the root zone; the object of the work is to develop a rational and economic fertilization policy. The work has been based on two types of soil, representing extreme situations encountered in practice; one soil is calcareous and the other non-calcareous. A set of columnsiwas assembled, each column having a length of 1 m and a cross-section of 32 cm2 ; solutions of 59Fe and 54Mn were added to these columns both in sulphate and chelate form. A definite amount of water, proportional to the requirements .of citrus plantations, was intermittently passed through these columns. Soil samples were taken periodically and the total activity and the activity of the assimilable and non-assimilable fractions of the elements being studied were measured. At the same time an apparatus involving a collimated scintillation detector was developed to follow the vertical migration of these ions in soils; the water drained from the columns after each irrigation was analysed radiochemically for the same purpose. (author)

  5. Heavy metals in some French forest soils : Distribution, origin and controlling factors

    OpenAIRE

    Probst, Anne; Hernandez, Laura; Probst, Jean-Luc; Ulrich, Erwin

    2003-01-01

    The lowest heavy metal contents are observed in acid soils while the highest contents are in the mollic andosol and in the calcaric cambisol. Cr and Ni concentrations increase with depth in all soils, except the podzol. Co, Cu, Zn behaviour depends on the soil. Cu and Zn decrease with depth in some acid soils. Pb and Cd accumulate in all surface horizons. In the dystric planosol and stagnic luvisol, heavy metals accumulate in deep soil horizons (important clay content). The abundance order of...

  6. A laboratory test of NOM-assisted remediation of arsenic and copper contaminated soils

    DEFF Research Database (Denmark)

    Rasmussen, Signe Bonde; Jensen, Julie Katrine; Borggaard, Ole K.

    2015-01-01

    Soils contaminated by arsenic (As) and copper (Cu) must be remediated because As and Cu are non-degradable and toxic. On moderately contaminated soils, As and Cu may be removed by in-situ plant uptake (phytoremediation), whereas strongly contaminated soils must be removed and cleaned by soil...... washing at a soil disposal site (ex-situ). Strong bonding of As and Cu to soil solids requires the use of strong complexants to release the elements. Often synthetic chemicals such as EDTA and NTA are used. Since such chemicals are environmentally problematic, their replacement with natural organic matter...... (NOM) such as humic substances (HS) and citrate might be attractive. To test this possibility, a moderately contaminated calcareous urban soil from a soil depot (called the CRC soil) and a soil from a wood impregnation site (called the CCA soil) highly contaminated with As and Cu were extracted...

  7. Characteristics of Phosphorous Adsorption and Desorption by Organo-Mineral Colloidal Complexes of Purple Paddy Soils

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The kinetic characteristics of P adsorption and desorption by organo-mineral colloidal complexes (OMC)were studied using acid, calcareous and neutral purple paddy soils taken from Chongqing and Sichuan, China.The results showed that the P adsorption capacity of the organo-mineral colloidal complexes differed with the soil types, being higher for the acid and calcareous purple soils than for the neutral purple soils. Partial removal of the organic matter increased the adsorption capacity of the colloidal complexes. A very significant positive correlation was found between the amounts of P desorbed from OMC and the P saturation degrees.The P adsorption reaction was quick at the early stage and slowed later. The raise of temperature increased P adsorption capacity and P adsorption rate of the colloidal complexes. The adsorption processes could be described by the Elovich equation.

  8. Humification degree of Rendzina soil humic acids influenced by carbonate leaching and land use

    Directory of Open Access Journals (Sweden)

    Radmanović Svjetlana B.

    2015-01-01

    Full Text Available The humification degrees of humic acids extracted from calcareous and decarbonated Rendzinas under different land use were characterized upon their optical properties, to evaluate the influence of carbonate leaching (decarbonation and different land uses. Decarbonation influenced the humification degree of humic acids positively. Base leaching and acidification of decarbonated Rendzinas led to a decrease in humification degree of humic acids. In calcareous Rendzinas, the humification degree of humic acids was in descending order: grassland>arable land>forest land, and in decarbonated Rendzinas: arable land>grassland>forest land. The humification degree of humic acids was higher in the calcareous forest and grassland Rendzinas compared to decarbonated Rendzinas, analogously in decarbonated arable land compared to calcareous arable land Rendzinas. Differences in the humification degree of humic acids among various land uses that emerged between calcareous and decarbonated Rendzinas indicate the dominant influence of soil chemical characteristics (carbonate content and pH value compared with the quantity and quality of the organic litter input.

  9. Ocean Acidification: Investigation and Presentation of the Effects of Elevated Carbon Dioxide Levels on Seawater Chemistry and Calcareous Organisms

    Science.gov (United States)

    Buth, Jeffrey M.

    2016-01-01

    Ocean acidification refers to the process by which seawater absorbs carbon dioxide from the atmosphere, producing aqueous carbonic acid. Acidic conditions increase the solubility of calcium carbonate, threatening corals and other calcareous organisms that depend on it for protective structures. The global nature of ocean acidification and the…

  10. Influence of Blended Cements with Calcareous Fly Ash on Chloride Ion Migration and Carbonation Resistance of Concrete for Durable Structures

    Directory of Open Access Journals (Sweden)

    Michał A. Glinicki

    2016-01-01

    Full Text Available The objective of this paper is to examine the possible use of new blended cements containing calcareous fly ash in structural concrete, potentially adequate for structural elements of nuclear power plants. The investigation included five new cements made with different contents of non-clinker constituents: calcareous fly ash, siliceous fly ash, ground granulated blastfurnace slag, and a reference cement—ordinary Portland cement. The influence of innovative cements on the resistance of concrete to chloride and carbonation exposure was studied. Additionally, an evaluation of the microstructure was performed using optical microscopy on concrete thin sections. Test results revealed a substantial improvement of the resistance to chloride ion penetration into concrete containing blended cements. The resistance was higher for increased clinker replacement levels and increased with curing time. However, concrete made with blended cements exhibited higher depth of carbonation than the Portland cement concrete, except the Portland-fly ash cement with 14.3% of calcareous fly ash. The thin sections analysis confirmed the values of the carbonation depth obtained from the phenolphthalein test. Test results indicate the possible range of application for new cements containing calcareous fly ash.

  11. Zanclean/Piacenzian transition on Cyprus (SE Mediterranean): calcareous nannofossil and Sea Surface Temperatures evidence of sapropel formation

    Science.gov (United States)

    Athanasiou, Maria; Triantaphyllou, Maria; Bouloubassi, Ioanna; Dimiza, Margarita; Gogou, Alexandra; Klein, Vincent; Parinos, Constantine; Theodoroyu, George

    2016-04-01

    Quantitative analyses of calcareous nannofossils in the sediments of Pissouri South section on the island of Cyprus have produced a paleoceanographic record reflecting the paleoclimatic conditions during Zanclean/Piacenzian transition. According to the performed calcareous nannofossil biostratigraphy the studied section is correlated with MNN14/15 and MNN16 calcareous nannofossil biozones and is astronomically dated between 4.065 and 3.217 Ma. Intervals of increased organic carbon content along with the positive values of Florisphaera profunda, Helicosphaera sellii, Discoaster spp. and the subsequent increase of stratification S-index correspond to the sapropel deposition during periods of wetter climate and intense continental runoff especially from the river Nile. These layers are alternating with grey marly intervals, featured by the increased values of small placoliths of Reticulofenestra and Gephyrocapsa species, which are indicative of eutrophic conditions during intense surface waters mixing. Pissouri South section comprises a SSTs sequence using alkenone unsaturation index (Uk 37) providing with the first continuous record from SE Mediterranean covering the Zanclean/Piacenzian (Pliocene) transition (~ 4.1-3.2 Ma). Correlation of the total alkenone concentration to the calcareous nannofossil assemblage and especially representatives among Noelaerhabdaceae family revealed that Pseudoemiliania lacunosa probably had similar temperature sensitivity to that of Emiliania huxleyi, currently producing alkenones in present day oceans.Our data support the prevalence of a generally warm phase characterized by the absence of high-frequency climate variations in the southeastern Mediterranean during the Zanclean/Piacenzian (Early/Late Pliocene) transition.

  12. Miocene oceanographic changes of the western equatorial Atlantic (Ceara Rise) based on calcareous dinoflagellate cysts

    Science.gov (United States)

    Heinrich, S.; Zonneveld, K. A. F.; Willems, H.

    2010-09-01

    The middle- and upper Miocene represent a time-interval of major changes in palaeoceanography that favoured the cooling of the climate and culminated in the Northern Hemisphere Glaciation (NHG). The basis for the development of the modern deepwater circulation pattern, e.g. thermohaline circulation, was hereby established. Tectonic events played a key role in the progressing Miocene oceanography, such as the narrowing of the Panama gateway (e.g. Duque-Caro 1990) and the possible linked changes in North Atlantic Deep Water formation (Lear et al. 2003). However, the complex interaction between the closing of the Panama Gateway, the development of NADW, and thus the oceanographic progression towards our present day circulation is far from being fully understood. We want to improve the understanding of these processes by establishing a detailed palaeoceanographic reconstruction of the western equatorial Atlantic Ocean on the basis of calcareous dinoflagellate cyst (dinocyst) associations. Within this study, we investigated sediment samples from ODP Site 926A by defining the calcareous dinocyst assemblage. Site 926A is located at the southwestern flank of the Ceara Rise, an area of highest sensitivity to global deep water circulation changes. At about 12 Ma, when NADW production increased (e.g. Wright et al. 1992), we see a distinct increase in the absolute abundances of the calcareous dinocysts. This might be related to enhanced productivity or to better carbonate preservation. At 11.3 Ma, Leonella granifera, a species known to be strongly related to terrestrial input occurs. This could be a signal for the initiation of the Amazon River as a transcontinental river with the development of the Amazon fan (11.8 - 11.3 Ma; Figueiredo et al. 2009) in relation to Andean tectonism. References: Duque-Caro, H. (1990): Neogene stratigraphy, paleoceanography and palebiology in Northwest South America and the evolution of the Panama Seaway. Palaeogeography, Palaeoclimatology

  13. Calcareous sinter from ancient aqueducts as a source of data in paleoclimate, tectonics and hydrology

    Science.gov (United States)

    Surmelihindi, G.; Passchier, C. W.

    2010-12-01

    During the lifetime the Roman Empire (300BC-400AD), about 1200 major aqueducts were built to supply cities in the Mediterranean with drinking water. The ruins of many of these channels contain sinter (calcium carbonate), which was deposited at a rate of 0.5-5 mm/year over the life of the aqueduct, usually 50-200 but up to 1000 years. Calcareous sinter inside the ancient aqueduct channels can give important insight into paleoclimatology in the form of temperature and rainfall, reflect palaeohydrology of water, water chemistry, flow rate, bacterial activity and source area of the water. This type of data is important to build climate models and to understand earthquake and flood patterns in the Mediterranean, and can be a new, additional source of information besides speleothems, travertine and tufa deposits. In our study we focus on Mediterranean climate patterns, and selected four aqueduct sites from Southern Turkey, Greece and Italy. The calcareous sinter deposits may reflect annual or subannual lamination characterized by alternating light, dense, coarse-grained and dark, porous, microcrystalline layers which are thought to represent winter and summer conditions respectively. Moreover, abrupt changes in the sequence of lamination can be a signal of natural hazards such as earthquakes or flood events. Deposits from the aqueduct of Patara (Southern Turkey) show 40-50 laminae couples, which may be annual layers. δ18O and δ 13C stable isotope data indicate high cyclicity within the sinter samples from Patara during the Roman period. Higher δ18O values correspond with dark, porous layers and lower values with light, dense layers. Major geochemical analyses show similar seasonal changes. Electron microprobe study shows that within dark laminae, detrital Fe, Mg, K, Al and Si are enriched whereas the light layers have high Ca content. Trace element analyses by LA-ICP-MS also indicate higher Mg/Ca and Sr/Ca values in the dark layers, which can be interpreted in terms

  14. Cadmium sorption and mobility in sludge-amended soil

    International Nuclear Information System (INIS)

    Cadmium sorption was examined in three soils that were unamended, freshly amended, or preconditioned with gamma-irradiated sewage sludge. Metal sorption in the same soils treated with a CaCl2-extract of the sludge was also studied. Cadmium sorption was greatest in the unamended soils, less in soils preconditioned with sludge, and least in the freshly amended soils and sludge-extract-treated soils. The authors attempted to explain the treatment effects on the basis of reduced free metal ion activity, but the explanations were not adequate. Despite the reduction in metal retention effected by various treatments, cadmium mobility was very limited. Short- or long-term leaching studies showed cadmium movement to be limited to 1 or 2 m below the zone of sludge (109Cd) incorporation. Cadmium mobility is expected to be very limited in calcareous soils, regardless of sludge treatments. 24 references, 1 figure, 5 tables

  15. Foraminiferans as food for Cephalaspideans (Gastropoda: Opisthobranchia), with notes on secondary tests around calcareous foraminiferans

    DEFF Research Database (Denmark)

    Cedhagen, Tomas

    1996-01-01

    The food of four species of Cephalaspidea (Philine aperta, Philine denticulata, Philine scabra and Cylichna cylindracea) was studied in animals collected on silty clay bottoms at 20-35 m depth on the west coast of Sweden. The specimens were dissected. Only calcareous foraminiferans were found in...... agglutinating foraminiferans surround themselves with a “secondary test”, a cyst or covering of foreign particles around the test. This structure has earlier been called a “reproductive cyst” or “feeding cyst” in some species. “Secondary tests” are primarily connected with feeding, but might also be a...... preadaptation for other purposes. It might, in species like Ammonia batavus, have become a kind of antipredatory device or mimicry. A predator might conceive such a species as an agglutinating species and neglect it. The secondary test is a delicate structure in most species and is easily destroyed by the rough...

  16. Mechanical robustness of the calcareous tubeworm Hydroides elegans: warming mitigates the adverse effects of ocean acidification.

    Science.gov (United States)

    Li, Chaoyi; Meng, Yuan; He, Chong; Chan, Vera B S; Yao, Haimin; Thiyagarajan, V

    2016-01-01

    Development of antifouling strategies requires knowledge of how fouling organisms would respond to climate change associated environmental stressors. Here, a calcareous tube built by the tubeworm, Hydroides elegans, was used as an example to evaluate the individual and interactive effects of ocean acidification (OA), warming and reduced salinity on the mechanical properties of a tube. Tubeworms produce a mechanically weaker tube with less resistance to simulated predator attack under OA (pH 7.8). Warming (29°C) increased tube volume, tube mineral density and the tube's resistance to a simulated predatory attack. A weakening effect by OA did not make the removal of tubeworms easier except for the earliest stage, in which warming had the least effect. Reduced salinity (27 psu) did not affect tubes. This study showed that both mechanical analysis and computational modeling can be integrated with biofouling research to provide insights into how fouling communities might develop in future ocean conditions. PMID:26820060

  17. Trace fossils assemblage and depositional environment of Turonian calcareous sandstones in the southern Benue Trough, Nigeria

    Science.gov (United States)

    Akpan, Etie B.; Nyong, Eyo E.

    A calcareous sandstone sequence that forms part of the Eze-Aku Formation (Reyment) features an assemblage of ichnofossils in a section exposed on a quarry face. The traces encountered include horizontal burrows, some of which are preserved as casts, lined with organic matter and belonging to the ichnogenera Gyrolithes, Pholeus and Arthrophycus. Three other types of trace fossils are described as horizontal crawling trails, flat impressions and cylindrical shafts without formal names. Gyrolithes are by far the dominant traces in this sequence. The degree of bioturbation is high in every horizon. Body fossils are very rare except for scattered occurrence of fragments of calcitic pelecypod shells. Ichnological and lithological considerations suggest that the sediments were deposited in an aerated shallow shelf environment which supported an assemblage of decapods, worms and other shallow water marine benthos. Deposition was generally below wave base under a continuous but relatively slow rate of sedimentation.

  18. SPRINGS WITH CALCAREOUS TUFA IN THE VALLEY OF THE JAMNE CREEK IN GORCE

    Directory of Open Access Journals (Sweden)

    Roksana Krause

    2015-01-01

    Full Text Available The study gives a detail characteristic of a hard water springs habitat with the communities of Cratoneurion commutati (habitat code of Nature 2000: 7220, localized within Nature 2000 protected area Ostoja Gorczańska PLH120018, in an upper part of the valley of Jamne creek. The plants are described along with the main habitat parameters, namely: altitude, exposition, slope gradient, insolation, type of bedrock, water flow regime and the spring outflow efficiency. The temperature, pH, electrical conductivity were measured in the field, the concentrations of Ca and Mg in spring water were measured by Atomic Absorption Spectroscopy (AAS. The investigated headwater areas are small (0.7–80 m2 and highly differentiated by the intensity of calcareous tufa precipitation and the degree of plant cover development.

  19. Use of Amynthas gracilis (Oligochaeta, Megascolecidae) and Bougainvillea litter for rehabilitation of overexploited soils, in Campeche, Yucatan Peninsula, Mexico.

    Science.gov (United States)

    Huerta, Esperanza; Alonso Gongora, Erick

    2014-05-01

    Yucatan peninsula is one of the recent emerged lands in Mexico; where more of the soils have low organic matter content, and/or the organic horizon is thin (2-5cm). The industry of material extraction for construction purposes is well developed in Yucatan Peninsula, due to the fact of the calcareous material that can be obtained by the maternal rock. Therefore, the material extraction promotes the desertification of the areas, and soil erosion. Bougainvillea sp is a tropical and subtropical woody, evergreen, shrubby vine (Kobayashi et al. 2007), it has a wide range of distribution and it roots are superficial, what allows the plant to inhabit soils with a thin layer of soil organic matter. Earthworms as ecosystem engineers (Jones et al. 1994) can modify their environment, forming borrows and incorporation organic matter into the soil. The aim of this study was to rehabilitate soils without organic matter horizon by the use of earthworms and Bougainvillea litter. The study was developed at mesocosmos level in the laboratory of soils at El Colegio de la Frontera Sur, Unidad Campeche, Mexico. Individual of anecic earthworms were collected and reproduced previously, anecic worms can better incorporate organic matter in to the soil than epigeics or endogeics worms, in Mexican tropical terrestrial ecosystems, anecic worms are almost absent or scarce. In this study we used the exotic earthworm Amynthas gracilis (native in Taiwan),that used to inhabit banana plantations with low technology in southeast Mexico, as exotic has a wide range of tolerance to different amounts of soil organic matter and pH. Four treatments with 4 replicas were established: a) calcareous soil without organic matter horizon+earthworms+litter, b) calcareous soil with organic matter horizon+ earthworms+litter, c) calcareous soil without organic matter horizon+litter, d) calcareous soil with organic matter horizon+litter. After 60 days of study, we observed how earthworms developed successfully in

  20. Retention supports and geochemical interactions of Trace Elements in two soils irrigated by sewage (Meknes, Morocco

    Directory of Open Access Journals (Sweden)

    Zein OULD ARBY

    2013-05-01

    Full Text Available The Ourzirha area located in the north-western of the Meknes City is an important agricultural region. This region is one of the principal suppliers of agricultural products to the Meknes citizens. However, the cultivated areas in the Ourzirha region are irrigated by a raw wastewater in major part. To explain and to predict the principal supports of the Trace Elements retention in these soils, two profiles subject to a sewage spreading are taken, a calcareous soil and a vertisol. Based on the vertical evolution of different studied parameters and the selective affinities of Trace Elements to the active soil fractions present in our profiles, we are tried to determine the various interactions between the considered Trace Elements and the clay, calcite and organic matter contents in studied profiles. The results of this study showed the importance of clay and organic matter as a dominant supports of these pollutants, especially in surface soil. In the calcareous soil, the calcite content influences strongly the distribution of Trace Elements along this profile. The mechanisms of the Trace Elements retention on studied profiles are considered as a selective adsorption on organic matter, clay and on calcite essentially. In fact, the possibility of a weak co-precipitation with calcite and organic matter in the calcareous soil isn't excluding. Also, in the vertisol probably, the Trace Elements contents are strongly influenced by the particular entering, favoured by a macro-porosity of this profile.

  1. Spatial and seasonal reef calcification in corals and calcareous crusts in the central Red Sea

    KAUST Repository

    Roik, Anna

    2015-12-14

    The existence of coral reef ecosystems critically relies on the reef carbonate framework produced by scleractinian corals and calcareous crusts (i.e., crustose coralline algae). While the Red Sea harbors one of the longest connected reef systems in the world, detailed calcification data are only available from the northernmost part. To fill this knowledge gap, we measured in situ calcification rates of primary and secondary reef builders in the central Red Sea. We collected data on the major habitat-forming coral genera Porites, Acropora, and Pocillopora and also on calcareous crusts (CC) in a spatio-seasonal framework. The scope of the study comprised sheltered and exposed sites of three reefs along a cross-shelf gradient and over four seasons of the year. Calcification of all coral genera was consistent across the shelf and highest in spring. In addition, Pocillopora showed increased calcification at exposed reef sites. In contrast, CC calcification increased from nearshore, sheltered to offshore, exposed reef sites, but also varied over seasons. Comparing our data to other reef locations, calcification in the Red Sea was in the range of data collected from reefs in the Caribbean and Indo-Pacific; however, Acropora calcification estimates were at the lower end of worldwide rates. Our study shows that the increasing coral cover from nearshore to offshore environments aligned with CC calcification but not coral calcification, highlighting the potentially important role of CC in structuring reef cover and habitats. While coral calcification maxima have been typically observed during summer in many reef locations worldwide, calcification maxima during spring in the central Red Sea indicate that summer temperatures exceed the optima of reef calcifiers in this region. This study provides a foundation for comparative efforts and sets a baseline to quantify impact of future environmental change in the central Red Sea.

  2. CALCAREOUS NANNOFOSSIL BIOSTRATIGRAPHY OF UPPER CALLOVIAN-LOWER BERRIASIAN SUCCESSIONS FROM THE SOUTHERN ALPS, NORTH ITALY

    Directory of Open Access Journals (Sweden)

    CRISTINA EMANUELA CASELLATO

    2010-11-01

    Full Text Available Calcareous nannofossil biostratigraphy was investigated in uppermost Callovian-lower Berriasian sections from Southern Alps, previously detected through magnetostratigraphy, in order to achieve an integrated stratigraphic framework valid at low latitudes. Nannofossil investigations were carried out on smear slides and ultra-thin sections, revealing generally scarce to common abundances and poor-moderate preservation of nannofloras. An exhaustive taxonomic revision was performed to unambiguously separate forms which are transitional between two species and better delineate rapidly evolving groups. Four new species have been described: Zeugrhabdotus fluxus, Nannoconus puer, Nannoconus erbae, Hexalithus geometricus. Particular attention was paid to taxonomical aspects of primitive nannoconids, appearing and evolving across the early-late Tithonian transition and the Tithonian/Berriasian boundary intervals; the revision was also verified at DSDP Site 534A from Atlantic Ocean. Fourty-eight nannofossil bioevents were detected and the results help to increase potential stratigraphic resolution in this interval. Thirty-seven nannofossil bioevents in the upper Kimmeridgian-lower Berriasian interval have been directly correlated to magnetostratigraphy (CM22-CM17 revealing a systematically older stratigraphic occurrence of these taxa than previously reported. A revised and partly new Tethyan calcareous nannofossil zonation scheme is here proposed for the uppermost Callovian-lower Berriasian interval. It consists of seven bio-zones and eight subzones based on thirty-one bioevents, thirteen of them related to dissolution resistant taxa assuring highest reproducibility even in sections with high diagenetic overprint. The proposed biostratigraphic scheme gives higher resolution than previous zonations, especially for the Callovian-Kimmeridgian interval, where no biozonation was available for the Tethyan Realm. 

  3. Spatial and seasonal reef calcification in corals and calcareous crusts in the central Red Sea

    Science.gov (United States)

    Roik, Anna; Roder, Cornelia; Röthig, Till; Voolstra, Christian R.

    2016-06-01

    The existence of coral reef ecosystems critically relies on the reef carbonate framework produced by scleractinian corals and calcareous crusts (i.e., crustose coralline algae). While the Red Sea harbors one of the longest connected reef systems in the world, detailed calcification data are only available from the northernmost part. To fill this knowledge gap, we measured in situ calcification rates of primary and secondary reef builders in the central Red Sea. We collected data on the major habitat-forming coral genera Porites, Acropora, and Pocillopora and also on calcareous crusts (CC) in a spatio-seasonal framework. The scope of the study comprised sheltered and exposed sites of three reefs along a cross-shelf gradient and over four seasons of the year. Calcification of all coral genera was consistent across the shelf and highest in spring. In addition, Pocillopora showed increased calcification at exposed reef sites. In contrast, CC calcification increased from nearshore, sheltered to offshore, exposed reef sites, but also varied over seasons. Comparing our data to other reef locations, calcification in the Red Sea was in the range of data collected from reefs in the Caribbean and Indo-Pacific; however, Acropora calcification estimates were at the lower end of worldwide rates. Our study shows that the increasing coral cover from nearshore to offshore environments aligned with CC calcification but not coral calcification, highlighting the potentially important role of CC in structuring reef cover and habitats. While coral calcification maxima have been typically observed during summer in many reef locations worldwide, calcification maxima during spring in the central Red Sea indicate that summer temperatures exceed the optima of reef calcifiers in this region. This study provides a foundation for comparative efforts and sets a baseline to quantify impact of future environmental change in the central Red Sea.

  4. Soil-geomorphology interactions and paleoclimatic implications of an ornithogenic soil toposequence on Rata Island, Fernando de Noronha Archipelago, South Atlantic

    Science.gov (United States)

    de Oliveira, Fábio Soares; Schaefer, Carlos Ernesto G. R.; Abrahão, Walter Antônio Pereira; Clemente, Eliane de Paula; Simas, Felipe Nogueira Bello

    2014-07-01

    The formation of highly phosphatized soils on sites of avian activity is a common feature of oceanic islands. We characterized a toposequence of phosphatic soils on Rata Island, to evaluate the soil genesis based on local topographic variations. For this purpose, four soils ranging from the upper hill down to the lowest landscape position on the island, representing a range of parent materials (basalt and calcareous sands), were analyzed. In the lowest landscape position a shallow Regosol was identified, strongly influenced by birds and marine sprays, developed on “karstified” Pleistocene calcarenites; the three other soils in the upper part of the toposequence are Ornithogenic Cambisols, ranging from a deep Cambisol profile on Basalt lava to intermediate Cambisols on mixed colluvial sediments of the basalt/calcareous. The lowermost Regosol is associated with a rugged landscape with strong calcarenite dissolution and karstification. The soil phosphatization is clearly an inherited process of the Late Quaternary age, when climate conditions were different. Initial weathering took place in the last interglacial period, under wetter conditions during which the Tertiary basalts were strongly weathered, leaving corestones in a saprolitic, oxidized mass. In the late Pleistocene, a gentle surface distributed these weathering products along the pediment slopes as colluvial materials, whereas in the coastal areas aeolian processes formed large sand dunes composed of reworked calcareous sands from marine sources during a time of very low sea level. During this time, widespread bird activity accounted for secondary apatite formation on the surface of calcareous oolites. Finally, the Holocene warming was accompanied by increasing sea level, enhanced tropical weathering, Fe and Al mobility and variscite formation superimposed on degraded Ca-phosphates, forming two phase phosphatic aggregates.

  5. Electrical Characteristics and Desorption Kinetics of Soil Boron

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The status and activities of boron in soils were studied by the approach of electro-ultrafiltration (EUF). The samples of soils, including brown-red soil and calcareous alluvial soil, were collected from Hubei Province of China. The soil samples were incubated in saturated water and then their nutrients were ultrafiltrated with EUF equipment. Filtration and extraction were conducted in accordance with routine process, but fractions in anode and cathode were all collected. Analyses of B, K+, Mg2+, Ca2+, C1- and pH in fractions supposed that boron existed not only in a simple form of borate but also in ion-pair with cations partly in acidic soil,and borate was the primary form existing in the calcareous soil. In studying desorption kinetics with EUF,the boron content of Fractions 2~6 was accumulated, and the accumulative quantities were fit to time factors in three kinetic equations: the zero-order, first-order, and arabolic diffusion equations. Fit degree of the parabolic diffusion equation was the best, followed by the zero-order quation, and the first-order equation was the worst.

  6. Changes in metal availability, desorption kinetics and speciation in contaminated soils during repeated phytoextraction with the Zn/Cd hyperaccumulator Sedum plumbizincicola.

    Science.gov (United States)

    Li, Zhu; Jia, Mingyun; Wu, Longhua; Christie, Peter; Luo, Yongming

    2016-02-01

    Phytoextraction is one of the most promising technologies for the remediation of metal contaminated soils. Changes in soil metal availability during phytoremediation have direct effects on removal efficiency and can also illustrate the interactive mechanisms between hyperaccumulators and metal contaminated soils. In the present study the changes in metal availability, desorption kinetics and speciation in four metal-contaminated soils during repeated phytoextraction by the zinc/cadmium hyperaccumulator Sedum plumbizincicola (S. plumbizincicola) over three years were investigated by chemical extraction and the DGT-induced fluxes in soils (DIFS) model. The available metal fractions (i.e. metal in the soil solution extracted by CaCl2 and by EDTA) decreased greatly by >84% after phytoextraction in acid soils and the deceases were dramatic at the initial stages of phytoextraction. However, the decreases in metal extractable by CaCl2 and EDTA in calcareous soils were not significant or quite low. Large decreases in metal desorption rate constants evaluated by DIFS were found in calcareous soils. Sequential extraction indicated that the acid-soluble metal fraction was easily removed by S. plumbizincicola from acid soils but not from calcareous soils. Reducible and oxidisable metal fractions showed discernible decreases in acid and calcareous soils, indicating that S. plumbizincicola can mobilize non-labile metal for uptake but the residual metal cannot be removed. The results indicate that phytoextraction significantly decreases metal availability by reducing metal pool sizes and/or desorption rates and that S. plumbizincicola plays an important role in the mobilization of less active metal fractions during repeated phytoextraction. PMID:26650084

  7. Steel Slag as an Iron Fertilizer for Corn Growth and Soil Improvement in a Pot Experiment

    Institute of Scientific and Technical Information of China (English)

    WANG Xian; CAI Qing-Sheng

    2006-01-01

    The feasibility of steel slag used as an iron fertilizer was studied in a pot experiment with corn. Slag alone or acidified slag was added to two Fe-deficient calcareous soils at different rates. Results showed that moderate rates (10 and 20 g kg-1)of slag or acidified slag substantially increased corn dry matter yield and Fe uptake. Application of steel slag increased the residual concentration of ammonium bicarbonate-diethylenetriamine pentaacetic acid (AB-DTPA) extractable Fe in the soils. The increase of extractable Fe was usually proportional to the application rate, and enhanced by the acidification of slag. Steel slag appeared to be a promising and inexpensive source of Fe to alleviate crop Fe chlorosis in Fe-deficient calcareous soils.

  8. SOME PHYSICAL AND CHEMICAL PROPERTIES OF THE RICE GROWN SOILS OF CENTRAL ANATOLIA REGION

    OpenAIRE

    TABAN, SÜleyman; Alpaslan, Mehmet; HASHEMI, Aioub G.; EKEN, Dürdane

    1997-01-01

    The aim of this study was to determine the fertility status of the rice grown soils of Central Anatolia region. For this purpose, 40 soil samples were taken and analyzed for some physical and chemical properties. In general, the experimental soils were clay and loamy clay in texture, medium alkaline in reaction (pH) and moderately calcareous. 60, 25, 30 and 95 % of the soils studied were found to be deficient in total-N, plant available phosphorus, zinc and manganese, respectively. On the ot...

  9. Effect of the Soil pH on the Alkaloid Content of Lupinus angustifolius

    OpenAIRE

    Gisela Jansen; Hans-Ulrich Jürgens; Edgar Schliephake; Frank Ordon

    2012-01-01

    Field studies were conducted in growing seasons 2004, 2005, and 2010 to investigate the effect of different soil pH values on the alkaloid content in seeds of Lupinus angustifolius. Two-year experiments with eleven cultivars were carried out in acid soils with an average of pH=5.8 (Mecklenburg-Western Pomerania) and on calcareous soils with an average pH of 7.1 (Bavaria), respectively. In addition, in 2010, eight cultivars were grown in field experiments in soils with pH values varying betwee...

  10. Using multi-proxy palaeoecology to test a relict status of refugial populations of calcareous-fen species in the Western Carpathians

    Czech Academy of Sciences Publication Activity Database

    Hájková, Petra; Horsák, M.; Hájek, Michal; Jankovská, Vlasta; Jamrichová, Eva; Moutelíková, J.

    2015-01-01

    Roč. 25, č. 4 (2015), s. 702-715. ISSN 0959-6836 Institutional support: RVO:67985939 Keywords : biodiversity * calcareous fen * fossil record * Holocene extinction * Western Carpathians Subject RIV: EF - Botanics Impact factor: 2.283, year: 2014

  11. Biocalcite, a multifunctional inorganic polymer: Building block for calcareous sponge spicules and bioseed for the synthesis of calcium phosphate-based bone

    OpenAIRE

    Xiaohong Wang; Heinz C. Schröder; Müller, Werner E. G.

    2014-01-01

    Calcium carbonate is the material that builds up the spicules of the calcareous sponges. Recent results revealed that the calcium carbonate/biocalcite-based spicular skeleton of these animals is formed through an enzymatic mechanism, such as the skeleton of the siliceous sponges, evolutionarily the oldest animals that consist of biosilica. The enzyme that mediates the calcium carbonate deposition has been identified as a carbonic anhydrase (CA) and has been cloned from the calcareous sponge s...

  12. Soil warming affects soil organic matter chemistry of all density fractions of a mountain forest soil

    Science.gov (United States)

    Schnecker, Jörg; Wanek, Wolfgang; Borken, Werner; Schindlbacher, Andreas

    2016-04-01

    this C-rich calcareous forest soil.

  13. A rapid method for the determination of uranium, thorium and vanadium in calcareous samples by ICP-AES

    International Nuclear Information System (INIS)

    A rapid method for the determination of uranium, thorium and vanadium in calcareous samples of western Rajasthan by Inductively Coupled Plasma Atomic Emission Spectrometry (ICP-AES) after HNO3 leaching and ammonia precipitation was developed. Analytes were quantitatively leached out and pre-concentrated by ammonia precipitation reaction. The effect of various experimental parameters such as acidity, sample amounts and leaching time on the recovery and determination of these elements were investigated in detail. A number of calcareous samples were analysed by the present method. Results were found in good agreement with 5-10% RSD variation with the pre-analysed calcrete samples prepared by usual method of sample preparation using HF and HNO3. (author)

  14. The Eocene Rusayl Formation, Oman, carbonaceous rocks in calcareous shelf sediments: Environment of deposition, alteration and hydrocarbon potential

    Energy Technology Data Exchange (ETDEWEB)

    Dill, H.G.; Wehner, H.; Kus, J. [Federal Institute for Geosciences and Natural Resources, P.O. Box 510163, D-30631 Hannover (Germany); Botz, R. [University Kiel, Geological-Paleontological Department, Olshausenstrasse 40-60, D-24118 Kiel (Germany); Berner, Z.; Stueben, D. [Technical University Karlsruhe, Institute for Mineralogy and Geochemistry, Fritz-Haber-Weg 2, D-76131 Karlsruhe (Germany); Al-Sayigh, A. [Sultan Qaboos University, Geological Dept. PO Box 36, Al-Khod (Oman)

    2007-10-01

    Paralic carbonaceous series intercalated among calcareous shelf sediments have seldom been investigated. During the early Eocene, calcareous and siliciclastic sediments were deposited on a wide shelf in front of low-reliefed hinterland in the Al Khawd region in NE Oman. The siliciclastic-calcareous sediments originated from strongly reworked debris of the Arabic Shield. The underlying Semail Ophiolite did not act as a direct source of debris but provided some heat to increase the maturity of carbonaceous rocks and modify the isotope signal of the calcareous minerals in the Rusayl Formation. A multidisciplinary approach involving sedimentology, mineralogy, chemistry, coal petrography and paleontology resulted in the establishment of nine stratigraphic lithofacies units and provides the reader with a full picture from deposition of the mixed carbonaceous-calcareous-siliciclastic rocks to the most recent stages of post-depositional alteration of the Paleogene formations. The calcareous Jafnayn Formation (lithofacies unit I) developed in a subtidal to intertidal regime, influenced episodically by storms. Deepening of the calcareous shelf towards younger series was ground to a halt by paleosols developing on a disconformity (lithofacies unit II) and heralding the onset of the Rusayl Formation. The stratigraphic lithofacies units III and IV reflect mangrove swamps which from time to time were flooded through washover fans from the open sea. The presence of Spinozonocolpites and the taxon Avicennia, which today belong to a coastal marsh vegetational community, furnish palynological evidence to the idea of extensive mangrove swamps in the Rusayl Formation [El Beialy, S.Y., 1998. Stratigraphic and palaeonenvironmental significance of Eocene palynomorphs from the Rusayl Shale Formation, Al Khawd, northern Oman. Review of Palaeobotany and Palynology 102, 249-258]. During the upper Rusayl Formation (lithofacies units V through VII) algal mats episodically flooded by marine

  15. Ammonium citrate as enhancement for electrodialytic soil remediation and investigation of soil solution during the process

    DEFF Research Database (Denmark)

    Dias-Ferreira, Celia; Kirkelund, Gunvor Marie; Ottosen, Lisbeth M.

    2015-01-01

    Seven electrodialytic experiments were conducted using ammonium citrate as enhancing agent to remediate copper and chromium-contaminated soil from a wood-preservation site. The purpose was to investigate the effect of current density (0.2, 1.0 and 1.5 mA cm−2), concentration of enhancing agent (0...... to remediate metal polluted soils at neutral to alkaline pH by choosing a good enhancement solution........25, 0.5 and 1.0 M) and remediation times (21, 42 and 117 d) for the removal of Cu and Cr from a calcareous soil. To gain insight on metal behavior, soil solution was periodically collected using suction cups. It was seen that current densities higher than 1.0 mA cm−2 did not increase removal and thus...

  16. Productivity response of calcareous nannoplankton to Eocene Thermal Maximum 2 (ETM2

    Directory of Open Access Journals (Sweden)

    M. Dedert

    2012-05-01

    Full Text Available The Early Eocene Thermal Maximum 2 (ETM2 at ~53.7 Ma is one of multiple hyperthermal events that followed the Paleocene-Eocene Thermal Maximum (PETM, ~56 Ma. The negative carbon excursion and deep ocean carbonate dissolution which occurred during the event imply that a substantial amount (103 Gt of carbon (C was added to the ocean-atmosphere system, consequently increasing atmospheric CO2(pCO2. This makes the event relevant to the current scenario of anthropogenic CO2 additions and global change. Resulting changes in ocean stratification and pH, as well as changes in exogenic cycles which supply nutrients to the ocean, may have affected the productivity of marine phytoplankton, especially calcifying phytoplankton. Changes in productivity, in turn, may affect the rate of sequestration of excess CO2 in the deep ocean and sediments. In order to reconstruct the productivity response by calcareous nannoplankton to ETM2 in the South Atlantic (Site 1265 and North Pacific (Site 1209, we employ the coccolith Sr/Ca productivity proxy with analysis of well-preserved picked monogeneric populations by ion probe supplemented by analysis of various size fractions of nannofossil sediments by ICP-AES. The former technique of measuring Sr/Ca in selected nannofossil populations using the ion probe circumvents possible contamination with secondary calcite. Avoiding such contamination is important for an accurate interpretation of the nannoplankton productivity record, since diagenetic processes can bias the productivity signal, as we demonstrate for Sr/Ca measurements in the fine (<20 μm and other size fractions obtained from bulk sediments from Site 1265. At this site, the paleoproductivity signal as reconstructed from the Sr/Ca appears to be governed by cyclic changes, possibly orbital forcing, resulting in a 20–30% variability in Sr/Ca in dominant genera as obtained by ion probe. The ~13 to 21

  17. Reconstruction of Middle Eocene - Late Oligocene Southern Ocean paleoclimate through calcareous nannofossils and stable isotopes

    Science.gov (United States)

    Villa, Giuliana; Fioroni, Chiara; Persico, Davide; Pea, Laura; Bohaty, Steve

    2010-05-01

    The transition from the ice free early Paleogene world to the glaciated conditions of the early Oligocene has been matter of discussion in the last years. This transition has not been monotonic but punctuated by numerous transient cooling and warming events. Here we present a summary of recent studies based on Nannofossil response to climatic changes during the Eocene and Oligocene. Collected data issue from high latitudes ODP Sites 748, 738, 744, 689 and 690. Based on a detailed revision of the biostratigraphy carried out through quantitative analysis, we conducted paleoecological studies on calcareous nannofossils through the late middle Eocene to the - late Oligocene interval to identify abundance variations of selected taxa in response to changes in sea surface temperature (SST) and trophic conditions. The nannofossil-based interpretation has been compared with detailed oxygen and carbon stable isotope stratigraphy confirming the climate variability in the Southern Ocean for this time interval. We identify the Middle Eocene Climatic optimum (MECO) event, related with the regional exclusion of Paleogenic warm-water taxa from the Southern Ocean, followed by the progressive cooling trend particularly emphasized during the cooling events at about 39 Ma, 37 Ma and 35.5 Ma. In the earliest Oligocene, marked changes in calcareous nannofossil assemblages are strikingly associated with the Oi-1 event recorded in perfect accordance with the oxygen isotope records. For most of the Oligocene we recorded a cold phase, while a warming trend is detected in the late Oligocene. In addiction, a marked increase of taxa thriving in eutrophic conditions coupled with a decrease in oligotrophic taxa, suggests the presence of a time interval (from about 36 Ma to about 26 Ma) with prevailing eutrophic conditions that correspond to an increase of the carbon stable isotope curve. This interval well corresponds with the clay mineral concentration that shows at Site 738 a higher

  18. [Effects of dissolved organic matter on napropamide adsorption and transport in soil system].

    Science.gov (United States)

    Ma, Ai-jun; Zhou, Li-xiang; He, Ren-hong

    2006-02-01

    Dissolved organic matter (DOM) can affect the environmental behaviors of herbicides in soil. Batch adsorption and column experiments were conducted to measure the sorption and leaching of napropamide in soils in the presence of DOM derived from green manure (GM) and sewage sludge (SS). DOM reduced sorption of napropamide significantly onto the tested soils, consequently which facilitated the transport of napropamide exhibited by soil column experiment. The sorption inhibition and the increased mobility of napropamide caused by DOM of GM origin were more significant than that of SS origin for the same soil. Within the selected concentration range of the napropamide and DOM in this study napropamide sorption isotherm could be described well by the Freundlich equation. In comparison with the control, DOM of GM and SS origins could reduce napropamide adsorption by 22.9% and 11.3% in the yellow-brown soil and 9.5% and 6.5% in the calcareous soil, respectively. Correspondingly, in the presence of DOM the leaching losses of napropamide in soil column increased by 73.42% and 26.87% in the yellow-brown soil and 43.54% and 28.29% in the calcareous soil, respectively. PMID:16686205

  19. On the peritidal cycles and their diagenetic evolution in the Lower Jurassic carbonates of the Calcare Massiccio Formation (Central Apennines)

    OpenAIRE

    Brandano Marco; Corda Laura; Tomassetti Laura; Testa Davide

    2015-01-01

    This paper shows the environmental changes and high-frequency cyclicity recorded by Lower Jurassic shallow-water carbonates known as the Calcare Massiccio Formation which crop out in the central Apennines of Italy. Three types of sedimentary cycle bounded by subaerial erosion have been recognized: Type I consists of a shallowing upward cycle with oncoidal floatstones to rudstones passing gradationally up into peloidal packstone alternating with cryptoalgal laminites and often bounded by desic...

  20. Thermal Sprayed Aluminium for Subsea Heat Exchanger Surfaces : Effect of Temperature on Protection Current Requirement and Calcareous Development

    OpenAIRE

    Wilson, Håvard

    2014-01-01

    More and more equipment in the Oil and Gas Industry are being placed Subsea. Thisincludes subsea coolers with high internal temperatures. With high temperatures comewith challenges within material selection and corrosion. Traditional material choices like carbon steel and organic coatings with cathodic protection (CP) is not an option for subsea coolers. This is due to insulating properties to the organic coatings and the dense calcareous deposits which form on the surface of the steel.Therma...

  1. Peat characteristics and groundwater geochemistry of calcareous fens in the Minnesota River Basin, U.S.A

    Science.gov (United States)

    Almendinger, J.E.; Leete, J.H.

    1998-01-01

    . Calcareous fens in Minnesota are spring-seepage peatlands with a distinctive flora of rare calciphilic species. Peat characteristics and groundwater geochemistry were determined for six calcareous fens in the Minnesota River Basin to better understand the physical structure and chemical processes associated with stands of rare vegetation. Onset of peat accumulation in three of the fens ranged from about 4,700 to 11,000 14C yrs BP and probably resulted from a combination of climate change and local hydrogeologic conditions. Most peat cores had a carbonate-bearing surface zone with greater than 10% carbonates (average 27%, dry wt basis), an underlying carbonate-depleted zone with 10% or less carbonates (average 4%), and a carbonate-bearing lower zone again with greater than 10% carbonates (average 42%). This carbonate zonation was hypothesized to result from the effect of water-table level on carbonate equilibria: carbonate precipitation occurs when the water table is above a critical level, and carbonate dissolution occurs when the water table is lower. Other processes that changed the major ion concentrations in upwelling groundwater include dilution by rain water, sulfate reduction or sulfide oxidation, and ion adsorption or exchange. Geochemical modeling indicated that average shallow water in the calcareous fens during the study period was groundwater mixed with about 6 to 13% rain water. Carbonate precipitation in the surface zone of calcareous fens could be decreased by a number of human activities, especially those that lower the water table. Such changes in shallow water geochemistry could alter the growing conditions that apparently sustain rare fen vegetation.

  2. A high local species richness and biodiversity within high-latitude calcareous aggregates of tube-building polychaetes

    OpenAIRE

    Haanes, Hallvard; Gulliksen, Bjørn

    2011-01-01

    In general, biodiversity and species richness follow the latitudinal diversity gradient and decrease from the tropics towards the poles. Exceptions have however been recorded, as for deep coldwater coral reefs at high latitudes, which comprise biodiversity hotspots. Here we assess and characterise the high-latitude (69 degrees N) species richness and diversity of a local shallow-water fauna associated with small calcareous aggregations of a serpulid polychaete. A dense and very species r...

  3. Upper Cenomanian – Lower Turonian (Cretaceous calcareous algae from the Eastern Desert of Egypt: taxonomy and significance

    Directory of Open Access Journals (Sweden)

    Ioan I. Bucur

    2010-04-01

    Full Text Available An assemblage of calcareous algae (dasycladaleans and halimedaceans is described from the Upper Cenomanian to Lower Turonian of the Galala and Maghra el Hadida formations (Wadi Araba, northern Eastern Desert, Egypt. The following taxa have been identified: Dissocladella sp., Neomeris mokragorensis RADOIČIĆ & SCHLAGINTWEIT 2007, Salpingoporella milovanovici RADOIČIĆ 1978, Trinocladus divnae RADOIČIĆ 2006, Trinocladus cf. radoicicae ELLIOTT 1968, and Halimeda cf. elliotti CONARD & RIOULT, 1977. Most of the species are recorded from the first time from Egypt. Three of the identified algae (T. divnae, S. milovanovici and H. elliotti also occur in Cenomanian limestones of the Mirdita zone, Serbia, suggesting a trans-Tethyan distribution of these taxa during the early Late Cretaceous. The abundance and preservation of the algae suggest an autochthonous occurrence which can be used for the characterization of the depositional environment. The recorded calcareous as well as the sedimentologic and palaeontologic context of the Galala Formation support an open-lagoonal (non-restricted, warm-water setting. The Maghra el Hadida Formation was mainly deposited in a somewhat deeper, open shelf setting. Calcareous algae (Halimeda cf. elliotti CONARD & RIOULT are restricted to one level in the uppermost Lower Turonian which indicates a brief return to shallow-water deposition after a significant deepening with maximum flooding during the early Early Turonian.

  4. The status of phosphorus in Thai soils and P evaluation using EDTA-NaF extraction method

    Directory of Open Access Journals (Sweden)

    Toru Matoh

    2003-07-01

    Full Text Available Although the available P extracted by Bray II method in tropical soil is low, most of tropical plants can grow well. The objective of this study was to study P status and to evaluate the available P extracted by EDTA-NaF method. Top soil and sub soil of 10 dominant soil series in Thailand were analyzed for some chemical properties and characterization of the forms of phosphorus using EDTA-NaF extraction and successive phosphorus extraction by the modified Sekiya method. The soil total P concentration was 38-1137 mg P2O5 kg-1. The available Bray II-P was very low to high (1-76 mg P2O5 kg-1, and it approximated 0.17-12% of the total P. Iron and aluminum phosphates were the main fraction of inorganic P in acid soil, whereas Ca phosphates were in calcareous soils. Organic P content accounted for 33-67% and most of them were bound with Fe and Al in acid soils and Ca in calcareous soils. P extracted by EDTA-NaF reagent was obviously larger than that of Bray II reagent. The EDTA-NaF extracted P [high molecular weight organic P (HMWP+ inorganic P (EDTA ext Pi] was 7-46% and 1-6% of total P in acid soils and calcareous soils respectively. The EDTA ext Pi tended to be larger than HMWP except in Tk soil. The total amount of extracted P correlated well with Al-Pi and Fe-Pi which were the main fraction of inorganic P. It also correlated with HMWP, but HMWP did not correlate with organic P determine by ignition method and Ca-Po, Fe-Po and Al-Po. The EDTA-NaF method may be suitable for P evaluation in the soils which have high amounts of Fe-Pi, Al -Pi and organic P widely distributed in Thailand.

  5. Role of carbonates in soil organic matter stabilization in agricultural Mediterranean soils

    Science.gov (United States)

    Apesteguía, Marcos; Virto, Iñigo; Plante, Alain

    2016-04-01

    Carbonated soils are present in many semiarid areas, where lithogenic and secondary carbonates are important constituents of the soil mineral matrix. The presence of CaCO3 in calcareous soils has been described as an organic matter stabilization agent mainly due to chemical stabilization mechanisms. In two recent studies in the north of Spain the importance of CaCO3 on soil physical characteristics was highlighted, as they were observed to be acting as macroaggregates stabilization agents. A third study was carried out on the same experimental site, with the hypothesis that the observed differences in aggregation may favor organic matter stabilization in carbonate-containing soils. With that aim we studied the soil physical characteristics (water retention and porosity) and the bioavailability of soil organic matter (SOM) in the two contrasting soils in that site, one Typic Calcixerept (CALC) and one Calcic Haploxerept (DECALC). Bioavailability was evaluated trough the measurement of mineralization rates in a 30 days soil incubations. Intact and disaggregated samples were incubated to evaluate the effect of physical protection on SOM bioavailability in whole soil and macroaggregates 2-5 mm samples. Therefore, four fractions of each soil were studied: intact whole soil soil (D-WS), intact macroaggregates 2-5 mm (I-Magg), and disaggregated macroaggregates (D-Magg). Soil organic carbon content was greater in CALC and had smaller mineralization rates during incubation, indicating a smaller organic matter bioavailability for microbial decomposition. However, the greater increment of mineralization observed in DECALC after disaggregation, together with the scarce differences observed in physical characteristics among both soils, indicate that physical protection was not responsible of greater SOM stability in CALC soil. New hypotheses are needed to explain the observed better protection of organic matter in carbonate-rich Mediterranean soils.

  6. Effect of land use change on soil properties and functions

    Science.gov (United States)

    Tonutare, Tonu; Kõlli, Raimo; Köster, Tiina; Rannik, Kaire; Szajdak, Lech; Shanskiy, Merrit

    2014-05-01

    For good base of sustainable land management and ecologically sound protection of soils are researches on soil properties and functioning. Ecosystem approach to soil properties and functioning is equally important in both natural and cultivated land use conditions. Comparative analysis of natural and agro-ecosystems formed on similar soil types enables to elucidate principal changes caused by land use change (LUC) and to elaborate the best land use practices for local pedo-ecological conditions. Taken for actual analysis mineral soils' catena - rendzina → brown soils → pseudopodzolic soils → gley-podzols - represent ca 1/3 of total area of Estonian normal mineral soils. All soils of this catena differ substantially each from other by calcareousness, acidity, nutrition conditions, fabric and humus cover type. This catena (representative to Estonian pedo-ecological conditions) starts with drought-prone calcareous soils. Brown (distributed in northern and central Estonia) and pseudopodzolic soils (in southern Estonia) are the most broadly acknowledged for agricultural use medium-textured high-quality automorphic soils. Dispersedly distributed gley-podzols are permanently wet and strongly acid, low-productivity sandy soils. In presentation four complex functions of soils are treated: (1) being a suitable soil environment for plant cover productivity (expressed by annual increment, Mg ha-1 yr-1); (2) forming adequate conditions for decomposition, transformation and conversion of fresh falling litter (characterized by humus cover type); (3) deposition of humus, individual organic compounds, plant nutrition elements, air and water, and (4) forming (bio)chemically variegated active space for soil type specific edaphon. Capacity of soil cover as depositor (3) depends on it thickness, texture, calcareousness and moisture conditions. Biological activity of soil (4) is determined by fresh organic matter influx, quality and quantity of biochemical substances and humus

  7. Selective separation of silica from a siliceous-calcareous phosphate rock

    Institute of Scientific and Technical Information of China (English)

    Guo Fang; Li Jun

    2011-01-01

    Selective separation of silica from a siliceous-calcareous phosphate ore that had been sieved into different size fractions is investigated by a combination of chemical analysis, zeta potential measurement and FTIR and XPS techniques. Scrubbing is a better choice than flotation for removing silica from the coarse fractions. The P2O5 grade of the coarse fractions is increased to about 30% by scrubbing and the product yields are higher than those obtained by flotation. The silica in the fine fraction is separated by reverse flotation. An alkyl amine salt (DAH) is an effective collector and the P2Os grade of the fine fraction can be increased by 7% to beyond 30% under acidic conditions. The higher zeta potential obtained using DAH suggests that it is more strongly absorbed onto the ore panicles than the other cationic collectors.FTIR and XPS results confirm physical absorption of the cationic collector onto the ore surface. They also indicate that calcite is dissolved at low pH values, which increases the Si concentration on the ore surface.

  8. Life-cycle traits of Paraleucilla magna, a calcareous sponge invasive in a coastal Mediterranean Basin.

    Directory of Open Access Journals (Sweden)

    Caterina Longo

    Full Text Available The calcareous sponge Paraleucilla magna, originally observed along the Brazilian coast (Atlantic Ocean, is the only allochthonous invasive species of Porifera reported in the Mediterranean Sea. A 1-year investigation of the population dynamics and life-cycle of this exotic species in the Mar Piccolo di Taranto (southern Italy, central Mediterranean Sea has provided a good opportunity to test how environmental variations can influence its life-cycle and to ascertain what strategy can be adopted to successfully colonize a new environment. In the Mar Piccolo di Taranto, P. magna exhibits marked temporal changes in biomass. The studied specimens reproduce almost all year round, showing a seasonal pattern that peaks during warm months. This prolonged sexual activity allows P. magna to continuously produce young specimens, with repeated recruitment events taking place throughout the year, thus offsetting the seasonal mortality of adult specimens. This r-strategy enables the non-indigenous sponge to achieve a high degree of maintenance over relatively long periods (ten years at least.

  9. A Neogene calcareous nannofossil biozonation scheme for the deep offshore Niger Delta

    Science.gov (United States)

    Fadiya, Lawrence Suyi; Salami, Babajide Moshood

    2015-12-01

    A detailed calcareous nannofossil analysis was carried out on the deep-water offshore Niger Delta strata penetrated by eight wells in order to erect a basin-wide Neogene biozonation scheme for the region. Four of the wells penetrated Miocene to Early Pliocene strata while the others drilled through Miocene sediments. The recorded rich and diversified nannofossil suites enabled the subdivision of the Neogene sequences into 13 zones [NN1 (CN1a) - Early Miocene to NN13 (CN10c) - Early Pliocene] and 15 subzones. Five (NN1, NN2, NN4, NN5 and NN11) zones are divided into subzones based on First and Last occurrences plus relative abundance of marker species. Dearth of nannofossils in the Middle Miocene NN5-NN8 zones precludes a refined zonation construction for the interval. Several new criteria are suggested for delineating new and previously erected zones. The resulting refined scheme offers an improved stratigraphic framework for correlation of thin reservoir units within and across Niger Delta fields.

  10. Hydrated calcareous oil-shale ash as potential filter media for phosphorus removal in constructed wetlands.

    Science.gov (United States)

    Kaasik, Ago; Vohla, Christina; Mõtlep, Riho; Mander, Ulo; Kirsimäe, Kalle

    2008-02-01

    The P-retention in hydrated calcareous ash sediment from oil-shale burning thermal power plants in Estonia was studied. Batch experiments indicate good (up to 65 mg P g(-1)) P-binding capacity of the hydrated oil-shale ash sediment, with a removal effectiveness of 67-85%. The high phosphorus sorption potential of hydrated oil-shale ash is considered to be due to the high content of reactive Ca-minerals, of which ettringite Ca6Al2(SO4)3(OH)12.26H2O and portlandite Ca(OH)2 are the most important. The equilibrium dissolution of ettringite provides free calcium ions that act as stable nuclei for phosphate precipitation. The precipitation mechanism of phosphorus removal in hydrated ash plateau sediment is suggested by Ca-phosphate formation in batch experiments at different P-loadings. Treatment with a P-containing solution causes partial-to-complete dissolution of ettringite and portlandite, and precipitation of Ca-carbonate and Ca-phosphate phases, which was confirmed by X-ray diffraction (XRD) and scanning electron microscope (SEM)-EDS studies. Thus, the hydrated oil-shale ash sediment can be considered as a potential filtration material for P removal in constructed wetlands for wastewater treatment. PMID:17959214

  11. The use of point load test for Dubai weak calcareous sandstones

    Directory of Open Access Journals (Sweden)

    Amr Farouk Elhakim

    2015-08-01

    Full Text Available Intact rock is typically described according to its uniaxial compressive strength (UCS. The UCS is needed in the design of geotechnical engineering problems including stability of rock slopes and design of shallow and deep foundations resting on and/or in rocks. Accordingly, a correct measurement/evaluation of the UCS is essential to a safe and economic design. Typically, the UCS is measured using the unconfined compression tests performed on cylindrical intact specimens with a minimum length to width ratio of 2. In several cases, especially for weak and very weak rocks, it is not possible to extract intact specimens with the needed minimum dimensions. Thus, alternative tests (e.g. point load test, Schmidt hammer are used to measure rock strength. The UCS is computed based on the results of these tests through empirical correlations. The literature includes a plethora of these correlations that vary widely in estimating rock strength. Thus, it is paramount to validate these correlations to check their suitability for estimating rock strength for a specific location and geology. A review of the available correlations used to estimate the UCS from the point load test results is performed and summarized herein. Results of UCS, point load strength index and Young's modulus are gathered for calcareous sandstone specimens extracted from the Dubai area. A correlation for estimating the UCS from the point load strength index is proposed. Furthermore, the Young's modulus is correlated to the UCS.

  12. Long-range crystalline order in spicules from the calcareous sponge Paraleucilla magna (Porifera, Calcarea).

    Science.gov (United States)

    Rossi, Andre L; Campos, Andrea P C; Barroso, Madalena M S; Klautau, Michelle; Archanjo, Bráulio S; Borojevic, Radovan; Farina, Marcos; Werckmann, Jacques

    2014-09-01

    We investigated the ultrastructure and crystallographic orientation of spicules from the calcareous sponge Paraleucilla magna (subclass Calcaronea) by transmission and scanning electron microscopy using two different methods of sample preparation: ultramicrotomy and focused ion beam (FIB). It was found that the unpaired actine from the spicules was oriented in the [211] zone axis. The plane that contains the unpaired actine and divides symmetrically the paired actines is the (-120). This plane is a mirror plane of the hexagonal lattice system. All the spicule types analyzed presented the same crystallographic orientation. Electron nanodiffraction maps from 4μm×4μm regions prepared by FIB showed disorientation of <2° between diffraction patterns obtained from neighbor regions, indicating the presence of a unique, highly aligned calcite crystalline phase. Among the eight FIB sections obtained, four presented high pore density. In one section perpendicular to the actine axis pores were observed only in the center of the spicule aligned in a circular pattern and surrounded by a faint circular contour with a larger radius. The presence of amorphous carbon representative of organic molecules detected by electron energy loss spectroscopy was correlated neither with porosity nor with specific lattice planes. PMID:24487057

  13. The use of point load test for Dubai weak calcareous sandstones

    Institute of Scientific and Technical Information of China (English)

    Amr Farouk Elhakim

    2015-01-01

    Intact rock is typically described according to its uniaxial compressive strength (UCS). The UCS is needed in the design of geotechnical engineering problems including stability of rock slopes and design of shallow and deep foundations resting on and/or in rocks. Accordingly, a correct measure-ment/evaluation of the UCS is essential to a safe and economic design. Typically, the UCS is measured using the unconfined compression tests performed on cylindrical intact specimens with a minimum length to width ratio of 2. In several cases, especially for weak and very weak rocks, it is not possible to extract intact specimens with the needed minimum dimensions. Thus, alternative tests (e.g. point load test, Schmidt hammer) are used to measure rock strength. The UCS is computed based on the results of these tests through empirical correlations. The literature includes a plethora of these correlations that vary widely in estimating rock strength. Thus, it is paramount to validate these correlations to check their suitability for estimating rock strength for a specific location and geology. A review of the available correlations used to estimate the UCS from the point load test results is performed and summarized herein. Results of UCS, point load strength index and Young’s modulus are gathered for calcareous sandstone specimens extracted from the Dubai area. A correlation for estimating the UCS from the point load strength index is proposed. Furthermore, the Young’s modulus is correlated to the UCS.

  14. Seasonal exposure to drought and air warming affects soil Collembola and mites.

    Directory of Open Access Journals (Sweden)

    Guo-Liang Xu

    Full Text Available Global environmental changes affect not only the aboveground but also the belowground components of ecosystems. The effects of seasonal drought and air warming on the genus level richness of Collembola, and on the abundance and biomass of the community of Collembola and mites were studied in an acidic and a calcareous forest soil in a model oak-ecosystem experiment (the Querco experiment at the Swiss Federal Research Institute WSL in Birmensdorf. The experiment included four climate treatments: control, drought with a 60% reduction in rainfall, air warming with a seasonal temperature increase of 1.4 °C, and air warming + drought. Soil water content was greatly reduced by drought. Soil surface temperature was slightly increased by both the air warming and the drought treatment. Soil mesofauna samples were taken at the end of the first experimental year. Drought was found to increase the abundance of the microarthropod fauna, but reduce the biomass of the community. The percentage of small mites (body length ≤ 0.20 mm increased, but the percentage of large mites (body length >0.40 mm decreased under drought. Air warming had only minor effects on the fauna. All climate treatments significantly reduced the richness of Collembola and the biomass of Collembola and mites in acidic soil, but not in calcareous soil. Drought appeared to have a negative impact on soil microarthropod fauna, but the effects of climate change on soil fauna may vary with the soil type.

  15. Comparative uptake of plutonium from soils by Brassica juncea and Helianthus annuus

    Energy Technology Data Exchange (ETDEWEB)

    Lee, J.H.; Hossner, L.R.; Attrep, M.; Kung, K.S

    2002-12-01

    Extractability of Pu from soils was most affected by pH and amounts of clay, salts, and carbonates. - Plutonium uptake by Brassica juncea (Indian mustard) and Helianthus annuus (sunflower) from soils with varying chemical composition and contaminated with Pu complexes (Pu-nitrate [{sup 239}Pu(NO{sub 3}){sub 4}], Pu-citrate [{sup 239}Pu(C{sub 6}H{sub 5}O{sub 7}){sup +}], and Pu-diethylenetriaminepentaacetic acid (Pu-DTPA [{sup 239}Pu-C{sub 14}H{sub 23}O{sub 10}N{sub 3}]) was investigated. Sequential extraction of soils incubated with applied Pu was used to determine the distribution of Pu in the various soil fractions. The initial Pu activity levels in soils were 44.40-231.25 Bq g{sup -1} as Pu-nitrate, Pu-citrate, or Pu-DTPA. A difference in Pu uptake between treatments of Pu-nitrate and Pu-citrate without chelating agent was observed only with Indian mustard in acidic Crowley soil. The uptake of Pu by plants was increased with increasing DTPA rates, however, the Pu concentration of plants was not proportionally increased with increasing application rate of Pu to soil. Plutonium uptake from Pu-DTPA was significantly higher from the acid Crowley soil than from the calcareous Weswood soil. The uptake of Pu from the soils was higher in Indian mustard than in sunflower. Sequential extraction of Pu showed that the ion-exchangeable Pu fraction in soils was dramatically increased with DTPA treatment and decreased with time of incubation. Extractability of Pu in all fractions was not different when Pu-nitrate and Pu-citrate were applied to the same soil. More Pu was associated with the residual Pu fraction without DTPA application. Consistent trends with time of incubation for other fractions were not apparent. The ion-exchangeable fraction, assumed as plant-available Pu, was significantly higher in acid soil compared with calcareous soil with or without DTPA treatment. When the calcareous soil was treated with DTPA, the ion-exchangeable Pu was comparatively less

  16. Comparative uptake of plutonium from soils by Brassica juncea and Helianthus annuus

    International Nuclear Information System (INIS)

    Extractability of Pu from soils was most affected by pH and amounts of clay, salts, and carbonates. - Plutonium uptake by Brassica juncea (Indian mustard) and Helianthus annuus (sunflower) from soils with varying chemical composition and contaminated with Pu complexes (Pu-nitrate [239Pu(NO3)4], Pu-citrate [239Pu(C6H5O7)+], and Pu-diethylenetriaminepentaacetic acid (Pu-DTPA [239Pu-C14H23O10N3]) was investigated. Sequential extraction of soils incubated with applied Pu was used to determine the distribution of Pu in the various soil fractions. The initial Pu activity levels in soils were 44.40-231.25 Bq g-1 as Pu-nitrate, Pu-citrate, or Pu-DTPA. A difference in Pu uptake between treatments of Pu-nitrate and Pu-citrate without chelating agent was observed only with Indian mustard in acidic Crowley soil. The uptake of Pu by plants was increased with increasing DTPA rates, however, the Pu concentration of plants was not proportionally increased with increasing application rate of Pu to soil. Plutonium uptake from Pu-DTPA was significantly higher from the acid Crowley soil than from the calcareous Weswood soil. The uptake of Pu from the soils was higher in Indian mustard than in sunflower. Sequential extraction of Pu showed that the ion-exchangeable Pu fraction in soils was dramatically increased with DTPA treatment and decreased with time of incubation. Extractability of Pu in all fractions was not different when Pu-nitrate and Pu-citrate were applied to the same soil. More Pu was associated with the residual Pu fraction without DTPA application. Consistent trends with time of incubation for other fractions were not apparent. The ion-exchangeable fraction, assumed as plant-available Pu, was significantly higher in acid soil compared with calcareous soil with or without DTPA treatment. When the calcareous soil was treated with DTPA, the ion-exchangeable Pu was comparatively less influenced. This fraction in the soil was more affected with time of incubation. The lowest

  17. Soils of sinkholes: effects of slope aspect and lateral transport of sediments on soil variation

    Science.gov (United States)

    Smirnova, Maria; Tsibart, Anna; Abramova, Anna; Koshovskii, Timur; Gennadiev, Alexander

    2015-04-01

    Karst landscapes are highly fragile and particularly vulnerable to subsidence and soil erosion. In karst region there may be hundreds or even thousands of sinkholes and other karst landforms in a small area so that the flat surface is actually absent. The effect of slope aspect on karst landscapes are resulted in different amount of solar radiation and increase of moisture along slopes. In European Russia semiarid landscapes the wind transport of the snow resulted in addition moistening of the soil situated on the eastern slope of depressions. Our research is devoted to the investigation of soil catenas on the slopes of subsidence sinkhole in "Bogdo-Baskuntschak" natural reserve (semiarid landscape). It based on field research of 4 soil catenas situated on the slopes of eastern, northern, western and south exposures. The profile of the sinkhole is an inverted cone (elongated from west to east), slope length varies from 8 to 12 meters, slope gradient - between 40-55% (eastern slope is the shortest and steepest). The short slope length and soil diversity that the sinkholes provided are beneficial for investigation of slope aspect and effect of lateral transport on soil formation. The main feature of sinkhole soil cover is a considerable variety and their high complexity. The lateral transport of sediments resulted in dramatic changes of soil within catenas. Haplic calcisols and arenosols calcaric, situated on the inter-sinkhole flat surface and upper parts of the slopes are substituted by cambisols and leptosols in the middle part of the slopes and colluvic regosols humic in the lower part of the slopes and sinkhole bottom. Soil formation and accumulation of sediments occur simultaneously and lead to the weak soil formation at the middle and lower sections of sinkhole side slopes. The thickness of humus horizon increases from the top to the bottom of sinkhole notably - from 8-12 cm on the upper and middle part of the slopes to 240 cm on the bottom of the sinkhole

  18. Gaseous Loss of Nitrogen from Fertilizers Applied to Wheat on a Calcareous Soil in North China Plain

    Institute of Scientific and Technical Information of China (English)

    CAIGUIXIN; YANGZHEN; 等

    1998-01-01

    Nitrogen(N)losses from ammonium bicarbonate or urea applied to wheat and then followed immediately by irrigation were investigated.Ammonia volatilization was determined by a micrometeorological method (ammonia sampler),total N loss was estimated by the 15N mass balance method ,and denitrification loss was measured by the diference method(calculated from the difference between the total N loss and ammonia loss) and a direct method (measuring the emission of (N2+N2O)-15N).Total ammonia losses from ammonium bicarbonate and urea in 33 days were 8.7% and 0.9% of the applied nitrogen ,respectively.The corresponding total N losses were 21.6% and 29.5%,Apparent denitrification losses(by the difference method) were rather high,being 12.9% from ammonium bicarbonate and 28.6% from urea .However,no emission of (N2+N2O)-15N was detected using the direct method.

  19. Regulating mineralization rates of Tithonia diversifolia and Lantana camara prunings to improve phosphorus availability in calcareous soils

    OpenAIRE

    Y. Nuraini; N. Sukmawatie

    2014-01-01

    The effect of mixing of Tithonia diversifolia and Lantana camara prunings to improve synchronization between P released from the prunings with crop demand for P was studied in a laboratory and in a glasshouse. Tithonia diversifolia prunings (Td), Lantana camara prunings (Lc), and farmyard manure (Pk) were thoroughly mixed with the proportion (% of dry weight) of; 25Td +75 Lc ; 50Td +50 Lc ; 75Td +25 Lc ; 90Lc +10 Pk ; 45Td +45 +10 Lc Pk ; 100Td and 100Lc, and then mixed with 100 g of air-drie...

  20. Evaluation of Estimated Daily Intake (EDI of Cadmium and Lead for Rice (Oryza sativa L. in Calcareous Soils

    Directory of Open Access Journals (Sweden)

    Ali Chamannejadian

    2013-04-01

    Full Text Available The excessive amounts of cadmium and lead in food chain can cause health problems for humans and ecosystem. Rice is an important food in human diet. Therefore this study was conducted in order to investigate cadmium and Lead concentrations in seed rice (Oryza saliva of paddy fields in southwest of Iran. A total of 70 rice seed samples were collected from paddy fields in five regions of Khuzestan province, Southwest Iran, during harvesting time. In the samples cadmium and Lead concentrations were measured. To assess the daily intake of Cadmium and Lead by rice, daily consumption of rice was calculated. The results showed that average concentrations of Cadmium and Lead in rice seeds were 273.6 and 121.8 μg/kg, respectively. Less than 72% of rice seed samples had Cadmium concentrations above 200 μg/kg (i.e. Guide value for cadmium; and less than 3% had Lead concentrations above 150 μg/kg (i.e. Guide value for Lead. The estimated daily intakes of cadmium by the local population was calculated to 0.59 μg/day kg bw, which corresponds to 59% of the tolerable daily intakes (i.e. 1 μg/day kg bw. Eleven out of 70 samples (15.71% exceed the tolerable daily intakes. The dietary intakes for Lead in the local population ranged from 0.22 to 0.47 μg/day kg bw. Tolerable daily intakes for Lead is 3.6 μg/day kg bw. As a whole, long term consumption of the local rice may bear high risk of heavy metal exposure to the consumer in the study region.

  1. Calcareous palaeosols and temples in the floodplain of Thebes, Egypt: droughts and decisions

    Science.gov (United States)

    Graham, Angus; Hunter, Morag A.; Pennington, Benjamin T.; Strutt, Kristian D.

    2014-05-01

    The Egypt Exploration Society Theban Harbours and Waterscapes Survey (THaWS) works in the area around modern Luxor (Egypt), and investigates the extent to which the Egyptians manipulated the Nile and floodplain through canal and basin construction. A current focus of the project is to understand the relationship between the floodplain and a series of temples on the West Bank. A longstanding puzzle on the West Bank is why the temple of Amenhotep III (1390-1352 BCE) is not located in the same area as all the others. While 19 kings of the Egyptian New Kingdom (1550-1070 BCE) built their temples on the toe-slope of the limestone cliffs fronting onto the edge of the modern alluvium, Amenhotep's sits entirely on the modern floodplain. Egyptologists have suggested this was done to allow the inundation of the Nile to wash into the temple, symbolising and recreating the essential Egyptian cosmogony of the primeval mound. However, was it possible that a period of low Nile discharge enabled him to build on the alluvium whilst keeping the temple dry from the Nile floods? The project is testing this hypothesis through an interdisciplinary approach which provides focussed information on the development of the floodplain over historic time periods. It combines geophysical survey (Electrical Resistivity Tomography, Ground Penetrating Radar and magnetometry) with geoarchaeology using an Eijkelkamp hand auger and gouge auger with facies being dated using the stratigraphic sequence of ceramic fragments within them. Two fieldwork seasons have been carried out to date (Graham et al. 2012, 2013). Calcareous palaeosols c. 4m below the surface have been identified in three separate augers across a distance of 3 km on the West Bank floodplain, suggesting a period of low inundation levels / drought. At one of the locations an ancient surface appears to lie 0.3-0.4m above the calcisol. Ceramic fragments from this unit tentatively indicate a New Kingdom date. The strontium isotope record from

  2. Molecular phylogenetic evaluation of classification and scenarios of character evolution in calcareous sponges (Porifera, Class Calcarea.

    Directory of Open Access Journals (Sweden)

    Oliver Voigt

    Full Text Available Calcareous sponges (Phylum Porifera, Class Calcarea are known to be taxonomically difficult. Previous molecular studies have revealed many discrepancies between classically recognized taxa and the observed relationships at the order, family and genus levels; these inconsistencies question underlying hypotheses regarding the evolution of certain morphological characters. Therefore, we extended the available taxa and character set by sequencing the complete small subunit (SSU rDNA and the almost complete large subunit (LSU rDNA of additional key species and complemented this dataset by substantially increasing the length of available LSU sequences. Phylogenetic analyses provided new hypotheses about the relationships of Calcarea and about the evolution of certain morphological characters. We tested our phylogeny against competing phylogenetic hypotheses presented by previous classification systems. Our data reject the current order-level classification by again finding non-monophyletic Leucosolenida, Clathrinida and Murrayonida. In the subclass Calcinea, we recovered a clade that includes all species with a cortex, which is largely consistent with the previously proposed order Leucettida. Other orders that had been rejected in the current system were not found, but could not be rejected in our tests either. We found several additional families and genera polyphyletic: the families Leucascidae and Leucaltidae and the genus Leucetta in Calcinea, and in Calcaronea the family Amphoriscidae and the genus Ute. Our phylogeny also provided support for the vaguely suspected close relationship of several members of Grantiidae with giantortical diactines to members of Heteropiidae. Similarly, our analyses revealed several unexpected affinities, such as a sister group relationship between Leucettusa (Leucaltidae and Leucettidae and between Leucascandra (Jenkinidae and Sycon carteri (Sycettidae. According to our results, the taxonomy of Calcarea is in

  3. Molecular phylogenetic evaluation of classification and scenarios of character evolution in calcareous sponges (Porifera, Class Calcarea).

    Science.gov (United States)

    Voigt, Oliver; Wülfing, Eilika; Wörheide, Gert

    2012-01-01

    Calcareous sponges (Phylum Porifera, Class Calcarea) are known to be taxonomically difficult. Previous molecular studies have revealed many discrepancies between classically recognized taxa and the observed relationships at the order, family and genus levels; these inconsistencies question underlying hypotheses regarding the evolution of certain morphological characters. Therefore, we extended the available taxa and character set by sequencing the complete small subunit (SSU) rDNA and the almost complete large subunit (LSU) rDNA of additional key species and complemented this dataset by substantially increasing the length of available LSU sequences. Phylogenetic analyses provided new hypotheses about the relationships of Calcarea and about the evolution of certain morphological characters. We tested our phylogeny against competing phylogenetic hypotheses presented by previous classification systems. Our data reject the current order-level classification by again finding non-monophyletic Leucosolenida, Clathrinida and Murrayonida. In the subclass Calcinea, we recovered a clade that includes all species with a cortex, which is largely consistent with the previously proposed order Leucettida. Other orders that had been rejected in the current system were not found, but could not be rejected in our tests either. We found several additional families and genera polyphyletic: the families Leucascidae and Leucaltidae and the genus Leucetta in Calcinea, and in Calcaronea the family Amphoriscidae and the genus Ute. Our phylogeny also provided support for the vaguely suspected close relationship of several members of Grantiidae with giantortical diactines to members of Heteropiidae. Similarly, our analyses revealed several unexpected affinities, such as a sister group relationship between Leucettusa (Leucaltidae) and Leucettidae and between Leucascandra (Jenkinidae) and Sycon carteri (Sycettidae). According to our results, the taxonomy of Calcarea is in desperate need of a

  4. The impact of the Maastrichtian cooling on the marine nutrient regime -- Evidence from midlatitudinal calcareous nannofossils

    Science.gov (United States)

    Linnert, Christian; Engelke, Julia; Wilmsen, Markus; Mutterlose, Jörg

    2016-06-01

    The latest Campanian-earliest Maastrichtian interval is well known as a period of intense climate cooling. This cooling caused a distinctive bipolar biogeographic distribution of calcareous nannofossil assemblages: High-latitude settings were dominated by newly evolving endemic taxa, former cosmopolitan species disappeared at the same time, and equatorial communities experienced an invasion of cool water taxa. The impact of this cooling on northern midlatitude assemblages is, however, less well known. In order to overcome this gap we studied the Kronsmoor section (northwest Germany). This section provides a continuous upper Campanian -- lower Maastrichtian succession with moderately to well preserved nannofossils. Uppermost Campanian assemblages are dominated by Prediscosphaera cretacea; other common taxa include Prediscosphaera stoveri, Watznaueria barnesiae, and Micula staurophora. The lower Maastrichtian is characterized by lower numbers of P. cretacea and frequent Kamptnerius magnificus, Arkhangelskiella cymbiformis, and Cribrosphaerella ehrenbergii. These changes reflect, in part, the Campanian-Maastrichtian boundary cooling since some successful taxa (e.g., K. magnificus) are related to cool surface waters. Other shifts in the nannofossil communities were perhaps the result of a changing nutrient regime. Stronger latitudinal gradients may have increased wind velocities and thus the eolian input of ferruginous dust required by N-fixing bacteria. The enhanced high-latitude deep water formation probably changed the bottom water environment in disfavor of denitrificating organisms. A decline of chemical weathering and fluviatile transport may have reduced the amount of bioavailable phosphate. These processes led to an increased nitrate and a decreased phosphate content shifting the nutrient regime from nitrate toward phosphate limitation.

  5. Ocean acidification alters the calcareous microstructure of the green macro-alga Halimeda opuntia

    Science.gov (United States)

    Wizemann, André; Meyer, Friedrich W.; Hofmann, Laurie C.; Wild, Christian; Westphal, Hildegard

    2015-09-01

    Decreases in seawater pH and carbonate saturation state ( Ω) following the continuous increase in atmospheric CO2 represent a process termed ocean acidification, which is predicted to become a main threat to marine calcifiers in the near future. Segmented, tropical, marine green macro-algae of the genus Halimeda form a calcareous skeleton that involves biotically initiated and induced calcification processes influenced by cell physiology. As Halimeda is an important habitat provider and major carbonate sediment producer in tropical shallow areas, alterations of these processes due to ocean acidification may cause changes in the skeletal microstructure that have major consequences for the alga and its environment, but related knowledge is scarce. This study used scanning electron microscopy to examine changes of the CaCO3 segment microstructure of Halimeda opuntia specimens that had been exposed to artificially elevated seawater pCO2 of ~650 µatm for 45 d. In spite of elevated seawater pCO2, the calcification of needles, located at the former utricle walls, was not reduced as frequent initiation of new needle-shaped crystals was observed. Abundance of the needles was ~22 % µm-2 higher and needle crystal dimensions ~14 % longer. However, those needles were ~42 % thinner compared with the control treatment. Moreover, lifetime cementation of the segments decreased under elevated seawater pCO2 due to a loss in micro-anhedral carbonate as indicated by significantly thinner calcified rims of central utricles (35-173 % compared with the control treatment). Decreased micro-anhedral carbonate suggests that seawater within the inter-utricular space becomes CaCO3 undersaturated ( Ω < 1) during nighttime under conditions of elevated seawater pCO2, thereby favoring CaCO3 dissolution over micro-anhedral carbonate accretion. Less-cemented segments of H. opuntia may impair the environmental success of the alga, its carbonate sediment contribution, and the temporal storage of

  6. The influence of the soil on spring and autumn phenology in European beech.

    Science.gov (United States)

    Arend, Matthias; Gessler, Arthur; Schaub, Marcus

    2016-01-01

    Tree phenology is a key discipline in forest ecology linking seasonal fluctuations of photoperiod and temperature with the annual development of buds, leaves and flowers. Temperature and photoperiod are commonly considered as main determinants of tree phenology while little is known about interactions with soil chemical characteristics. Seedlings of 12 European beech (Fagus sylvatica L.) provenances were transplanted in 2011 to model ecosystems and grown for 4 years on acidic or calcareous forest soil. Spring bud burst and autumnal leaf senescence were assessed in the last 2 years, 2013 and 2014, which were characterized by contrasting annual temperatures with a very warm spring and autumn in 2014. In 2013, spring bud burst and autumnal leaf senescence were advanced on acidic soil with a greater effect on leaf senescence. Hence, the vegetation period 2013 was shorter on this soil type compared with that on calcareous soil. In 2014, a similar soil effect was observed for spring bud burst while autumnal leaf senescence and the length of the vegetation period were not affected, probably due to interferences with the overall extension of the vegetation period in this exceptionally warm year. A different soil responsiveness was observed among the provenances with early bursting or senescing provenances being more sensitive than late bursting or senescing provenances. The findings of this study highlight the soil as an ecologically relevant factor in tree phenology and might help explain existing uncertainties in current phenology models. PMID:26420791

  7. Kinetic modeling of antimony(III) oxidation and sorption in soils.

    Science.gov (United States)

    Cai, Yongbing; Mi, Yuting; Zhang, Hua

    2016-10-01

    Kinetic batch and saturated column experiments were performed to study the oxidation, adsorption and transport of Sb(III) in two soils with contrasting properties. Kinetic and column experiment results clearly demonstrated the extensive oxidation of Sb(III) in soils, and this can in return influence the adsorption and transport of Sb. Both sorption capacity and kinetic oxidation rate were much higher in calcareous Huanjiang soil than in acid red Yingtan soil. The results indicate that soil serve as a catalyst in promoting oxidation of Sb(III) even under anaerobic conditions. A PHREEQC model with kinetic formulations was developed to simulate the oxidation, sorption and transport of Sb(III) in soils. The model successfully described Sb(III) oxidation and sorption data in kinetic batch experiment. It was less successful in simulating the reactive transport of Sb(III) in soil columns. Additional processes such as colloid facilitated transport need to be quantified and considered in the model. PMID:27214003

  8. Fate of corrosion products released from stainless steel in marine sediments and seawater. Part 3. Calcareous ooze

    International Nuclear Information System (INIS)

    The physicochemical forms and partitioning of corrosion products released from stainless steel upon exposure to selected environmental conditions is the subject of this investigation. This report describes the influence of calcareous sediment on the rate of release and fate of corrosion products produced when neutron-activated stainless steel specimens were exposed to a Globigerina ooze taken from the Northeast Pacific Ocean. The calcareous ooze used in this study consists largely of planktonic formanifera tests and was found to be about 90% CaCO3. The trace metal content of this sediment was typical of average deep-sea carbonate sediments, and the ratios of trace elements to Ti were not remarkably different from a coastal clayey silt or a Northeast Pacific pelagic red clay. Most (>80%) of the trace metals extracted by sequential chemical treatment were associated with reductant-soluble materials, i.e., amorphous Mn and Fe oxides, or were incorporated in the carbonate substrate. Specimens of neutron-activated stainless steel exposed to calcareous ooze suspended in seawater under aerated and non-oxygenated conditions released corrosion products at rates of 1.7 and 4.2 μg year-1 cm-2, respectively. Almost 90% of the corrosion products (60Co activity) released under aerated conditions were relatively labile. Of these materials, over 80% were soluble upon treatment with a strong complexing agent, DTPA, indicating that adsorption of corrosion products as cations had been the major mechanism of incorporation into the sediment. In the absence of O2, a large fraction (approx. 80%) of the corrosion products were also relatively labile. Larger fractions of the corrosion products were soluble, easily dissolved, or present as carbonates or sulfides under non-oxygenated conditions than they were for the aerated treatment

  9. Physicochemical conditions of skarn formation in contact of the Alvand batholith with the meta-calcareous rocks, Hamedan, western Iran

    Directory of Open Access Journals (Sweden)

    Adel Saki

    2012-04-01

    Full Text Available The Cheshin meta-calcareous rocks (Permo Triassic in southeast Hamedan outcrop in association with a variety of pelitic schists and hornfels rocks. The intrusion of the Alvand Batholith (Jurassic age into pelitic and calcareous host rocks has produced metamorphic rocks in the Hamedan area (Cheshin village. On the basis of the dominance of calcite/dolomite, silicate and ore minerals, the calcareous rocks can be divided into two groups: a marbles and calc-silicates; b skarn rocks. The ore bodies occur in a contact zone between sillimanite-hornfels and calc-silicate rocks and formed the skarn rocks. Based on mineralogy, skarn rocks in the studied area consist mainly of diopside, garnet, tremolite, vesuvianite, epidote and ore minerals (magnetite and hematite. The skarnification processes occurred at two stages: (1 prograde metamorphism; and (2 retrograde metamorphism. The first stage involved prograde metasomatism and anhydrous minerals such as garnet and pyroxene formed. Second stage of retrograde skarn development is also recognized. In addition to Fe, Si and Mg, substantial amounts of Fe, along with volatile components were added to the skarn system. Consequently, considerable amounts of hydrous minerals, oxides and carbonates replaced the anhydrous minerals in the host rocks and hydrous minerals such as epidote+chlorite+amphibole formed. Using multiple equilibria by THERMOCALC® program, temperature (~630 ºC, pressure (~4 kbar, and fluid composition (XCO2 as low as 0.17 have been calculated for the formation of the calc-silicate rocks. Skarn mineralogy shows good agreement with these calculations.

  10. Nitrogen partitioning in oak leaves depends on species, provenance, climate conditions and soil type.

    Science.gov (United States)

    Hu, B; Simon, J; Kuster, T M; Arend, M; Siegwolf, R; Rennenberg, H

    2013-01-01

    Climate-tolerant tree species and/or provenances have to be selected to ensure the high productivity of managed forests in Central Europe under the prognosticated climate changes. For this purpose, we studied the responses of saplings from three oak species (i.e. Quercus robur, Q. petraea and Q. pubescens) and provenances of different climatic origin (i.e. low or high rainfall, low or high temperature habitats) with regard to leaf nitrogen (N) composition as a measure of N nutrition. Saplings were grown in model ecosystems on either calcareous or acidic soil and subjected to one of four treatments (control, drought, air warming or a combination of drought and air warming). Across species, oak N metabolism responded to the influence of drought and/or air warming with an increase in leaf amino acid N concentration at the expense of structural N. Moreover, provenances or species from drier habitats were more tolerant to the climate conditions applied, as indicated by an increase in amino acid N (comparing species) or soluble protein N (comparing provenances within a species). Furthermore, amino acid N concentrations of oak leaves were significantly higher on calcareous compared to acidic soil. From these results, it can be concluded that seeds from provenances or species originating from drier habitats and - if available - from calcareous soil types may provide a superior seed source for future forest establishment. PMID:22934888

  11. Behaviour of oxyfluorfen in soils amended with edaphic biostimulants/biofertilizers obtained from sewage sludge and chicken feathers. Effects on soil biological properties.

    Science.gov (United States)

    Rodríguez-Morgado, Bruno; Gómez, Isidoro; Parrado, Juan; Tejada, Manuel

    2014-09-01

    We studied the behaviour of oxyfluorfen herbicide at a rate of 4 l ha(-1) on biological properties of a Calcaric Regosol amended with two edaphic biostimulants/biofertilizers (SS, derived from sewage sludge; and CF, derived from chicken feathers). Oxyfluorfen was surface broadcast on 11 March 2013. Two days after application of oxyfluorfen to soil, both biostimulants/biofertilizers (BS) were also applied to the soil. An unamended soil without oxyfluorfen was used as control. For 2, 4, 7, 9, 20, 30, 60, 90 and 120 days of the application of herbicide to the soil and for each treatment, the soil dehydrogenase, urease, β-glucosidase and phosphatase activities were measured. For 2, 7, 30 and 120 days of the application of herbicide to the soil and for each treatment, soil microbial community was determined. The application of both BS to soil without the herbicide increased the enzymatic activities and soil biodiversity, mainly at 7 days of beginning the experiment. However, this stimulation was higher in the soil amended with SS than for CF. The application of herbicide in organic-amended soils decreased the inhibition of soil enzymatic activities and soil biodiversity. Possibly, the low-molecular-weight protein content easily assimilated by soil microorganisms is responsible for less inhibition of these soil biological properties. PMID:24859703

  12. The impacts of long-term intensive agriculture on the Vertisol properties in a calcareous region.

    Science.gov (United States)

    Rezapour, Salar; Najari, S; Ghaemian, N

    2015-05-01

    Morphological, physicochemical, and mineralogical properties of Vertisols (Chromic Calcixererts, Typic Haploxererts, and Typic Calcixererts) influenced under farming practices and adjoining uncultivated soils were investigated in order to contribute to the understanding of changes derived by intensive cultivation (over five decades). The study revealed that A-horizon thickness enhanced from 20 cm in the uncultivated soil to 30 cm in the cultivated soil for Typic Haploxererts and Typic Calcixererts. Under cropping, calcium carbonate contents decreased (a drop of 10 to 53%) reflecting accelerated leaching and/or erosion by cultivation. For most of the studied soils, a pronounced depletion was recorded at values of soil organic carbon (23-64%), soluble cations (4-96%), and exchangeable cations (9-42%) after cropping. A considerable positive change in soil quality was observed with cultivation as recorded by a declining trend in soil electrical conductivity (a drop of 12 to 17%) and exchangeable sodium percentage (a drop of 9 to 12%). On average, the concentration of free and crystalline Fe oxides progressively increased for Chromic Calcixererts and Typic Calcixererts following intensive cultivation. Cropping operations considerably promoted the alteration of illite and chlorite minerals into expandable minerals linked with changes in soil physicochemical properties mainly the increase in cation exchange capacity. Land productivity index (LPI), evaluated based on parametric approach, suggested that Chromic Calcixererts and Typic Haploxererts highlighted a decreasing trend in LPI values (a drop of 5 to 7%) while Typic Calcixererts manifested an increasing pattern in the index (a rise of 13%) with long-term intensive cropping. PMID:25864078

  13. Geochemistry of Soil Formation in south China Sea Islands

    Institute of Scientific and Technical Information of China (English)

    GONGZI-TONG; HUANGBIAO

    1995-01-01

    The soils in South China sea Islands(SCSI)were divided into three types,nmaely,phospho-calc soils,skeletisols and coastic solonchake,which were derived from bio-clastic and strongly calcareous sediments.In comparison with their parent materials,the phospho-Calc soils have higher contents of P,Zn Cu,Ba,and Cd,which tend to increase gradually with time,and lower contents of Mg,Ca,Sr,B,V,Pb,and Mo,which tend to decrease by degrees with time,The above-mentioned constituents in skeletisols and coastic solonchaks are similar to those in their parent materials except for P and Na,The factors affecting element distribution are mainly special bioclimate and parent material,meanwhile,resulting in the remakable influence on element distribution through soil-forming time.

  14. Assessing the potential impact of water-based drill cuttings on deep-water calcareous red algae using species specific impact categories and measured oceanographic and discharge data.

    Science.gov (United States)

    Nilssen, Ingunn; dos Santos, Francisco; Coutinho, Ricardo; Gomes, Natalia; Cabral, Marcelo Montenegro; Eide, Ingvar; Figueiredo, Marcia A O; Johnsen, Geir; Johnsen, Ståle

    2015-12-01

    The potential impact of drill cuttings on the two deep water calcareous red algae Mesophyllum engelhartii and Lithothamnion sp. from the Peregrino oil field was assessed. Dispersion modelling of drill cuttings was performed for a two year period using measured oceanographic and discharge data with 24 h resolution. The model was also used to assess the impact on the two algae species using four species specific impact categories: No, minor, medium and severe impact. The corresponding intervals for photosynthetic efficiency (ΦPSIImax) and sediment coverage were obtained from exposure-response relationship for photosynthetic efficiency as function of sediment coverage for the two algae species. The temporal resolution enabled more accurate model predictions as short-term changes in discharges and environmental conditions could be detected. The assessment shows that there is a patchy risk for severe impact on the calcareous algae stretching across the transitional zone and into the calcareous algae bed at Peregrino. PMID:26412110

  15. Fate and Transport of Road Salt During Snowmelt Through a Calcareous Fen: Kampoosa Bog, Stockbridge, Massachusetts

    Science.gov (United States)

    Rhodes, A. L.; Guswa, A. J.; Pufall, A.

    2007-12-01

    Kampoosa Bog is the largest and most ecologically diverse calcareous lake-basin fen in Massachusetts. Situated within a 4.7 km2 drainage basin, the open fen (approx. 20 acres) consists of a floating mat of sedges (incl. Carex aquatilis and Cladium mariscoides) that overlie peat and lake clay deposits. Mineral weathering of marble bedrock within the drainage basin supplies highly alkaline ground and surface waters to the fen basin. The natural chemistry has been greatly altered by road salt runoff from the Massaschusetts Turnpike, and in question is whether disturbance from the Turnpike and a gas pipline has facilitated aggressive growth by the invasive species Phragmites australis. Considered to be one of the most significant rare species habitats in the state, Massachusetts has designated Kampoosa Bog an Area of Critical Environmental Concern, and a committee representing several local, regional, and state agencies, organizations, and citizens manages the wetland. The purpose of this study is to characterize the hydrologic and chemical response of the wetland during snowmelt events to understand the fate and movement of road salt (NaCl). Concentrations of Na and Cl in the fen groundwater are greatest close to the Turnpike. Concentrations decrease with distance downstream but are still greatly elevated relative to sites upstream of the Turnpike. During snowmelt events, the fen's outlet shows a sharp rise in Na and Cl concentrations at the onset of melting that is soon diluted by the added meltwater. The Na and Cl flux, however, is greatest at peak discharge, suggesting that high-flow events are significant periods of export of dissolved salts from the fen. Pure dissolution of rock salt produces an equal molar ratio between Na and Cl, and sodium and chloride imbalances in stream and ground waters suggest that ~20% of the Na is stored on cation exchange sites within the peat. The largest imbalances between Na and Cl occur deeper within the peat, where the peat is

  16. Dynamics of peat accumulation and marl flat formation in a calcareous fen, midwestern United States

    Science.gov (United States)

    Miner, J.J.; Ketterling, D.B.

    2003-01-01

    The age and sequence of peat accumulation were investigated at a calcareous fen in northeastern Illinois, USA. The purpose of this study was to identify the processes that form and sustain marl flats, which are areas of marl or tufa substrate within the fen that contain numerous rare plant species. Geomorphic, stratigraphic, and radiocarbon evidence was used to establish the processes and chronology of peat accumulation and erosion adjacent to each marl flat. The age of the base of the peat deposit varies greatly throughout the fen, ranging from 14,679 calibrated years before present (cal. years BP) to nearly modern, indicating that colonization of the sand and gravel substrate by peat occurred throughout the period from the Late Pleistocene to present. Adjacent to one marl flat, trends in basal peat age and thickness show that peat accumulation has progressed laterally inward from both sides, suggesting that the marl flat has been infilling with peat progressively by accumulation at the margins since at least 5,370 cal. years BP or longer. A second marl flat in the fen is surrounded by older, thick peat of differing ages on either edge and is bounded by fresh scarps, indicating that the marl flat currently is expanding laterally by erosion into the preexisting peat blanket. These two examples suggest a continuously repeating process, where erosion of the accumulated peat blanket forms a marl flat, which is later covered by peat accumulation. Trends in basal peat age elsewhere in the fen suggest that other marl flats may have existed in the past that have been completely infilled with peat. This study suggests that marl flat formation is a natural process that has been occurring for millennia, continuously creating habitat for the rare plant species that occupy marl flats. There is no evidence that the marl flats at this site are indicative of anthropogenic disturbance, so that management options for these areas are limited to maintaining the quality and quantity

  17. COMPARISON OF SOIL PHOSPHORUS TEST METHODS

    Directory of Open Access Journals (Sweden)

    Brigita Popović

    2010-06-01

    Full Text Available Soil-P test is obligate chemical analysis for soil productivity estimation and most frequent used method in Croatia is AL method (soil extraction by ammoniumlactate solution at pH 3.75. Howewer, in some soils AL method (especially calcareous could be inaccurate for phosphorus fertilizer recommendations and crop response could be inadequate. Hence, the aim of this research was to compare 6 different P-tests: Olsen, Morgan, Bray1, Bray 2, CAL and DL. Each of these methods had a different pH of extraction solutios: Olsen (pH 8.5, Morgan (4,8, Bray 1 and Bray 2 (2.6, CAL (4.1 DL (3.7. Aiming to compare these 7 soil tests, 360 soil samples were collected from the continental part od Croatia. The soil pH, organic matter, AL-P2O5 and % CaCO3 were analyzed. All samples were grouped according to soil pH in two groups (pHKCl 6 179 samples. Phosphorus content on the average decreased: Bray 1 > DL > AL > CAL > Bray 2> Olsen > Morgan. Significant corellations were estimeted between AL and Olsen P test (r= 0.88, AL and Bray 1 P test (r=0.68, Olsen and Bray 1 P test (r= 0,75 and CAL and DL P tests (r=0.45. In the analysed samples total phospohrus content was recorded in all samples and portion of organic phosphorus in total phosporus in soil ranged from 0.54 to 78.29 %. The developed models are very simple and useful because they can predict soil phosphurus using only one soil test data. The models were validated and showed that all recorded corelations in this study were precise and approved the aforementioned models accuracy.

  18. Exploring variations in upper ocean structure for the last 2Ma of the Nansha area by means of calcareous nannofossils

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    A great number of calcareous nannofossils have been found in the deep-sea sediments of 2.32 Ma at ODP Site 1143 located in the Nansha area, the southern South China Sea. The number of coccoliths varies from about 0.5 × 106 up to almost 53 × 106 coccoliths/g sediment, with an average of 16 × 106 coccoliths/g sediment. The accumulation rate of total coccoliths varies from 1 × 106 to 278 × 106coccoliths/cm2 ka. The nannofossil assemblages are usually dominated by a Iower-photic species-Florisphaera profunda, of which the average percentage is about 70% in all samples. The absolute abundance and the accumulation rate of nannofossils as well as the per centage of F. profunda display significant oscillations on two different time scales. One is the fluc tuation coincident with the glacial-interglacial cycle, and the other is the long-term changes on a time scale longer than 100 ka. Six evolutionary stages of calcareous nannofossils could be divided for the last 2.32 Ma, from which we can reconstruct the changes in the depth of nutricline of the Nansha area. In this paper, the possible mechanism resulting in these variations is also discussed.

  19. Evidence of compositional and ultrastructural shifts during the development of calcareous tubes in the biofouling tubeworm, Hydroides elegans.

    Science.gov (United States)

    Chan, Vera Bin San; Vinn, Olev; Li, Chaoyi; Lu, Xingwen; Kudryavtsev, Anatoliy B; Schopf, J William; Shih, Kaimin; Zhang, Tong; Thiyagarajan, Vengatesen

    2015-03-01

    The serpulid tubeworm, Hydroides elegans, is an ecologically and economically important species whose biology has been fairly well studied, especially in the context of larval development and settlement on man-made objects (biofouling). Nevertheless, ontogenetic changes associated with calcareous tube composition and structures have not yet been studied. Here, the ultrastructure and composition of the calcareous tubes built by H. elegans was examined in the three early calcifying juvenile stages and in the adult using XRD, FTIR, ICP-OES, SEM and Raman spectroscopy. Ontogenetic shifts in carbonate mineralogy were observed, for example, juvenile tubes contained more amorphous calcium carbonate and were predominantly aragonitic whereas adult tubes were bimineralic with considerably more calcite. The mineral composition gradually shifted during the tube development as shown by a decrease in Sr/Ca and an increase of Mg/Ca ratios with the tubeworm's age. The inner tube layer contained calcite, whereas the outer layer contained aragonite. Similarly, the tube complexity in terms of ultrastructure was associated with development. The sequential appearance of unoriented ultrastructures followed by oriented ultrastructures may reflect the evolutionary history of serpulid tube biominerals. As aragonitic structures are more susceptible to dissolution under ocean acidification (OA) conditions but are more difficult to be removed by anti-fouling treatments, the early developmental stages of the tubeworms may be vulnerable to OA but act as the important target for biofouling control. PMID:25600412

  20. Soils - Soil Data Viewer

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — Soil Data Viewer is a tool built as an extension to ArcMap that allows a user to create soil-based thematic maps. The application can also be run independent of...

  1. Acidification of forest soil in Russia: From 1893 to present

    Science.gov (United States)

    Lapenis, A.G.; Lawrence, G.B.; Andreev, A.A.; Bobrov, A.A.; Torn, M.S.; Harden, J.W.

    2004-01-01

    It is commonly believed that fine-textured soils developed on carbonate parent material are well buffered from possible acidification. There are no data, however, that document resistance of such soils to acidic deposition exposure on a timescale longer than 30-40 years. In this paper, we report on directly testing the long-term buffering capacity of nineteenth century forest soils developed on calcareous silt loam. In a chemical analysis comparing archived soils with modern soils collected from the same locations ???100 years later, we found varying degrees of forest-soil acidification in the taiga and forest steppe regions. Land-use history, increases in precipitation, and acidic deposition were contributing factors in acidification. The acidification of forest soil was documented through decreases in soil pH and changes in concentrations of exchangeable calcium and aluminum, which corresponded with changes in communities of soil microfauna. Although acidification was found at all three analyzed locations, the trends in soil chemistry were most pronounced where the highest loading of acidic deposition had taken place. Copyright 2004 by the American Geophysical Union.

  2. Changes in the properties of solonetzic soil complexes in the dry steppe zone under anthropogenic impacts

    Science.gov (United States)

    Lyubimova, I. N.; Novikova, A. F.

    2016-05-01

    Long-term studies of changes in the properties of solonetzic soil complexes of the dry steppe zone under anthropogenic impacts (deep plowing, surface leveling, irrigation, and post-irrigation use) have been performed on the Privolzhskaya sand ridge and the Khvalyn and Ergeni plains. The natural morphology of solonetzic soils was strongly disturbed during their deep ameliorative plowing. At present, the soil cover consists of solonetzic agrozems (Sodic Protosalic Cambisols (Loamic, Aric, Protocalcic)), textural (clay-illuvial) calcareous agrozems (Eutric Cambisols (Loamic, Aric, Protocalcic)), agrosolonetzes (Endocalcaric Luvisols (Loamic, Aric, Cutanic, Protosodic), agrochestnut soils (Eutric Cambisols (Siltic, Aric)), and meadowchestnut soils (Haplic Kastanozems). No features attesting to the restoration of the initial profile of solonetzes have been found. The dynamics of soluble salts and exchangeable sodium differ in the agrosolonetzes and solonetzic agrozems. A rise in pH values takes place in the middle part of the soil profiles on the Khvalyn and Ergeni plains.

  3. A RESEARCH ON SOIL FERTILITY AND OTHER PROBLEMS AT BURHANİYE VICINITY

    Directory of Open Access Journals (Sweden)

    Mehmet ŞAHİN

    1995-03-01

    Full Text Available The research was carried out with aim of determining fertility and other problems in the vicinity of Burhaniye. The research soils are alluvial soils. The climate is moderate and semi humid. The vegetation are agricultural plants. The topography is almost smooth. Dominant soil farming processes are weak calcification and podsolization, eluviasyon, illuviasyon, loss, translocation and synthesis. The aspect of horizonation is weak. Hydraulic conductivity classes are moderately slow, medium and moderately speed. Drainage classes are medium and poor. Texture classes are medium, moderately fine and fine. These soils are insaline soils. Reaction classes are slightly alkali and moderately alkali. Calcareous classes are trace, few and moderately few. Organic matter classes are very few, few, medium and high. Phosphorus and potassium classes are very few, few, medium and high. In addition some fertility, soil management and other related problems are exist. For example forming of compacting and plow pan.

  4. Effects of biochar amendment and arbuscular mycorrhizal fungi inoculation on availability of soil phosphorus and growth of maize

    OpenAIRE

    A.E. Mau; S.R. Utami

    2014-01-01

    A glasshouse experiment was conducted to study the interactive effects of biochar amendment and arbuscular mycorrhizal fungi (AMF) inoculation on phosphorus uptake by maize (Zea mayze L.) grown on a calcareous soil of Kupang, East Nusa Tenggara. The biochar was made of cow dung. Twelve treatment combinations (three biochars levels of 0, 5 and 7.5 g/kg of soil, and four AMF inoculation levels of 0, 5, 10 and 15 spores / kg of soil) were arranged in a completely randomized block design with thr...

  5. Chemical denudation rates of a small torrential catchment in the Northern Calcareous Alps

    Science.gov (United States)

    Trost, Georg; Robl, Jörg; Hauzenberger, Christoph; Hilberg, Sylke; Schmidt, Rudolf

    2016-04-01

    Our understanding on the decay of alpine landscapes and the pace of landscape adjustment to climatic or tectonic changes rely on catchment wide erosion rates. In general, these data stem from cosmogenic isotope dating of quartz grains and are therefore only applicable at catchments providing suitable bedrock. However, denudation caused by the dissolution of rocks is not explicitly considered by this method. In the Northern Calcareous Alps (NCA) crystalline rocks are missing and intensive karstification suggests that chemical denudation is an important player for destroying topography. In this study we present chemical denudation rates derived from measuring the dissolved load of an alpine catchment located in the country of Salzburg, Austria. The catchment has a drainage area of about 7 km2 and is predominantly covered by limestone rich glacial deposits and carbonatic rocks as characteristic for the NCA. In order to obtain catchment wide chemical denudation rates we have integrated discharge time series that where measured by a permanent water gauge of the Austrian Service for Torrent and Avalanche Control to compute the total discharge of the investigated catchment over a period of one year. During the same period samples were taken at several campaigns to consider variations of the dissolved load. Samples were taken at high and low run-off conditions to study the effect of precipitation and at different locations along the tributaries to account for lithological variations of the river beds on the dissolved load. The concentrations of various cations in water samples were measured by the ICP-MS facility at the University of Graz. For the investigation period of one year 3.02 ∗ 106m3 of discharge was measured at the catchment outlet. The summed cation-concentration is varying between about 85 mg/l for dry-conditions and 75 mg/l for rainy-conditions at the gauge and consists predominantly of Ca+ cations. Based on the total discharge of the river integrated over a

  6. Recorders of reef environment histories: stable isotopes in corals, giant clams, and calcareous algae

    Science.gov (United States)

    Aharon, Paul

    1991-06-01

    Time-series δ18O and δ13C records from cohabiting massive coral Porites australiensis and giant clam Tridacna gigas from the Great Barrier Reed of Australia, and from calcareous green algae in a core through modern Halimeda bioherm accreting in the eastern Java Sea, provide insights into the complex links between environmental factors and stable isotopes imprinted in these reef skeletal materials. The aragonitic coral and giant clam offer 20 years and 15 years of growth history, respectively. The giant clam yields mean δ18O and δ13C values of-0.5±0.5‰ and 2.2±0.2‰ ( n=67), which agree well with the predicted equilibrium values. The coral yields mean δ18O and δ13C values of-5.6±0.5‰ and-1.8±0.7‰ ( n=84), offering a striking example of kinetic and metabolic fractionation effects. Although both the coral and giant clam harbor symbionts and were exposed to a uniform ambient environment during their growth histories, their distinct isotopic compositions demonstrate dissimilar calcification pathways. The δ18O records contain periodicities corresponding to the alternating annual density bands revealed by X-radiography and optical transmitted light. Attenuation of the δ18O seasonal amplitudes occurring in the giant clam record 8 years after skeletal growth commenced is attributed to a changeover from fast to slow growth rates. Extreme seasonal δ18O amplitudes of up to 2.2‰ discerned in both the coral and giant clam records exceed the equivalent seasonal temperature contrast in the reef environment, and are caused by the combined effect of rainfall and evaporation during the monsoon and dry seasons, respectively. Thus in addition of being useful temperature recorders, reef skeletal material of sufficient longevity, such as Porites and Tridacna, may also indicate rainfall variations. Changing growth rates, determined from the annual growth bands, may exert a primary control on the coral δ13C record which shows a remarkable negative shift of 1.7

  7. Abundance and potential metabolic activity of methanogens in well-aerated forest and grassland soils of an alpine region.

    Science.gov (United States)

    Hofmann, Katrin; Praeg, Nadine; Mutschlechner, Mira; Wagner, Andreas O; Illmer, Paul

    2016-02-01

    Although methanogens were recently discovered to occur in aerated soils, alpine regions have not been extensively studied for their presence so far. Here, the abundance of archaea and the methanogenic guilds Methanosarcinales, Methanococcales, Methanobacteriales, Methanomicrobiales and Methanocella spp. was studied at 16 coniferous forest and 14 grassland sites located at the montane and subalpine belts of the Northern Limestone Alps (calcareous) and the Austrian Central Alps (siliceous) using quantitative real-time PCR. Abundance of archaea, methanogens and the methanogenic potentials were significantly higher in grasslands than in forests. Furthermore, methanogenic potentials of calcareous soils were higher due to pH. Methanococcales, Methanomicrobiales and Methanocella spp. were detected in all collected samples, which indicates that they are autochthonous, while Methanobacteriales were absent from 4 out of 16 forest soils. Methanosarcinales were absent from 10 out of 16 forest soils and 2 out of 14 grassland soils. Nevertheless, together with Methanococcales they represented the majority of the 16S rRNA gene copies quantified from the grassland soils. Contrarily, forest soils were clearly dominated by Methanococcales. Our results indicate a higher diversity of methanogens in well-aerated soils than previously believed and that pH mainly influences their abundances and activities. PMID:26712349

  8. CHANGE OF BIOLOGICAL ACTIVITY OF RENDZINA SOILS OF WESTERN CAUCASUS AT POLLUTION BY ZINC, CADMIUM, MOLYBDENUM AND SELENIUM

    Directory of Open Access Journals (Sweden)

    Tatlok D. R.

    2015-02-01

    Full Text Available Rendzina soils are very widespread in the Caucasus. Because of their ecological and genetic characteristics Rendzina has significant buffering capacity to chemical pollution. The object of investigation was calcareous leached soil. Location selection - Azishskaya ridge on the border of the Republic of Adygea and the Krasnodar region. As pollutants, we have selected Zn, Cd, Mo, Se, since soil contamination with these elements in the south of Russia is not uncommon. Contamination of zinc, cadmium, molybdenum and selenium causes deterioration in the biological properties of calcareous soils of the Western Caucasus. We have investigated the toxicity of the elements formed following series due to their influence on Rendzina soils: Zn> Se> Cd> = Mo. The study attempted to analyze the entire range of concentrations of the examined elements in the soil, currently occurring in nature. In most cases, all the investigated substances registered direct correlation between the concentration of the pollutant in the soil and the degree of reduction of biological indicators. The activity of catalase and dehydrogenase cellulolytic ability, plenty of bacteria of the genus Azotobacter, length of roots of radish can be used to monitor, diagnose and regulation of chemical pollution of soil Zn, Cd, Mo, Se

  9. Evaluation of Soil Labile Phosphorus Using a Double—Labeling (32P and 33P) Technique

    Institute of Scientific and Technical Information of China (English)

    WANGGUANG-HUO

    1992-01-01

    Isotopic exchangeability of phosphorus in four Chinese soils with and without P application was studied by 32P and 33P double-labeling technique in relation to routine chemical extractions.The results showed that Bray-I and Bray-Ⅱ reagents could extract most of the fast exchangeable P.Not all of the Olsen-P belonged to fast exchangeable P,but it was about the same quantity of fast exchangeable P in a calcareous soil and a neutral soil without P application.Sequential fractionation of the soil phosphorus showed that most of the added radioisotopes in high P fixation red soils were tightly held by iron and aluminium oxides,which could be totally extracted only by 0.1M NaOH solution.In the neutral and calcareous soils most of the radioisotopes added were loosely held on the surface of soil particles and could be extracted by anion exchange resin.Phosphate application increased the resin-P fraction significantly for all the soils studied.

  10. Two new species of calcareous sponges (Porifera: Calcarea) from the deep Antarctic Eckstrom Shelf and a revised list of species found in Antarctic waters

    DEFF Research Database (Denmark)

    Rapp, Hans Tore; Göcke, Christian; Tendal, Ole Secher;

    2013-01-01

    The paper reports on two new species of calcareous sponges (Porifera, Calcarea) from the Antarctic Weddell Sea, Clathrina brandtae sp. nov. and Leucetta delicata sp. nov., collected at 600 m depth during the ANT XXIV/2-SYSTCO expedition in January 2008. The new species are described based on a...

  11. Reconsideration of the so-called Oligocene fauna in the asphaltic deposits of Buton (Malay Archipelago) — 2. Young-Neogene Foraminifera and calcareous Algae

    NARCIS (Netherlands)

    Keyzer, F.G.

    1952-01-01

    Miopliocene marls from the island of Buton yield a large marine foraminiferal fauna and some calcareous algae. Three-hundred and thirthy-three species have been identified. Two genera, twenty-three species and four varieties are described as new. The existence of mud-volcanoes in young neogene time

  12. Evolution and Production of Calcareous Nannoplankton During the Cretaceous as Proxies of LIP-induced Oceanic Fertilization, Acidification and Anoxia

    Science.gov (United States)

    Erba, E.; Bottini, C.; Tiraboschi, D.

    2008-12-01

    Through the Phanerozoic, biota have been intimately linked to Earth's degassing inducing major changes in composition and structure of the ocean-atmosphere system. Emplacement of large igneous provinces (LIPs) has been the primary natural source of atmCO2 with dramatic consequences on climate and ecosystems. During the mid-Cretaceous the Ontong Java-Manihiki and Caribbean Plateaus LIPs are recognized as responsible of pCO2 as high as 2000 ppm. Coeval biocalcification crises occurred in pelagic and neritic settings, suggesting a causal link between high concentrations of carbon dioxide and drops in benthic and planktonic calcifiers' efficiency. Within the oceanic biosphere, calcareous nannoplankton play a key-role as: (1) is widespread and consists of cosmopolitan and endemic taxa; (2) has a 220 My-long evolutionary history; (3) is one the most effective calcite producers; (4) is relevant for the C cycle; (5) is extremely sensitive to environmental variations. Diversity pulses of Cretaceous calcareous nannoplankton are grossly coeval with LIP construction, climate and sea-level changes, variations in ocean structure and composition, suggesting that evolutionary patterns are closely linked to environmental modifications. We explored time-intervals of LIP formation marked by nannoplankton adaptation/evolution, quantifying evolutionary rates, species richness, abundance, calcite production and morphometry. High-resolution investigations of the initial phase of both early Aptian oceanic anoxic event (OAE) 1a and latest Cenomanian OAE 2 pointed out major evolutionary changes, decreases in heavily calcified nannoliths and occurrence of dwarf coccoliths. Nannoplankton calcification crises and dwarfism is here interpreted as forced by rapidly increasing pCO2 during formation of the Ontong Java-Maniniki and Caribbean Plateaus. Alternatively or concurrently, calcification crash and dwarfism might result from enhanced fertility associated to OAE1a and OAE2 regardless of ocean

  13. Soil micronutrients and its uptake by rice plant. Part of a coordinated programme on isotope-aided micronutrient studies in rice production with special reference to zinc deficiencies

    International Nuclear Information System (INIS)

    A series of field and greenhouse experiments with flooded rice was carried out on contrasting soil types of Korea to study the zinc status of soils, evaluate the chemical methods for extracting zinc from soils in terms of ability to identify zinc deficiency, perform 65Zn-aided experiments including the residual effects of zinc fertilizers to evaluate the efficiency of zinc sources and methods of zinc application to rice, and associated studies on factors affecting zinc nutrition in rice such as effect of organic matter and chelates. The results show that i) 0.05 N HCl solution for extracting available zinc in soil was effective to separating the soils which require zinc fertilizer application. The proposed zinc value to identify is 2.4 ppm. Among rice soils surveyed, the red-yellow podsolic soil derived from basalt, the reddish-brown lateritic soil of calcareous material and newly reclaimed saline soils were shown to be below this limit; ii) 5 kg Zn/ha as zinc sulphate introduced the highest response in terms of % Zndff, total zinc yield in rice plant, and the fertilizer zinc use efficiency. Applying higher zinc amounts, in case of 20 kg Zn/ha, retarded nitrogen uptake by the plant and as a result the rice grain yield was decreased; iii) Significant yields increases due to the residual effects of zinc fertilizers were obtained on the second and third crops; iv) On the zinc-deficient calcareous soil the use of chelated zinc sources is recommended

  14. Responses of lucerne (Medicago sativa L.) and rhizobia to copper-based fungicide application in two contrasting soils

    Science.gov (United States)

    Schneider, Martin; Dober, Melanie; Jöchlinger, Lisa; Keiblinger, Katharina; Soja, Gerhard; Mentler, Axel; Zechmeister-Boltenstern, Sophie; Bruckner, Alexander; Golestani Fard, Alireza; Wenzel, Walter; Zehetner, Franz

    2016-04-01

    For more than 120 years, salts of copper (Cu) have been used in viticulture to prevent damages by fungal diseases. Due to restrictions in the use of synthetic fungicides and mineral fertilizers, organic viticulture depends on Cu as well as on biological nitrogen fixation. Here, we conducted an eco-toxicological pot experiment with an acidic, sandy soil and a calcareous, loamy soil and incrementally increasing fungicide application rates from 0 to 5000 mg Cu kg-1 soil. Lucerne (Medicago sativa L. cultivar. Plato) was grown in the pots for 3 months under greenhouse conditions. Acetylene reduction assays performed with harvested nodules showed no response to elevated soil Cu concentrations indicating that the nitrogen fixing capacity of rhizobia was not compromised by Cu in our experiment. Nevertheless, the nodule biomass was very sensitive to Cu and strongly decreased due to reduced amounts of fine roots and less energy supply by the plant. Legumes are known to be Cu-sensitive, and our contribution also showed a decrease in harvest by 50 % (EC50) at 21 mg kg-1 plant Cu tissue concentration in the acidic soil and at 30 mg kg-1 in the calcareous soil. This corresponded to diffusional fluxes measured by diffusive gradients in thin films (DGT) of 202 and 368 fmol cm-2 s-1, respectively. DGT measurements showed that in the acidic soil, Cu was 2 to 10 times more available for plants, depending on the concentration applied, than in the calcareous soil. A modeling approach for estimating the effective concentration (EC) by including the DGT-estimated plant Cu content and the pH produced more accurate values (NRMSE of 21.9 to 20.1 %) than EC directly estimated from DGT.

  15. Origin, distribution and transformation of authigenic carbonates in loessic soils

    Directory of Open Access Journals (Sweden)

    Martin Kolesár

    2015-01-01

    Full Text Available Processes of authigenic carbonates formation are component part of terrestrial biogeochemical cycle of carbon, which starts with co-accumulation of oxalic acid and Ca in Ca- oxalates. After plant decay are these biominerals slowly transformed under the influence of microbial processes into authigenic carbonates (calcites, depending on soil condition. The formation of authigenic calcites runs over in soil system where is rather high Ca and Mg concentration, presence of oxalomorphic plants and sufficient oxalotrophic stability of microorganisms. In addition to Ca-oxalates, Ca and Mg ions necessary for carbonate formation comes also from air (precipitation, dust, mineral weathering, subsurface water flow and decaying organic matter. The distribution pattern of authigenic calcites with depth, the size and shape of individual forms of calcites on loessic soils of SW Slovakia, as it is resulted from micromorphological study indicate that through the historical development of that soils as landscape units, soil water regime has played decisive role at vertical redistribution of forms (size, shape of authigenic calcites. To this witness the depth of variation of needle calcite zones and horizons of micritic calcites occurrence depending on soil types (leaching. Needle shape calcite zones which approach closest to the soil surface, gradually coalescence to the horizons of micritic calcites with the depth. Micritic calcites are without, or with microsparitic domains. Our study concurrently support the ideas of their inorganic origin depending on evaporitic soil regime. This formations have its own historic dynamics on which depends also the preservation of calcaric nature of soils.

  16. Green Manure Addition to Soil Increases Grain Zinc Concentration in Bread Wheat

    OpenAIRE

    Aghili, Forough; Gamper, Hannes A.; Eikenberg, Jost; Khoshgoftarmanesh, Amir H.; Afyuni, Majid; Schulin, Rainer; Jansa, Jan; Frossard, Emmanuel

    2014-01-01

    Zinc (Zn) deficiency is a major problem for many people living on wheat-based diets. Here, we explored whether addition of green manure of red clover and sunflower to a calcareous soil or inoculating a non-indigenous arbuscular mycorrhizal fungal (AMF) strain may increase grain Zn concentration in bread wheat. For this purpose we performed a multifactorial pot experiment, in which the effects of two green manures (red clover, sunflower), ZnSO4 application, soil γ-irradiation (elimination of n...

  17. Soil-geochemical factors controlling the distribution and oral bioaccessibility of nickel, vanadium and chromium in soil

    International Nuclear Information System (INIS)

    Highlights: • Two soil-geochemical factors were identified accounting for 69% of total variance. • Low chromium bioaccessible fractions were linked to basalt bedrock factors. • Bioaccessible nickel was associated with peat and calcareous soil components. • The median vanadium bioaccessible fraction was 7%; chromium 1% and nickel 15%. - Abstract: Geogenic nickel (Ni), vanadium (V) and chromium (Cr) are present at elevated levels in soils in Northern Ireland. Whilst Ni, V and Cr total soil concentrations share common geological origins, their respective levels of oral bioaccessibility are influenced by different soil-geochemical factors. Oral bioaccessibility extractions were carried out on 145 soil samples overlying 9 different bedrock types to measure the bioaccessible portions of Ni, V and Cr. Principal component analysis identified two components (PC1 and PC2) accounting for 69% of variance across 13 variables from the Northern Ireland Tellus Survey geochemical data. PC1 was associated with underlying basalt bedrock, higher bioaccessible Cr concentrations and lower Ni bioaccessibility. PC2 was associated with regional variance in soil chemistry and hosted factors accounting for higher Ni and V bioaccessibility. Eight percent of total V was solubilised by gastric extraction on average across the study area. High median proportions of bioaccessible Ni were observed in soils overlying sedimentary rock types. Whilst Cr bioaccessible fractions were low (max = 5.4%), the highest measured bioaccessible Cr concentration reached 10.0 mg kg−1, explained by factors linked to PC1 including high total Cr concentrations in soils overlying basalt bedrock

  18. Spatial changes in soil organic carbon density and storage of cultivated soils in China from 1980 to 2000

    Science.gov (United States)

    Yu, Yanyan; Guo, Zhengtang; Wu, Haibin; Kahmann, Julia A.; Oldfield, Frank

    2009-06-01

    We address the spatial changes in organic carbon density and storage in cultivated soils in China from 1980 to 2000 on the basis of measured data from individual studies and those acquired during the second national soil survey in China. The results show a carbon gain in ˜66% of the cultivated area of China as a whole with the increase in soil organic carbon (SOC) density mostly ranging from 10% to 30%. Soil organic carbon density increased in fluvi-aquic soils (fluvisols, Food and Agriculture Organization (FAO) of the United Nations) in north China, irrigated silting soils (calcaric fluvisols) in northwest China, latosolic red earths (haplic acrisols/alisols), and paddy soils (fluvisols/cambisols) in south China. In contrast, significant decreases are observed in black soils (phaeozems) in northeast China and latosols (haplic acrisols) in southwest China. No significant changes are detected in loessial soils (calcaric regosols) and dark loessial soils (calcisols) in the loess plateau region. The total SOC storage and average density in the upper 20 cm in the late 1990s are estimated to be ˜5.37 Pg C and 2.77 kg/m2, respectively, compared with the values of ˜5.11 Pg C and 2.63 kg/m2 in the early 1980s. This reveals an increase of SOC storage of 0.26 Pg C and suggests an overall carbon sink for cultivated soils in China, which has contributed 2-3% to the global terrestrial ecosystem carbon absorption from 1980 to 2000. Statistical analyses suggest an insignificant contribution to the observed SOC increase from climate change, and we infer that it is mostly attributable to improved agricultural practices. Despite the SOC density increases over 20 years, the SOC density of the cultivated soils in China in the late 1990s is still ˜30% lower compared to their uncultivated counterparts in comparable soil types, suggesting a considerable potential for SOC restoration through improving management practices. Assuming a restoration of ˜50% of the lost SOC in the next 30

  19. Methodology for the elaboration of Natura 2000 sites designation acts in the Walloon Region (Belgium: calcareous grasslands in the Lesse-and-Lomme area

    Directory of Open Access Journals (Sweden)

    Mahy G.

    2005-01-01

    Full Text Available In the Walloon Region (Belgium, 239 sites have been selected to be included in the Natura 2000 network. The next step is to write designation acts in order to legally protect these 221,000 ha. In this pilot study, a designation act was elaborated for a Natura 2000 site of 2,569 ha and located in the Lesse-and-Lomme area within the Calestienne region. Although the site includes 40 ha of calcareous grasslands, characterised by an exceptional flora and fauna, this habitat is very threatened by abandonment and fragmentation.The methodology used to elaborate the designation act is presented with respect to calcareous grassland. Firstly, in spring and summer 2003, an accurate map of natural habitats was produced, with every single patch of calcareous grassland being mapped. Information was also collected in order to evaluate conservation status. Based on this information, conservation status was then assessed with respect to three different criteria: (1 integrity of the cortege species, (2 habitat structure and (3 degradations. Thirdly, the site was divided into objective zones according to the different habitats and species of Community interest found in the site. Hence, an objective zone was delineated for calcareous grasslands. This objective zone was then divided in several management units. Finally, at these different spatial levels (site, objective zone, management unit, management measures were suggested. As a result, in the draft designation act, the target is to maintain or restore 230 ha of calcareous grassland, instead of the existing 40 ha. This ambitious target requires large-scale restoration and an efficient grazing scheme. These will need important resources for their successful implementation

  20. Multi-decadal variations in calcareous holozooplankton in the California Current System: Thecosome pteropods, heteropods, and foraminifera

    Science.gov (United States)

    Ohman, Mark D.; Lavaniegos, Bertha E.; Townsend, Annie W.

    2009-09-01

    We examine long-term (1951-2008) variability of three major taxa of calcareous holozooplankton (aragonite-secreting thecosome pteropods and heteropods, and calcite-secreting large planktonic foraminifera) in light of recent interest in the impingement of waters undersaturated with respect to aragonite onto continental shelf depths in the California Current System. We assess interannual variability in springtime abundances of zooplankton sampled in the epipelagic layer, using CalCOFI (California Cooperative Oceanic Fisheries Investigations) zooplankton samples from two regions: Southern California (SC) and Central California (CC). Thecosome pteropods show no evidence of recent declines in abundance in SC or CC waters. In SC, sampling was sufficient to conclude that heteropods and large foraminifera also show no evidence of declines in abundance in recent years. These results do not preclude as-yet undetected changes in vertical distributions or shell morphology, and underscore the importance of sustained in situ measurement programs in order to detect and understand changes to pelagic ecosystems.

  1. Age of the Tananwan Formation in Northern Taiwan: A Reexamination of the Magnetostratigraphy and Calcareous Nannofossil Biostratigraphy

    Directory of Open Access Journals (Sweden)

    Chorng-Shern Horng

    2014-01-01

    Full Text Available Over the past two decades, the succession strata of the Tananwan Formation exposed horizontally on the Linkou Tableland in northwestern Taiwan has been either dated to a short time interval of 0.9 - 0.7 Ma or assigned to a vague long period within the Matuyama Epoch covering probably both the Olduvai and Jaramillo normal events. In this study, a reexamination of magnetostratigraphy and calcareous nannofossil biostratigraphy of this formation was carried out. The results show that the strata with stable remanent magnetizations have reversed magnetic polarities only, and the layers with marine sedimentary facies consistently contain specimens of large Gephyrocapsa. These updated results suggest that the Tananwan Formation was deposited within the interval of 1.46 - 1.24 Ma, corresponding to a short period of reversed magnetic polarity of the Matuyama Epoch.

  2. Upper Frasnian and Lower Tournaisian events and evolution of calcareous foraminifera — close links to climatic changes

    Science.gov (United States)

    Kalvoda, Jiří

    The extinctions of the calcareous foraminiferal fauna at the Frasnian-Famennian and Famennian-Tournaisian boundaries appear to be connected with more than one event in each case (episodic gradualism), 4 of them seeming to be most important — the Kellwasser and Crickites event in the first case and the Hangenberg and sulcata event in the second case. The cumulative nature of extinctions is in contradiction with impact theory. The Famennian is then marked by 2 radiations — in the marginifera and in the expansa Zones. Both extinctions and radiations are closely linked to global changes in carbonate sedimentation and they seem to be best explained by climatic fluctuations of the glacial/interglacial type which were accompanied by aridity/humidity oscillations.

  3. Calcareous nannofossils and sedimentary facies in the Upper Cretaceous Bozeş Formation (Southern Apuseni Mountains, Romania

    Directory of Open Access Journals (Sweden)

    Ramona Balc

    2012-02-01

    Full Text Available The lithology, sedimentology and biostratigraphy of the Bozes Formation, which crop out in the SE Metaliferi Mountains (Apuseni Mts. have been investigated in order to establish the age of the deposits and the depositional environment. The sedimentary structures and facies are interpreted as indicating a deep-water depositional environment, representing part of a submarine fan lobe. Three facies assemblages have been identified and described. Calcareous nannofossils were used to determine the age of the investigated deposits. The presence of Lucianorhabdus cayeuxii and Calculites obscurus indicates the CC17 biozone, while UC13 Zone is pointed out by the continuous occurrence of Arkhangelskiella cymbiformis and the absence of Broinsonia parca parca. Thus, the age of the studied deposits is Late Santonian -?Early Campanian.

  4. Soil erosion in Iran: Issues and solutions

    Science.gov (United States)

    Hamidreza Sadeghi, Seyed; Cerdà, Artemi

    2015-04-01

    Iran currently faces many soil erosion-related problems (see citations below). These issues are resulted from some inherent characteristic and anthropogenic triggering forces. Nowadays, the latter plays more important rule to accelerate the erosion with further emphasis on soil erosion-prone arid and semi arid regions of the country. This contribution attempts to identify and describe the existing main reasons behind accelerated soil erosion in Iran. Appropriate solutions viz. structural and non-structural approaches will be then advised to combat or minimise the problems. Iran can be used as a pilot research site to understand the soil erosion processes in semiarid, arid and mountainous terrain and our research will review the scientific literature and will give an insight of the soil erosion rates in the main factors of the soil erosion in Iran. Key words: Anthropogenic Erosion, Land Degradation; Sediment Management; Sediment Problems Acknowledgements The research projects GL2008-02879/BTE, LEDDRA 243857 and PREVENTING AND REMEDIATING DEGRADATION OF SOILS IN EUROPE THROUGH LAND CARE (RECARE)FP7-ENV-2013- supported this research. References Aghili Nategh, N., Hemmat, A., & Sadeghi, M. (2014). Assessing confined and semi-confined compression curves of highly calcareous remolded soil amended with farmyard manure. Journal of Terramechanics, 53, 75-82. Arekhi, S., Bolourani, A. D., Shabani, A., Fathizad, H., Ahamdy-Asbchin, S. 2012. Mapping Soil Erosion and Sediment Yield Susceptibility using RUSLE, Remote Sensing and GIS (Case study: Cham Gardalan Watershed, Iran). Advances in Environmental Biology, 6(1), 109-124. Arekhi, S., Shabani, A., Rostamizad, G. 2012. Application of the modified universal soil loss equation (MUSLE) in prediction of sediment yield (Case study: Kengir Watershed, Iran). Arabian Journal of Geosciences, 5(6), 1259-1267.Sadeghi, S. H., Moosavi, V., Karami, A., Behnia, N. 2012. Soil erosion assessment and prioritization of affecting factors at plot

  5. 电动修复对Cd污染土壤肥力的影响%Enhancement of Soil Fertility by Electrokinetic Remediation of Calcareous Soil Spiked with Cadmium

    Institute of Scientific and Technical Information of China (English)

    句炳新; 申哲民; 吴旦; 陈学军; 王文华

    2006-01-01

    以上海潮土为对象,研究了电动力学(1V·cm-1)对土壤肥力的影响.修复前后测量的指标有土壤有机质(SOM)、pH、电导率(EC)、氧化还原电位(ORP)、有效N、速效P、速效K.结果表明,Cd浓度约为100 mg·kg-1的模拟污染土壤经电动力学处理60 h后,Cd的平均去除效率为68%.土壤中有效N、速效P和速效K分别平均提高为原来的1.45、4.25和3.29倍,同时TOC增加了3.96%.总之,电动力学修复后,土壤的肥力有了明显提升,表明电动力学在有效去除土壤中Cd的同时还能提升土壤的肥力,是一种可行的土壤修复技术.

  6. Calcareous Bio-Concretions in the Northern Adriatic Sea: Habitat Types, Environmental Factors that Influence Habitat Distributions, and Predictive Modeling.

    Directory of Open Access Journals (Sweden)

    Annalisa Falace

    Full Text Available Habitat classifications provide guidelines for mapping and comparing marine resources across geographic regions. Calcareous bio-concretions and their associated biota have not been exhaustively categorized. Furthermore, for management and conservation purposes, species and habitat mapping is critical. Recently, several developments have occurred in the field of predictive habitat modeling, and multiple methods are available. In this study, we defined the habitats constituting northern Adriatic biogenic reefs and created a predictive habitat distribution model. We used an updated dataset of the epibenthic assemblages to define the habitats, which we verified using the fuzzy k-means (FKM clustering method. Redundancy analysis was employed to model the relationships between the environmental descriptors and the FKM membership grades. Predictive modelling was carried out to map habitats across the basin. Habitat A (opportunistic macroalgae, encrusting Porifera, bioeroders characterizes reefs closest to the coastline, which are affected by coastal currents and river inputs. Habitat B is distinguished by massive Porifera, erect Tunicata, and non-calcareous encrusting algae (Peyssonnelia spp.. Habitat C (non-articulated coralline, Polycitor adriaticus is predicted in deeper areas. The onshore-offshore gradient explains the variability of the assemblages because of the influence of coastal freshwater, which is the main driver of nutrient dynamics. This model supports the interpretation of Habitat A and C as the extremes of a gradient that characterizes the epibenthic assemblages, while Habitat B demonstrates intermediate characteristics. Areas of transition are a natural feature of the marine environment and may include a mixture of habitats and species. The habitats proposed are easy to identify in the field, are related to different environmental features, and may be suitable for application in studies focused on other geographic areas. The habitat

  7. Evaluation of the assimilation of As by vegetables in contaminated soils submitted to a remediation process

    Science.gov (United States)

    Pérez-Sirvent, Carmen; Martinez Sanchez, Maria Jose; Agudo, Ines; Belen Martinez, Lucia; Bech, Jaume

    2016-04-01

    A greenhouse trial was carried out to evaluate the assimilation of heavy metals by three types of plants (lettuce, onion and broccoli), different parts of which are destined for human and farm animals consumption (leaves, roots, fruits). The experiments were carried out to check the validity of the use of calcareous materials to recover soils contaminated with heavy metals. The aim of this work was to apply a technology for decontamination to ensure that As do not enter into the trophic chain at risky levels and analyze and to assess the risk pre and post operational of the different treatments proposed. The materials used was a soils to be remediated (mining soils) and the materials used for remediation were lime filler and Construction and Demolition Waste (CDW). The plants were cultivated in greenhouse with several types of soil. Five experiments were used, namely, Tc (contaminated soil), T1 (uncontaminated soil (blank soil)), T2 (50% T1 + 50% Tc), T3 (Tc + (25%) lime residues coming from quarries) and T4 (Tc + (25%) residues coming from demolition and construction activities). The entire project involves twenty experiments which were prepared from soils highly contaminated mixed with two types of calcareous materials. The total As content of the soils samples, rhizosphere and vegetable samples, were measured and the translocation factor (TF), which is defined as the ratio of metal concentration in the leaves or shoots to the roots, and the Bioconcentration factor (BCF), which is defined as the ratio of metal concentration in the roots to that in soil were calculated. The use of CDR is shown to be a suitable way for remediating soils contaminated by metals. The methodology permits a revalorization of CDW.

  8. Interrelationships between soil cover and plant cover depending on land use

    Directory of Open Access Journals (Sweden)

    Tiina Köster

    2013-05-01

    Full Text Available Interrelationships between soil cover and plant cover of normally developed (or postlithogenic mineral soils are analysed on the basis of four sampling soil groups. The four-link pedo-ecological sequence of analysed soils, rendzinas → brown soils → pseudopodzolic soils → gley-podzols, forms a representative cross section in relation to the normal mineral soils of Estonia. All groups differ substantially from each other in terms of soil properties (calcareousness, acidity, nutrition conditions, profile fabric and humus cover. The primary tasks of the research were (1 to elucidate the main pedo-ecological characteristics of the four soil groups and their suitability for plant cover, (2 to evaluate comparatively soils in terms of productivity, sustainability, biodiversity and environmental protection ability and (3 to analyse possibilities for ecologically sound matching of soil cover with suitable plant cover. On the basis of the same material, the influence of land-use change on humus cover (epipedon fabric, properties of the entire soil cover and soil–plant interrelationship were also analysed. An ecosystem approach enables us to observe particularities caused by specific properties of a soil type (species, variety in biological turnover and in the formation of biodiversity.

  9. EFFECTS OF IRRIGATION WITH DEPURATED LIVESTOCK EFFLUENTS ON SOILS. A CASE STUDY FROM CENTRAL ITALY

    Directory of Open Access Journals (Sweden)

    Rosa Francaviglia

    2010-12-01

    Full Text Available The work deals with the qualitative modifications of a Calcaric fluvisol after irrigation with fresh water and depurated pig-slurry effluents (aerobic and anaerobic treatment, and phytodepuration with a reed bed system. The accumulation of nutrients (nitrogen and phosphorus and heavy metals (Cd, Co, Cr, Cu, Ni, Pb, Zn as total and as bio-available forms in the soil was evaluated, together with soil aggregate stability index, hydraulic conductivity of the saturated soil and the in situ infiltration rate. The experimental field was divided into three plots, and cultivated with silage maize for three years (2003-2005. Results showed that the irrigation with depurated and phytodepurated effluents produced significant changes in the soil chemical properties controlling soil permeability, and influenced the bio-available fraction of heavy metals.

  10. Impact of land-use on carbon storage as dependent on soil texture: evidence from a desertified dryland using repeated paired sampling design.

    Science.gov (United States)

    Ye, Xuehua; Tang, Shuangli; Cornwell, William K; Gao, Shuqin; Huang, Zhenying; Dong, Ming; Cornelissen, Johannes H C

    2015-03-01

    Desertification resulting from land-use affects large dryland areas around the world, accompanied by carbon loss. However it has been difficult to interpret different land-use contributions to carbon pools owing to confounding factors related to climate, topography, soil texture and other original soil properties. To avoid such confounding effects, a unique systematic and extensive repeated design of paired sampling plots of different land-use types was adopted on Ordos Plateau, N China. The sampling enabled to quantify the effects of the predominant land-use types on carbon storage as dependent on soil texture, and to define the most promising land-use choices for carbon storage, both in grassland on sandy soil and in desert grassland on brown calcareous soil. The results showed that (1) desertification control should be an effective measure to improve the carbon sequestration in sandy grassland, and shrub planting should be better than grass planting; (2) development of man-made grassland should be a good choice to solve the contradictions of ecology and economy in desert grassland; (3) grassland on sandy soil is more vulnerable to soil degradation than desert grassland on brown calcareous soil. The results may be useful for the selection of land-use types, aiming at desertification prevention in drylands. Follow-up studies should directly investigate the role of soil texture on the carbon storage dynamic caused by land-use change. PMID:25560656

  11. Soil compaction in forest soils

    OpenAIRE

    TURGUT, Bülent

    2012-01-01

    Soil compaction is a widespread degradation process in forest sites. Soil degradation occurring on the structural formation of a natural soil system by rainfall or mechanical outer forces generally results in soil particles to be rearranged tighter than its previous status. In this case, soil compaction -defined as the increase in bulk density of soil- develops with negative effects on soil-plant-water relations. With the compaction, the density of soil increases while the porosity rate decre...

  12. Changes of Organic Matter, N, P and K Content of Soils in Red Soil Areas Under Long-Term Experiment

    Institute of Scientific and Technical Information of China (English)

    JIANG Duan-sheng; ZENG Xi-bai; GAO Ju-sheng; LI Lian-fang

    2008-01-01

    The content of organic matter (OM), nitrogen (N), phosphorus (P), and potassium (K) in the three selected soils, including Calcaric Purpli-Orthic Primosols (purple sand-shale parent material), Dystric Turbi-Anthric Primosols (quaternary red clay parent material) and Typic Udi-Sandic Primosols (granite parent material) were studied under a long-term experiment by using crop straw and inorganic fertilizers at the Hunan Red Soil Experiment Station of Chinese Academy of Agricultural Sciences. The results showed that the contents of OM, N, P and K in the three selected soils increased after 23 years application of crop straw and inorganic fertilizers, but the contents increased much less when crop straw or inorganic fertilizers was applied alone. The nutrient contents in the three soils developed from granite changed more remarkably than those in the soil derived from quaternary red clay and purple sand-shale. It was also found that the contents of OM, N, and P increased slightly in the treatments without applying fertilizers or returning the crop straw to the root bed. Combined application of inorganic fertilizers and crop straw could remarkably increase the contents of OM, alkali- hydrolyzable N and available K, the positive correlation between application of organic fertilizers and increase of OM in soil did not always happened, it provided evidence for the relation between appropriate C/N ratio and accumulation of OM in soil. The increase of nutrient content was influenced by the soil properties. By comparing the contents of nutrient in 0-20 cm depth in the three different soils, it was concluded that the most increases of OM, alkali-hydrolyzable N, and available P were observed in Typic Udi-Sandic Primosols with the average increase by 3.03, 27.38, and 21.73 mg kg-1, respectively. The available K increased in Dystric Turbi-Anthric Primosols with the average increase by 25.82 mg kg-1, while it decreased in Calcaric Purpli-Orthic Primosols and Typic Udi

  13. Simulation of soil temperature dynamics with models using different concepts.

    Science.gov (United States)

    Sándor, Renáta; Fodor, Nándor

    2012-01-01

    This paper presents two soil temperature models with empirical and mechanistic concepts. At the test site (calcaric arenosol), meteorological parameters as well as soil moisture content and temperature at 5 different depths were measured in an experiment with 8 parcels realizing the combinations of the fertilized, nonfertilized, irrigated, nonirrigated treatments in two replicates. Leaf area dynamics was also monitored. Soil temperature was calculated with the original and a modified version of CERES as well as with the HYDRUS-1D model. The simulated soil temperature values were compared to the observed ones. The vegetation reduced both the average soil temperature and its diurnal amplitude; therefore, considering the leaf area dynamics is important in modeling. The models underestimated the actual soil temperature and overestimated the temperature oscillation within the winter period. All models failed to account for the insulation effect of snow cover. The modified CERES provided explicitly more accurate soil temperature values than the original one. Though HYDRUS-1D provided more accurate soil temperature estimations, its superiority to CERES is not unequivocal as it requires more detailed inputs. PMID:22792047

  14. Effect of soil type and soil management on soil physical, chemical and biological properties in commercial organic olive orchards in Southern Spain

    Science.gov (United States)

    Gomez, Jose Alfonso; Auxiliadora Soriano, Maria; Montes-Borrego, Miguel; Navas, Juan Antonio; Landa, Blanca B.

    2014-05-01

    One of the objectives of organic agriculture is to maintain and improve soil quality, while simultaneously producing an adequate yield. A key element in organic olive production is soil management, which properly implemented can optimize the use of rainfall water enhancing infiltration rates and controlling competition for soil water by weeds. There are different soil management strategies: eg. weed mowing (M), green manure with surface tillage in spring (T), or combination with animal grazing among the trees (G). That variability in soil management combined with the large variability in soil types on which organic olive trees are grown in Southern Spain, difficult the evaluation of the impact of different soil management on soil properties, and yield as well as its interpretation in terms of improvement of soil quality. This communications presents the results and analysis of soil physical, chemical and biological properties on 58 soils in Southern Spain during 2005 and 2006, and analyzed and evaluated in different studies since them. Those 58 soils were sampled in 46 certified commercial organic olive orchards with four soil types as well as 12 undisturbed areas with natural vegetation near the olive orchards. The four soil types considered were Eutric Regosol (RGeu, n= 16), Eutric Cambisol (CMeu, n=16), Calcaric Regosol (RGca, n=13 soils sampled) and Calcic Cambisol (CMcc), and the soil management systems (SMS) include were 10 light tillage (LT), 16 sheep grazing (G), 10 tillage (T), 10 mechanical mowing (M), and 12 undisturbed areas covered by natural vegetation (NV-C and NV-S). Our results indicate that soil management had a significant effect on olive yield as well as on key soil properties. Among these soil properties are physical ones, such as infiltration rate or bulk density, chemical ones, especially organic carbon concentration, and biological ones such as soil microbial respiration and bacterial community composition. Superimpose to that soil

  15. Ophiolitic detritus in Kimmeridgian resedimented limestones and its provenance from an eroded obducted ophiolitic nappe stack south of the Northern Calcareous Alps (Austria

    Directory of Open Access Journals (Sweden)

    Gawlick Hans-Jürgen

    2015-12-01

    Full Text Available The causes for the Middle to Late Jurassic tectonic processes in the Northern Calcareous Alps are still controversially discussed. There are several contrasting models for these processes, formerly designated “Jurassic gravitational tectonics”. Whereas in the Dinarides or the Western Carpathians Jurassic ophiolite obduction and a Jurassic mountain building process with nappe thrusting is widely accepted, equivalent processes are still questioned for the Eastern Alps. For the Northern Calcareous Alps, an Early Cretaceous nappe thrusting process is widely favoured instead of a Jurassic one, obviously all other Jurassic features are nearly identical in the Northern Calcareous Alps, the Western Carpathians and the Dinarides. In contrast, the Jurassic basin evolutionary processes, as best documented in the Northern Calcareous Alps, were in recent times adopted to explain the Jurassic tectonic processes in the Carpathians and Dinarides. Whereas in the Western Carpathians Neotethys oceanic material is incorporated in the mélanges and in the Dinarides huge ophiolite nappes are preserved above the Jurassic basin fills and mélanges, Jurassic ophiolites or ophiolitic remains are not clearly documented in the Northern Calcareous Alps. Here we present chrome spinel analyses of ophiolitic detritic material from Kimmeridgian allodapic limestones in the central Northern Calcareous Alps. The Kimmeridgian age is proven by the occurrence of the benthic foraminifera Protopeneroplis striata and Labyrinthina mirabilis, the dasycladalean algae Salpingoporella pygmea, and the alga incertae sedis Pseudolithocodium carpathicum. From the geochemical composition the analysed spinels are pleonastes and show a dominance of Al-chromites (Fe3+–Cr3+–Al3+ diagram. In the Mg/(Mg+ Fe2+ vs. Cr/(Cr+ Al diagram they can be classified as type II ophiolites and in the TiO2 vs. Al2O3 diagram they plot into the SSZ peridotite field. All together this points to a harzburgite

  16. DESCRIPTION OF CERTAIN ASPECTS OF THE PRODUCTION POTENTIAL OF SOILS TAMAN PENINSULA

    Directory of Open Access Journals (Sweden)

    Lukyanov A. A.

    2015-10-01

    Full Text Available The work presents the results of the scientific research in the Taman Peninsula soil properties. We carry out the historic review of the studies in the Taman Peninsula soils, and its geological structure. We present morphological characteristics of the soil profile for the southern, calcareous, ultra heavy loam chernozem developed from the loessial loams and forming genetic horizons. The studies of the humus content in the soils show the associations between its percentage and the type and intensity of the agricultural use. Studies of the soils structure and composition demonstrate marked aggravation of the soils physical properties caused by grape growing. The best results of the particle size analysis have been achieved for the woodland soils. In woodlands, after their establishment, the soils under the grass and crown layers develop free of the anthropogenic impact. We register self-supporting growth of organic matter and natural processes of soil fertility recovery; therefore, such soils are characterized with a greater content of organic matter as compared to the soils under grape plantings cultivated in the monoculture regime. Reduced soil organic matter (humus content in vineyards results from the disturbed biological interchange of the matter and increased anthropogenic impact causing erosion processes

  17. Soil Formation and Taxonomy in Yeşilırmak River Terraces

    Directory of Open Access Journals (Sweden)

    Alper Durak

    2014-02-01

    Full Text Available In this study, the soils of which parent material is alluvial and formed Yeşilırmak river terraces were investigated. For this purposes four different profiles were excavated in the study area. Then twenty-seven soil samples were taken from horizons of four profiles and their physical and chemical analyses were done for soil taxonomy research. Profile of Kumocagi and Cakil were classified in subgroup as Typic Ustipsamments, Havaalanı and Mera profiles were classified Typic Haplustolls and Typic Argiustolls subgroups respectively. The pH values of soils varied between 7.38-8.41. These soils can be classified as low and highly basic. Most of the soil series had an irregular pH distribution in the profile. The range of carbonate content of the soils was 0.8-25.4%. Although carbonate content of soils showed a very wide range, majority of them can be classified as highly calcareous. In most of soils carbonate content was distributed irregulary in the profile. Organic matter content were between 0.14-6.11% in the soils. Although organic matter contents of the soils changed in a wide range most of them had low organic matter content. Organic matter content was over 4% in the surface horizon of only two profiles. Research result showed that, alluvial parent material, particle size, topograpy and time have different effect on investigation soils.

  18. Discovery of laterally extensive drape of siliciclastic silt in the Northern Calcareous Alps, Austria: Late-glacial to ?early Holocene aeolian deposition.

    Science.gov (United States)

    Gild, Charlotte; Geitner, Clemens; Haas, Jean Nicolas; Sanders, Diethard

    2016-04-01

    Field surveys in the Northern Calcareous Alps (NCA, a nappe stack of Triassic carbonate rocks) revealed a drape, or drapes, typically 20-40 cm in thickness of siliciclastic silt over extensive landscape areas, from valley floors to LGM (Last Glacial Maximum) nunataks. The drape veneers substrates ranging from country rocks to diverse post-LGM deposits - the latter with depositional and/or erosional topographies. The drape mostly is overlain by vegetated organic material and, in turn, tops inactive/abandoned post-LGM successions of fluvial (including kame terrace), alluvial fan, scree slope, LGM basal till, and rock-avalanche origin. The drape extends over kilometers at least (limit of field investigation in specific areas), up to LGM nunatak plateaus. Deposystems (e.g., scree slopes, alluvial fans) on carbonate-rocky terrain that remained active until the Holocene are not topped by the drape; a level of siliciclastic silt, however, was spotted within a few of these successions. The possibility that several levels of silt are intercalated within or top post-glacial deposits cannot be excluded at present; the large lateral extent and the stratigraphic position, however, suggest that at least most locations pertain to a single widespread level (with that reservation, we prefer to speak in singular of the drape). Over the inspected area (~ 90 x 20 km), the drape consists mainly of silt-sized grains of quartz, feldspars, micas, and amphiboles; at a few sites, calci- or dolosilt are admixed. Most of the grains are angular to subrounded, some grains show features of corrosion. Preliminary palynological analyses of this silt - seven locations from LGM nunataks to kame terrace and alluvial fans - suggest vegetation types that, together, may be assigned to palaeoclimates ranging from the late-glacial (Younger Dryas?) to the middle Holocene. A few of the pollen spectra appear to record sparse vegetation cover allowing for enhanced aeolian deposition, but other spectra (e

  19. Technical Note: Towards resolving in situ, centimeter-scale location and timing of biomineralization in calcareous meiobenthos - the calcein-osmotic pump method

    Science.gov (United States)

    Bernhard, J. M.; Phalen, W. G.; McIntyre-Wressnig, A.; Mezzo, F.; Wit, J. C.; Jeglinski, M.; Filipsson, H. L.

    2015-09-01

    Insights into oceanographic environmental conditions such as paleoproductivity, deep-water temperatures, salinity, ice volumes, and nutrient cycling have all been obtained from geochemical analyses of biomineralized carbonate of marine organisms. However, we cannot fully understand geochemical proxy incorporation and the fidelity of such in species until we better understand fundamental aspects of their ecology such as where and when these (micro)organisms calcify. Here, we present an innovative method using osmotic pumps and the fluorescent marker calcein to help identify where and when calcareous meiofauna calcify in situ. Method development initially involved juvenile quahogs (Mercenaria mercenaria); subsequent method refinement involved a neritic benthic foraminiferal community. Future applications of this method will allow determining the in situ growth rate in calcareous organisms and provide insights about microhabitats where paleoceanographically relevant benthic foraminifera actually calcify.

  20. Comparison of the analgesic effect of ultrasound and low-level laser therapy in patients suffering from plantar fasciitis (calcar calcanei)

    Science.gov (United States)

    Navratil, Leos; Skopek, Jiri; Hronkova, Hana; Kymplova, Jaroslava; Knizek, Jiri

    2001-10-01

    To compare the effectiveness of the two therapeutic approaches, ultrasound and low level laser (LLLT) used in 181 patients suffering from calcar calcanei-plantar fasciitis. The effectiveness of the treatment was determined according to the evaluation of the patient using certain criteria described in the table. The complete disappearance of pain was seen in 50% of 60 patients treated with US and partial improvement in 16.6% and 69 patients were treated with LLLT from which 67% described complete pain relief, and 20% partial improvement. The results show that the LLLT is a good therapeutic approach in the treatment of pain in patients suffering from calcar calcanei-plantar fasciitis. The treatment with laser was significantly more successful then the ultrasound therapy, which is currently the most common therapy used for plantar fasciitis.

  1. 不同土壤对白黎檬光合特性的影响%Effects of Different Soils on Photosynthetic Characteristics of Citrus limonia

    Institute of Scientific and Technical Information of China (English)

    吴素芳; 樊卫国

    2012-01-01

    To explore the adaptability for C. limonia to different soils, the seedlings were planted separately in pots with metamorphic rocks cane yellow soil, quaternary red clay cane yellow soil, yellow calcareous soil, brown calcareous soil and black calcareous soil. Photosynthetic characteristics of C. limonia in five different soils were studied, and the relation between soil nutrient and photosynthetic rate(Pn) of C. li-monia was analyzed. The results showed that; (i) Pn of C. limonia in black calcareous soil was the highest[8.91 μmol CO2/(m2 o s) ], chlorophyll(Chl) content was also the highest(2.24 mg/g‐1, and the adaptability range to light intensity was the widest; Pn and Chi content of C. limonia in yellow calcareous soil took the second place, while Pn and Chi content in quaternary red clay cane yellow soil were both the lowest[ 1.17 μ.molC02/(m2 · g) and 0.73 mg/g]. The effects of alkaline hydrolysis N, available Fe and available Cu in different soils on Pn of C. limonia were significant, while other mineral elements in different soils on Pn of C. limonia were not significant. (ii) Under the same climate condition, the adaptability changes of Pn content, Chl content and basic light requirement characteristics of C. limonia occurred on different soils, and black calcareous soil was the most conducive to the improvement of light utilization efficiency of C. limonia.%为了探索白黎檬对不同土壤的适应性,采用盆栽土培试验研究了白黎檬在变质岩母质黄壤、第4纪红色粘土母质黄壤、黄色石灰土、棕色石灰土和黑色石灰土5种土壤上的光合特性,分析土壤养分含量与白黎檬光合速率(Pn)的关系.结果表明:①黑色石灰土上白黎檬的Pn最大,为8.91 μmolCO2/(m2·s)叶绿素(Chl)含量最高,为2.24 mg/g,对光照强度的适应范围最大;黄色石灰土上白黎檬的Pn及Chl含量都仅次于黑色石灰土,而第4纪红色粘土母质黄壤上白黎檬的Pn最小,为1.17 μmolCO2/(m2

  2. Agronomic application of olive mill wastewater: Effects on maize production and soil properties.

    Science.gov (United States)

    Belaqziz, Majdouline; El-Abbassi, Abdelilah; Lakhal, El Khadir; Agrafioti, Evita; Galanakis, Charis M

    2016-04-15

    This study investigates the effect of direct amendment of olive mill wastewater (OMW) on the fertility of soil, described as poor in the area of Marrakech (semi-arid region) in Morocco. The treated plots were amended with untreated OMW generated by a traditional extraction process at the amount of 10 L/m(2)/year during two consecutive years. Results of these two years treatments with crude OMW at relatively high dose reveal an important increase in soil physicochemical characteristics, namely electric conductivity (EC), Na(+,) K(+), phosphorus, nitrogen, organic matter and soluble phenolic compounds. EC of treated soil was enhanced from 0.34 to 2.91 mS/cm as compared to the control soil. After spreading OMW in soil, the amounts of its nutritive elements increased by 81% for nitrogen, 66% for phosphorus and 88% for potassium. The accumulation of phenolic compounds and the increase of total peroxidase activity in plants provide evidence of their protective role against the physiological stress induced by OMW. However, this enrichment in mineral and nutritive elements decreased three months after OMW application, revealing OMW biodegradation in the studied calcareous soil. In parallel, an increase in the contents of the soluble phenolic compounds on the upper layer of soil was denoted and maize plants growth was efficiently raised. Significant amelioration was obtained notably in terms of fresh and dry weight of leaves, leaves area, spikes fresh and dry weight, 100 seeds weight and straw yield (37, 54, 27, 24, 14 and 9% respectively). Along with the correct choice of convenient soils notably calcareous ones and tolerant crops such as maize, this method could constitute an efficient approach for avoiding problems attributed to the uncontrolled disposal of these effluents and an effective strategy to regenerate degraded soils and represents an economical alternative that provides a local fertilizer. PMID:26899012

  3. Vegetation-induced spatial variability of soil redox properties in wetlands

    Science.gov (United States)

    Szalai, Zoltán; Jakab, Gergely; Kiss, Klaudia; Ringer, Marianna; Balázs, Réka; Zacháry, Dóra; Horváth Szabó, Kata; Perényi, Katalin

    2016-04-01

    Vegetation induced land patches may result spatial pattern of on soil Eh and pH. These spatial pattern are mainly emerged by differences of aeration and exudation of assimilates. Present paper focuses on vertical extent and temporal dynamics of these patterns in wetlands. Two study sites were selected: 1. a plain wetland on calcareous sandy parent material (Ceglédbercel, Danube-Tisza Interfluve, Hungary); 2. headwater wetland with calcareous loamy parent material (Bátaapáti, Hungary). Two vegetation patches were studied in site 1: sedgy (dominated by Carex riparia) and reedy (dominated by Phragmites australis). Three patches were studied in site2: sedgy1 (dominated by C vulpina), sedgy 2 (C. riparia); nettle-horsetail (Urtica dioica and Equisetum arvense). Boundaries between patches were studied separately. Soil redox, pH and temperature studied by automated remote controlled instruments. Three digital sensors (Ponsell) were installed in each locations: 20cm and 40cm sensors represent the solum and 100 cm sensor monitors the subsoil). Groundwater wells were installed near to triplets for soil water sampling. Soil Eh, pH and temperature values were recorded in each 10 minutes. Soil water sampling for iron and DOC were carried out during saturated periods. Spatial pattern of soil Eh is clearly caused by vegetation. We measured significant differences between Eh values of the studied patches in the solum. We did not find this kinds horizontal differences in the subsoil. Boundaries of the patches usually had more reductive soil environment than the core areas. We have found temporal dynamics of the spatial redox pattern. Differences were not so well expressed during wintertime. These spatial patterns had influence on the DOC and iron content of porewater, as well. Highest temporal dynamics of soil redox properties and porewater iron could be found in the boundaries. These observations refer to importance patchiness of vegetation on soil chemical properties in

  4. A Simple Method for Measuring Soil Redistribution on Hillslopes

    Science.gov (United States)

    Chandler, D. G.

    2002-12-01

    Human activities and associated land-use changes often result in accelerated soil movement on hillslopes. The impacts of such soil movement can be dramatic both on- and off-site. Appropriate strategies for mitigation or control erosion and mass movements are especially critical for application in tropical countries, where steep slopes are increasingly converted from forest to agricultural use and are subject to intense precipitation. The immediacy of the need for erosion control and limited access to research institutions often results in a gap between extension and testing of erosion control strategies for these settings. To address this need, a transect datum technique was developed to assess rates of soil redistribution and loss on steep, deforested slopes with thin, calcareous soil in the Philippines. The method is simple, inexpensive and robust and does not require disturbing the soil surface, as do erosion pins. Application of the technique for three years to several land uses, including contour hedgerows, a contour-plowed field without hedgerows, slash/burn no-till, and pasture demonstrated the technique sensitive enough to measure fluctuations in soil height associated with changing bulk density, soil redistribution and loss and slumping of the terraces within the contour-hedgerow system.

  5. Soil survey of Solid Waste Storage Area 6

    International Nuclear Information System (INIS)

    An intensive soil survey was made of Solid Waste Storage Area (SWSA) 6 (Oak Ridge National Laboratory) at a scale of 1:1200. The amount of chemical weathering, the thickness of upland soils, and the depth to unoxidized rock are dependent on slope gradient, water-flow pathways, degree of rock fracturing, and the extent of soil and rock erosion by late Pleistocene and Holocene geomorphic processes. Foot-slope landforms have generally concave slope shapes where sediment accumulates. Colluvium stratigraphy exhibits at least one lithologic discontinuity, but there may be two discontinuities preserved in some thicker colluvia. One or more paleosols, either complete or partially truncated, are preserved in these concave landforms. Alluvial soils were not examined in detail but were separated from colluvial soils because of their wetness. A small area of ancient alluvium was located on a stable upland summit that formed the highest elevation in SWSA-6. On the nearly level summit, a thin loess cap was preserved on the older alluvial soil. Upland and colluvial soils are all highly leached and strongly acid even though they are formed from a calcareous parent rock. The highly fractured rock, being relatively permeable, has been leached free of carbonates in the upper levels so that there is a wide pH gradient from the surface downward. Most of the soils were classified as Ultisols, with minimal areas of Alfisols, Inceptisols, and Entisols. Based on the soil survey, representative landforms and soils will be selected to study physical, chemical, and mineralogical properties of the soil and weathered rock. Those properties will be used to predict both the amount and duration of leachate filtration and purification in downward migration to the water table or lateral migration through colluvial and alluvial soils to ground-water seeps

  6. Elucidating key factors affecting radionuclide aging in soils

    International Nuclear Information System (INIS)

    Mechanistic studies allow at present to describe the processes governing the short-term interaction of radiostrontium and radiocaesium in soils. The initial sorption step can be described through the estimation of the soil-soil solution distribution coefficient from soil parameters, as cationic exchange capacity, radiocaesium interception potential and concentration of competing ions in the soil solution. After the initial soil-radionuclide interaction, a fraction of radionuclide is no longer available for exchange with the solution, and it remains fixed in the solid fraction. At present, the initial fixed fraction of a radionuclide in a given soil cannot be predicted from soil properties. Besides, little is known about soil and environmental factors (e.g., temperature; hydric regime) provoking the increase in the fixed fraction with time, the so-called aging process. This process is considered to control the reduction of food contamination with time at contaminated scenarios. Therefore, it is crucial to be able to predict the radionuclide aging in the medium and long term for a better risk assessment, especially when a decision has to be made between relying on natural attenuation versus implementing intervention actions. Here we study radiostrontium and radiocaesium aging in a set of soils, covering a wide range of soil types of contrasting properties (e.g., loamy calcareous; podzol; chernozem, organic). Three factors are separately and simultaneously tested: time elapsed since contamination, temperature and hydric regime. Changes in the radionuclide fixed fraction are estimated with a leaching test based on the use of a mild extractant solution. In addition to this, secondary effects on the radiocaesium interception potential in various soils are also considered. (author)

  7. How a Sphagnum fuscum-dominated bog changed into a calcareous fen: the unique Holocene history of a Slovak spring-fed mire

    OpenAIRE

    Hajkova, Petra; Grootjans, A. B.; Lamentowicz, Mariusz; Rybnickova, Eliska; Madaras, Mikulas; Opravilova, Vera; Michaelis, Dierk; Hajek, Michal; Joosten, Hans; Wolejko, Leslaw; Rybníčková, Eliška; Madaras, Mikuláš; Opravilová, Věra; Wołejko, Lesław; Hajkova, T.

    2012-01-01

    In general, mires develop by autogenic succession from more groundwater-fed to more rainwater-fed. This study from a calcareous mire in the West Carpathians (Slovakia) describes a similar development in the Early Holocene, followed by a reverse development in the Middle and Late Holocene. Pollen, macrofossil and testate amoeba analyses show that the site started as a minerotrophic open fen woodland. After 10 700 cal a BP autogenic succession led to the accumulation of at least 1 m of Sphagnum...

  8. What do results of common sequential fractionation and single-step extractions tell us about P binding with Fe and Al compounds in non-calcareous sediments?

    Czech Academy of Sciences Publication Activity Database

    Jan, Jiří; Borovec, Jakub; Kopáček, Jiří; Hejzlar, Josef

    2013-01-01

    Roč. 47, č. 2 (2013), s. 547-557. ISSN 0043-1354 R&D Projects: GA ČR(CZ) GA206/09/1764; GA MZe(CZ) QH81012; GA MZe(CZ) QI102A265 Institutional support: RVO:60077344 Keywords : sequential fractionation * ascorbate and oxalate extration * non-calcareous sediments Subject RIV: DA - Hydrology ; Limnology Impact factor: 5.323, year: 2013

  9. Thermally Sprayed Aluminum (TSA) with Cathodic Protection as Corrosion Protection for Steel in Natural Seawater : Characterization of Properties on TSA and Calcareous Deposit

    OpenAIRE

    Egtvedt, Solveig

    2011-01-01

    Cathodic protection is an effective corrosion protection for structures submerged in seawater. In addition to applying the current need to lower the metal below the protection potential, a resulting increase in interfacial pH leads to precipitation of calcareous deposit. This deposited layer act as a barrier against oxygen diffusion on the surface, hence lowering the current demand of the structure. However, this layer will also hinder the thermal conductivity, and is therefore unwanted at th...

  10. The Effect of Chloride and Sulfate Ions on the Adsorption of Cd2+ on Clay and Sandy Loam Egyptian Soils

    OpenAIRE

    EL-Hefnawy, Mohamed E.; Selim, Elmetwaly M.; Assaad, Faiz F.; Ismail, Ali I.

    2014-01-01

    Adsorption of Cd2+ on two types of Egyptian soils: clay (alluvial) and sandy loam (calcareous), was studied. Effect of changing the matrix electrolyte type and concentration was used to mimic the natural soil salts. Kinetics and thermodynamic parameters of the adsorption were calculated at two different electrolyte concentrations: 0.05 N and 0.15 N. The adsorption was described by Langmuir and Freundlich isotherms. Results showed that lower concentration of the NaCl or Na2SO4 electrolytes (0....

  11. Effect of ambient Mg/Ca ratio on Mg fractionation in calcareous marine invertebrates: A record of the oceanic Mg/Ca ratio over the Phanerozoic

    Science.gov (United States)

    Ries, Justin B.

    2004-11-01

    The Mg/Ca ratio of seawater has changed significantly over the Phanerozoic, primarily as a function of the rate of ocean-crust production. Echinoids, crabs, shrimps, and calcareous serpulid worms grown in artificial seawaters encompassing the range of Mg/Ca ratios that existed throughout the Phanerozoic exhibit a direct nonlinear relationship between skeletal and ambient Mg/Ca. Specimens grown in seawater with the lowest Mg/Ca (˜1) changed their mineralogy to low-Mg calcite (MgCO3), suggesting that these high-Mg calcareous organisms would have produced low-Mg calcite in the Cretaceous, when oceanic Mg/Ca was lowest (˜1). These results support the empirical evidence that the skeletal chemistry of calcareous organisms has varied significantly over the Phanerozoic as a function of the Mg/Ca of seawater, and that the Mg/Ca of unaltered fossils of such organisms may be a record of oceanic Mg/Ca throughout the Phanerozoic. Mg fractionation algorithms, which relate skeletal Mg/Ca, seawater Mg/Ca, and temperature, were derived from these and other experiments. They can be used to estimate paleoceanic Mg/ Ca ratios and temperatures from fossil skeletal Mg/Ca of the organisms evaluated. Pale oceanic Mg/Ca ratios, recalculated by using the echinoderm Mg fractionation algorithm from published fossil echinoid Mg/Ca, crinoid Mg/Ca, and paleotemperature data, are consistent with other estimates and models of oceanic Mg/Ca over the Phanerozoic.

  12. Applications of some non destructive testing techniques to the characterization of calcareous rocks: ultrasounds, X and gamma-ray radiography, tomography, neutron radiography

    International Nuclear Information System (INIS)

    NUCLEART Laboratory has been developping various techniques of conservation of art objects made of wood or stone. It has, among others, achieved a technique of strengthening porous stone objects, by resin impregnation followed by polymerization under gamma rays. The good conduct of such operations implies the existence of characterization means, before and after treatment of the objects. Two means of rocks characterization have been studied: - ultrasound techniques, - radiography techniques. The first part consists in a general description of the calcareous rocks morphology and a presentation of the studied specimens. The second part deals with the application of ultrasound techniques to rocks. Experimentally, one pays particular attention to the specific aspects of ultrasounds propagation inside materials like porous rocks, and especially diffusion phenomena. Results were interpreted in terms of propagation medium structure. Practical interest for rocks control through such techniques has been underligned. The third part concerns the application of radiographic techniques to calcareous rocks. Experimental work consists in establishing exposure curves for a wide range of energy, and the images quality determination. Through a statistics approach, and using digitalization techniques, one has done an exhaustive study of the radiographic noise. Moreover two techniques close to conventional radiography were explored: neutron radiography and X-ray tomography. Their specificity and interest in the case of calcareous rocks have been shown

  13. Using O2 to study the relationships between soil CO2 efflux and soil respiration

    Directory of Open Access Journals (Sweden)

    A. Angert

    2014-08-01

    Full Text Available Soil respiration, is the sum of respiration processes in the soil, and is a major flux in the global carbon cycle. It is usually assumed that the CO2 efflux is equal to the soil respiration rate. Here we challenge this assumption by combining measurements of CO2 with high-precision measurements of O2. These measurements were conducted on different ecosystems and soil types, and included measurements of air-samples taken from the soil profile of three Mediterranean sites, a temperate forest, and two alpine forests. Root-free soils from the alpine sites were also incubated at the lab. We found that the ratio between the CO2 efflux to the O2 influx (which we defined as apparent respiratory quotient, ARQ was in the range of 0.14 to 1.23, which strongly deviates from 0.9 ± 0.1, which is the ratio expected from the elemental composition of average plants and soil organic matter. At the Mediterranean sites these deviations were explained as a result of CO2 dissolution in the soil water and transformation to bi-carbonate in these high pH soils, and by carbonates dissolution and precipitation processes. Thus, correct estimate of the short-term, chamber-based biological respiratory flux in such soils can only be made by dividing the measured CO2 efflux by the average (efflux weighted soil profile ARQ. We demonstrated that applying this approach to a semiarid pine forest resulted in estimated short-term respiration rate 3.8 times higher than the chamber-measured surface CO2 efflux (8.8 μmol CO2 m−2 s−1 instead of 2.3 μmol CO2 m−2 s−1, at the time of measurement. The ARQ values that were often found for the more acidic soils were lower than 0.7, and hence surprising. These values might be the result of the oxidation of reduced iron, which could previously form during times of high soil moisture and local anaerobic conditions inside aggregates. Further research is needed to confirm that low ARQ found in non-calcareous soils, is the result of this

  14. Nitrogen isotope compositions and spatial distribution characteristics of soil in the process of karst rocky desertification

    International Nuclear Information System (INIS)

    Isotopic composition and spatial distribution characteristic of total nitrogen of the surficial soil in karst rocky desertification area, including different types, different grades and different disturbed modes karst rocky desertification within the same small catchment, which belong to the Wangjiazhai peak-cluster depression basin and located in Qingzhen City, Guizhou Province were discussed in this study. Results showed that δ 15N values of total nitrogen in top soil in yellow soil area were mainly between +0.35‰ ∼ +6.82% with the average of +4.50‰, and between +2.70‰ ∼ +6.50‰ in black calcareous with the average of +4.27‰. In both yellow soil area and black calcareous area, there were no significant difference in the δ 15N values of total nitrogen on sample lands of rocky desertification at different levels, different ways of interruption and different slope positions, and no obvious difference on the whole (P≤0.05), which is mainly due to the high habitat heterogeneity of karst area. (authors)

  15. Seasonal variation in bryophytes cover in the calcareous mire belianske luky, slovakia

    International Nuclear Information System (INIS)

    While making investigations of glacial relic bryophytes in Belianske luky mire, we recorded seasonal change in cover of selected bryophytes. It was decided to perform repeated monitoring between 2008-2010, in three replicates each year. In particular, the main observation was the decreasing cover of Campylium stellatum and Drepanocladus cossonii in the course of the year. In order to explain the seasonal change, we have sampled physico-chemical features of the examined sites: pH, redox potential (ORP), conductivity, total dissolved solids (TDS), salinity, dissolved oxygen, chemical oxygen demand (COD), CaCO/sub 3/, NO/sub 3/, SO/sub 4/, NH/sub 4/ and Cl. Results show that within investigated sites the distribution of Campylium stellatum and Drepanocladus cossonii was mostly limited by decreasing concentration of NH/sub 4/ and increasing concentration of NO/sub 3/ in the course of the year. The phylogenetic diversity of the bacterial community in the water sample from Belianske luky meadows was investigated using a PCR of the 16SrRNA gene. After screening by Terminal Restriction Fragment Length Polymorphism (T-RFLP) method, we made in silico analysis, confirming the presence of nitrifying bacteria.The seasonal variation in bryophytes cover is induced by the synergic influence of decomposition of organic substances in soils, by nitrifying bacteria activity and by unstable the water table. (author)

  16. Reduction of soil pollution by usingwaste of the limestone in the cement industry

    Science.gov (United States)

    Muñoz, M. Cecilia Soto; Robles Castillo, Marcelo; Blanco Fernandez, David; Diaz Gonzalez, Marcos; Naranjo Lamilla, Pedro; Moore Undurraga, Fernando; Pardo Fabregat, Francisco; Vidal, Manuel Miguel Jordan; Bech, Jaume; Roca, Nuria

    2016-04-01

    In the cement manufacturing process (wet) a residue is generated in the flotation process. This builds up causing contamination of soil, groundwater and agricultural land unusable type. In this study to reduce soil and water pollution 10% of the dose of cement was replaced by waste of origin limestone. Concretes were produced with 3 doses of cement and mechanical strengths of each type of concrete to 7, 28 and 90 days were determined. the results indicate that the characteristics of calcareous residue can replace up to 10% of the dose of cement without significant decreases in strength occurs. It is noted that use of the residue reduces the initial resistance, so that the dose of cement should not be less than 200 kg of cement per m3. The results allow recommends the use of limestone waste since it has been observed decrease in soil and water contamination without prejudice construction material Keywords: Soil contamination; Limestone residue; Adding concrete

  17. Degradation of 14C-lindane in soils of planting ginseng

    International Nuclear Information System (INIS)

    14C-Lindane was used to study degradation of Lindane (γ-BHC) in different types of soil of planting ginseng. Results indicated that Lindane was very slowly mineralized after a 228 day's incubation period in closed system. It took about 9 years to completely mineralize Lindane in the chernozem, and 11 years in the brown calcareous at 20 ppm in the soils. In addition, the rate of Lindane mineralized depended on population and number of microorganism. In this test the fungi played more important role than the bacteria in the Lindane mineralization. 14C-Lindane residues extracted from the soils were 77.43%-80.54%, and Lindane residues associated with the soils were 13.11%-20.77%

  18. Biostratigrafia a foraminiferi del Cretaceo Superiore della successione di Parco Priore (Calcare di Altamura, Piattaforma Apula, Italia Meridionale

    Directory of Open Access Journals (Sweden)

    Luigi Spalluto

    2008-03-01

    Full Text Available This study focuses on the biostratigraphic analysis of an Upper Cretaceous 57 m-thick stratigraphicsedimentary succession outcropping in a quarry at Parco Priore, near the city of Altamura in theMurge (Southern Italy.In the studied area the Upper Cretaceous shallow water carbonate successions represent restrictedfacies deposited in inner shelf settings within the Apulian Platform (sensu D’Argenio, 1974. Duringthe Mesozoic, the Apulian Platform was one of the peri-adriatic platforms (D’Argenio, 1974 localizedalong the southern margin of the Tethys. These platforms have been often compared to the presentdayBahamas islands for their general shape, size, subsidence rates as well as their inner platformarchitecture (Bernoulli, 2001.The studied sedimentary succession, belonging to the Calcare di Altamura formation, is mainlycharacterised by bedded white-reddish bioclastic, often re-crystallised or dolomitised, mudstones/wackestones. White-grey calcarenitic and calcisiltitic bedded limestones and thin bedded palaeosoillevels are also present. The micropalaeontological assemblage is dominated by benthic foraminifers(Accordiella conica, Cuneolina pavonia, Moncharmontia apenninica, Minouxia conica, Rotorbinellascarsellai, Dicyclina schlumbergeri, Murgeina apula, Cuneolina spp., Pseudolituonella sp.,Aeolisaccus kotori, miliolids, textularids and dasycladacean algae (mainly Thaumatoporellaparvovesiculifera.This benthic association allows to refer the Parco Priore succession to the Coniacian‒lowerCampanian time interval. Sedimentological, lithological and micropalaeontological characteristicsof the studied succession point to a low-energy inner carbonate platform setting with occasional subaerialexposures.

  19. 14C dating of freshwater carbonate sediments with special reference to calcareous tufas and laminated lake sediments

    International Nuclear Information System (INIS)

    The sequence of laminated sediment of the lake Gosciaz, Poland, covers more than 13,000 years and is actually the longest sequence known so far. Besides of reconstructing past environmental changes, this sequence offers an excellent possibility for studying natural C-14 variations and calibrating the C-14 time scale in a range beyond 6,000 years B.P. The floating varve chronology based on previously taken sediment cores which cover a period of 9,682 years, has been improved by this study. Relative water level changes of the lake during the past 11,500 years have been reconstructed by means of C-14 and C-13 measurements carried out on carbonate fractions of the lake sediments. Periodical variations in the width of annual layers were found. The periods identified are 11 years and 22 years (solar cycle), 35 years (Bruckner cycle), and 200 years. The ratio of summer layer width and the total width of the annual layer shows secular changes which correlate with paleotemperature records. The duration of the Younger Dryas period was determined by combining the floating varve chronology with isotope and pollen analyses of the sediment material. A value of 1,500 years was found. The study also included radiocarbon dating of calcareous tufa taken from different study areas. 26 refs, 26 figs, 6 tabs

  20. Growth and carbon fixation rate of calcareous algae cricosphaera carterae. Sekkaiso cricosphaera carterae no zoshoku to tanso kotei sokudo

    Energy Technology Data Exchange (ETDEWEB)

    Seki, M.; Furusaki, S. (The University of Tokyo, Tokyo (Japan). Faculty of Engineering); Shigematsu, K. (Sumitomo Chemical Co. Ltd., Osaka (Japan)); Shigeta, K. (Kanagawa Prefectural Office, Yokohama (Japan))

    1993-09-10

    Notice has been given on a calcareous alga among micro marine algae that play an important role in carbon circulation, and the representative alga, Cricosphaera carterae was cultured to discuss growth and carbon fixation rate experimentally. It was found that nutrient salt is taken in more actively in the bright period during which no fission occurs, and less actively during the growth stage in the dark period. Dependence of nitrate concentration on specific growth rate was measured with semi-continuous culture and two formulas were formulated. The specific growth rate was 0.53/d at an average nitrogen concentration on the ocean surface of 15 mg/m[sup 3]. The maximum specific growth rate was 0.9/d, and the fixing ratio of inorganic carbon to organic carbon was roughly 0.1. Further, the alga was cultured with CO2 concentration doubled (to 715 ppm), where no large difference was discovered in the growth and the inorganic carbon fixation. From these findings, the carbon fixation amount due to algae on the entire earth was calculated to roughly 4 billion tons per year. 23 refs., 10 figs., 4 tabs.