Organic acid enhanced electrodialytic extraction of lead from contaminated soil fines in suspension

DEFF Research Database (Denmark)

Jensen, Pernille Erland; Ahring, Birgitte Kiær; Ottosen, Lisbeth M.

2007-01-01

for decontamination of the sludge was investigated. The ability of 11 organic acids to extract Pb from the fine fraction of contaminated soil (grains soil fines in suspension......The implementation of soil washing technology for the treatment of heavy metal contaminated soils is limited by the toxicity and unwieldiness of the remaining heavy metal contaminated sludge. In this work, the feasibility of combining electrodialytic remediation with heterotrophic leaching...... was tested. Five of the acids showed the ability to extract Ph from the soil fines in excess of the effect caused solely by pH changes. Addition of the acids, however, severely impeded EDR, hence promotion of EDR by combination with heterotrophic leaching was rejected. In contrast, enhancement of EDR...

Electrodialytic Remediation of Soil Slurry-Removal of Cu, Cr, and As

DEFF Research Database (Denmark)

Ottosen, Lisbeth M.; Jensen, Pernille Erland; Hansen, Henrik K.

2009-01-01

Severe soil contamination is often found at old wood preservation sites and a common combination of pollutants is Cu, Cr, and As. In the present work it is tested if simultaneous removal of Cu, Cr, and As can be obtained in an electrodialytic cell where the polluted soil is remediated as a stirred...... experiments; an experiment where the soil was suspended in distilled water and the remediation lasted 3 weeks with 2.5 mA and an experiment with acidification of the soil suspension with HNO3 to pH about 1.0 (2 weeks and 5 mA). The best separation of pollutants and soil was obtained in the experiment...... with suspension in distilled water. Based on soil concentrations, good Cu removal (95%) was obtained in both experiments. Removal of Cr was most efficient from the acidified soil suspension (74%). Both Cu and Cr concentrations were below the limiting values after the remediation. The As concentration, however...

Electrodialytic remediation of solid waste

DEFF Research Database (Denmark)

Hansen, Henrik K.; Ottosen, Lisbeth M.; Karlsmose, Bodil

1996-01-01

Electrodialytic remediation of heavy metal polluted solid waste is a method that combines the technique of electrodialysis with the electromigration of ions in the solid waste. Results of laboratory scale remediation experiments of soil are presented and considerations are given on how to secure...

Electrodialytic remediation of polychlorinated biphenyls contaminated soil with iron nanoparticles and two different surfactants

DEFF Research Database (Denmark)

Gomes, Helena I.; Dias-Ferreira, Celia; Ottosen, Lisbeth M.

2014-01-01

Polychlorinated biphenyls (PCB) are persistent organic pollutants (POP) that strongly adsorb in soils and sediments. There is a need to develop new and cost-effective solutions for the remediation of PCB contaminated soils. The suspended electrodialytic remediation combined with zero valent iron......ZVI showed encouraging tendencies and a base is thus formed for further optimization towards a new method for remediation of PCB polluted soils....... nanoparticles (nZVI) could be a competitive alternative to the commonly adapted solutions of incineration or landfilling. Surfactants can enhance the PCB desorption, dechlorination, and the contaminated soil cleanup. In this work, two different surfactants (saponin and Tween 80) were tested to enhance PCB...

Solidification of metal oxide from electrokinetic-electrodialytic decontamination

Energy Technology Data Exchange (ETDEWEB)

Koo, Daeseo; Park, Uk-Ryang; Kim, Gye-Nam; Kim, Seung-Soo; Moon, Jei-Kwon [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2015-05-15

Electrokinectic-electrodialytic decontamination technology reduced 80% of the concentration of the uranium soil waste to below the concentration of self-disposal. After conducting electrokinectic-electrodialytic decontamination, more than 10% of the remainder of radioactive waste from the cathodes of electrokinectic-electrodialytic equipment were produced. To dispose of such waste, it is necessary to solidify second radioactive waste owing to the requirements of radioactive waste from public corporations. In this study, a solidification experiment was carried out using a polymer. At first, a sampling of second radioactive waste was conducted. Then, second radioactive waste and a polymer were mixed. Third, the solidified state between the second radioactive waste and polymer was checked. In our next study, an experiment for the requirements of a public radioactive waste corporation will be conducted.

SEQUENTIAL ELECTRODIALYTIC EXTRACTION OF PHOSPHORUS COMPOUNDS

DEFF Research Database (Denmark)

2017-01-01

The present invention relates to an apparatus for electrodialytic extraction of phosphorus from a particulate material in suspension and to a method for electrodialytic phosphorus recovery, which uses the apparatus. The method may be applied for wastewater treatment, and/or treatment of particulate...... material rich in phosphorus. The present invention provides an apparatus for electrodialytic extraction of phosphorus from a particulate material comprising acidic and/or alkaline soluble phosphorus compounds, in suspension, comprising: • a first electrodialytic cell comprising a first anolyte compartment...

Influence of a Stone and a Screw in the Soil on Electrodialytic Remediation

DEFF Research Database (Denmark)

Ottosen, Lisbeth M.; Hansen, Henrik; Ribeiro, Alexandre B.

1999-01-01

It is common to find pieces of construction waste in abandoned industrial sites. Experimental work confirm that both metallic pieces and non-conducting pieces as e.g. a large stone will influence the electrodialytic remediation.......It is common to find pieces of construction waste in abandoned industrial sites. Experimental work confirm that both metallic pieces and non-conducting pieces as e.g. a large stone will influence the electrodialytic remediation....

Effect of pulse current on energy consumption and removal of heavy metals during electrodialytic soil remediation

DEFF Research Database (Denmark)

Sun, Tian Ran

pathways to unacceptable dosages, leading to intolerable adverse effects on both public health and the environment. In the last decades, soil and water remediation have gained growing awareness, as the necessity becomes clearer for development of such techniques for elimination of the negative impact from......: transport of water (electroosmosis) and ions (electromigration), with electromigration being the most important transport process when treating heavy metal contaminated soils. Electrodialytic remediation (EDR), one of the enhanced electrochemical remediation techniques, is developed at the Technical...... compartments. Therefore no current is wasted for carrying ions from one electrode compartment to the other. The EDR technique has been tested for decontamination of a variety of different heavy metal polluted particulate materials: mine tailings, soil, different types of fly ashes, sewage sludge, freshwater...

The effect of Soil Temperature on Electrodialytic Remediation

DEFF Research Database (Denmark)

Kristensen, Iben Vernegren

1999-01-01

The electrodialytic remediation of copper, zinc and lead contaminated kaolin was studied at three different temperatures (0-39 degrees centrigrate). It is shown that an increase in temperature increases the rate of remediation for all three metals. Copper and zinc shows similar rate constants......, while for lead, the rate constant obtained are significantly smaller. The increased remediation rate is presumed to be due mainly to the lowering of the viscosity....

Effects of pulse current on energy consumption and removal of heavy metals during electrodialytic soil remediation

DEFF Research Database (Denmark)

Sun, Tian R.; Ottosen, Lisbeth M.

2012-01-01

industrially polluted soils were performed. At a current density of 0.1mA/cm2 in soil 1 and 0.2mA/cm2 in soil 2, there was no difference on energy consumption and removal of heavy metals between pulse current and constant current experiments, but at higher current experiments (i.e., 0.2mA/cm2 in soil 1 and 0......The aims of this paper were to investigate the possibility for energy saving when using a pulsed electric field during electrodialytic soil remediation (EDR) and the effect of the pulsed current on removal of heavy metals. Eight experiments with constant and pulse current in the different.......8mA/cm2 in soil 2) the energy was saved 67% and 60% and the removal of heavy metals was increased 17–76% and 31–51% by pulse current in soil 1 and soil 2, respectively. When comparing the voltage drop at different parts of EDR cells, it was found that the voltage drop of the area across cation...

Effect of pulse current on acidification and removal of Cu, Cd, and As during suspended electrodialytic soil remediation

DEFF Research Database (Denmark)

Sun, Tian Ran; Ottosen, Lisbeth M.; Jensen, Pernille Erland

2013-01-01

The effect of pulse current on the acidification process and the removal of heavy metals during suspended electrodialytic soil remediation were investigated in this work. Eight experiments with constant and pulse current in two polluted soils were conducted using a 3-compartment membrane cell......, predominately working under overlimiting current density conditions. Soil 1 was sampled from a pile of excavated soil at a site with mixed industrial pollution (Cu and Cd), and soil 2 was sampled from the top layer of a wood preservation site (Cu and As). Results showed that pulse current improved...... the acidification by supplying more reactive H+ ions (defined as the H+ ions causing release of heavy metals from soil particles). The molar ratio of reactive H+ ions to total produced H+ ions (RH+/PH+) was higher in every pulse current experiment than in the corresponding constant current experiment. In addition...

Ammonium citrate as enhancement for electrodialytic soil remediation and investigation of soil solution during the process.

Science.gov (United States)

Dias-Ferreira, Celia; Kirkelund, Gunvor M; 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 (0.25, 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 using too high current densities can be a waste of energy. Desorption rate is important and both remediation time and ammonium citrate concentration are relevant parameters. It was possible to collect soil solution samples following an adaptation of the experimental set-up to ensure continuous supply of ammonium citrate to the soil in order to keep it saturated during the remediation. Monitoring soil solution gives valuable information on the evolution of remediation and helps deciding when the soil is remediated. Final concentrations in the soil ranged from 220 to 360 mg Cu kg(-1) (removals: 78-86%) and 440-590 mg Cr kg(-1) (removals: 35-51%), being within the 500 mg kg(-1) limit for a clean soil only for Cu. While further optimization is still required for Cr, the removal percentages are the highest achieved so far, for a real Cu and Cr-contaminated, calcareous soil. The results highlight EDR potential to remediate metal polluted soils at neutral to alkaline pH by choosing a good enhancement solution. Copyright © 2014 Elsevier Ltd. All rights reserved.

Degradation of oil products in a soil from a Russian Barents hot-spot during electrodialytic remediation

DEFF Research Database (Denmark)

Pedersen, Kristine B.; Lejon, Tore; Jensen, Pernille Erland

2016-01-01

A highly oil-polluted soil from Krasnoe in North-West Russia was used to investigate the degradation of organic pollutants during electrodialytic remediation. Removal efficiencies were up to 70 % for total hydrocarbons (THC) and up to 65 % for polyaromatic hydrocarbons (PAH). Relatively more...... of the lighter PAH compounds and THC fractions were degraded. A principal component analysis (PCA) revealed a difference in the distribution of PAH compounds after the remediation. The observed clustering of experiments in the PCA scores plot was assessed to be related to the stirring rate. Multivariate analysis...... of the experimental settings and final concentrations in the 12 experiments revealed that the stirring rate of the soil suspension was by far the most important parameter for the remediation for both THC and PAH. Light was the second most important variable for PAH and seems to influence degradation. The experimental...

Electrodialytic Remediation of Copper Mine Tailings

DEFF Research Database (Denmark)

Hansen, H.K.; Rojo, A.; Ottosen, L.M.

2012-01-01

This work compares and evaluates sixteen electrodialytic laboratory remediation experiments on copper mine tailings. Different parameters were analysed, such as remediation time, addition of desorbing agents, and the use of pulsed electrical fields.......This work compares and evaluates sixteen electrodialytic laboratory remediation experiments on copper mine tailings. Different parameters were analysed, such as remediation time, addition of desorbing agents, and the use of pulsed electrical fields....

Electrodialytic removal of heavy metals from MSWI fly ashes

Energy Technology Data Exchange (ETDEWEB)

Pedersen, A.J.; Ottosen, L.M.; Villumsen, A. [Dept. of Civil Engineering, Technical Univ. of Denmark, Lyngby (Denmark)

2001-07-01

In this work a method called electrodialytic remediation, which is a combination of electrokinetic remediation and electrodialysis, is used for the extraction of heavy metals from MSWI fly ashes. It is shown that the use of electric current enhances the metal desorption significantly compared to traditional, chemical extraction. The metals of concern are Cd, Pb, Zn, Cu and Cr. Addition of ammonium citrate to the ash before and during remediation enhances the desorption and removal rate of all the examined heavy metals (Cd, Pb, Zn, Cu and Cr) compared to experiments only added distilled water. By introducing continuous stirring of the ash slurry during electrodialytic remediation, it is shown that the remediation rate is improved significantly compared to 'traditional' electrodialytic remediation experiments. The development of the acidic front is avoided due to better pH-control, and a better contact between the ash particles and the liquid is achieved. Up to 62% of the initial Cd, 8.3% Pb, 73% Zn, 59% Cu, and 20% Cr has been removed from two different fly ashes in electrodialytic remediation experiments. (orig.)

Electrodialytic decontamination of spent ion exchange resins

International Nuclear Information System (INIS)

Nott, B.R.

1982-01-01

Development of a novel electrodialytic decontamination process for the selective removal of radioactive Cs from spent ion exchange resins containing large amounts of Li is described. The process involves passage of a dc electric current through a bed of the spent ion exchange resin in a specially designed electrodialytic cell. The radiocesium so removed from a volume of the spent resin is concentrated onto a much smaller volume of a Cs selective sorbent to achieve a significant radioactive waste volume reduction. Technical feasibility of the electrodialytic resin decontamination process has been demonstrated on a bench scale with a batch of simulated spent ion exchange resin and using potassium cobalt ferrocyanide as the Cs selective sorbent. A volume reduction factor between 10 and 17 has been estimated. The process appears to be economically attractive. Improvements in process economics can be expected from optimization of the process. Other possible applications of the EDRD process have been identified

Electrodialytic removal of cadmium from straw combustion fly ash

DEFF Research Database (Denmark)

Hansen, Henrik K.; Ottosen, Lisbeth M.; Villumsen, Arne

2004-01-01

Fly ash from straw combustion contains valuable nutrients when returned to agricultural soils. In many instances, however, this fly ash may contain heavy metals, such as cadmium, at levels which often exceed the limits given by the Danish legislation. Thus before utilizing the nutrients, cadmium...... must be removed from these ashes. The use of an electrodialytic remediation method to remove cadmium from fly ash arising from straw combustion and containing 11.2 mg Cd kg$+-1$/ DM (dry matter) was accessed. After 36 days of remediation at a constant current density of 5.6 mA cm$+-2$/ more than 97...

Electrodialytic removal of heavy metals from fly ashes

DEFF Research Database (Denmark)

Pedersen, Anne Juul

2002-01-01

The aim of the Ph.D. work was to develop the electrodialytic remediation method for removal of heavy metals from fly ashes. The work was focused on two types of fly ashes: fly ashes from wood combustion and fly ashes from municipal solid waste incineration.......The aim of the Ph.D. work was to develop the electrodialytic remediation method for removal of heavy metals from fly ashes. The work was focused on two types of fly ashes: fly ashes from wood combustion and fly ashes from municipal solid waste incineration....

Electrodialytic soil remediation

DEFF Research Database (Denmark)

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

1997-01-01

It is not possible for all heavy metal polluted soils to remediate it by an applied electric field alone. A desorbing agent must in different cases be added to the soil in order to make the process possible or to make it cost effective......It is not possible for all heavy metal polluted soils to remediate it by an applied electric field alone. A desorbing agent must in different cases be added to the soil in order to make the process possible or to make it cost effective...

Electrodialytic removal of cadmium from wastewater sludge

DEFF Research Database (Denmark)

Jakobsen, M. R.; Fritt-Rasmussen, Janne; Nielsen, S.

2004-01-01

This paper presents for the first time laboratory results demonstrating electrodialytic removal of Cd from wastewater sludge, which is a method originally developed for soil remediation. During the remediation a stirred suspension of wastewater sludge was exposed to an electric dc field. The liquid....../solid (ml/g fresh sludge) ratio was between 1.4 and 2. Three experiments were performed where the sludge was suspended in distilled water, citric acid or HNO"3. The experimental conditions were otherwise identical. The Cd removal in the three experiments was 69, 70 and 67%, respectively, thus the removal...... was approximately the same. Chemical extraction experiments with acidic solutions showed that 5-10 times more Cd could be extracted from decomposed sludge than from fresh sludge. It is likely that the mobilization of Cd during decomposition of the sludge contributes to the efficient removal of Cd...

Electrodialytic remediation of CCA treated waste wood in pilot scale

DEFF Research Database (Denmark)

Pedersen, Anne Juul; Christensen, Iben Vernegren; Ottosen, Lisbeth M.

2005-01-01

study the utility of the method Electrodialytic Remediation was demonstrated for handling of CCA treated waste wood in pilot scale. The electrodialytic remediation method, which uses a low level DC current as the cleaning agent, combines elektrokinetic movement of ions in the wood matrix with the princi......-ples of electrodialysis. It has previously been shown that it is possible to remove Cu, Cr and As from CCA treated wood using electrodialytic remediation in laboratory scale (Ribeiro et al., 2000; Kristensen et al., 2003), but until now, the method had not been studied in larger scale. The pilot scale plant used...... in this study was designed to contain up to 2 m3 wood chips. Six remediation experiments were carried out. In these experiments, the process was up-scaled stepwise by increasing the distance between the electrodes from initially 60 cm to fi-nally 150 cm. The remediation time was varied between 11 and 21 days...

Treatment of MSW fly ashes using the electrodialytic remediation technique

DEFF Research Database (Denmark)

Ferreira, Celia; Ribeiro, Alexandra B.; Ottosen, Lisbeth M.

2004-01-01

In the present work the electrodialytic remediation technique is applied for the treatment of fly ash, a hazardous by-product resulting from the incineration of municipal solid waste. Results are presented for an experiment conducted for 40 days at 38 mA, with a continuously stirred cell. Experim......In the present work the electrodialytic remediation technique is applied for the treatment of fly ash, a hazardous by-product resulting from the incineration of municipal solid waste. Results are presented for an experiment conducted for 40 days at 38 mA, with a continuously stirred cell...

Electrodialytic remediation of copper mine tailings

DEFF Research Database (Denmark)

Hansen, Henrik K.; Rojo, A.; Ottpsen, Lisbeth M.

2005-01-01

electrodialytic remediation experiments on copper mine tailings. The results show that electric current could remove copper from watery tailing if the potential gradient was higher than 2V/cm during 21 days. With addition of sulphuric acid, the process was enhanced because the pH decreased to around 4...

Electrodialytic removal of heavy metals from municipal solid waste incineration fly ash using ammonium citrate as assisting agent

DEFF Research Database (Denmark)

Pedersen, Anne Juul; Ottosen, Lisbeth M.; Villumsen, Arne

2005-01-01

Electrodialytic remediation, an electrochemically assisted separation method, has previ-ously shown potential for removal of heavy metals from municipal solid waste incineration (MSWI) fly ashes. In this work electrodialytic remediation of MSWI fly ash using ammonium citrate as assisting agent...

Removal of selected heavy metals from MSW fly ash by the electrodialytic process

DEFF Research Database (Denmark)

Ferreira, Célia Maria Dias; Jensen, Pernille Erland; Ottosen, Lisbeth M.

2005-01-01

This paper aims to assess the applicability of the electrodialytic remediation technique for the removal of zinc, lead, copper and cadmium from municipal solid waste (MSW) incinerator fly ash. A broad range of experimental conditions were studied including current densities, remediation times, use...... of assisting agents and cell design. Several operational problems were identified during the electrodialytic experiments, among which are formation of precipitates, dryness of sample and partial dissolution of sample creating preferential pathways for the electric current. These problems may explain the low...

Electrodialytic removal of Cd from biomass combustion fly ash

DEFF Research Database (Denmark)

Pedersen, Anne Juul; Ottosen, Lisbeth M.; Simonsen, Peter

2004-01-01

Due to a high concentration of Cd, biomass combustion fly ash often fails to meet the Danish legislative requirements for recycling on agricultural fields. In this work the potential of using the method Electrodialytic Remediation to reduce the concentration of Cd in different biomass combustion....... The initial Cd concentration in the ashes varied between 8.8 mg Cd/kg DM (co-firing ash) and 64 mg Cd/kg DM (pre-washed straw ash), and pH varied from 3.7 to 13.3. In spite of large differences in ash characteristics, the electrodialytic remediation experiments indicated a good remediation potential for all...... four ashes. Final Cd concentrations below 2.0 mg Cd/kg were reached in all ashes within 14 days of remediation and legislative requirements were met. After further optimization of the remediation process on the pre-washed straw ash, limiting concentrations were reached after only 48 hours...

Electrodialytic remediation of suspended mine tailings

DEFF Research Database (Denmark)

Hansen, Henrik K.; Rojo, Adrian; Pino, Denisse

2008-01-01

This work shows the laboratory results of nine electrodialytic remediation experiments on copper mine tailings. A newly designed remediation cell, where the solids were kept in suspension by airflow, was tested. The results show that electric current could remove copper from suspended tailings...... efficiency from 1% to 80% compared to experiments with no stirring but with the same operational conditions. This showed the crucial importance of having the solids in suspension and not settled during the remediation....

Characterization and electrodialytic treatment of wood combustion fly ash for the removal of cadmium

International Nuclear Information System (INIS)

Pedersen, A.J.

2003-01-01

Due to a high content of macronutrients and a potential liming capacity, recycling of ashes from biomass combustion to agricultural fields as fertilisers and/or for soil improvement is considered in Denmark and other countries utilising biomass as an energy source. However, the fly ash fractions especially contain amounts of the toxic heavy metal cadmium that may exceed the limiting values for agricultural utilisation given by the Danish Environmental Protection Agency. In this work the advances of using an electrodialytic remediation method to reduce the Cd content in wood combustion fly ash--for the aim of recycling--was described. Initial characterisation of the experimental ash showed that the Cd content exceeded the limiting values for agricultural use and therefore needed treatment before being recycled. The pH in the ash was very high (13.3), and the Cd was not soluble at these alkaline conditions. However, significant amounts of Cd could be extracted at neutral to alkaline conditions using an ammonium citrate solution as a desorption agent. Electrodialytic remediation experiments showed that, under optimised remediation conditions using a mixture of ammonium citrate (0.25 M) and NH 3 (1.25%) as an assisting agent, more than 70% of the initial Cd could be removed from the wood fly ash. The results also indicated that a continuous out-separation of Cd from the aqueous process solutions is possible. Thereby, recycling of the (nutrient rich) process solutions as well as of the remediated ash seems achievable

Electrodialytic removal of Cd from biomass combustion fly ash suspensions

DEFF Research Database (Denmark)

Kirkelund, Gunvor M.; Ottosen, Lisbeth M.; Damoe, Anne J.

2013-01-01

was investigated with the aim of enabling reuse of the ashes. The ashes originated from combustion of straw (two ashes), wood chips, and co-firing of wood pellets and fuel oil, respectively. A series of laboratory scale electrodialytic remediation experiments were conducted with each ash. The initial Cd...

Oxalic acid as an assisting agent for the electrodialytic remediation of chromated copper arsenate treated timber waste

DEFF Research Database (Denmark)

Ribeiro, Alexandra B.; Mateus, Eduardo P.; Ottosen, Lisbeth M.

1999-01-01

The electrodialytic process is proposed as a technique for the remediation of chromated copper arsenate treated timber waste, using oxalic acid as assisting agent. The method prowed succesfull 93% Cu, 95% Cr and 99% As was removed from the timber.......The electrodialytic process is proposed as a technique for the remediation of chromated copper arsenate treated timber waste, using oxalic acid as assisting agent. The method prowed succesfull 93% Cu, 95% Cr and 99% As was removed from the timber....

The use of desorbing agents in electrodialytic remediation of harbour sediment

DEFF Research Database (Denmark)

Nystrøm, Gunvor Marie; Pedersen, Anne Juul; Ottosen, Lisbeth M.

2006-01-01

Electrodialytic removal of Cu, Zn, Pb and Cd from contaminated harbour sediment was made with the emphasis of testing the effectiveness of different desorbing agents: HCl, NaCl, citric acid, lactic acid, ammonium citrate and distilled water. Extraction experiments with the desorbing agents were...

Electrochemical soil remediation - accelerated soil weathering?

Energy Technology Data Exchange (ETDEWEB)

Ottosen, L.M.; Villumsen, A.; Hansen, H.K.; Jensen, P.E.; Pedersen, A.J. [Dept. of Civil Engineering, Technical Univ. of Denmark, Lyngby (Denmark); Ribeiro, A.B. [Dept. of Environmental Sciences and Engineering, New Univ. of Lisbon, Monte da Caparica (Portugal)

2001-07-01

In electrochemical soil remediation systems, where enhancement solutions and complexing agents are not used, a developing acidic front is mobilizing the heavy metals and the electric current is removing the mobilized elements from the soil. The hypotheses investigated in this paper is whether this process may be comparable to the chemical soil weathering that occurs in the environment due to the acidic rain, where the mobilized elements are removed from the soil by the penetrating water. Even through the weathering process is highly accelerated in the electrochemical cell. This paper shows results from electrodialytic remediation experiments performed with four different Danish heavy metal polluted soils. The main emphasis is laid on the relation between the developing acidic front and electromigration of Cu, Zn, Mn, Mg, Fe and Ca. (orig.)

Experimental and modeling of the electrodialytic and dialytic treatment of a fly ash containing Cd, Cu and Pb

DEFF Research Database (Denmark)

Lima, A.T.; Ribeiro, A.B.; Rodriguez-Maroto, J.M.

2010-01-01

A one-dimensional model is developed for simulating the electrodialytic and dialytic treatment of a fly ash containing cadmium, copper and lead. Two experimental systems have been used, a column of ash and a stirred ash suspension. The movement of Cd, Cu and Pb has been modeled taking into account...... takes into account that OH- generated on the cathode, during the electrodialytic remediation, is periodically neutralized by the addition of nitric acid in the cathode compartment. The anion and cation-exchange membranes are simply represented as ionic filters that preclude the transport of the cations...

Electrodialytic remediation of municipal solid waste incineration residues using different membranes

DEFF Research Database (Denmark)

Parés Viader, Raimon; Jensen, Pernille Erland; Ottosen, Lisbeth M.

2017-01-01

In the present work, three different commercial membrane brands were used in an identical electrodialytic cell setup and operating conditions, in order to reduce the leaching of metals and salt anions of two types of municipal solid waste incineration residues: air pollution control residues...... as a technology to upgrade municipal solid waste incineration residues....

Electrodialytic Remediation of Different Cu-Polluted Soils

DEFF Research Database (Denmark)

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

1999-01-01

Based on characterization of a polluted soil a proper desorbing agent to be added to the soil before the remediation can be found. The desorbing agent can improve the remediation according to both energy consumption and duration of the action......Based on characterization of a polluted soil a proper desorbing agent to be added to the soil before the remediation can be found. The desorbing agent can improve the remediation according to both energy consumption and duration of the action...

Electrodialytic remediation of harbour sediment in suspension - Evaluation of effects induced by changes in stirring velocity and current density on heavy metal removal and pH

DEFF Research Database (Denmark)

Kirkelund, Gunvor Marie; Ottosen, Lisbeth M.; Villumsen, Arne

2009-01-01

Electrodialytic remediation was used to remove heavy metals from a suspension of dredged harbour sediment. The studied metals Cu, Pb, Zn and Cd are normally strongly bound in anoxic sediment. Six electrodialytic laboratory remediation experiments were made, lasting 14 days and under oxic conditions...

Characterization and electrodialytic treatment of wood combustion fly ash for removal of cadmium

DEFF Research Database (Denmark)

Pedersen, Anne Juul

2003-01-01

especially contain amounts of the toxic heavy metal cadmium that may exceed the limiting values for agricultural utilisation given by the Danish Environmental Protection Agency.In this work the advances of using an electrodialytic remediation method to reduce the Cd content in wood combustion fly ash...... conditions. However, significant amounts of Cd could be extracted at neutral to alkaline conditions using an ammonium citrate solution as a desorption agent.Electrodialytic remediation experiments showed that, under optimised remediation conditions using a mixture of ammonium citrate (0.25M) and NH"3 (1.......25%) as an assisting agent, more than 70% of the initial Cd could be removed from the wood fly ash. The results also indicated that a continuous out-separation of Cd from the aqueous process solutions is possible. Thereby, recycling of the (nutrient rich) process solutions as well as of the remediated ash seems...

Preliminary treatment of MSW fly ash as a way of improving electrodialytic remediation

DEFF Research Database (Denmark)

Ferreira, Célia Maria Dias; Jensen, Pernille Erland; Ottosen, Lisbeth M.

2008-01-01

In the current work electrodialytic remediation (EDR) was applied to remove heavy metals from municipal solid waste (MSW) fly ash, a hazardous waste collected during flue gas treatment. Tests were conducted to evaluate if EDR could be improved by introducing a preliminary treatment in which very...... soluble salts were removed. Three different preliminary treatments were conducted with different L:S ratios and pH. Treatment in which metal release and L/S ratio were lower was selected for EDR. Electrodialytic remediation was performed at a constant current of 38 mA, for 14 days, using gluconate...... as a solubilisation enhancement agent. Conductivity and pH were monitored and electrolyte samples were collected every 4 days to evaluate metal release over time. It was found that the preliminary treatment reduces fouling of the ion-exchange membranes used in EDR and drastically increases the removal of metals...

Characterization of municipal solid waste incineration fly ash before and after electrodialytic treatment

DEFF Research Database (Denmark)

Pedersen, Anne Juul; Gardner, Kevin H.

2003-01-01

Municipal solid waste incineration (MSWI) fly ash, which has been treated electrodialytically for the removal of heavy metals, may have changed characteristics compared to untreated fly ash. In this study, MSWI fly ash was characterized with respect to leaching properties (pH static leaching...

Effect of different extracting solutions on the electrodialytic remediation of CCA-treated wood waste Part I. - Behaviour of Cu and Cr

DEFF Research Database (Denmark)

Velizarova, E.; Ribeiro, A. B.; Mateus, E.

2004-01-01

Removal of Cu and Cr from chromated copper arsenate (CCA)-treated wood waste under batch electrodialytic conditions was studied. The effect of different types of extracting solutions, such as deionised water or aqueous solutions of NaCl, formic acid, oxalic acid, and EDTA, on the magnitude...... and direction of the fluxes of Cu- and Cr-containing species in the electrodialytic cell was investigated. Oxalic acid was found to have the best performance if simultaneous removal of the two elements is required (removal efficiencies of 80.5% for Cu and 87.4% for Cr, respectively). A mixture of oxalic acid...... and formic acid also led to similar removal efficiencies. In these experiments, the target elements were accumulated in both the anode and cathode compartments of the electrodialytic cell due to the formation of negatively charged complexes with the organic acids used besides the free cationic forms...

Electroremediation of PCB contaminated soil combined with iron nanoparticles: Effect of the soil type

DEFF Research Database (Denmark)

Gomes, Helena I.; Dias-Ferreira, Celia; Ottosen, Lisbeth M.

2015-01-01

Polychlorinated biphenyls (PCB) are carcinogenic and persistent organic pollutants that accumulate in soils and sediments. Currently, there is no cost-effective and sustainable remediation technology for these contaminants. In this work, a new combination of electrodialytic remediation and zero...... nanoparticles. Remediation experiments are made with two different historically PCB contaminated soils, which differ in both soil composition and contamination source. Soil 1 is a mix of soils with spills of transformer oils, while Soil 2 is a superficial soil from a decommissioned school where PCB were used...... as windows sealants. Saponin, a natural surfactant, was also tested to increase the PCB desorption from soils and enhance dechlorination. Remediation of Soil 1 (with highest pH, carbonate content, organic matter and PCB concentrations) obtained the maximum 83% and 60% PCB removal with the two...

Electrodialytic recovery of phosphorus from chemically precipitated sewage sludge ashes

DEFF Research Database (Denmark)

Parés Viader, Raimon; Jensen, Pernille Erland; Ottosen, Lisbeth M.

Phosphorus scarcity requires improved recover and reuse of urban sources; the recycling of this nutrient from sewage sludge has become increasingly important in the last years. Using an innovative electrodialytic process, the present study shows the potential for P separation from Fe and Al...... precipitated sewage sludge ash using this technique, with a recovery rate of around 70%. Furthermore, heavy metals were removed from the phosphorous fraction, producing a pure and safe phosphorus source in the end....

Electrodialytic recovery of phosphorus from chemically precipitated sewage sludge ashes

DEFF Research Database (Denmark)

Viader, Raimon Parés; Erland Jensen, Pernille; Ottosen, Lisbeth M.

Phosphorus scarcity requires improved recover and reuse of urban sources; the recycling of this nutrient from sewage sludge has become increasingly important in the last years. Using an innovative electrodialytic process, the present study shows the potential for P separation from Fe and Al...... precipitated sewage sludge ash using this technique, with a recovery rate of around 70%. Furthermore, heavy metals were removed from the phosphorous fraction, producing a pure and safe phosphorus source in the end...

Electrodialytic Separation of Phosphorus and Heavy Metals from Two Types of Sewage Sludge Ash

DEFF Research Database (Denmark)

Ottosen, Lisbeth M.; Jensen, Pernille Erland; Kirkelund, Gunvor Marie

2014-01-01

of P and heavy metals is required. The present work is an experimental screening of a new combination of acid extraction and electrodialysis–electrodialytic separation (EDS) for simultaneous P recovery and removal of heavy metals. Experiments were conducted with two different ashes; rich in Fe or Al...

Ultrathin Sicopion Composite Cation-Exchange Membranes: Characteristics and Electrodialytic Performance following a Conditioning Procedure

Directory of Open Access Journals (Sweden)

Erik Ayala-Bribiesca

2012-01-01

Full Text Available The aim of this work was to investigate the properties of Sicopion membranes: an ultrathin (≈20 μm composite cation-exchange membrane (CEM made from sulphonated poly(ether-ether-ketone (SPEEK containing different levels of sulphonic-functionalized silica particles (SFSPs. Sicopion membranes were conditioned according to the French Normalization Association procedure, consisting in a series of acid and alkaline washes, and their electrodialytic characteristics were compared to an existent commercial food-grade membrane (CMX-SB. Electrical conductivity of Sicopion membranes was higher than that of CMX-SB membranes (9.92 versus 6.98 mS/cm, as well as their water content (34.0 versus 27.6%. As the SFSP level was reduced, the ion-exchange capacity (IEC of Sicopion membranes increased. Concerning their electrodialytic performances, Sicopion membranes presented a lower demineralization rate than CMX-SB membranes (35.9 versus 45.5%, due to an OH− leakage through the pores created by dislodging the SFSP particles during the conditioning procedure.

Phosphorous recovery from sewage sludge ash suspended in water in a two-compartment electrodialytic cell

DEFF Research Database (Denmark)

Ottosen, Lisbeth M.; Jensen, Pernille Erland; Kirkelund, Gunvor Marie

2016-01-01

was suspended in water in the anolyte, which was separated from the catholyte by a cation exchange membrane. Electrolysis at the anode acidified the SSA suspension, and hereby P, Cu, Pb, Cd and Zn were extracted. The heavy metal ions electromigrated into the catholyte and were thus separated from the filtrate......Phosphorus (P) is indispensable for all forms of life on Earth and as P is a finite resource, it is highly important to increase recovery of P from secondary resources. This investigation is focused on P recovery from sewage sludge ash (SSA) by a two-compartment electrodialytic separation (EDS......) technique. Two SSAs are included in the investigation and they contained slightly less P than phosphate rock used in commercial fertilizer production and more heavy metals. The two-compartment electrodialytic technique enabled simultaneous recovery of P and separation of heavy metals. During EDS the SSA...

Electrodialytic remediation of CCA-treated waste wood in a 2 m3 pilot plant

DEFF Research Database (Denmark)

Christensen, Iben Vernegren; Pedersen, Anne Juul; Ottosen, Lisbeth M.

2006-01-01

Waste wood that has been treated with chromated-copper-arsenate (CCA) poses a potential environmental problem due to the content of copper, chromium and arsenic. A pilot plant for electrodialytic remediation of up to 2 m3 wood has been designed and tested and the results are presented here. Sever...

Electrodialytic extraction of heavy metals from Greenlandic MSWI fly ash as a function of remediation time and L/S ratio

DEFF Research Database (Denmark)

Kirkelund, Gunvor Marie; Jensen, Pernille Erland; Ottosen, Lisbeth M.

2013-01-01

, where the fly ash was suspended in distilled water in different liquid to solid (L/S) ratios. Remediation times of 7 and 14 days were tested and the current strength was 50 mA in all experiments. The highest removal was seen when an acidic pH in the fly ash suspension was obtained. In an experiment...... lasting 14 days with L/S 10, up to 60 % Cd, 45 % Zn, 20 % Ni and Ba was removed. Regardless of the remediation time and L/S ratio, the fraction of soluble Ba, Cr and Pb decreased due to the electrodialytic remediation. The electrodialytic remediation method showed potential as a treatment method...

The influence of electrodialytic remediation on dioxin (PCDD/PCDF) levels in fly ash and air pollution control residues.

Science.gov (United States)

Dias-Ferreira, Celia; Kirkelund, Gunvor M; Jensen, Pernille E

2016-04-01

Fly ash and Air Pollution Control (APC) residues collected from three municipal solid waste incinerators in Denmark and Greenland were treated by electrodialytic remediation at pilot scale for 8-10 h. This work presents for the first time the effect of electrodialytic treatment on polychlorinated dibenzo-p-dioxins (PCDD) and polychlorinated dibenzofurans (PCDF), and how these levels impact on the valorization options for fly ash and APC residue. PCDD/PCDF levels in the original residues ranged between 4.85 and 197 ng g(-1), being higher for the electrostatic precipitator fly ash. The toxic equivalent (TEQ) varied ten fold, ranging 0.18-2.0 ng g(-1) I-TEQ, with penta and hexa-homologs being most significant for toxicity. After the electrodialytic treatment PCDD/PCDF levels increased in the residues (between 1.4 and 2.0 times). This does not mean PCDD/PCDF were synthesized, but else that soluble materials dissolve, leaving behind the non-water soluble compounds, such as PCDD/PCDF. According to the Basel Convention, PCDD/PCDF levels in these materials is low (residue could eventually be valorized, for instance as construction material, provided end-of-waste criteria are set and that a risk assessment of individual options is carried out, including the end-of-life stage when the materials become waste again. Copyright © 2016 Elsevier Ltd. All rights reserved.

Investigations of Cu, Pb and Zn partitioning by sequential extraction in harbour sediments after electrodialytic remediation

DEFF Research Database (Denmark)

Kirkelund, Gunvor Marie; Ottosen, Lisbeth M.; Villumsen, Arne

2010-01-01

remediation time. A three step sequential extraction scheme (BCR), with an extra residual step, was used to evaluate the heavy metal distribution in the sediments before and after electrodialytic remediation. Cu was mainly associated with the oxidisable phase of the sediment, both before and after remediation...

Acidification of Harbour sediment and removal of heavy metals induced by water splitting in electrodialytic remediation

DEFF Research Database (Denmark)

Nystrøm, Gunvor Marie; Ottosen, Lisbeth M.; Villumsen, Arne

2005-01-01

of compartments and ion exchange membranes differed. Totally, 14 electrodialytic experiments were made, with varying remediation time, current densities, and liquid to solid ratio (L/S). pH in the sediment decreased slightly after 1 day of remediation, even if the sediment had a high buffering capacity...

Elemental analysis of ash residue from combustion of CCA treated wood waste before and after electrodialytic extraction

DEFF Research Database (Denmark)

Pedersen, Anne Juul; Ottosen, Lisbeth M.

2006-01-01

Element distribution in a combined fly ash and bottom ash from combustion of copper chromate arsenate (CCA) treated wood waste was investigated by scanning electron microscopy (SEM/EDX) before and after electrodialytic extraction. The untreated ash contained various particles, including pieces...... of incompletely combusted wood rich in Cr and Ca, and irregular particles rich in Si, Al and K. Cr was also found incorporated in silica-based matrix particles. As was associated with Ca in porous (char) particles, indicating that Ca-arsenates had been formed during combustion. Cu was associated with Cr...... in the incompletely combusted wood pieces and was also found in almost pure form in a surface layer of some matrix particles – indicating surface condensation of volatile Cu species. In treated ash, Ca and As were no longer found together, indicating that Ca-arsenates had been dissolved due to the electrodialytic...

Electrodialytic removal of heavy metals from different fly ashes. Influence of heavy metal speciation in the ashes

DEFF Research Database (Denmark)

Pedersen, Anne Juul; Ottosen, Lisbeth M.; Villumsen, Arne

2003-01-01

Electrodialytic Remediation has recently been suggested as a potential method for removal of heavy metals from fly ashes. In this work electrodialytic remediation of three different fly ashes, i.e. two municipal solid waste incinerator (MSWI) fly ashes and one wood combustion fly ash was studied...... in lab scale, and the results were discussed in relation to the expected heavy metal speciation in the ashes. In initial leaching experiments the pH-dependent desorption characteristics of the heavy metals Cd, Pb, Zn and Cu were analogous in the two MSWI ashes, and thus it was expected......-moval efficiencies were observed, especially for Pb and Zn. Cd, the sole heavy metal of environmental concern in the wood ash, was found more tightly bonded in this ash than in the two MSWI ashes. It was suggested that complex Cd-silicates are likely phases in the wood ash whereas more soluble, condensed phases...

Electrodialytic extraction of Cr from water-washed MSWI fly ash by changing pH and redox conditions

DEFF Research Database (Denmark)

Chen, Wan; Kirkelund, Gunvor Marie; Jensen, Pernille Erland

2018-01-01

Electrodialytic process offers a range of possibilities to waste management by electrodialytic separation (EDS) of heavy metals, depending on how the process is designed. Using three EDS cell setups (two two-compartment and one three-compartment) and their combinations, the extraction of Cr from...... rate of 27.5%, is an improvement on the single-step that extracted maximum 3.1%. The highest extraction was obtained due to the combined extraction of Cr(III) under low pH (accompanied with high redox) conditions and Cr(VI) under high pH (low redox) conditions subsequently. The Cr leaching from...... the treated ashes with acidic pH was lower than from those with alkaline pH; after the three-step treatment, Cr leaching was much lower from the coarse fraction (> 50 µm), as compared to the fine (≤ 50 µm) or the unsieved ash. As for the coarse fraction, two/three-step treatment reduced the leaching of Cr...

Electrodialytic extraction of Cu, Pb and Cl from municipal solid waste incineration fly ash suspended in water

DEFF Research Database (Denmark)

Ottosen, Lisbeth M.; Lima, Ana Teresa; Pedersen, Anne Juul

2006-01-01

that is least soluble. Hence electrodialytic treatment of the ash suspended in water is not a solution to improve the ash quality in terms of Pb. The water-soluble Cl content per unit weight of the original ash was 12.4%. The removal of water-soluble Cl was efficient and >98% of Cl was removed (calculated......The possibility of using fly ash from municipal solid waste incineration (MSWI) in, for example, concrete is considered. MSWI fly ash, however, has too high a concentration of heavy metals, which may cause leaching problems during use or problems with waste handling at the end of the lifetime...... of the concrete. The Cl content in MSWI fly ash is also too high and will cause corrosion problems in reinforced concrete. The possibility of removing some of the unwanted heavy metals (Cu and Pb) together with Cl from an MSWI fly ash suspended in water using an electrodialytic separation method was investigated...

Comparison of 2-compartment, 3-compartment and stack designs for electrodialytic removal of heavy metals from harbour sediments

DEFF Research Database (Denmark)

Pedersen, Kristine B.; Ottosen, Lisbeth M.; Jensen, Pernille Erland

2015-01-01

Comparisons of cell and stack designs for the electrodialytic removal of heavy metals from two harbour sediments, were made. Multivariate modelling showed that sediment properties and experimental set-ups had the highest influence on the heavy metal removal indicating that they should be modelled...

Effect of long-term electrodialytic soil remediation on Pb removal and soil weathering

DEFF Research Database (Denmark)

Skibsted, Gry; Ottosen, Lisbeth M.; Elektorowicz, Maria

2017-01-01

Weathering of soil minerals during long-term electrochemical soil remediation was evaluated for two different soils: an industrially Pb contaminated soil with high carbonate content and an unpolluted soil with low carbonate content. A constant current of 5 mA was applied for 842 days, and sampling...... was made 22 times during the treatment. The overall qualitative mineral composition was unaffected by electrodialysis, except for calcite removal which was complete. However, dissolution and removal of Al, Fe, Si, Mg, Ca and Pb from the soil during the treatment exceeded the fraction extractable by...... digestion in 7 M HNO3, and provided evidence of enhanced mineral dissolution induced by the current. Nevertheless, the total dissolved Si and Al only constituted 0.2-0.3 % and 1.1-3.5 % of the total content, while the Pb overall removal from the contaminated soil was only 8.1 %. An observed reduction in the...

An optimised method for electrodialytic removal of heavy metals from harbour sediments

DEFF Research Database (Denmark)

Pedersen, Kristine B.; Jensen, Pernille Erland; Ottosen, Lisbeth M.

2015-01-01

A 2-compartment electrodialytic cell set-up for treatment of solid materials has in many respects proven superior to other types of cells in removing heavy metals from sediments. Most notably, remediation times were shorter, energy consumption was lower and higher removal efficiencies were observed....... By employing m1ultivariate modelling and investigating additional experimental variables, the relative importance of variables effecting remediation was determined and response surfaces for heavy metal removal were calculated. Employing optimal conditions it was possible to remove targeted metals (Pb, Cu, Zn...

The effect of soil type on the electrodialytic remediation of lead-contaminated soil

DEFF Research Database (Denmark)

Jensen, Pernille Erland; Ottosen, Lisbeth M.; Harmon, Thomas C.

2007-01-01

experiments with ten representative industrially Pb-contaminated surface soils. Results indicate that Pb-speciation is of primary importance. Specifically, organic matter and stable compounds like PbCrO4 can impede and possibly even preclude soil remediation. In soils rich in carbonate, where the acidic front...... to the catholyte. Thus, the presence of carbonate negatively influences the remediation time. Pb bound to soluble organic matter is also transported towards the anolyte during EDR. The primary effect of the mainly insoluble organic matter commonly present in surface soil is however to immobilize Pb and impede...

Test of electrodialytic upgrading of MSWI APC residue in pilot scale: focus on reduced metal and salt leaching

DEFF Research Database (Denmark)

Kirkelund, Gunvor Marie; Jensen, Pernille Erland; Villumsen, Arne

2010-01-01

that is adapted from conventional electrodialysis, e.g. used in desalination of solutions. The APC residue was treated in a suspension (8 kg APC residue and 80 L tap water) and circulated through an electrodialytic (ED) stack consisting of 50 cell pairs separated by ion exchange membranes. A direct current...

Mercury Levels In Fly Ash And Apc Residue From Municipal Solid Waste Incineration Before And After Electrodialytic Remediation

DEFF Research Database (Denmark)

Dias-Ferreira, Celia; Kirkelund, Gunvor Marie; Jensen, Pernille Erland

2016-01-01

carbon. Two distinct behaviours were observed for mercury as a result of the electrodialytic treatment. This element became enriched in the MSWI residues from the semi-dry system with activated carbon, whereas it decreased in ESP’s and cyclone’s FA. This work presents for the first time information about...

Electrodialytic upgrading of MSWI APC residue from hazardous waste to secondary resource

DEFF Research Database (Denmark)

Jensen, Pernille Erland; Kirkelund, Gunvor Marie; Parés Viader, Raimon

.g. for substitution of cement or fillers in concrete. In general leaching could not be reduced by optimizing current density and treatment time in the pilot scale stack treatment unit, as hypothesized, even though there was evidence of dependency on current density for e.g. zinc, this was not true for most elements......The aim of this project was to contribute to the development of electrodialytic treatment technology of air pollution control residues (APC) from municipal solid waste incineration (MSWI) to obtain maximal leaching reduction by optimization of treatment time and current density for different types...

A comparative study on Cu, Cr and As removal from CCA-treated wood waste by dialytic and electrodialytic processes

DEFF Research Database (Denmark)

Velizarova, Emiliya; Ribeiro, Alexandra B.; Ottosen, Lisbeth M.

2002-01-01

In this study, electrodialytic and dialytic techniques were used for Cu, Cr and As removal from 20-years out-of-service CCA-treated Pinus pinaster Ait. pole. The effect of applying direct current, as "cleaning agent", of up to 120mA was investigated. Focus was given to a parallel comparison...

Electrodialytic remediation of copper mine tailings: Comparing different operational conditions

DEFF Research Database (Denmark)

Rojo, Adrian; Hansen, Henrik K.; Ottosen, Lisbeth M.

2006-01-01

This work compares and evaluates sixteen electrodialytic laboratory remediation experiments on copper mine tailings. Different parameters were analyzed, such as remediation time, voltage drop, addition of desorbing agents, and the use of pulsed electrical fields. The results show that electric...... of copper citrate complexes. Using pulsed electric fields the remediation process with sulphuric acid addition was also improved by a decrease in the polarization cell. Main results: considering remediation with watery tailing as the base line, for three weeks experiments no copper removal was observed......, adding sulphuric acid total copper removal reached 39%. Adding citric acid, total copper removal was improved in terms of remediation time: after 5h experiment copper removal was 16% instead of 9% obtained after 72h with sulphuric acid addition. Using pulsed electric fields total copper removal was also...

Modeling of electrodialytic and dialytic removal of Cr, Cu and As from CCA-treated wood chips

DEFF Research Database (Denmark)

Ribeiro, Alexandra; Rodriguez-Maroto, J.M.; Mateus, Eduardo

2007-01-01

+ and NO3 used as electrolyte solutions in the electrode compartments, and oxalate ions and protons incorporated with the oxalic acid solution during wood chips incubation. The model simulation also takes into account that OH generated on the cathode, during electrodialytic remediation, is periodically...... neutralized by addition of nitric acid in the cathode compartment. The anion and cation-exchange membranes are simply represented as ionic filters that preclude the transport of co-ions (the cations and anions respectively) with the exception of H+, which is retarded but considered to pass through the anion...

Electrodialytically treated MSWI APC residue as substitute for cement in mortar

DEFF Research Database (Denmark)

Kirkelund, Gunvor Marie; Geiker, Mette Rica; Jensen, Pernille Erland

2014-01-01

Air pollution control (APC) residues from municipal solid waste incineration (MSWI) are considered hazardous waste and need pretreatment prior to possible reuse. Here, two MSWI APC residues, from which the most mobile fraction of heavy metals and salts has been removed by carbonation and/or elect......Air pollution control (APC) residues from municipal solid waste incineration (MSWI) are considered hazardous waste and need pretreatment prior to possible reuse. Here, two MSWI APC residues, from which the most mobile fraction of heavy metals and salts has been removed by carbonation and....../or electrodialytic remediation, were used in Portland cement mortar. Mortar bars with 15 % weight replacement of cement by APC residues showed compressive strengths up to 40 MPa after 28/32 days. Heavy metal and salt leaching from both crushed and monolithic mortars with APC residues was generally similar...

Phosphorus recovery from sewage sludge ash through an electrodialytic process

DEFF Research Database (Denmark)

Guedes, Paula; Couto, Nazare; Ottosen, Lisbeth M.

2014-01-01

The electrodialytic separation process (ED) was applied to sewage sludge ash (SSA) aiming at phosphorus (P) recovery. As the SSA may have high heavy metals contents, their removal was also assessed. Two SSA were sampled, one immediately after incineration (SA) and the other from an open deposit (SB......). Both samples were ED treated as stirred suspensions in sulphuric acid for 3,7 and 14 days. After 14 days, phosphorus was mainly mobilized towards the anode end (approx. 60% in the SA and 70% in the SB), whereas heavy metals mainly electromigrated towards the cathode end. The anolyte presented...... a composition of 98% of P, mainly as orthophosphate, and 2% of heavy metals. The highest heavy metal removal was achieved for Cu (ca. 80%) and the lowest for Pb and Fe (between 4% and 6%). The ED showed to be a viable method for phosphorus recovery from SSA, as it promotes the separation of P from the heavy...

Simultaneous electrodialytic removal of PAH, PCB, TBT and heavy metals from sediments

DEFF Research Database (Denmark)

Pedersen, Kristine B.; Lejon, Tore; Jensen, Pernille Erland

2017-01-01

with the need of different remedial actions for each pollutant. In this study, electrodialytic remediation (EDR) of sediments was found effective for simultaneous removal of heavy metals and organic pollutants for sediments from Arctic regions - Sisimiut in Greenland and Hammerfest in Norway. The influence...... was found to be important for the removal of heavy metals and TBT, while photolysis was significant for removal of PAH, PCB and TBT. In addition, dechlorination was found to be important for the removal of PCB. The highest removal efficiencies were found for heavy metals, TBT and PCB (>40%) and lower......Contaminated sediments are remediated in order to protect human health and the environment, with the additional benefit of using the treated sediments for other activities. Common for many polluted sediments is the contamination with several different pollutants, making remediation challenging...

The relative influence of electrokinetic remediation design on the removal of As, Cu, Pb and Sb from shooting range soils

DEFF Research Database (Denmark)

Pedersen, Kristine B.; Jensen, Pernille Erland; Ottosen, Lisbeth M.

2018-01-01

to simultaneously optimise the removal by applying a stirred set-up, placement of the anode directly in the soil suspension, sieving the soil (analysis is a valuable tool for evaluating remediation measures depending soil...... and analysis was applied for assessing the efficiency of electrodialytic remediation treatment and variable importance varied for each of the studied metals. In general, applying a stirred set-up improved the metal removal, acidification time and reduced the energy consumption. The placement of the anode...... directly in the soil did not significantly influence the removal of Al, Mg, Mn, As and Pb, while moderately influencing the removal of Cu. Multivariate analysis (projections onto latent structures) revealed similar variable importance and optimal settings for removal of Cu and Pb. It is hence possible...

Electrodialytic removal of heavy metals and chloride from municipal solid waste incineration fly ash and air pollution control residue in suspension - test of a new two compartment experimental cell

DEFF Research Database (Denmark)

Kirkelund, Gunvor Marie; Magro, Cátia; Guedes, Paula

2015-01-01

Municipal solid waste incineration (MSWI) residues such as fly ash and air pollution control (APC) residues are classified as hazardous waste and disposed of, although they contain potential resources. The most problematic elements in MSWI residues are leachable heavy metals and salts. For reuse...... of MSWI residues in for instance concrete, the aim of remediation should be reduction of the heavy metal leaching, while at the same time keeping the alkaline pH, so the residue can replace cement. In this study a MSWI residues were subjected to electrodialytic remediation under various experimental...... heavy metal leaching except when the pH was reduced to a level below 8 for the fly ash. On the other hand, Cr leaching increased by the electrodialytic treatment. Cl leaching from the MSWI residues was less dependent on experimental conditions and was reduced in all experiments compared to the initial...

Electrodialytic removal of cadmium from biomass combustion fly ash in larger scale

DEFF Research Database (Denmark)

Pedersen, Anne Juul; Ottosen, Lisbeth M.; Simonsen, Peter

2005-01-01

Due to a high concentration of the toxic heavy metal cadmium (Cd), biomass combustion fly ash often fails to meet the Danish legislative requirements for recycling on agricultural fields. It has previously been shown that it is possible to reduce the concentration of Cd in different bio ashes...... significantly by using electrodialytic remediation, an electrochemically assisted extraction method. In this work the potential of the method was demonstrated in larger scale. Three different experimental set-ups were used, ranging from bench-scale (25 L ash suspension) to pilot scale (0.3 - 3 m3......). The experimental ash was a straw combustion fly ash suspended in water. Within 4 days of remediation, Cd concentrations below the limiting concentration of 5.0 mg Cd/kg DM for straw ash were reached. On the basis of these results, the energy costs for remediation of ash in industrial scale have been estimated...

Electrodialytic remediation of fly ash from co-combustion of wood and straw

DEFF Research Database (Denmark)

Chen, Wan; Jensen, Pernille Erland; Ottosen, Lisbeth M.

2015-01-01

The heavy metal content in fly ash from biomass combustion, such as straw, wood and sludge, often needs reducing before the ash can be used as fertilizer for agricultural land or as a component in the production of construction materials. In this study, fly ash from a boiler fueled with wood chips...... and straw was treated either by electrodialytic remediation (EDR) directly or by a combination of EDR and pre-wash with distilled water to investigate the possibilities of reducing the heavy metal content and reusing nutrients as fertilizer and bulk material in construction materials. Different experimental....../pre-wash-EDR treated ash mainly contained quartz, and the X-ray diffraction (XRD) peaks of K salts had disappeared. This shows that the potassium fertilizer potential was lost in the treated ashes, but the quartz mineral is beneficial in construction materials, such as ceramics. The K fertilizer could be recovered...

Electroremediation of PCB contaminated soil combined with iron nanoparticles: Effect of the soil type.

Science.gov (United States)

Gomes, Helena I; Dias-Ferreira, Celia; Ottosen, Lisbeth M; Ribeiro, Alexandra B

2015-07-01

Polychlorinated biphenyls (PCB) are carcinogenic and persistent organic pollutants that accumulate in soils and sediments. Currently, there is no cost-effective and sustainable remediation technology for these contaminants. In this work, a new combination of electrodialytic remediation and zero valent iron particles in a two-compartment cell is tested and compared to a more conventional combination of electrokinetic remediation and nZVI in a three-compartment cell. In the new two-compartment cell, the soil is suspended and stirred simultaneously with the addition of zero valent iron nanoparticles. Remediation experiments are made with two different historically PCB contaminated soils, which differ in both soil composition and contamination source. Soil 1 is a mix of soils with spills of transformer oils, while Soil 2 is a superficial soil from a decommissioned school where PCB were used as windows sealants. Saponin, a natural surfactant, was also tested to increase the PCB desorption from soils and enhance dechlorination. Remediation of Soil 1 (with highest pH, carbonate content, organic matter and PCB concentrations) obtained the maximum 83% and 60% PCB removal with the two-compartment and the three-compartment cell, respectively. The highest removal with Soil 2 were 58% and 45%, in the two-compartment and the three-compartment cell, respectively, in the experiments without direct current. The pH of the soil suspension in the two-compartment treatment appears to be a determining factor for the PCB dechlorination, and this cell allowed a uniform distribution of the nanoparticles in the soil, while there was iron accumulation in the injection reservoir in the three-compartment cell. Copyright © 2015 Elsevier Ltd. All rights reserved.

Application of Microbial Products to Promote Electrodialytic Remediation of Heavy Metal Contaminated Soil

DEFF Research Database (Denmark)

Jensen, Pernille Erland

2006-01-01

remediation (EDR) method for efficient treatment of Pb-contaminated soil by application of microbial products. Mobilization of Pb in soil by complexation with exopolymers and whole or disintegrated cells was investigated in column studies. Although exopolymers were previously shown to mobilize Pb in soil...... as potential methods for promotion of EDR of Pb contaminated soil. By these methods mobilization of Pb would occur due to complexation with much smaller substances than the previously examined and rejected exopolymers, why they were considered more efficient for mobilization of Pb in an electric current field...... also rejected, primarily due to the insufficient concentrations produced by microorganisms in general and the unrealistic high costs of industrially produced siderophores in relation to the low value of the product to be treated. Furthermore no detection of siderophore production was possible during...

A Comparison of Electrokinetic Method and Electrokinetic-electrodialytic Method for Soil Decontamination

Energy Technology Data Exchange (ETDEWEB)

Kim, Gyenam; Kim, Seungsoo; Park, Ukrang; Han, Gyuseong; Moon, Jeikwon [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2014-05-15

The electrokinetic decontamination equipment and electrokinetic-elctrodialytic decontamination equipment were manufactured to decontaminate the contaminated soil. The removal efficiency according to the lapsed time by the electrokinetic decontamination equipment and the electrokinetic-elctrodialytic decontamination equipment was investigated through several experiments. The difference between the removal efficiency of the electrokinetic-elctrodialytic decontamination without anion exchange membrane and that of with anion exchange membrane was investigated through several experiments. In addition, the removal efficiency trend according to different cesium radioactivity of soil was drawn out through several experiments.

A Comparison of Electrokinetic Method and Electrokinetic-electrodialytic Method for Soil Decontamination

International Nuclear Information System (INIS)

Kim, Gyenam; Kim, Seungsoo; Park, Ukrang; Han, Gyuseong; Moon, Jeikwon

2014-01-01

The electrokinetic decontamination equipment and electrokinetic-elctrodialytic decontamination equipment were manufactured to decontaminate the contaminated soil. The removal efficiency according to the lapsed time by the electrokinetic decontamination equipment and the electrokinetic-elctrodialytic decontamination equipment was investigated through several experiments. The difference between the removal efficiency of the electrokinetic-elctrodialytic decontamination without anion exchange membrane and that of with anion exchange membrane was investigated through several experiments. In addition, the removal efficiency trend according to different cesium radioactivity of soil was drawn out through several experiments

Electrodialytic separation of alkali-element ions with the aid of ion-exchange membranes

International Nuclear Information System (INIS)

Gurskii, V.S.; Moskvin, L.N.

1988-01-01

Electrodialytic separation of ions bearing charges of the same sign with the aid of ion-exchange membranes has been examined in the literature in relation to the so-called ideal membranes, which do not exhibit selectivity with respect to one ion type in ion exchange. It has been shown that separation on such membranes is effective only for counterions differing in size of charge. A matter of greater importance from the practical standpoint is the possibility of using electrodialysis for separating ions bearing like charges and having similar properties, including ionic forms of isotopes of the same element. In this paper they report a comparative study of ion separation, with reference to the Cs-Na pair, by electrodialysis through various types of cation-exchange membranes. Changes of the solution concentration in the cathode compartment were monitored by measurement of 22 Na and 137 Cs activities

Effects from different types of construction refuse in the soil on electrodialytic remediation

DEFF Research Database (Denmark)

Ottosen, Lisbeth M.; Eriksson, Thomas; Hansen, Henrik K.

2002-01-01

At abandoned industrial sites some of the previous buildings are often left behind. If the soil at such site is polluted with heavy metals and is to be remediated by an electrochemical method, the construction refuse within the soil matrix will influence the remediation action. The influence of d...

Screening of variable importance for optimizing electrodialytic remediation of heavy metals from polluted harbour sediments

DEFF Research Database (Denmark)

Pedersen, Kristine B.; Lejon, Tore; Ottosen, Lisbeth M.

2015-01-01

Using multivariate design and modelling, the optimal conditions for electrodialytic remediation (EDR) of heavy metals were determined for polluted harbour sediments from Hammerfest harbour located in the geographic Arctic region of Norway. The comparative importance of the variables, current......) was computed and variable importance in the projection was used to assess the influence of the experimental variables. Current density and remediation time proved to have the highest influence on the remediation of the heavy metals Cr, Cu, Ni, Pb and Zn in the studied experimental domain. In addition......, it was shown that excluding the acidification time improved the PLS model, indicating the importance of applying a limited experimental domain that covers the removal phases of each heavy metal in the specific sediment. Based on PLS modelling, the optimal conditions for remediating the Hammerfest sediment were...

Recycling of MSWI fly ash in clay bricks-effect of washing and electrodialytic treatment

DEFF Research Database (Denmark)

Chen, Wan; Klupsch, Ewa; Kirkelund, Gunvor Marie

2017-01-01

Fly ash generated from municipal solid waste incineration (MSWI) is a hazardous waste due to presence and leachability of heavy metals and organic pollutants (e.g. dioxins and polycyclic aromatic hydrocarbons). In 2000, approximately 25 Mt/year of fly ash was generated in USA, Japan and EU...... (Reijnders 2005). Electrodialytic remediation (EDR) is one technique for MSWI fly ash treatment (Ferreira et al. 2005), where an electric DC field is applied to an ash-water suspension to extract and separate heavy metal by migration towards anode or cathode through ion exchange membranes. Ferreira et al....... (2008) observed that in MSWI ash treated by water washing and EDR, metals were mainly in the strongly bonded and residual phases, indicating a reduction in the ash’s environmental risk. Belmonte et al. (2016) made Greenlandic bricks (∼2 g discs) containing 20% and 40% of EDR treated MSWI fly ash...

Diagnostic analysis of electrodialysis in mine tailing materials

DEFF Research Database (Denmark)

Hansen, Henrik K.; Ribeiro, Alexandra B.; Mateus, Eduardo

2007-01-01

Removal of heavy metals from mine tailings and soil contaminated by copper mining activities was studied under batch electrodialytic conditions. Two types of mine tailings were treated: (i) freshly produced tailings coming directly from the flotation process, and (ii) tailings deposited...... in a tailings pond, for approximately 20 years. The main contaminant was copper-found in concentration around 800-1800 ppm. The fractionation of copper and other characteristics of the tailings differ for the two tailings, indicating natural oxidation reactions in the old deposited ones. Electrodialytical...

Electrodialytic treatment of sewage sludge ash for the recovery of phosphorous and separation of heavy metals

DEFF Research Database (Denmark)

Ebbers, Benjamin; Ottosen, Lisbeth M.; Jensen, Pernille Erland

2012-01-01

Mobilization and extraction of both phosphorus (P) and heavy metals (HM) from sewage sludge ash through means of acidification has been studied extensively. However, separation of both P and HM after mobilization to provide reusable materials has proven to be challenging. This study presents...... a combination of acidification and electrodialytic separation (EDS) to mobilize and separate P and HM from sewage sludge ash (SSA). The EDS experimental setup consists of three compartments, separated by ion exchange membranes which are located at either side of the stirred ash suspension. Through application...... of a direct current to electrodes in the outer compartments, ionic complexes migrate and concentrate in the electrode compartments in accordance to their charge. Application of both EDS and acidification of the ash resulted in an increased release of phosphorus from the ash, but did not always result...

Simultaneous electrodialytic removal of PAH, PCB, TBT and heavy metals from sediments.

Science.gov (United States)

Pedersen, Kristine B; Lejon, Tore; Jensen, Pernille E; Ottosen, Lisbeth M

2017-08-01

Contaminated sediments are remediated in order to protect human health and the environment, with the additional benefit of using the treated sediments for other activities. Common for many polluted sediments is the contamination with several different pollutants, making remediation challenging with the need of different remedial actions for each pollutant. In this study, electrodialytic remediation (EDR) of sediments was found effective for simultaneous removal of heavy metals and organic pollutants for sediments from Arctic regions - Sisimiut in Greenland and Hammerfest in Norway. The influence of sediment properties and experimental settings on the remediation process was studied by employing multivariate analysis. The importance of the variables studied varied with the pollutant and based on these results it was possible to assess removal processes for the different pollutants. Desorption was found to be important for the removal of heavy metals and TBT, while photolysis was significant for removal of PAH, PCB and TBT. In addition, dechlorination was found to be important for the removal of PCB. The highest removal efficiencies were found for heavy metals, TBT and PCB (>40%) and lower removal efficiencies for PAH (<35%). Copyright © 2017 Elsevier Ltd. All rights reserved.

Treatment of a suspension of PCB contaminated soil using iron nanoparticles and electric current

DEFF Research Database (Denmark)

Comes, Helena I.; Ottosen, Lisbeth M.; Ribeiro, Alexandra B.

2015-01-01

Contaminated soils and sediments with polychlorinated biphenyls (PCB) are an important environmental problem due to the persistence of these synthetic aromatic compounds and to the lack of a cost-effective and sustainable remediation technology. Recently, a new experimental setup has been proposed...... using electrodialytic remediation and iron nanoparticles. The current work compares the performance of this new setup (A) with conventional electrokinetics (setup B). An historically contaminated soil with an initial PCB concentration of 258 mu g kg-1 was treated during 5, 10, 20 and 45 d using...... different amounts of iron nanoparticles in both setups A and B. A PCB removal of 83% was obtained in setup A compared with 58% of setup B. Setup A also showed additional advantages, such as a higher PCB dechlorination, in a shorter time, with lower nZVI consumption, and with the use of half of the voltage...

The influence of sediment properties and experimental variables on the efficiency of electrodialytic removal of metals from sediment

DEFF Research Database (Denmark)

Pedersen, Kristine B.; Lejon, Tore; Jensen, Pernille Erland

2017-01-01

Chemometrics was used to determine the influence of sediment properties and experimental settings for the electrodialytic removal (EDR) of Cu, Pb and Zn from six harbour sediments from Greenland and Norway. A Projection onto latent structures (PLS) model revealed that the most important sediment...... properties for achieving acidification (lag-phase, pH > 4), necessary for desorbing and mobilising metals in the polluted sediments, were buffer capacity and grain size distribution. Higher stirring rate reduced the acidification time, stressing the importance of thorough mixing of the sediment suspension...... to achieve a fast and uniform acidification. PLS models were calculated to determine the influence of sediment properties on the removal of metals during EDR, which was observed to vary depending on the targeted metal and the stage of the remediation. In general, buffer capacity, grain size distribution...

Electrodialytic removal of Cu, Cr, and As from chromated copper arsenate-treated timber waste

Energy Technology Data Exchange (ETDEWEB)

Ribeiro, A.B.; Mateus, E.P.; Ottosen, L.M.; Bech-Nielsen, G.

2000-03-01

Waste of wood treated with chromated copper arsenate (CCA) is expected to increase in volume over the next decades. Alternative disposal options to landfilling are becoming more attractive to study, especially those that promote reuse. The authors have studied the electrodialytic removal of Cu, Cr, and As from CCA-treated timber wastes. The method uses a low-level direct current as the cleaning agent, combining the electrokinetic movement of ions in the matrix with the principle of electrodialysis. The technique was tested in four experiments using a laboratory cell on sawdust of an out-of-service CCA-treated Pinus pinaster Ait. pole. The duration of all the experiments was 30 days, and the current density was kept constant at 0.2 mA/cm{sup 2}. The experiments differ because in one the sawdust was saturated with water (experiment 1) and in the rest it was saturated with oxalic acid, 2.5, 5, and 7.5% (w/w), respectively, in experiments 2--4. The highest removal rates obtained were 93% of Cu, 95% of Cr, and 99% of As in experiment 2. Other experimental conditions might possibly optimize the removal rates.

Screening the possibility for removing cadmium and other heavy metals from wastewater sludge and bio-ashes by an electrodialytic method

DEFF Research Database (Denmark)

Ottosen, Lisbeth M.; Pedersen, Anne Juul; Hansen, Henrik K.

2007-01-01

in wastewater sludge and bio-ashes (straw and wood) using an electrodialytic method. The waste products were treated as stirred suspensions. During the remediation the suspension was acidified from water splitting at the anion exchange membrane and the acidification mobilized Cd that was removed...... with Cd, and the wood ash had a high initial pH (13.3). The mass of wastewater sludge and bio-ashes decreased during treatment but the concentration of other heavy metals (Pb, Ni, Cu and Zn) was not increased to exceed limiting values in remediated matrix.......Both wastewater sludge and fly ash from combustion of biomass (bio-ash) have traditionally been applied to agricultural land in Denmark. However, Cd concentrations often exceed limiting values. The present study is a preliminary investigation of the possibility for reducing the Cd concentration...

Electrochemical analysis of ion-exchange membranes with respect to a possible use in electrodialytic decontamination of soil polluted with heavy metals

DEFF Research Database (Denmark)

Hansen, Henrik; Ottosen, Lisbeth M.; Laursen, Søren

1997-01-01

Transport numbers in different metal chloride solutions were estimated using the emf method for two ion-exchange membranes: Ionics CR67 HMR412 (cation-exchange membrane) and Ionics AR204 SXRA 7639 (anion-exchange membrane). The cation-exchange membrane was found to work nearly ideally for Na...... experiments taken as a simplified simulation of the electrokinetic decontamination method showed that it was possible to remove all ions in the simulated soil volume, with a sharp increase in the potential difference over the soil volume as a result, and that it was possible to control the metal content...

Electrodialytic remediation of fly ash from co-combustion of wood and straw

International Nuclear Information System (INIS)

Chen, Wan; Jensen, Pernille E.; Ottosen, Lisbeth M.; Kirkelund, Gunvor M.

2015-01-01

The heavy metal content in fly ash from biomass combustion, such as straw, wood and sludge, often needs reducing before the ash can be used as fertilizer for agricultural land or as a component in the production of construction materials. In this study, fly ash from a boiler fueled with wood chips and straw was treated either by electrodialytic remediation (EDR) directly or by a combination of EDR and pre-wash with distilled water to investigate the possibilities of reducing the heavy metal content and reusing nutrients as fertilizer and bulk material in construction materials. Different experimental set-ups were tested for EDR treatment primarily of Cd and Pb as well as of Cu and Zn. Elemental contents such as K, P and Ni were compared in ash samples before and after treatment. The results showed that pre-washing caused an increase in total concentrations of most heavy metals because the highly soluble fraction, mainly KCl and K 2 SO 4 , was removed. After EDR treatment, the Cd concentration was reduced to below 2 mg kg −1 in all ash samples with high and stable average removal of above 95%, no matter how high the initial concentration was. The amount of Pb removed varied from 12% to 67%. Even though Pb was extracted from the ash samples, its concentrations in the treated ash samples were elevated due to the ash dissolution, except in the case of pre-washed ash treated in a two-compartment EDR cell, where the mass of Pb removed was the highest with a final concentration of about 100 mg kg −1 . The two-compartment EDR cell probably performed better due to a fast acidification process. In addition, this process was less energy-consuming. However, the fast acidification did in turn affect the leaching property of the treated ash, such as As and Ni, exceeding the limiting concentrations. The EDR/pre-wash-EDR treated ash mainly contained quartz, and the X-ray diffraction (XRD) peaks of K salts had disappeared. This shows that the potassium fertilizer potential was

Screening the possibility for removing cadmium and other heavy metals from wastewater sludge and bio-ashes by an electrodialytic method

International Nuclear Information System (INIS)

Ottosen, Lisbeth M.; Pedersen, Anne J.; Hansen, Henrik K.; Ribeiro, Alexandra B.

2007-01-01

Both wastewater sludge and fly ash from combustion of biomass (bio-ash) have traditionally been applied to agricultural land in Denmark. However, Cd concentrations often exceed limiting values. The present study is a preliminary investigation of the possibility for reducing the Cd concentration in wastewater sludge and bio-ashes (straw and wood) using an electrodialytic method. The waste products were treated as stirred suspensions. During the remediation the suspension was acidified from water splitting at the anion exchange membrane and the acidification mobilized Cd that was removed to the electrode compartments. Even though the matrices were very different the remediation was successful in all cases. After treatment the Cd concentration in the ashes allowed for spreading at agricultural land and the limiting concentration of 0.8 mg Cd/kg for the wastewater sludge was almost reached (0.84 and 0.88 mg Cd/kg). The main differences of the waste products influencing the remediation process were: the sludges had a high content of organic particles that were mobilized by electrophoresis and fouled the anion exchange membrane; the straw-ash contained a lot of chloride, which formed anionic complexes with Cd, and the wood ash had a high initial pH (13.3). The mass of wastewater sludge and bio-ashes decreased during treatment but the concentration of other heavy metals (Pb, Ni, Cu and Zn) was not increased to exceed limiting values in remediated matrix

Calculation of Radioactivity Concentration on Cover Depth of Contaminated Zone for Self-Disposal

Energy Technology Data Exchange (ETDEWEB)

Koo, Daeseo; Sung, Hyun-Hee; Kim, Gye-Nam; Kim, Seung-Soo; Kim, Ilgook; Han, Gyu Seong; Choi, Jong-Won [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2015-10-15

We have a lot of uranium contaminated soil and concrete wastes owing to dismantlement of uranium conversion facility. There are several radioactive material disposal methods such as regulation exemption, decontamination and long term storage. It is necessary for us to perform permanent disposal of these wastes. To acquire radiation dose under self-disposal from them, the study on decontamination of some uranium contaminated soil and concrete wastes was performed using electrokinectic-electrodialytic. In this study, we evaluated radiation dose on the cover depth of contaminated zone from the wastes under radiation dose limit using RESRAD Version 6.5. At first, the calculation of the radiation dose on the wastes of contaminated zone are carried out. The second, the cover depth of contaminated zone are analyzed. The application to self-disposal of contaminated zone are also analyzed. To acquire radiation dose under self-disposal from uranium contaminated soil and concrete wastes, we decontaminated some uranium contaminated soil and concrete wastes using electrokinectic-electrodialytic. To perform self-disposal of the quantity (30,000kg) of contaminated zone, the calculating conditions for radiation dose on the cover depth of contaminated zone are as follows. The area of contaminated zone is 10m{sup 2}. The thickness of contaminated zone is 2 m. The cover depth of contaminated zone are analyzed. The application to self-disposal of contaminated zone are also analyzed. Therefore, as the cover depth increases, the uranium concentration has an increasing trend. It realize that the cover depth of contaminated zone is adequate < 2m at the quantity(30,000kg) of contaminated zone. As the cover depth increases, the uranium concentration has a decreasing trend. As the cover depth increases, the radiation dose(residents) has also a decreasing trend.

Difusion constraints and neuron-glia interaction dduring aging

Czech Academy of Sciences Publication Activity Database

Syková, Eva; Mazel, Tomáš; Šimonová, Zuzana

1998-01-01

Roč. 33, 7/8 (1998), s. 837-851 ISSN 0531-5565 R&D Projects: GA ČR GA309/96/0884; GA ČR GV307/96/K226; GA MZd IZ3423; GA ČR GV309/97/K048 Institutional research plan: CEZ:AV0Z5039906 Keywords : apparents diffusion coefficient * extracellular space Subject RIV: FH - Neurology

Age Effect on Autonomic Cardiovascular Control in Pilots

Science.gov (United States)

2000-08-01

Nantcheva**, M. Vukov *** *National Center of Hygiene, Medical Ecology and Nutrition 15 Dimitar Nestorov Blvd. 1431 Sofia, Bulgaria "**Military Medical...values and critique. Inter. Physiol. Behav. Sci. 1997, 3, of health risk compared with referents. 202-219. 14. Fluckiger L., Boivin J ., Quilliot D...during flight. Aviat. Space Chapman and Hall. 1991, 590 pp. Environ Med. 1998,4, 360-367. 4. Berntson G., Cacioppo J ., Quigley K. Autonomic 18. Hellman J

Suspended electrodialytic extraction of toxic elements for detoxification of three different mine tailings

DEFF Research Database (Denmark)

Jensen, Pernille Erland; Ottosen, Lisbeth M.; Hansen, H.K.

2016-01-01

have shown that electrokinetic treatment can remove Cd, Cu, Pb, and Zn from tailings soils; As from tailings; and Cu from tailings. Still, however, a major concern is the long treatment-time required for the element-transport through the tailings matrix. Therefore several enhancement methods have been...

Electrochemical Remediation of Dredged Material for Beneficial Use

DEFF Research Database (Denmark)

Pedersen, Anne Juul; Gardner, Kevin H.

2003-01-01

Two different methods, electrodialytic and electroosmotic remediation, were used to demonstrate the potential of electrochemical methods for remediation of contaminated harbor sediments. In two three-week-long laboratory experiments using electrodialysis and electroosmosis, respectively...

Soil fertility management: Impacts on soil macrofauna, soil aggregation and soil organic matter allocation.

NARCIS (Netherlands)

Ayuke, F.O.; Brussaard, L.; Vanlauwe, B.; Six, J.; Lelei, D.K.; Kibunja, C.N.; Pulleman, M.M.

2011-01-01

Maintenance of soil organic matter through integrated soil fertility management is important for soil quality and agricultural productivity, and for the persistence of soil faunal diversity and biomass. Little is known about the interactive effects of soil fertility management and soil macrofauna

Soil physical properties affecting soil erosion in tropical soils

International Nuclear Information System (INIS)

Lobo Lujan, D.

2004-01-01

The total vegetated land area of the earth is about 11,500 hectare. Of this, about 12% is in South America. Of this, about 14% is degraded area. Water erosion, chemical degradation, wind erosion, and physical degradation have been reported as main types of degradation. In South America water erosion is a major process for soil degradation. Nevertheless, water erosion can be a consequence of degradation of the soil structure, especially the functional attributes of soil pores to transmit and retain water, and to facilitate root growth. Climate, soil and topographic characteristics determine runoff and erosion potential from agricultural lands. The main factors causing soil erosion can be divided into three groups: Energy factors: rainfall erosivity, runoff volume, wind strength, relief, slope angle, slope length; Protection factors: population density, plant cover, amenity value (pressure for use) and land management; and resistance factors: soil erodibility, infiltration capacity and soil management. The degree of soil erosion in a particular climatic zone, with particular soils, land use and socioeconomic conditions, will always result from a combination of the above mentioned factors. It is not easy to isolate a single factor. However, the soil physical properties that determine the soil erosion process, because the deterioration of soil physical properties is manifested through interrelated problems of surface sealing, crusting, soil compaction, poor drainage, impeded root growth, excessive runoff and accelerated erosion. When an unprotected soil surface is exposed to the direct impact of raindrops it can produce different responses: Production of smaller aggregates, dispersed particles, particles in suspension and translocation and deposition of particles. When this has occurred, the material is reorganized at the location into a surface seal. Aggregate breakdown under rainfall depends on soil strength and a certain threshold kinetic energy is needed to start

Radiation Dose for Self-Disposal due to the Quantity of Radioactive Waste

Energy Technology Data Exchange (ETDEWEB)

Koo, Daeseo; Sung, Hyun-Hee; Kim, Seung-Soo; Kim, Gye-Nam; Choi, Jong-Won [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2016-10-15

In this study, we evaluated resident radiation dose due to cover depth on contaminated zone such as uranium contaminated soil and concrete wastes under radiation dose limit using RESRAD Version 7.0. The uranium concentration of contaminated zone due to the cover depth are also analyzed. Possibility for self-disposal of uranium contaminated soil and concrete wastes is evaluated from these calculating data. There are several radioactive material disposal methods such as regulation exemption, decontamination and long term storage. To acquire radiation dose under self-disposal from them, the study on decontamination of some uranium contaminated soil and concrete wastes was performed using electrokinectic-electrodialytic. We evaluated radiation dose due to cover depth on contaminated zone such as uranium contaminated soil and concrete wastes under radiation dose limit using RESRAD Version 7.0. As cover depth increases, the tolerable uranium concentration increases up to cover depth (1.5 m) and then it showed saturated uranium concentration above cover depth (1.5 m). Therefore, to carry out self-disposal on the quantity (1000 drums≒300,000 kg) of radioactive waste is easier than to carry out on the quantity (2000 drums≒600,000 kg) of radioactive waste owing to the large tolerable uranium concentration for self-disposal of radioactive waste. As cover depth increases, the individual radiation dose rate decreased up to cover depth (1.5 m) and then it showed saturated individual radiation dose rate above cover depth (1.5 m)

Uranium Concentration of Contaminated Zone due to the Cover Depth for Self-Disposal

International Nuclear Information System (INIS)

Koo, Dae Seo; Sung, Hyun Hee; Kim, Gye Nam; Kim, Seung Soo; Kim, Il Gook; Han, Gyu Seong; Choi, Jong Won

2016-01-01

To acquire radiation dose under self disposal from them, the study on decontamination of some uranium contaminated soil and concrete wastes was performed using electrokinetic-electrodialytic. In this study, we evaluated radiation dose due to cover depth on contaminated zone such as uranium contaminated soil and concrete wastes under radiation dose limit using RESRAD Version 6.5. At first, the calculation of the radiation dose on the contaminated zone are carried out. The second, the uranium concentration of contaminated zone due to the cover depth are also analyzed. The uranium contaminated soil and concrete wastes under radiation dose limit by decontaminating them have application to self-disposal of contaminated zone. The area of contaminated zone is 1,500 m"2. The thickness of contaminated zone is 2 m. The length parallel to aquifer flow is 43.702m. The age of the residents on contaminated zone is 15 years old. The period of evaluation on the contaminated zone is from regulation exemption of uranium contaminated soil and concrete wastes till 1,000 years. The calculation of the radiation dose on contaminated zone are carried out. The uranium concentration of contaminated zone due to the cover depth was also analyzed. as the cover depth increases, the uranium concentration has an increasing trend. As the cover depth increases, radiation dose of a person has a decreasing trend. As the cover depth increases, the radiation dose of residents has also a decreasing trend.

Radiation Dose for Self-Disposal due to the Quantity of Radioactive Waste

International Nuclear Information System (INIS)

Koo, Daeseo; Sung, Hyun-Hee; Kim, Seung-Soo; Kim, Gye-Nam; Choi, Jong-Won

2016-01-01

In this study, we evaluated resident radiation dose due to cover depth on contaminated zone such as uranium contaminated soil and concrete wastes under radiation dose limit using RESRAD Version 7.0. The uranium concentration of contaminated zone due to the cover depth are also analyzed. Possibility for self-disposal of uranium contaminated soil and concrete wastes is evaluated from these calculating data. There are several radioactive material disposal methods such as regulation exemption, decontamination and long term storage. To acquire radiation dose under self-disposal from them, the study on decontamination of some uranium contaminated soil and concrete wastes was performed using electrokinectic-electrodialytic. We evaluated radiation dose due to cover depth on contaminated zone such as uranium contaminated soil and concrete wastes under radiation dose limit using RESRAD Version 7.0. As cover depth increases, the tolerable uranium concentration increases up to cover depth (1.5 m) and then it showed saturated uranium concentration above cover depth (1.5 m). Therefore, to carry out self-disposal on the quantity (1000 drums≒300,000 kg) of radioactive waste is easier than to carry out on the quantity (2000 drums≒600,000 kg) of radioactive waste owing to the large tolerable uranium concentration for self-disposal of radioactive waste. As cover depth increases, the individual radiation dose rate decreased up to cover depth (1.5 m) and then it showed saturated individual radiation dose rate above cover depth (1.5 m)

Uranium Concentration of Contaminated Zone due to the Cover Depth for Self-Disposal

Energy Technology Data Exchange (ETDEWEB)

Koo, Dae Seo; Sung, Hyun Hee; Kim, Gye Nam; Kim, Seung Soo; Kim, Il Gook; Han, Gyu Seong; Choi, Jong Won [KAERI, Daejeon (Korea, Republic of)

2016-05-15

To acquire radiation dose under self disposal from them, the study on decontamination of some uranium contaminated soil and concrete wastes was performed using electrokinetic-electrodialytic. In this study, we evaluated radiation dose due to cover depth on contaminated zone such as uranium contaminated soil and concrete wastes under radiation dose limit using RESRAD Version 6.5. At first, the calculation of the radiation dose on the contaminated zone are carried out. The second, the uranium concentration of contaminated zone due to the cover depth are also analyzed. The uranium contaminated soil and concrete wastes under radiation dose limit by decontaminating them have application to self-disposal of contaminated zone. The area of contaminated zone is 1,500 m{sup 2}. The thickness of contaminated zone is 2 m. The length parallel to aquifer flow is 43.702m. The age of the residents on contaminated zone is 15 years old. The period of evaluation on the contaminated zone is from regulation exemption of uranium contaminated soil and concrete wastes till 1,000 years. The calculation of the radiation dose on contaminated zone are carried out. The uranium concentration of contaminated zone due to the cover depth was also analyzed. as the cover depth increases, the uranium concentration has an increasing trend. As the cover depth increases, radiation dose of a person has a decreasing trend. As the cover depth increases, the radiation dose of residents has also a decreasing trend.

iSOIL: Interactions between soil related sciences - Linking geophysics, soil science and digital soil mapping

Science.gov (United States)

Dietrich, Peter; Werban, Ulrike; Sauer, Uta

2010-05-01

High-resolution soil property maps are one major prerequisite for the specific protection of soil functions and restoration of degraded soils as well as sustainable land use, water and environmental management. To generate such maps the combination of digital soil mapping approaches and remote as well as proximal soil sensing techniques is most promising. However, a feasible and reliable combination of these technologies for the investigation of large areas (e.g. catchments and landscapes) and the assessment of soil degradation threats is missing. Furthermore, there is insufficient dissemination of knowledge on digital soil mapping and proximal soil sensing in the scientific community, to relevant authorities as well as prospective users. As one consequence there is inadequate standardization of techniques. At the poster we present the EU collaborative project iSOIL within the 7th framework program of the European Commission. iSOIL focuses on improving fast and reliable mapping methods of soil properties, soil functions and soil degradation risks. This requires the improvement and integration of advanced soil sampling approaches, geophysical and spectroscopic measuring techniques, as well as pedometric and pedophysical approaches. The focus of the iSOIL project is to develop new and to improve existing strategies and innovative methods for generating accurate, high resolution soil property maps. At the same time the developments will reduce costs compared to traditional soil mapping. ISOIL tackles the challenges by the integration of three major components: (i)high resolution, non-destructive geophysical (e.g. Electromagnetic Induction EMI; Ground Penetrating Radar, GPR; magnetics, seismics) and spectroscopic (e.g., Near Surface Infrared, NIR) methods, (ii)Concepts of Digital Soil Mapping (DSM) and pedometrics as well as (iii)optimized soil sampling with respect to profound soil scientific and (geo)statistical strategies. A special focus of iSOIL lies on the

Membrane resistance : The effect of salinity gradients over a cation exchange membrane

NARCIS (Netherlands)

Galama, A. H.; Vermaas, D. A.; Veerman, J.; Saakes, M.; Rijnaarts, H. H. M.; Post, J. W.; Nijmeijer, K.

2014-01-01

Ion exchange membranes (IEMs) are used for selective transport of ions between two solutions. These solutions are often different in concentration or composition. The membrane resistance (R-M) is an important parameter affecting power consumption or power production in electrodialytic processes. In

Membrane resistance: The effect of salinity gradients over a cation exchange membrane

NARCIS (Netherlands)

Galama, A.H.; Vermaas, D.A.; Veerman, J.; Saakes, M.; Rijnaarts, H.; Post, J.W.; Nijmeijer, K.

2014-01-01

Ion exchange membranes (IEMs) are used for selective transport of ions between two solutions. These solutions are often different in concentration or composition. The membrane resistance (R-M) is an important parameter affecting power consumption or power production in electrodialytic processes. In

Soil and Soil Water Relationships

OpenAIRE

Easton, Zachary M.; Bock, Emily

2017-01-01

Discusses the relationships between soil, water and plants. Discusses different types of soil, and how these soils hold water. Provides information about differences in soil drainage. Discusses the concept of water balance.

Soil metagenomics and tropical soil productivity

OpenAIRE

Garrett, Karen A.

2009-01-01

This presentation summarizes research in the soil metagenomics cross cutting research activity. Soil metagenomics studies soil microbial communities as contributors to soil health.C CCRA-4 (Soil Metagenomics)

Assessment the effect of homogenized soil on soil hydraulic properties and soil water transport

Science.gov (United States)

Mohawesh, O.; Janssen, M.; Maaitah, O.; Lennartz, B.

2017-09-01

Soil hydraulic properties play a crucial role in simulating water flow and contaminant transport. Soil hydraulic properties are commonly measured using homogenized soil samples. However, soil structure has a significant effect on the soil ability to retain and to conduct water, particularly in aggregated soils. In order to determine the effect of soil homogenization on soil hydraulic properties and soil water transport, undisturbed soil samples were carefully collected. Five different soil structures were identified: Angular-blocky, Crumble, Angular-blocky (different soil texture), Granular, and subangular-blocky. The soil hydraulic properties were determined for undisturbed and homogenized soil samples for each soil structure. The soil hydraulic properties were used to model soil water transport using HYDRUS-1D.The homogenized soil samples showed a significant increase in wide pores (wCP) and a decrease in narrow pores (nCP). The wCP increased by 95.6, 141.2, 391.6, 3.9, 261.3%, and nCP decreased by 69.5, 10.5, 33.8, 72.7, and 39.3% for homogenized soil samples compared to undisturbed soil samples. The soil water retention curves exhibited a significant decrease in water holding capacity for homogenized soil samples compared with the undisturbed soil samples. The homogenized soil samples showed also a decrease in soil hydraulic conductivity. The simulated results showed that water movement and distribution were affected by soil homogenizing. Moreover, soil homogenizing affected soil hydraulic properties and soil water transport. However, field studies are being needed to find the effect of these differences on water, chemical, and pollutant transport under several scenarios.

Soil microbiology and soil health assessment

Science.gov (United States)

Soil scientists have long recognized the importance of soil biology in ecological health. In particular, soil microbes are crucial for many soil functions including decomposition, nutrient cycling, synthesis of plant growth regulators, and degradation of synthetic chemicals. Currently, soil biologis...

Soil pollution and soil protection

OpenAIRE

Haan, de, F.A.M.; Visser-Reijneveld, M.I.

1996-01-01

This book was compiled from lecture handouts prepared for the international postgraduate course on soil quality, entitled 'Soil Pollution and Soil Protection' given jointly by the universities of Wageningen (The Netherlands), Gent and Leuven (Belgium), under the auspices of the international Training Centre (PHLO) of Wageningen Agricultural University.Of the three environmental compartments air, water and soil, it is soil that varies most in composition under natural conditions. The effects o...

Comparison of different MSWI fly ash treatment processes on the thermal behavior of As, Cr, Pb and Zn in the ash

DEFF Research Database (Denmark)

Chen, Wan; Kirkelund, Gunvor Marie; Jensen, Pernille Erland

2017-01-01

To reduce heavy metal leaching and stabilize municipal solid waste incineration (MSWI) fly ash, different methods and combination of methods were tested: water washing, electrodialytic separation and thermal treatment at 1000°C. A comparison of heavy metal concentration and leaching levels of As...

Soil shrinkage characteristics in swelling soils

International Nuclear Information System (INIS)

Taboada, M.A.

2004-01-01

The objectives of this presentation are to understand soil swelling and shrinkage mechanisms, and the development of desiccation cracks, to distinguish between soils having different magnitude of swelling, as well as the consequences on soil structural behaviour, to know methods to characterize soil swell/shrink potential and to construct soil shrinkage curves, and derive shrinkage indices, as well to apply them to assess soil management effects

Soil structural behaviour of flooded soils

International Nuclear Information System (INIS)

Taboada, M.A.

2004-01-01

The objectives of this presentation are to: identify factors determining of the structural behaviour of flooded soils, as compared to those acting in upland soils; analyse the influence of reductive processes on aggregate stabilising agents; discuss mechanisms of structural deterioration and recovery during the flooding-drying cycle, on the basis of a case study: cattle trampling effects in the flooding Pampa of Argentina. Flooded soils, now known as Hydric soils, are characteristic of wetlands and irrigated fields cropped to rice (paddy soils). In them, water covers the soil, or is present either at or near the surface of the soil all year or for varying periods of time during the year. Hydric soils belong to different taxa of the FAO-UNESCO Soil Map (2000). Fluvisols, Planosols and Gleysols are widespread distributed in the globe. The generation of redoximorphic features is due to different causes in each of them. Fluvisols are covered part of the year by surface water from river overflows; Planosols are soils having an impervious Bt horizon, supporting perched water during short periods; and Gleysols are soils affected by stagnant water tables during long periods

Soil-ecological risks for soil degradation estimation

Science.gov (United States)

Trifonova, Tatiana; Shirkin, Leonid; Kust, German; Andreeva, Olga

2016-04-01

Soil degradation includes the processes of soil properties and quality worsening, primarily from the point of view of their productivity and decrease of ecosystem services quality. Complete soil cover destruction and/or functioning termination of soil forms of organic life are considered as extreme stages of soil degradation, and for the fragile ecosystems they are normally considered in the network of their desertification, land degradation and droughts /DLDD/ concept. Block-model of ecotoxic effects, generating soil and ecosystem degradation, has been developed as a result of the long-term field and laboratory research of sod-podzol soils, contaminated with waste, containing heavy metals. The model highlights soil degradation mechanisms, caused by direct and indirect impact of ecotoxicants on "phytocenosis- soil" system and their combination, frequently causing synergistic effect. The sequence of occurring changes here can be formalized as a theory of change (succession of interrelated events). Several stages are distinguished here - from heavy metals leaching (releasing) in waste and their migration downward the soil profile to phytoproductivity decrease and certain phytocenosis composition changes. Phytoproductivity decrease leads to the reduction of cellulose content introduced into the soil. The described feedback mechanism acts as a factor of sod-podzolic soil self-purification and stability. It has been shown, that using phytomass productivity index, integrally reflecting the worsening of soil properties complex, it is possible to solve the problems dealing with the dose-reflecting reactions creation and determination of critical levels of load for phytocenosis and corresponding soil-ecological risks. Soil-ecological risk in "phytocenosis- soil" system means probable negative changes and the loss of some ecosystem functions during the transformation process of dead organic substance energy for the new biomass composition. Soil-ecological risks estimation is

Physical soil quality indicators for monitoring British soils

Science.gov (United States)

Corstanje, Ron; Mercer, Theresa G.; Rickson, Jane R.; Deeks, Lynda K.; Newell-Price, Paul; Holman, Ian; Kechavarsi, Cedric; Waine, Toby W.

2017-09-01

Soil condition or quality determines its ability to deliver a range of functions that support ecosystem services, human health and wellbeing. The increasing policy imperative to implement successful soil monitoring programmes has resulted in the demand for reliable soil quality indicators (SQIs) for physical, biological and chemical soil properties. The selection of these indicators needs to ensure that they are sensitive and responsive to pressure and change, e.g. they change across space and time in relation to natural perturbations and land management practices. Using a logical sieve approach based on key policy-related soil functions, this research assessed whether physical soil properties can be used to indicate the quality of British soils in terms of their capacity to deliver ecosystem goods and services. The resultant prioritised list of physical SQIs was tested for robustness, spatial and temporal variability, and expected rate of change using statistical analysis and modelling. Seven SQIs were prioritised: soil packing density, soil water retention characteristics, aggregate stability, rate of soil erosion, depth of soil, soil structure (assessed by visual soil evaluation) and soil sealing. These all have direct relevance to current and likely future soil and environmental policy and are appropriate for implementation in soil monitoring programmes.

Physical soil quality indicators for monitoring British soils

Directory of Open Access Journals (Sweden)

R. Corstanje

2017-09-01

Full Text Available Soil condition or quality determines its ability to deliver a range of functions that support ecosystem services, human health and wellbeing. The increasing policy imperative to implement successful soil monitoring programmes has resulted in the demand for reliable soil quality indicators (SQIs for physical, biological and chemical soil properties. The selection of these indicators needs to ensure that they are sensitive and responsive to pressure and change, e.g. they change across space and time in relation to natural perturbations and land management practices. Using a logical sieve approach based on key policy-related soil functions, this research assessed whether physical soil properties can be used to indicate the quality of British soils in terms of their capacity to deliver ecosystem goods and services. The resultant prioritised list of physical SQIs was tested for robustness, spatial and temporal variability, and expected rate of change using statistical analysis and modelling. Seven SQIs were prioritised: soil packing density, soil water retention characteristics, aggregate stability, rate of soil erosion, depth of soil, soil structure (assessed by visual soil evaluation and soil sealing. These all have direct relevance to current and likely future soil and environmental policy and are appropriate for implementation in soil monitoring programmes.

Soil

International Nuclear Information System (INIS)

Freudenschuss, A.; Huber, S.; Riss, A.; Schwarz, S.; Tulipan, M.

2002-01-01

Environmental soil surveys in each province of Austria have been performed, soils of about 5,000 sites were described and analyzed for nutrients and pollutants, the majority of these data are recorded in the soil information system of Austria (BORIS) soil database, http://www.ubavie.gv.at/umweltsituation/boden/boris), which also contains a soil map of Austria, data from 30 specific investigations mainly in areas with industry and results from the Austria - wide cesium investigation. With respect to the environmental state of soils a short discussion is given, including two geographical charts, one showing which sites have soil data (2001) and the other the cadmium distribution in top soils according land use (forest, grassland, arable land, others). Information related to the soil erosion, Corine land cover (Europe-wide land cover database), evaluation of pollutants in soils (reference values of As, Cd, Co, Cr, Cu, Hg, Mo, Ni, Se, Pb, Tl, Va, Zn, AOX, PAH, PCB, PCDD/pcdf, dioxin), and relevant Austrian and European standards and regulations is provided. Figs. 2, Tables 4. (nevyjel)

Soils

Science.gov (United States)

Emily Moghaddas; Ken Hubbert

2014-01-01

When managing for resilient forests, each soil’s inherent capacity to resist and recover from changes in soil function should be evaluated relative to the anticipated extent and duration of soil disturbance. Application of several key principles will help ensure healthy, resilient soils: (1) minimize physical disturbance using guidelines tailored to specific soil types...

Soil pollution and soil protection

NARCIS (Netherlands)

Haan, de F.A.M.; Visser-Reijneveld, M.I.

1996-01-01

This book was compiled from lecture handouts prepared for the international postgraduate course on soil quality, entitled 'Soil Pollution and Soil Protection' given jointly by the universities of Wageningen (The Netherlands), Gent and Leuven (Belgium), under the auspices of the international

Cross-cutting activities: Soil quality and soil metagenomics

OpenAIRE

Motavalli, Peter P.; Garrett, Karen A.

2008-01-01

This presentation reports on the work of the SANREM CRSP cross-cutting activities "Assessing and Managing Soil Quality for Sustainable Agricultural Systems" and "Soil Metagenomics to Construct Indicators of Soil Degradation." The introduction gives an overview of the extensiveness of soil degradation globally and defines soil quality. The objectives of the soil quality cross cutting activity are: CCRA-4 (Soil Metagenomics)

Soil invertebrates as bioindicators of urban soil quality

International Nuclear Information System (INIS)

Santorufo, Lucia; Van Gestel, Cornelis A.M.; Rocco, Annamaria; Maisto, Giulia

2012-01-01

This study aimed at relating the abundance and diversity of invertebrate communities of urban soils to chemical and physical soil characteristics and to identify the taxa most sensitive or tolerant to soil stressors. The invertebrate community of five urban soils in Naples, Italy, was sampled. To assess soil quality invertebrate community indices (Shannon, Simpson, Menhinick and Pielou indices), Acarina/Collembola ratios, and the soil biological quality index (QBS) were calculated. The chemical and physical characteristics of the soils strongly differed. Abundance rather than taxa richness of invertebrates were more affected by soil characteristics. The community was more abundant and diverse in the soils with high organic matter and water content and low metal (Cu, Pb, Zn) concentrations. The taxa more resistant to the urban environment included Acarina, Enchytraeids, Collembola and Nematoda. Collembolans appeared particularly sensitive to changing soil properties. Among the investigated indices, QBS seems most appropriate for soil quality assessment. - Highlights: ► The abundance and diversity of invertebrate communities was related to properties and metal contents of urban soils. ► Several (biodiversity) indices were calculated and compared to evaluate soil quality. ► Metal contamination affected invertebrate density and diversity. ► The taxa more tolerant to metal contamination were Acarina, Enchytraeids, Collembola and Nematoda. ► The soil biological quality index QBS index was most appropriate for soil quality assessment. - Soil metal contamination negatively affected soil invertebrate abundance and diversity.

Restoring Soil Quality to Mitigate Soil Degradation

Directory of Open Access Journals (Sweden)

Rattan Lal

2015-05-01

Full Text Available Feeding the world population, 7.3 billion in 2015 and projected to increase to 9.5 billion by 2050, necessitates an increase in agricultural production of ~70% between 2005 and 2050. Soil degradation, characterized by decline in quality and decrease in ecosystem goods and services, is a major constraint to achieving the required increase in agricultural production. Soil is a non-renewable resource on human time scales with its vulnerability to degradation depending on complex interactions between processes, factors and causes occurring at a range of spatial and temporal scales. Among the major soil degradation processes are accelerated erosion, depletion of the soil organic carbon (SOC pool and loss in biodiversity, loss of soil fertility and elemental imbalance, acidification and salinization. Soil degradation trends can be reversed by conversion to a restorative land use and adoption of recommended management practices. The strategy is to minimize soil erosion, create positive SOC and N budgets, enhance activity and species diversity of soil biota (micro, meso, and macro, and improve structural stability and pore geometry. Improving soil quality (i.e., increasing SOC pool, improving soil structure, enhancing soil fertility can reduce risks of soil degradation (physical, chemical, biological and ecological while improving the environment. Increasing the SOC pool to above the critical level (10 to 15 g/kg is essential to set-in-motion the restorative trends. Site-specific techniques of restoring soil quality include conservation agriculture, integrated nutrient management, continuous vegetative cover such as residue mulch and cover cropping, and controlled grazing at appropriate stocking rates. The strategy is to produce “more from less” by reducing losses and increasing soil, water, and nutrient use efficiency.

Electrodialytic remediation of sediments

DEFF Research Database (Denmark)

Jensen, Pernille Erland

Sediments of harbors and freshwaters are regularly dredged for various reasons: maintenance of navigational depths, recovery of recreational locations, and even environmental recovery. In the past, sediments dredged from harbors have been dumped at sea, however, environmental regulations now, in ...

Soil Survey Geographic (SSURGO) - Magnesic Soils

Data.gov (United States)

California Natural Resource Agency — Magnesic soils is a subset of the SSURGO dataset containing soil family selected based on the magnesic content and serpentinite parent material. The following soil...

Isolation and identification of soil fungi isolates from forest soil for flooded soil recovery

Science.gov (United States)

Hazwani Aziz, Nor; Zainol, Norazwina

2018-04-01

Soil fungi have been evaluated for their ability in increasing and recovering nitrogen, phosphorus and potassium content in flooded soil and in promoting the growth of the host plant. Host plant was cultivated in a mixture of fertile forest soil (nutrient-rich soil) and simulated flooded soil (nutrient-poor soil) in an optimized soil condition for two weeks. The soil sample was harvested every day until two weeks of planting and was tested for nitrogen, phosphorus and potassium concentration. Soil fungi were isolated by using dilution plating technique and was identified by Biolog’s Microbial Systems. The concentration of nitrogen, phosphorus, and potassium was found to be increasing after two weeks by two to three times approximately from the initial concentration recorded. Two fungi species were identified with probability more than 90% namely Aspergillus aculeatus and Paecilomyces lilacinus. Both identified fungi were found to be beneficial in enhancing plant growth and increasing the availability of nutrient content in the soil and thus recovering the nutrient content in the flooded soil.

Predicting Soil-Air and Soil-Water Transport Properties During Soil Vapor Extraction

DEFF Research Database (Denmark)

Poulsen, Tjalfe

Increased application of in-situ technology for control and removal of volatile organic compounds (VOC) in the subsurface has made the understanding of soil physical properties and their impact upon contaminant transport even more important. Knowledge of contaminant transport is important when...... properties of undisturbed soil from more easily measurable soil properties are developed. The importance of soil properties with respect to contaminant migration during remediation by soil vapor extraction (SVE) in the unsaturated zone was investigated using numerical simulations....

Soil forensics: How far can soil clay analysis distinguish between soil vestiges?

Science.gov (United States)

Corrêa, R S; Melo, V F; Abreu, G G F; Sousa, M H; Chaker, J A; Gomes, J A

2018-03-01

Soil traces are useful as forensic evidences because they frequently adhere to individuals and objects associated with crimes and can place or discard a suspect at/from a crime scene. Soil is a mixture of organic and inorganic components and among them soil clay contains signatures that make it reliable as forensic evidence. In this study, we hypothesized that soils can be forensically distinguished through the analysis of their clay fraction alone, and that samples of the same soil type can be consistently distinguished according to the distance they were collected from each other. To test these hypotheses 16 Oxisol samples were collected at distances of between 2m and 1.000m, and 16 Inceptisol samples were collected at distances of between 2m and 300m from each other. Clay fractions were extracted from soil samples and analyzed for hyperspectral color reflectance (HSI), X-ray diffraction crystallographic (XRD), and for contents of iron oxides, kaolinite and gibbsite. The dataset was submitted to multivariate analysis and results were from 65% to 100% effective to distinguish between samples from the two soil types. Both soil types could be consistently distinguished for forensic purposes according to the distance that samples were collected from each other: 1000m for Oxisol and 10m for Inceptisol. Clay color and XRD analysis were the most effective techniques to distinguish clay samples, and Inceptisol samples were more easily distinguished than Oxisol samples. Soil forensics seems a promising field for soil scientists as soil clay can be useful as forensic evidence by using routine analytical techniques from soil science. Copyright © 2017 The Chartered Society of Forensic Sciences. Published by Elsevier B.V. All rights reserved.

Effect of different soil washing solutions on bioavailability of residual arsenic in soils and soil properties.

Science.gov (United States)

Im, Jinwoo; Yang, Kyung; Jho, Eun Hea; Nam, Kyoungphile

2015-11-01

The effect of soil washing used for arsenic (As)-contaminated soil remediation on soil properties and bioavailability of residual As in soil is receiving increasing attention due to increasing interest in conserving soil qualities after remediation. This study investigates the effect of different washing solutions on bioavailability of residual As in soils and soil properties after soil washing. Regardless of washing solutions, the sequential extraction revealed that the residual As concentrations and the amount of readily labile As in soils were reduced after soil washing. However, the bioassay tests showed that the washed soils exhibited ecotoxicological effects - lower seed germination, shoot growth, and enzyme activities - and this could largely be attributed to the acidic pH and/or excessive nutrient contents of the washed soils depending on washing solutions. Overall, this study showed that treated soils having lower levels of contaminants could still exhibit toxic effects due to changes in soil properties, which highly depended on washing solutions. This study also emphasizes that data on the As concentrations, the soil properties, and the ecotoxicological effects are necessary to properly manage the washed soils for reuses. The results of this study can, thus, be utilized to select proper post-treatment techniques for the washed soils. Copyright © 2015 Elsevier Ltd. All rights reserved.

Diel hysteresis between soil respiration and soil temperature in a biological soil crust covered desert ecosystem.

Science.gov (United States)

Guan, Chao; Li, Xinrong; Zhang, Peng; Chen, Yongle

2018-01-01

Soil respiration induced by biological soil crusts (BSCs) is an important process in the carbon (C) cycle in arid and semi-arid ecosystems, where vascular plants are restricted by the harsh environment, particularly the limited soil moisture. However, the interaction between temperature and soil respiration remains uncertain because of the number of factors that control soil respiration, including temperature and soil moisture, especially in BSC-dominated areas. In this study, the soil respiration in moss-dominated crusts and lichen-dominated crusts was continuously measured using an automated soil respiration system over a one-year period from November 2015 to October 2016 in the Shapotou region of the Tengger Desert, northern China. The results indicated that over daily cycles, the half-hourly soil respiration rates in both types of BSC-covered areas were commonly related to the soil temperature. The observed diel hysteresis between the half-hourly soil respiration rates and soil temperature in the BSC-covered areas was limited by nonlinearity loops with semielliptical shapes, and soil temperature often peaked later than the half-hourly soil respiration rates in the BSC-covered areas. The average lag times between the half-hourly soil respiration rates and soil temperature for both types of BSC-covered areas were two hours over the diel cycles, and they were negatively and linearly related to the volumetric soil water content. Our results highlight the diel hysteresis phenomenon that occurs between soil respiration rates and soil temperatures in BSC-covered areas and the negative response of this phenomenon to soil moisture, which may influence total C budget evaluations. Therefore, the interactive effects of soil temperature and moisture on soil respiration in BSC-covered areas should be considered in global carbon cycle models of desert ecosystems.

Development of soil taxation and soil classification as furthered by the Austrian Soil Science Society

Science.gov (United States)

Baumgarten, Andreas

2013-04-01

Soil taxation and soil classification are important drivers of soil science in Austria. However, the tasks are quite different: whereas soil taxation aims at the evaluation of the productivity potential of the soil, soil classification focusses on the natural development and - especially nowadays - on functionality of the soil. Since the foundation of the Austrian Soil Science Society (ASSS), representatives both directions of the description of the soil have been involved in the common actions of the society. In the first years it was a main target to improve and standardize field descriptions of the soil. Although both systems differ in the general layout, the experts should comply with identical approaches. According to this work, a lot of effort has been put into the standardization of the soil classification system, thus ensuring a common basis. The development, state of the art and further development of both classification and taxation systems initiated and carried out by the ASSS will be shown.

SOIL Geo-Wiki: A tool for improving soil information

Science.gov (United States)

Skalský, Rastislav; Balkovic, Juraj; Fritz, Steffen; See, Linda; van der Velde, Marijn; Obersteiner, Michael

2014-05-01

Crowdsourcing is increasingly being used as a way of collecting data for scientific research, e.g. species identification, classification of galaxies and unravelling of protein structures. The WorldSoilProfiles.org database at ISRIC is a global collection of soil profiles, which have been 'crowdsourced' from experts. This system, however, requires contributors to have a priori knowledge about soils. Yet many soil parameters can be observed in the field without specific knowledge or equipment such as stone content, soil depth or color. By crowdsourcing this information over thousands of locations, the uncertainty in current soil datasets could be radically reduced, particularly in areas currently without information or where multiple interpretations are possible from different existing soil maps. Improved information on soils could benefit many research fields and applications. Better soil data could enhance assessments of soil ecosystem services (e.g. soil carbon storage) and facilitate improved process-based ecosystem modeling from local to global scales. Geo-Wiki is a crowdsourcing tool that was developed at IIASA for land cover validation using satellite imagery. Several branches are now available focused on specific aspects of land cover validation, e.g. validating cropland extent or urbanized areas. Geo-Wiki Pictures is a smart phone application for collecting land cover related information on the ground. The extension of Geo-Wiki to a mobile environment provides a tool for experts in land cover validation but is also a way of reaching the general public in the validation of land cover. Here we propose a Soil Geo-Wiki tool that builds on the existing functionality of the Geo-Wiki application, which will be largely designed for the collection and sharing of soil information. Two distinct applications are envisaged: an expert-oriented application mainly for scientific purposes, which will use soil science related language (e.g. WRB or any other global reference

Soil hydraulic properties of Cuban soils

International Nuclear Information System (INIS)

Ruiz, M.E.; Medina, H.

2004-01-01

Because soil hydraulic properties are indispensable for determining soil water retention and soil water movement, their input for deterministic crop simulation models is essential. From these models is possible to access the effect of the weather changes, soil type or different irrigation schedules on crop yields. With these models, possibilities are provided to answer questions regarding virtual 'what happen if' experiments with a minimum of fieldwork. Nevertheless, determining soil hydraulic properties can be very difficult owing to unavailability of necessary equipment or the lack of personal with the proper knowledge for those tasks. These deficiencies are a real problem in developing countries, and even more so when there is not enough financial possibilities for research work. This paper briefly presents the way these properties have been accessed for Cuban soils, which methods have been used and the work now in progress. (author)

Forest soils

Science.gov (United States)

Charles H. (Hobie) Perry; Michael C. Amacher

2009-01-01

Productive soils are the foundation of sustainable forests throughout the United States. Forest soils are generally subjected to fewer disturbances than agricultural soils, particularly those that are tilled, so forest soils tend to have better preserved A-horizons than agricultural soils. Another major contrast between forest and agricultural soils is the addition of...

Clay-illuvial soils in the Polish and international soil classifications

Directory of Open Access Journals (Sweden)

Kabała Cezary

2015-12-01

Full Text Available Soil with a clay-illuvial subsurface horizon are the most widespread soil type in Poland and significantly differ in morphology and properties developed under variable environmental conditions. Despite the long history of investigations, the rules of classification and cartography of clay-illuvial soils have been permanently discussed and modified. The distinction of clay-illuvial soils into three soil types, introduced to the Polish soil classification in 2011, has been criticized as excessively extended, non-coherent with the other parts and rules of the classification, hard to introduce in soil cartography and poorly correlated with the international soil classifications. One type of clay-illuvial soils (“gleby płowe” was justified and recommended to reintroduce in soil classification in Poland, as well as 10 soil subtypes listed in a hierarchical order. The subtypes may be combined if the soil has diagnostic features of more than one soil subtypes. Clear rules of soil name generalization (reduction of subtype number for one soil were suggested for soil cartography on various scales. One of the most important among the distinguished soil sub-types are the “eroded” or “truncated” clay-illuvial soils.

Soil structural quality assessment for soil protection regulation

Science.gov (United States)

Johannes, Alice; Boivin, Pascal

2017-04-01

Soil quality assessment is rapidly developing worldwide, though mostly focused on the monitoring of arable land and soil fertility. Soil protection regulations assess soil quality differently, focusing on priority pollutants and threshold values. The soil physical properties are weakly considered, due to lack of consensus and experimental difficulties faced with characterization. Non-disputable, easy to perform and inexpensive methods should be available for environmental regulation to be applied, which is unfortunately not the case. As a consequence, quantitative soil physical protection regulation is not applied, and inexpensive soil physical quality indicators for arable soil management are not available. Overcoming these limitations was the objective of a research project funded by the Swiss federal office for environment (FOEN). The main results and the perspectives of application are given in this presentation. A first step of the research was to characterize soils in a good structural state (reference soils) under different land use. The structural quality was assessed with field expertise and Visual Evaluation of the Soil Structure (VESS), and the physical properties were assessed with Shrinkage analysis. The relationships between the physical properties and the soil constituents were linear and highly determined. They represent the reference properties of the corresponding soils. In a second step, the properties of physically degraded soils were analysed and compared to the reference properties. This allowed defining the most discriminant parameters departing the different structure qualities and their threshold limits. Equivalent properties corresponding to these parameters but inexpensive and easy to determine were defined and tested. More than 90% of the samples were correctly classed with this method, which meets, therefore, the requirements for practical application in regulation. Moreover, result-oriented agri-environmental schemes for soil quality

Visual soil evaluation and soil compaction research

DEFF Research Database (Denmark)

M.L. Guimarães, Rachel; Keller, Thomas; Munkholm, Lars Juhl

2017-01-01

Following on from discussions that took place during the 19th International Conference of the International Soil Tillage Research Organization (ISTRO) in Montevideo, Uruguay, in 2012, the ISTRO working groups “Visual Soil Examination and Evaluation” (VSEE) and “Subsoil Compaction” decided...... to organize a joint workshop. The present special issue is an outcome from the workshop on “Soil structural quality of tropical soils: Visual evaluation methods and soil compaction prevention strategies” that was held 26–29 May 2014 in Maringá, Paraná, Brazil. There has been a long-lasting interest in Visual...... Soil Evaluation (VSE). An ISTRO working group was established more than 30 years ago with the objectives to exchange knowledge and experiences on field methods of visual-tactile soil assessment and to foster international cooperation on new or refined methods. The three previous meeting of the group...

[Microscopic soil fungi - bioindicators organisms contaminated soil].

Science.gov (United States)

Donerian, L G; Vodianova, M A; Tarasova, Zh E

In the paper there are considered methodological issues for the evaluation of soil biota in terms of oil pollution. Experimental studies have shown that under the exposure of a various levels of oil pollution meeting certain gradations of the state and optimal alteration in microbocenosis in sod-podzolic soils, there is occurred a transformation of structure of the complex of micromycetes and the accumulation of toxic species, hardly typical for podzolic soils - primarily represantatives of the genus Aspergillus (A.niger and A. versicolor), Paecilomyces (P.variotii Bainer), Trichoderma (T.hamatum), the genus of phytopathogens Fusarium (F.oxysporum), dermatophytes of genus Sporothrix (S. schenckii) and dark-colored melanin containing fungi of Dematiaceae family. Besides that there are presented data on the study of microbiocenosis of the urban soil, the urban soil differed from the zone soil, but shaped in similar landscape and climatic conditions, and therefore having a tendency to a similar response from the side of microorganisms inhabiting the soil. Isolated complex of soil microscopic fungi is described by many authors as a complex, characteristic for soils of megalopolises. This allowed authors of this work to suggest that in urban soils the gain in the occurrence of pathogenic species micromycetes also increases against a background of chronic, continuously renewed inflow of petroleum hydrocarbons from various sources of pollution. Because changes in the species composition of micromycetes occurred in accordance with the increasing load of oil, so far as microscopic soil fungi can be recommended as a bioindicator organisms for oil. In the article there is also provided information about the distinctive features of modern DNA identification method of soil microscopic fungi and accepted in our country methodology of isolation of micromycetes with the use of a nutrient Czapek medium.

SoilInfo App: global soil information on your palm

Science.gov (United States)

Hengl, Tomislav; Mendes de Jesus, Jorge

2015-04-01

ISRIC ' World Soil Information has released in 2014 and app for mobile de- vices called 'SoilInfo' (http://soilinfo-app.org) and which aims at providing free access to the global soil data. SoilInfo App (available for Android v.4.0 Ice Cream Sandwhich or higher, and Apple v.6.x and v.7.x iOS) currently serves the Soil- Grids1km data ' a stack of soil property and class maps at six standard depths at a resolution of 1 km (30 arc second) predicted using automated geostatistical mapping and global soil data models. The list of served soil data includes: soil organic carbon (), soil pH, sand, silt and clay fractions (%), bulk density (kg/m3), cation exchange capacity of the fine earth fraction (cmol+/kg), coarse fragments (%), World Reference Base soil groups, and USDA Soil Taxonomy suborders (DOI: 10.1371/journal.pone.0105992). New soil properties and classes will be continuously added to the system. SoilGrids1km are available for download under a Creative Commons non-commercial license via http://soilgrids.org. They are also accessible via a Representational State Transfer API (http://rest.soilgrids.org) service. SoilInfo App mimics common weather apps, but is also largely inspired by the crowdsourcing systems such as the OpenStreetMap, Geo-wiki and similar. Two development aspects of the SoilInfo App and SoilGrids are constantly being worked on: Data quality in terms of accuracy of spatial predictions and derived information, and Data usability in terms of ease of access and ease of use (i.e. flexibility of the cyberinfrastructure / functionalities such as the REST SoilGrids API, SoilInfo App etc). The development focus in 2015 is on improving the thematic and spatial accuracy of SoilGrids predictions, primarily by using finer resolution covariates (250 m) and machine learning algorithms (such as random forests) to improve spatial predictions.

Shaping an Optimal Soil by Root-Soil Interaction.

Science.gov (United States)

Jin, Kemo; White, Philip J; Whalley, William R; Shen, Jianbo; Shi, Lei

2017-10-01

Crop production depends on the availability of water and mineral nutrients, and increased yields might be facilitated by a greater focus on roots-soil interactions. Soil properties affecting plant growth include drought, compaction, nutrient deficiency, mineral toxicity, salinity, and submergence. Plant roots respond to the soil environment both spatially and temporally by avoiding stressful soil environments and proliferating in more favorable environments. We observe that crops can be bred for specific root architectural and biochemical traits that facilitate soil exploration and resource acquisition, enabling greater crop yields. These root traits affect soil physical and chemical properties and might be utilized to improve the soil for subsequent crops. We argue that optimizing root-soil interactions is a prerequisite for future food security. Copyright © 2017 Elsevier Ltd. All rights reserved.

Dryland soil microbial communities display spatial biogeographic patterns associated with soil depth and soil parent material

Science.gov (United States)

Steven, Blaire; Gallegos-Graves, La Verne; Belnap, Jayne; Kuske, Cheryl R.

2013-01-01

Biological soil crusts (biocrusts) are common to drylands worldwide. We employed replicated, spatially nested sampling and 16S rRNA gene sequencing to describe the soil microbial communities in three soils derived from different parent material (sandstone, shale, and gypsum). For each soil type, two depths (biocrusts, 0–1 cm; below-crust soils, 2–5 cm) and two horizontal spatial scales (15 cm and 5 m) were sampled. In all three soils, Cyanobacteria and Proteobacteria demonstrated significantly higher relative abundance in the biocrusts, while Chloroflexi and Archaea were significantly enriched in the below-crust soils. Biomass and diversity of the communities in biocrusts or below-crust soils did not differ with soil type. However, biocrusts on gypsum soil harbored significantly larger populations of Actinobacteria and Proteobacteria and lower populations of Cyanobacteria. Numerically dominant operational taxonomic units (OTU; 97% sequence identity) in the biocrusts were conserved across the soil types, whereas two dominant OTUs in the below-crust sand and shale soils were not identified in the gypsum soil. The uniformity with which small-scale vertical community differences are maintained across larger horizontal spatial scales and soil types is a feature of dryland ecosystems that should be considered when designing management plans and determining the response of biocrusts to environmental disturbances.

Why is the influence of soil macrofauna on soil structure only considered by soil ecologists ?

OpenAIRE

Bottinelli, N.; Jouquet, Pascal; Capowiez, Y.; Podwojewski, Pascal; Grimaldi, Michel; Peng, X.

2015-01-01

These last twenty years have seen the development of an abundant literature on the influence of soil macrofauna on soil structure. Amongst these organisms, earthworms, termites and ants are considered to play a key role in regulating the physical, chemical and microbiological properties of soils. Due to these influential impacts, soil ecologists consider these soil macro-invertebrates as ‘soil engineers’ and their diversity and abundance are nowadays considered as relevant bioindi...

Estimation of soil-soil solution distribution coefficient of radiostrontium using soil properties.

Science.gov (United States)

Ishikawa, Nao K; Uchida, Shigeo; Tagami, Keiko

2009-02-01

We propose a new approach for estimation of soil-soil solution distribution coefficient (K(d)) of radiostrontium using some selected soil properties. We used 142 Japanese agricultural soil samples (35 Andosol, 25 Cambisol, 77 Fluvisol, and 5 others) for which Sr-K(d) values had been determined by a batch sorption test and listed in our database. Spearman's rank correlation test was carried out to investigate correlations between Sr-K(d) values and soil properties. Electrical conductivity and water soluble Ca had good correlations with Sr-K(d) values for all soil groups. Then, we found a high correlation between the ratio of exchangeable Ca to Ca concentration in water soluble fraction and Sr-K(d) values with correlation coefficient R=0.72. This pointed us toward a relatively easy way to estimate Sr-K(d) values.

Soil tension mediates isotope fractionation during soil water evaporation

Science.gov (United States)

Gaj, Marcel; McDonnell, Jeffrey

2017-04-01

Isotope tracing of the water cycle is increasing in its use and usefulness. Many new studies are extracting soil waters and relating these to streamflow, groundwater recharge and plant transpiration. Nevertheless, unlike isotope fractionation factors from open water bodies, soil water fractionation factors are poorly understood and until now, only empirically derived. In contrast to open water evaporation where temperature, humidity and vapor pressure gradient define fractionation (as codified in the well-known Craig and Gordon model), soil water evaporation includes additionally, fractionation by matrix effects. There is yet no physical explanation of kinetic and equilibrium fraction from soil water within the soil profile. Here we present a simple laboratory experiment with four admixtures of soil grain size (from sand to silt to clay). Oven-dried samples were spiked with water of known isotopic composition at different soil water contents. Soils were then stored in sealed bags and the headspace filled with dry air and allowed to equilibrate for 24hours. Isotopic analysis of the headspace vapor was done with a Los Gatos Inc. water vapor isotope analyzer. Soil water potential of subsamples were measured with a water potential meter. We show for the first time that soil tension controls isotope fractionation in the resident soil water. Below a Pf 3.5 the δ-values of 18O and 2H of the headspace vapor is more positive and increases with increasing soil water potential. Surprisingly, we find that the relationship between soil tension and equilibrium fractionation is independent of soil type. However, δ-values of each soil type plot along a distinct evaporation line. These results indicate that equilibrium fractionation is affected by soil tension in addition to temperature. Therefore, at high soil water tension (under dry conditions) equilibrium fractionation is not consistent with current empirical formulations that ignore these effects. These findings may have

Soil! Get the Scoop - The Soil Science Society of America's International Year of Soils Campaign

Science.gov (United States)

Lindbo, David L.; Hopmans, Jan; Olson, Carolyn; Fisk, Susan; Chapman, Susan; van Es, Harold

2015-04-01

Soils are a finite natural resource and are nonrenewable on a human time scale. Soils are the foundation for food, animal feed, fuel and natural fiber production, the supply of clean water, nutrient cycling and a range of ecosystem functions. The area of fertile soils covering the world's surface is limited and increasingly subject to degradation, poor management and loss to urbanization. Increased awareness of the life-supporting functions of soil is called for if this trend is to be reversed and so enable the levels of food production necessary to meet the demands of population levels predicted for 2050. The Soil Science Society of America is coordinating with the Global Soil Partnership and other organizations around the world to celebrate the 2015 International Year of Soils and raise awareness and promote the sustainability of our limited soil resources. We all have a valuable role in communicating vital information on soils, a life sustaining natural resource. Therefore, we will provide resources to learn about soils and help us tell the story of soils. We will promote IYS on social media by sharing our posts from Facebook and Twitter. Additionally SSSA developed 12 monthly themes that reflect the diverse value of soils to our natural environment and society. Each month has information on the theme, a lesson plan, and other outreach activities. All information is available on a dedicated website www.soil.org/IYS. The site will be updated constantly throughout the year.

Progress towards GlobalSoilMap.net soil database of Denmark

DEFF Research Database (Denmark)

Adhikari, Kabindra; Bou Kheir, Rania; Greve, Mogens Humlekrog

2012-01-01

Denmark is an agriculture-based country where intensive mechanized cultivation has been practiced continuously for years leading to serious threats to the soils. Proper use and management of Danish soil resources, modeling and soil research activities need very detailed soil information. This study...... presents recent advancements in Digital Soil Mapping (DSM) activities in Denmark with an example of soil clay mapping using regression-based DSM techniques. Several environmental covariates were used to build regression rules and national scale soil prediction was made at 30 m resolution. Spatial...... content mapping, the plans for future soil mapping activities in support to GlobalSoilMap.net project initiatives are also included in this paper. Our study thought to enrich and update Danish soil database and Soil information system with new fine resolution soil property maps....

Impact of Soil Texture on Soil Ciliate Communities

Science.gov (United States)

Chau, J. F.; Brown, S.; Habtom, E.; Brinson, F.; Epps, M.; Scott, R.

2014-12-01

Soil water content and connectivity strongly influence microbial activities in soil, controlling access to nutrients and electron acceptors, and mediating interactions between microbes within and between trophic levels. These interactions occur at or below the pore scale, and are influenced by soil texture and structure, which determine the microscale architecture of soil pores. Soil protozoa are relatively understudied, especially given the strong control they exert on bacterial communities through predation. Here, ciliate communities in soils of contrasting textures were investigated. Two ciliate-specific primer sets targeting the 18S rRNA gene were used to amplify DNA extracted from eight soil samples collected from Sumter National Forest in western South Carolina. Primer sets 121F-384F-1147R (semi-nested) and 315F-959R were used to amplify soil ciliate DNA via polymerase chain reaction (PCR), and the resulting PCR products were analyzed by gel electrophoresis to obtain quantity and band size. Approximately two hundred ciliate 18S rRNA sequences were obtained were obtained from each of two contrasting soils. Sequences were aligned against the NCBI GenBank database for identification, and the taxonomic classification of best-matched sequences was determined. The ultimate goal of the work is to quantify changes in the ciliate community under short-timescale changes in hydrologic conditions for varying soil textures, elucidating dynamic responses to desiccation stress in major soil ciliate taxa.

Soil organic matter and soil biodiversity spots in urban and semi urban soils of southeast Mexico

Science.gov (United States)

Huerta, Esperanza

2015-04-01

We have observed how the constant use of compost or vermicompost has created spots of soil restoration in urban and semiurban soils of Chiapas (Huitepec and Teopisca), increasing soil organic matter amount, soil moisture and soil porosity, and enhancing then the presence of soil biodiversity; for example, in a Milpa with vermicompost (polyculture of Zea mays with Curcubita pepo, and Fasolius vulgaris) we have found a high density of an epigeic earthworm (640 ind.m2), Dichogaster bolahui, not present in the same type of soil just some meters of distance, in an Oak forest, where soil macroinvertebrates abundance decreased drastically. In another ecosystem within a Persea Americana culture, we found how above and below ground soil biodiversity is affected by the use of vermicompost, having clearly different microcosmos with and without vermicompost (30-50% more micro and macro invertebrates with vermicompost). So now in Campeche, within those soils that are classified by the mayas as tzequel, soils not use for agriculture, we have implemented home gardens and school gardens by the use of compost of vermicomposts in urban and semiurban soils. In school gardens (mainly primary schools) students have cultivated several plants with alimentary purposes; teachers have observed how the increase of soil biodiversity by the use of compost or vermicompost has enhanced the curiosity of children, even has promoted a more friendly behavior among students, they have learned how to do compost and how to apply it. Urban and semiurban soils can be modified by the use of compost and vermicompost, and soil biodiversity has extremely increased.

Soil physical properties on Venezuelan steeplands: Applications to soil conservation planning

International Nuclear Information System (INIS)

Delgado, F.

2004-01-01

This paper presents a framework to support decision making for soil conservation on Venezuelan steeplands. The general approach is based on the evaluation of two important land qualities: soil productivity and soil erosion risk, both closely related to soil physical properties. Soil productivity can be estimated from soil characteristics such as soil air-water relationships, soil impedances and soil fertility. On the other hand, soil erosion risk depends basically on soil hydrologic properties, rainfall aggressiveness and terrain slope. Two indexes are obtained from soil and land characteristics: soil productivity index (PI) and erosion risk index (ERI), each one evaluates the respective land quality. Subsequently, a matrix with these two qualities shows different land classes as well as soil conservation priorities, conservation requirements and proposed land uses. The paper shows also some applications of the soil productivity index as an approach to evaluate soil loss tolerance for soil conservation programs on tropical steeplands. (author)

Soil warming increases metabolic quotients of soil microorganisms without changes in temperature sensitivity of soil respiration

Science.gov (United States)

Marañón-Jiménez, Sara; Soong, Jenniffer L.; Leblans, Niki I. W.; Sigurdsson, Bjarni D.; Dauwe, Steven; Fransen, Erik; Janssens, Ivan A.

2017-04-01

Increasing temperatures can accelerate soil organic matter (SOM) decomposition and release large amounts of CO2 to the atmosphere, potentially inducing climate change feedbacks. Alterations to the temperature sensitivity and metabolic pathways of soil microorganisms in response to soil warming can play a key role in these soil carbon (C) losses. Here, we present results of an incubation experiment using soils from a geothermal gradient in Iceland that have been subjected to different intensities of soil warming (+0, +1, +3, +5, +10 and +20 °C above ambient) over seven years. We hypothesized that 7 years of soil warming would led to a depletion of labile organic substrates, with a subsequent decrease of the "apparent" temperature sensitivity of soil respiration. Associated to this C limitation and more sub-optimal conditions for microbial growth, we also hypothesized increased microbial metabolic quotients (soil respiration per unit of microbial biomass), which is associated with increases in the relative amount of C invested into catabolic pathways along the warming gradient. Soil respiration and basal respiration rates decreased with soil warming intensity, in parallel with a decline in soil C availability. Contrasting to our first hypothesis, we did not detect changes in the temperature sensitivity of soil respiration with soil warming or on the availability of nutrients and of labile C substrates at the time of incubation. However, in agreement to our second hypothesis, microbial metabolic quotients (soil respiration per unit of microbial biomass) increased at warmer temperatures, while the C retained in biomass decreased as substrate became limiting. Long-term (7 years) temperature increases thus triggered a change in the metabolic functioning of the soil microbial communities towards increasing energy costs for maintenance or resource acquisition, thereby lowering the capacity of C retention and stabilization of warmed soils. These results highlight the need

Parameterization of radiocaesium soil-plant transfer using soil characteristics

International Nuclear Information System (INIS)

Konoplev, A. V.; Drissner, J.; Klemt, E.; Konopleva, I. V.; Zibold, G.

1996-01-01

A model of radionuclide soil-plant transfer is proposed to parameterize the transfer factor by soil and soil solution characteristics. The model is tested with experimental data on the aggregated transfer factor T ag and soil parameters for 8 forest sites in Baden-Wuerttemberg. It is shown that the integral soil-plant transfer factor can be parameterized through radiocaesium exchangeability, capacity of selective sorption sites and ion composition of the soil solution or the water extract. A modified technique of (FES) measurement for soils with interlayer collapse is proposed. (author)

Soil salinity decreases global soil organic carbon stocks.

Science.gov (United States)

Setia, Raj; Gottschalk, Pia; Smith, Pete; Marschner, Petra; Baldock, Jeff; Setia, Deepika; Smith, Jo

2013-11-01

Saline soils cover 3.1% (397 million hectare) of the total land area of the world. The stock of soil organic carbon (SOC) reflects the balance between carbon (C) inputs from plants, and losses through decomposition, leaching and erosion. Soil salinity decreases plant productivity and hence C inputs to the soil, but also microbial activity and therefore SOC decomposition rates. Using a modified Rothamsted Carbon model (RothC) with a newly introduced salinity decomposition rate modifier and a plant input modifier we estimate that, historically, world soils that are currently saline have lost an average of 3.47 tSOC ha(-1) since they became saline. With the extent of saline soils predicted to increase in the future, our modelling suggests that world soils may lose 6.8 Pg SOC due to salinity by the year 2100. Our findings suggest that current models overestimate future global SOC stocks and underestimate net CO2 emissions from the soil-plant system by not taking salinity effects into account. From the perspective of enhancing soil C stocks, however, given the lower SOC decomposition rate in saline soils, salt tolerant plants could be used to sequester C in salt-affected areas. Copyright © 2012 Elsevier B.V. All rights reserved.

Soil functional types: surveying the biophysical dimensions of soil security

Science.gov (United States)

Cécillon, Lauric; Barré, Pierre

2015-04-01

Soil is a natural capital that can deliver key ecosystem services (ES) to humans through the realization of a series of soil processes controlling ecosystem functioning. Soil is also a diverse and endangered natural resource. A huge pedodiversity has been described at all scales, which is strongly altered by global change. The multidimensional concept soil security, encompassing biophysical, economic, social, policy and legal frameworks of soils has recently been proposed, recognizing the role of soils in global environmental sustainability challenges. The biophysical dimensions of soil security focus on the functionality of a given soil that can be viewed as the combination of its capability and its condition [1]. Indeed, all soils are not equal in term of functionality. They show different processes, provide different ES to humans and respond specifically to global change. Knowledge of soil functionality in space and time is thus a crucial step towards the achievement soil security. All soil classification systems incorporate some functional information, but soil taxonomy alone cannot fully describe the functioning, limitations, resistance and resilience of soils. Droogers and Bouma [2] introduced functional variants (phenoforms) for each soil type (genoform) so as to fit more closely to soil functionality. However, different genoforms can have the same functionality. As stated by McBratney and colleagues [1], there is a great need of an agreed methodology for defining the reference state of soil functionality. Here, we propose soil functional types (SFT) as a relevant classification system for the biophysical dimensions of soil security. Following the definition of plant functional types widely used in ecology, we define a soil functional type as "a set of soil taxons or phenoforms sharing similar processes (e.g. soil respiration), similar effects on ecosystem functioning (e.g. primary productivity) and similar responses to global change (land-use, management or

Dynamical soil-structure interactions: influence of soil behaviour nonlinearities

International Nuclear Information System (INIS)

Gandomzadeh, Ali

2011-01-01

The interaction of the soil with the structure has been largely explored the assumption of material and geometrical linearity of the soil. Nevertheless, for moderate or strong seismic events, the maximum shear strain can easily reach the elastic limit of the soil behavior. Considering soil-structure interaction, the nonlinear effects may change the soil stiffness at the base of the structure and therefore energy dissipation into the soil. Consequently, ignoring the nonlinear characteristics of the dynamic soil-structure interaction (DSSI) this phenomenon could lead to erroneous predictions of structural response. The goal of this work is to implement a fully nonlinear constitutive model for soils into a numerical code in order to investigate the effect of soil nonlinearity on dynamic soil structure interaction. Moreover, different issues are taken into account such as the effect of confining stress on the shear modulus of the soil, initial static condition, contact elements in the soil-structure interface, etc. During this work, a simple absorbing layer method based on a Rayleigh/Caughey damping formulation, which is often already available in existing Finite Element softwares, is also presented. The stability conditions of the wave propagation problems are studied and it is shown that the linear and nonlinear behavior are very different when dealing with numerical dispersion. It is shown that the 10 points per wavelength rule, recommended in the literature for the elastic media is not sufficient for the nonlinear case. The implemented model is first numerically verified by comparing the results with other known numerical codes. Afterward, a parametric study is carried out for different types of structures and various soil profiles to characterize nonlinear effects. Different features of the DSSI are compared to the linear case: modification of the amplitude and frequency content of the waves propagated into the soil, fundamental frequency, energy dissipation in

What is Soil?

Science.gov (United States)

It! What is Soil? Chip Off the Old Block Soil Forming Factors Matters of Life and Death Underneath It All Wise Choices A World of Soils Soil? 2 The Skin of the Earth 3 Soil Ingredients 4 Soil Recipes 5 CLORPT for Short >> What Is Soil? Soils Make Life Plants grow in and from

Modelling the Impact of Soil Management on Soil Functions

Science.gov (United States)

Vogel, H. J.; Weller, U.; Rabot, E.; Stößel, B.; Lang, B.; Wiesmeier, M.; Urbanski, L.; Wollschläger, U.

2017-12-01

Due to an increasing soil loss and an increasing demand for food and energy there is an enormous pressure on soils as the central resource for agricultural production. Besides the importance of soils for biomass production there are other essential soil functions, i.e. filter and buffer for water, carbon sequestration, provision and recycling of nutrients, and habitat for biological activity. All these functions have a direct feed back to biogeochemical cycles and climate. To render agricultural production efficient and sustainable we need to develop model tools that are capable to predict quantitatively the impact of a multitude of management measures on these soil functions. These functions are considered as emergent properties produced by soils as complex systems. The major challenge is to handle the multitude of physical, chemical and biological processes interacting in a non-linear manner. A large number of validated models for specific soil processes are available. However, it is not possible to simulate soil functions by coupling all the relevant processes at the detailed (i.e. molecular) level where they are well understood. A new systems perspective is required to evaluate the ensemble of soil functions and their sensitivity to external forcing. Another challenge is that soils are spatially heterogeneous systems by nature. Soil processes are highly dependent on the local soil properties and, hence, any model to predict soil functions needs to account for the site-specific conditions. For upscaling towards regional scales the spatial distribution of functional soil types need to be taken into account. We propose a new systemic model approach based on a thorough analysis of the interactions between physical, chemical and biological processes considering their site-specific characteristics. It is demonstrated for the example of soil compaction and the recovery of soil structure, water capacity and carbon stocks as a result of plant growth and biological

Apparent soil electrical conductivity in two different soil types

Directory of Open Access Journals (Sweden)

Wilker Nunes Medeiros

Full Text Available ABSTRACT Mapping the apparent soil electrical conductivity (ECa has become important for the characterization of the soil variability in precision agriculture systems. Could the ECa be used to locate the soil sampling points for mapping the chemical and physical soil attributes? The objective of this work was to examine the relations between ECa and soil attributes in two fields presenting different soil textures. In each field, 50 sampling points were chosen using a path that presented a high variability of ECa obtained from a preliminary ECa map. At each sampling point, the ECa was measured in soil depths of 0-20, 0-40 and 0-60 cm. In addition, at each point, soil samples were collected for the determination of physical and chemical attributes in the laboratory. The ECa data obtained for different soil depths was very similar. A large number of significant correlations between ECa and the soil attributes were found. In the sandy clay loam texture field there was no correlation between ECa and organic matter or between ECa and soil clay and sand content. However, a significant positive correlation was shown for the remaining phosphorus. In the sandy loam texture field the ECa had a significant positive correlation with clay content and a significant negative correlation with sand content. The results suggest that the mapping of apparent soil electrical conductivity does not replace traditional soil sampling, however, it can be used as information to delimit regions in a field that have similar soil attributes.

Soil Forming Factors

Science.gov (United States)

It! What is Soil? Chip Off the Old Block Soil Forming Factors Matters of Life and Death Underneath It All Wise Choices A World of Soils Soil Forming Factors 2 A Top to Bottom Guide 3 Making a Soil Monolith 4 Soil Orders 5 State Soil Monoliths 6 Where in the Soil World Are You? >> A Top to

Soil-structure interaction including nonlinear soil

OpenAIRE

Gicev, Vlado

2008-01-01

There are two types of models of soil-structure system depending upon the rigidity of foundation: models with rigid and models with flexible foundation. Main features of the soil-structure interaction phenomenon: -wave scattering, -radiation damping, -reduction of the system frequencies. In this presentation, the influence of interaction on the development of nonlinear zones in the soil is studied.

Solarization soil

International Nuclear Information System (INIS)

Abou Ghraibe, W.

1995-01-01

Solar energy could be used in pest control, in soil sterilization technology. The technique consists of covering humid soils by plastic films steadily fixed to the soil. Timing must be in summer during 4-8 weeks, where soil temperature increases to degrees high enough to control pests or to produce biological and chemical changes. The technique could be applied on many pests soil, mainly fungi, bacteria, nematods, weeds and pest insects. The technique could be used in greenhouses as well as in plastic film covers or in orchards where plastic films present double benefits: soil sterilization and production of black mulch. Mechanism of soil solarization is explained. Results show that soil solarization can be used in pest control after fruit crops cultivation and could be a method for an integrated pest control. 9 refs

Pesticide-soil microflora interactions in flooded rice soils

International Nuclear Information System (INIS)

Sethunathan, N.; Siddaramappa, R.; Siddarame Gowda, T.K.; Rajaram, K.P.; Barik, S.; Rao, V.R.

1976-01-01

Isotope studies revealed that gamma and beta isomers of HCH (hexachlorocyclohexane) decomposed rapidly in nonsterile soils capable of attaining redox potentials of -40 to -100mV within 20 days after flooding. Degradation was slow, however, in soils low in organic matter and in soils with extremely low pH and positive potentials, even after several weeks of flooding. Under flooded conditions, endrin decomposed to six metabolites in most soils. There is evidence that biological hydrolysis of parathion is more widespread than hitherto believed, particularly under flooded soil conditions. Applications of benomyl (fungicide) to a simulated-oxidized zone of flooded soils favoured heterotrophic nitrification. (author)

Soil mechanics and analysis of soils overlying cavitose bedrock

International Nuclear Information System (INIS)

Drumm, E.C.

1987-08-01

The stability of the residual soils existing at the West Chestnut Ridge Site, Oak Ridge Reservation, Tennessee, was evaluated. The weathered bedrock below this residual soil contains numerous solution cavities, and several karst features were identified. The West Chestnut Ridge site was evaluated with respect to deformation and collapse of the residual soil into the bedrock cavities. A finite element analysis investigated the effects of bedrock cavity radius, thickness of soil overburden, and surface surcharge upon the deformational and stability characteristics of the residual soil. The results indicate that for small cavity radii, the thickness of the soil cover has little effect on the zone of yielded soil. For large cavity radii, a smaller zone of distressed soil occurs under thick soil cover than under thin soil cover. Dimensionless curves are presented to enable the prediction of the vertical extent of the zone of yielded soil for a range of site geometries. Although the thick soil deposits (100 feet or greater) typically found on the ridges result in high stresses adjacent to the cavity, the area of the distressed or yielded soil is small and unlikely to extend to the surface. In addition, the surface deformation or subsidence is expected to be minimal. Thus, the siting of waste facilities on the ridges where the overburden is maximum would tend to reduce the effects of deformation into the cavities. 29 refs., 37 figs., 7 tabs

Soil physics and the water management of spatially variable soils

International Nuclear Information System (INIS)

Youngs, E.G.

1983-01-01

The physics of macroscopic soil-water behaviour in inert porous materials has been developed by considering water flow to take place in a continuum. This requires the flow region to consist of an assembly of representative elementary volumes, repeated throughout space and small compared with the scale of observations. Soil-water behaviour in swelling soils may also be considered as a continuum phenomenon so long as the soil is saturated and swells and shrinks in the normal range. Macroscale heterogeneity superimposed on the inherent microscale heterogeneity can take many forms and may pose difficulties in the definition and measurement of soil physical properties and also in the development and use of predictive theories of soil-water behaviour. Thus, measurement techniques appropriate for uniform soils are often inappropriate, and criteria for soil-water management, obtained from theoretical considerations of behaviour in equivalent uniform soils, are not applicable without modification when there is soil heterogeneity. The spatial variability of soil-water properties is shown in results from field experiments concerned with water flow measurements; these illustrate both stochastic and deterministic heterogeneity in soil-water properties. Problems of water management of spatially variable soils when there is stochastic heterogeneity appear to present an insuperable problem in the application of theory. However, for soils showing deterministic heterogeneity, soil-water theory has been used in the solution of soil-water management problems. Thus, scaling using similar media theory has been applied to the infiltration of water into soils that vary over a catchment area. Also, the drain spacing to control the water-table height in soils in which the hydraulic conductivity varies with depth has been calculated using groundwater seepage theory. (author)

[Soil Microbial Respiration Under Different Soil Temperature Conditions and Its Relationship to Soil Dissolved Organic Carbon and Invertase].

Science.gov (United States)

Wu, Jing; Chen, Shu-tao; Hu, Zheng-hua; Zhang, Xu

2015-04-01

In order to investigate the soil microbial respiration under different temperature conditions and its relationship to soil dissolved organic carbon ( DOC) and invertase, an indoor incubation experiment was performed. The soil samples used for the experiment were taken from Laoshan, Zijinshan, and Baohuashan. The responses of soil microbial respiration to the increasing temperature were studied. The soil DOC content and invertase activity were also measured at the end of incubation. Results showed that relationships between cumulative microbial respiration of different soils and soil temperature could be explained by exponential functions, which had P values lower than 0.001. The coefficient of temperature sensitivity (Q10 value) varied from 1.762 to 1.895. The Q10 value of cumulative microbial respiration decreased with the increase of soil temperature for all soils. The Q10 value of microbial respiration on 27 days after incubation was close to that of 1 day after incubation, indicating that the temperature sensitivity of recalcitrant organic carbon may be similar to that of labile organic carbon. For all soils, a highly significant ( P = 0.003 ) linear relationship between cumulative soil microbial respiration and soil DOC content could be observed. Soil DOC content could explain 31.6% variances of cumulative soil microbial respiration. For the individual soil and all soils, the relationship between cumulative soil microbial respiration and invertase activity could be explained by a highly significant (P soil microbial respiration.

SoilGrids1km--global soil information based on automated mapping.

Directory of Open Access Journals (Sweden)

Tomislav Hengl

Full Text Available BACKGROUND: Soils are widely recognized as a non-renewable natural resource and as biophysical carbon sinks. As such, there is a growing requirement for global soil information. Although several global soil information systems already exist, these tend to suffer from inconsistencies and limited spatial detail. METHODOLOGY/PRINCIPAL FINDINGS: We present SoilGrids1km--a global 3D soil information system at 1 km resolution--containing spatial predictions for a selection of soil properties (at six standard depths: soil organic carbon (g kg-1, soil pH, sand, silt and clay fractions (%, bulk density (kg m-3, cation-exchange capacity (cmol+/kg, coarse fragments (%, soil organic carbon stock (t ha-1, depth to bedrock (cm, World Reference Base soil groups, and USDA Soil Taxonomy suborders. Our predictions are based on global spatial prediction models which we fitted, per soil variable, using a compilation of major international soil profile databases (ca. 110,000 soil profiles, and a selection of ca. 75 global environmental covariates representing soil forming factors. Results of regression modeling indicate that the most useful covariates for modeling soils at the global scale are climatic and biomass indices (based on MODIS images, lithology, and taxonomic mapping units derived from conventional soil survey (Harmonized World Soil Database. Prediction accuracies assessed using 5-fold cross-validation were between 23-51%. CONCLUSIONS/SIGNIFICANCE: SoilGrids1km provide an initial set of examples of soil spatial data for input into global models at a resolution and consistency not previously available. Some of the main limitations of the current version of SoilGrids1km are: (1 weak relationships between soil properties/classes and explanatory variables due to scale mismatches, (2 difficulty to obtain covariates that capture soil forming factors, (3 low sampling density and spatial clustering of soil profile locations. However, as the SoilGrids system is

Bioavailability of radiocaesium in soil: parameterization using soil characteristics

Energy Technology Data Exchange (ETDEWEB)

Syssoeva, A.A.; Konopleva, I.V. [Russian Institute of Agricultural Radiology and Agroecology, Obninsk (Russian Federation)

2004-07-01

It has been shown that radiocaesium availability to plants strongly influenced by soil properties. For the best evaluation of TFs it necessary to use mechanistic models that predict radionuclide uptake by plants based on consideration of sorption-desorption and fixation-remobilization of the radionuclide in the soil as well as root uptake processes controlled by the plant. The aim of the research was to characterise typical Russian soils on the basis of the radiocaesium availability. The parameter of the radiocaesium availability in soils (A) has been developed which consist on radiocaesium exchangeability; CF -concentration factor which is the ratio of the radiocaesium in plant to that in soil solution; K{sub Dex} - exchangeable solid-liquid distribution coefficient of radiocaesium. The approach was tested for a wide range of Russian soils using radiocaesium uptake data from a barley pot trial and parameters of the radiocaesium bioavailability. Soils were collected from the arable horizons in different soil climatic zones of Russia and artificially contaminated by {sup 137}Cs. The classification of soils in terms of the radiocaesium availability corresponds quite well to observed linear relationship between {sup 137}Cs TF for barley and A. K{sub Dex} is related to the soil radiocaesium interception potential (RIP), which was found to be positively and strongly related to clay and physical clay (<0,01 mm) content. The {sup 137}Cs exchangeability were found to be in close relation to the soil vermiculite content, which was estimated by the method of Cs{sup +} fixation. It's shown radiocaesium availability to plants in soils under study can be parameterized through mineralogical soil characteristics: % clay and the soil vermiculite content. (author)

Soil microbes and soil respiration of Mongolian Steppe soils under grazing stress.

Science.gov (United States)

Bölter, Manfred; Krümmelbein, Julia; Horn, Rainer; Möller, Rolf; Scheltz, Annette

2012-04-01

Soils of Northern China were analysed for their microbiological and soil physical properties with respect to different grazing stress. An important factor for this is soil compaction and related aeration due to pore size shifts. Bulk density increases significantly with increasing grazing intensity and soil carbon contents show decreasing values from top to depth. Organic carbon (LOI) concentrations decrease significantly with increasing grazing intensity. The data on LOI (2-5.8%) approximate 10-30 mg C, our data on glucose show values between 0.4-1.2 mg, i.e. approx. 4% of total carbon. Numbers and biomass of bacteria show generally a decreasing trend of those data at grazed and ungrazed sites, numbers range between 0.4 and 8.7 x10(8) g(-1) d.wt., bacterial biomass between 0.4 and 3.8 microg Cg(-1). This need to be recorded in relation to soil compaction and herewith-hampered aeration and nutrient flow. The temperature-respiration data also allow getting an idea of the Q10-values for soil respiration. The data are between 2.24 (5-15 degrees C) and 1.2 (25-35 degrees C). Our data are presented with a general review of biological properties of Mongolian Steppe soils.

The Influence of Soil Particle on Soil Condensation Water

OpenAIRE

Hou Xinwei; Chen Hao; Li Xiangquan; Cui Xiaomei; Liu Lingxia; Wang Zhenxing

2013-01-01

The experiment results showed that the indoor experiment formed from the volume of soil hygroscopic water increased gradually with decreasing size of soil particles. In the outdoor experiments, the results showed that the formed condensation water in medium sand was greater than it was in fine sand; the soil hot condensation water was mainly formed in the top layer of soil between 0-5 cm. We also found that covering the soil surface with stones can increase the volume of formed soil condensat...

Soils - Volusia County Soils (Polygons)

Data.gov (United States)

NSGIC Local Govt | GIS Inventory — Soils: 1:24000 SSURGO Map. Polygon boundaries of Soils in Volusia County, downloaded from SJRWMD and created by NRCS and SJRWMD. This data set is a digital version...

Migration of 137Cs, 90Sr, 239,240Pu and 241Am in the chain soil-soil solution-plant. The soil-soil solution link

International Nuclear Information System (INIS)

Sokolik, G.A.; Ovsyannikova, S.V.; Kil'chitskaya, S.L.; Ehjsmont, E.A.; Zhukovich, N.V.; Kimlenko, I.M.; Duksina, V.V.; Rubinchik, S.Ya.

1999-01-01

The mobility of 137 Cs, 90 Sr, 239,240 Pu and 241 Am in the link soil-soil solution is analysed for different soil types on the basis of radionuclide distribution coefficients between solid and liquid soil phases. The distribution coefficients allow to differentiate soils in correlation with radionuclide migration rate from the solid phase to the soil solution. The reasons of different radionuclide mobility are considered

Soil Properties Database of Spanish Soils Volume I.-Galicia

International Nuclear Information System (INIS)

Trueba, C.; Millan, R.; Schmid, T.; Roquero, C.; Magister, M.

1998-01-01

The soil vulnerability determines the sensitivity of the soil after an accidental radioactive contamination due to Cs-13 7 and Sr-90. The Department de Impacto Ambiental de la Energia of CIEMAT is carrying out an assessment of the radiological vulnerability of the different Spanish soils found on the Iberian Peninsula. This requires the knowledge of the soil properties for the various types of existing soils. In order to achieve this aim. a bibliographical compilation of soil profiles has been made to characterize the different soil types and create a database of their properties. Depending on the year of publication and the type of documentary)' source, the information compiled from the available bibliography is very heterogeneous. Therefore, an important effort has been made to normalize and process the information prior to its incorporation to the database. This volume presents the criteria applied to normalize and process the data as well as the soil properties of the various soil types belonging to the Comunidad Autonoma de Galicia

Monitor Soil Degradation or Triage for Soil Security? An Australian Challenge

Directory of Open Access Journals (Sweden)

Andrea Koch

2015-04-01

Full Text Available The Australian National Soil Research, Development and Extension Strategy identifies soil security as a foundation for the current and future productivity and profitability of Australian agriculture. Current agricultural production is attenuated by soil degradation. Future production is highly dependent on the condition of Australian soils. Soil degradation in Australia is dominated in its areal extent by soil erosion. We reiterate the use of soil erosion as a reliable indicator of soil condition/quality and a practical measure of soil degradation. We describe three key phases of soil degradation since European settlement, and show a clear link between inappropriate agricultural practices and the resultant soil degradation. We demonstrate that modern agricultural practices have had a marked effect on reducing erosion. Current advances in agricultural soil management could lead to further stabilization and slowing of soil degradation in addition to improving productivity. However, policy complacency towards soil degradation, combined with future climate projections of increased rainfall intensity but decreased volumes, warmer temperatures and increased time in drought may once again accelerate soil degradation and susceptibility to erosion and thus limit the ability of agriculture to advance without further improving soil management practices. Monitoring soil degradation may indicate land degradation, but we contend that monitoring will not lead to soil security. We propose the adoption of a triaging approach to soil degradation using the soil security framework, to prioritise treatment plans that engage science and agriculture to develop practices that simultaneously increase productivity and improve soil condition. This will provide a public policy platform for efficient allocation of public and private resources to secure Australia’s soil resource.

Impacts of soil moisture content on visual soil evaluation

Science.gov (United States)

Emmet-Booth, Jeremy; Forristal, Dermot; Fenton, Owen; Bondi, Giulia; Creamer, Rachel; Holden, Nick

2017-04-01

Visual Soil Examination and Evaluation (VSE) techniques offer tools for soil quality assessment. They involve the visual and tactile assessment of soil properties such as aggregate size and shape, porosity, redox morphology, soil colour and smell. An increasing body of research has demonstrated the reliability and utility of VSE techniques. However a number of limitations have been identified, including the potential impact of soil moisture variation during sampling. As part of a national survey of grassland soil quality in Ireland, an evaluation of the impact of soil moisture on two widely used VSE techniques was conducted. The techniques were Visual Evaluation of Soil Structure (VESS) (Guimarães et al., 2011) and Visual Soil Assessment (VSA) (Shepherd, 2009). Both generate summarising numeric scores that indicate soil structural quality, though employ different scoring mechanisms. The former requires the assessment of properties concurrently and the latter separately. Both methods were deployed on 20 sites across Ireland representing a range of soils. Additional samples were taken for soil volumetric water (θ) determination at 5-10 and 10-20 cm depth. No significant correlation was observed between θ 5-10 cm and either VSE technique. However, VESS scores were significantly related to θ 10-20 cm (rs = 0.40, sig = 0.02) while VSA scores were not (rs = -0.33, sig = 0.06). VESS and VSA scores can be grouped into quality classifications (good, moderate and poor). No significant mean difference was observed between θ 5-10 cm or θ 10-20 cm according to quality classification by either method. It was concluded that VESS scores may be affected by soil moisture variation while VSA appear unaffected. The different scoring mechanisms, where the separate assessment and scoring of individual properties employed by VSA, may limit soil moisture effects. However, moisture content appears not to affect overall structural quality classification by either method. References

Fixation of Soil Using PEC and Separation of Fixed Soil

Energy Technology Data Exchange (ETDEWEB)

Choi, Yong Suk; Yang, Hee-Man; Lee, Kune Woo; Seo, Bum-Kyoung; Moon, Jei Kwon [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2014-10-15

Radioactive cesium (Cs-137) is the most apprehensive element due to its long half-lives, high solubility in water, and strong radiation emission in the form of gamma rays. Because the radioactivity is localized within topsoil, soil surface on topsoil should be fixed to prevent the spreading of the contaminated soils by wind and water erosion. Many methods have been developing for soil fixation to remove radioactive contaminants in soil and prevent to diffuse radioactive materials. Various materials have been used as fixatives such as clays, molecular sieves, polymer, and petroleum based products. One of the methods is a soil fixation or solidification using polyelectrolyte. Polyelectrolytes have many ionic groups and form the polyelectrolyte complex (PEC) due to electrostatic interaction of anion and cation in an aqueous solution. polyelectrolyte complex can fix soil particles by flocculation and formation of crust between soil. The method can prevent a spread of radioactive material by floating on a soil surface. The decontamination efficiency of the surface soils reached about 90%, and dust release was effectively suppressed during the removal of surface soils. However it has a problem that the removed soil must separate soil and polymer to treat as the waste. In this study, the fixation of soil by polyelectrolyte complex to suppress the spread of contaminant and the separation method of soil and polymer was investigated. The properties of polyelectrolyte complex solution and the stability of fixed soil by polyelectrolyte complex were investigated. The concentration of salt in the polyelectrolyte complex solution is a very important parameter for the soil fixation.

Soils

International Nuclear Information System (INIS)

Freudenschuss, A.; Huber, S.; Riss, A.; Schwarz, S.; Tulipan, M.

2001-01-01

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.)

Soil Organic Carbon in the Soil Scapes of Southeastern Tanzania

OpenAIRE

Rossi, Joni

2009-01-01

Soil organic carbon (SOC) is well known to maintain several functions. On the one hand, being the major component of soil organic matter (SOM),it is a determinant of soil physical and chemical properties, an important proxy for soil biological activity and a measure of soil productivity. Land use management that will enhance soil carbon (C) levels is therefore important for farmers and land use planners, particularly in semiarid and sub-humid Africa where severe soil degradation and desertifi...

Soil CO2 Dynamics in a Tree Island Soil of the Pantanal: The Role of Soil Water Potential

Science.gov (United States)

Johnson, Mark S.; Couto, Eduardo Guimarães; Pinto Jr, Osvaldo B.; Milesi, Juliana; Santos Amorim, Ricardo S.; Messias, Indira A. M.; Biudes, Marcelo Sacardi

2013-01-01

The Pantanal is a biodiversity hotspot comprised of a mosaic of landforms that differ in vegetative assemblages and flooding dynamics. Tree islands provide refuge for terrestrial fauna during the flooding period and are particularly important to the regional ecosystem structure. Little soil CO2 research has been conducted in this region. We evaluated soil CO2 dynamics in relation to primary controlling environmental parameters (soil temperature and soil water). Soil respiration was computed using the gradient method using in situ infrared gas analyzers to directly measure CO2 concentration within the soil profile. Due to the cost of the sensors and associated equipment, this study was unreplicated. Rather, we focus on the temporal relationships between soil CO2 efflux and related environmental parameters. Soil CO2 efflux during the study averaged 3.53 µmol CO2 m−2 s−1, and was equivalent to an annual soil respiration of 1220 g C m−2 y−1. This efflux value, integrated over a year, is comparable to soil C stocks for 0–20 cm. Soil water potential was the measured parameter most strongly associated with soil CO2 concentrations, with high CO2 values observed only once soil water potential at the 10 cm depth approached zero. This relationship was exhibited across a spectrum of timescales and was found to be significant at a daily timescale across all seasons using conditional nonparametric spectral Granger causality analysis. Hydrology plays a significant role in controlling CO2 efflux from the tree island soil, with soil CO2 dynamics differing by wetting mechanism. During the wet-up period, direct precipitation infiltrates soil from above and results in pulses of CO2 efflux from soil. The annual flood arrives later, and saturates soil from below. While CO2 concentrations in soil grew very high under both wetting mechanisms, the change in soil CO2 efflux was only significant when soils were wet from above. PMID:23762259

Effects of straw mulching on soil evaporation during the soil thawing ...

Indian Academy of Sciences (India)

26

Keywords: straw mulching, soil water evaporation, soil thawing period, freezing depth, soil liquid water .... moisture and the soil water evaporation process. The Songnen Plain ...... soils on soil infiltration and evaporation: Water Sci. Technol.

How does soil management affect carbon losses from soils?

Science.gov (United States)

Klik, A.; Trümper, G.

2009-04-01

Agricultural soils are a major source as well as a sink of organic carbon (OC). Amount and distribution of OC within the soil and within the landscape are driven by land management but also by erosion and deposition processes. At the other hand the type of soil management influences mineralization and atmospheric carbon dioxide losses by soil respiration. In a long-term field experiment the impacts of soil tillage systems on soil erosion processes were investigated. Following treatments were compared: 1) conventional tillage (CT), 2) conservation tillage with cover crop during the winter period (CS), and 3) no-till with cover crop during winter period (NT). The studies were carried out at three sites in the Eastern part of Austria with annual precipitation amounts from 650 to 900 mm. The soil texture ranged from silt loam to loam. Since 2007 soil CO2 emissions are measured with a portable soil respiration system in intervals of about one week, but also in relation to management events. Concurrent soil temperature and soil water content are measured and soil samples are taken for chemical and microbiological analyses. An overall 14-yr. average soil loss between 1.0 t.ha-1.yr-1 for NT and 6.1 t.ha-1.yr-1 for CT resulted in on-site OC losses from 18 to 79 kg ha-1.yr-1. The measurements of the carbon dioxide emissions from the different treatments indicate a high spatial variation even within one plot. Referred to CT plots calculated carbon losses amounted to 65-94% for NT plots while for the different RT plots they ranged between 84 and 128%. Nevertheless site specific considerations have to be taken into account. Preliminary results show that the adaptation of reduced or no-till management strategies has enormous potential in reducing organic carbon losses from agricultural used soils.

Soil biodiversity and soil community composition determine ecosystem multifunctionality

Science.gov (United States)

Wagg, Cameron; Bender, S. Franz; Widmer, Franco; van der Heijden, Marcel G. A.

2014-01-01

Biodiversity loss has become a global concern as evidence accumulates that it will negatively affect ecosystem services on which society depends. So far, most studies have focused on the ecological consequences of above-ground biodiversity loss; yet a large part of Earth’s biodiversity is literally hidden below ground. Whether reductions of biodiversity in soil communities below ground have consequences for the overall performance of an ecosystem remains unresolved. It is important to investigate this in view of recent observations that soil biodiversity is declining and that soil communities are changing upon land use intensification. We established soil communities differing in composition and diversity and tested their impact on eight ecosystem functions in model grassland communities. We show that soil biodiversity loss and simplification of soil community composition impair multiple ecosystem functions, including plant diversity, decomposition, nutrient retention, and nutrient cycling. The average response of all measured ecosystem functions (ecosystem multifunctionality) exhibited a strong positive linear relationship to indicators of soil biodiversity, suggesting that soil community composition is a key factor in regulating ecosystem functioning. Our results indicate that changes in soil communities and the loss of soil biodiversity threaten ecosystem multifunctionality and sustainability. PMID:24639507

Soil inoculation method determines the strength of plant-soil interactions

NARCIS (Netherlands)

Voorde, van de T.F.J.; Ruijten, M.; Putten, van der W.H.; Bezemer, T.M.

2012-01-01

There is increasing evidence that interactions between plants and biotic components of the soil influence plant productivity and plant community composition. Many plant–soil feedback experiments start from inoculating relatively small amounts of natural soil to sterilized bulk soil. These soil

Soil-soil solution distribution coefficient of soil organic matter is a key factor for that of radioiodide in surface and subsurface soils.

Science.gov (United States)

Unno, Yusuke; Tsukada, Hirofumi; Takeda, Akira; Takaku, Yuichi; Hisamatsu, Shun'ichi

2017-04-01

We investigated the vertical distribution of the soil-soil-solution distribution coefficients (K d ) of 125 I, 137 Cs, and 85 Sr in organic-rich surface soil and organic-poor subsurface soil of a pasture and an urban forest near a spent-nuclear-fuel reprocessing plant in Rokkasho, Japan. K d of 137 Cs was highly correlated with water-extractable K + . K d of 85 Sr was highly correlated with water-extractable Ca 2+ and SOC. K d of 125 I - was low in organic-rich surface soil, high slightly below the surface, and lowest in the deepest soil. This kinked distribution pattern differed from the gradual decrease of the other radionuclides. The thickness of the high- 125 I - K d middle layer (i.e., with high radioiodide retention ability) differed between sites. K d of 125 I - was significantly correlated with K d of soil organic carbon. Our results also showed that the layer thickness is controlled by the ratio of K d -OC between surface and subsurface soils. This finding suggests that the addition of SOC might prevent further radioiodide migration down the soil profile. As far as we know, this is the first report to show a strong correlation of a soil characteristic with K d of 125 I - . Further study is needed to clarify how radioiodide is retained and migrates in soil. Copyright © 2017 Elsevier Ltd. All rights reserved.

Predicting Soluble Nickel in Soils Using Soil Properties and Total Nickel.

Science.gov (United States)

Zhang, Xiaoqing; Li, Jumei; Wei, Dongpu; Li, Bo; Ma, Yibing

2015-01-01

Soil soluble nickel (Ni) concentration is very important for determining soil Ni toxicity. In the present study, the relationships between soil properties, total and soluble Ni concentrations in soils were developed in a wide range of soils with different properties and climate characteristics. The multiple regressions showed that soil pH and total soil Ni concentrations were the most significant parameters in predicting soluble Ni concentrations with the adjusted determination coefficients (Radj2) values of 0.75 and 0.68 for soils spiked with soluble Ni salt and the spiked soils leached with artificial rainwater to mimic field conditions, respectively. However, when the soils were divided into three categories (pH 8), they obtained better predictions with Radj2 values of 0.78-0.90 and 0.79-0.94 for leached and unleached soils, respectively. Meanwhile, the other soil properties, such as amorphous Fe and Al oxides and clay, were also found to be important for determining soluble Ni concentrations, indicating that they were also presented as active adsorbent surfaces. Additionally, the whole soil speciation including bulk soil properties and total soils Ni concentrations were analyzed by mechanistic speciation models WHAM VI and Visual MINTEQ3.0. It was found that WHAM VI provided the best predictions for the soils with pH 8. The Visual MINTEQ3.0 could provide better estimation for pH 8. These results indicated the possibility and applicability of these models to predict soil soluble Ni concentration by soil properties.

Importance of soil-water relation in assessment endpoint in bioremediated soils: Plant growth and soil physical properties

International Nuclear Information System (INIS)

Li, X.; Sawatsky, N.

1995-01-01

Much effort has been focused on defining the end-point of bioremediated soils by chemical analysis (Alberta Tier 1 or CCME Guideline for Contaminated Soils) or toxicity tests. However, these tests do not completely assess the soil quality, or the capability of soil to support plant growth after bioremediation. This study compared barley (Hordeum vulgare) growth on: (i) non-contaminated, agricultural topsoil, (2) oil-contaminated soil (4% total extractable hydrocarbons, or TEH), and (3) oil-contaminated soil treated by bioremediation (< 2% TEH). Soil physical properties including water retention, water uptake, and water repellence were measured. The results indicated that the growth of barley was significantly reduced by oil-contamination of agricultural topsoil. Furthermore, bioremediation did not improve the barley yield. The lack of effects from bioremediation was attributed to development of water repellence in hydrocarbon contaminated soils. There seemed to be a critical water content around 18% to 20% in contaminated soils. Above this value the water uptake by contaminated soil was near that of the agricultural topsoil. For lower water contents, there was a strong divergence in sorptivity between contaminated and agricultural topsoil. For these soils, water availability was likely the single most important parameter controlling plant growth. This parameter should be considered in assessing endpoint of bioremediation for hydrocarbon contaminated soils

Soil Properties Database of Spanish Soils Volume III.- Extremadura

International Nuclear Information System (INIS)

Trueba, C; Millan, R.; Schmid, T.; Roquero, C; Magister, M.

1998-01-01

The soil vulnerability determines the sensitivity of the soil after an accidental radioactive contamination due to Cs-13 7 and Sr-90. The Departamento de Impacto Ambiental de la Energia of CIEMAT is carrying out an assessment of the radiological vulnerability of the different Spanish soils found on the Iberian Peninsula. This requires the knowledge of the soil properties for the various types of existing soils. In order to achieve this aim, a bibliographical compilation of soil profiles has been made to characterize the different soil types and create a database of their properties. Depending on the year of publication and the type of documentary source, the information compiled from the available bibliography is very heterogeneous. Therefore, an important effort has been made to normalize and process the information prior to its incorporation to the database. This volume presents the criteria applied to normalized and process the data as well as the soil properties of the various soil types belonging to the Comunidad Autonoma de Extremadura. (Author) 50 refs

Soil protists: a fertile frontier in soil biology research.

Science.gov (United States)

Geisen, Stefan; Mitchell, Edward A D; Adl, Sina; Bonkowski, Michael; Dunthorn, Micah; Ekelund, Flemming; Fernández, Leonardo D; Jousset, Alexandre; Krashevska, Valentyna; Singer, David; Spiegel, Frederick W; Walochnik, Julia; Lara, Enrique

2018-05-01

Protists include all eukaryotes except plants, fungi and animals. They are an essential, yet often forgotten, component of the soil microbiome. Method developments have now furthered our understanding of the real taxonomic and functional diversity of soil protists. They occupy key roles in microbial foodwebs as consumers of bacteria, fungi and other small eukaryotes. As parasites of plants, animals and even of larger protists, they regulate populations and shape communities. Pathogenic forms play a major role in public health issues as human parasites, or act as agricultural pests. Predatory soil protists release nutrients enhancing plant growth. Soil protists are of key importance for our understanding of eukaryotic evolution and microbial biogeography. Soil protists are also useful in applied research as bioindicators of soil quality, as models in ecotoxicology and as potential biofertilizers and biocontrol agents. In this review, we provide an overview of the enormous morphological, taxonomical and functional diversity of soil protists, and discuss current challenges and opportunities in soil protistology. Research in soil biology would clearly benefit from incorporating more protistology alongside the study of bacteria, fungi and animals.

Soil Properties Database of Spanish Soils. Volume V.- Madrid

International Nuclear Information System (INIS)

Trueba, C.; Millan, R.; Schmid, T.; Roquero, C.; Magister, M.

1998-01-01

The soil vulnerability determines the sensitivity of the soil after an accidental radioactive contamination due to Cs-137 and Sr-90. The Departamento de Impacto Ambiental de la Energia of CIEMAT is carrying out an assessment of the radiological vulnerability of the different Spanish soils found on the Iberian Peninsula. This requires the knowledge of the soil properties for the various types of existing soils. In order to achieve this aim, a bibliographical compilation of soil profiles has been made to characterize the different soil types and create a database of their properties. Depending on the year of publication and the type of documentary source, the information compiled from the available bibliography is very heterogeneous. Therefore, an important effort has been made to normalize and process the information prior to its incorporation to the database. This volume presents the criteria applied to normalize and process the data as well as the soil properties of the various soil types belonging to the Comunidad Autonoma de Madrid. (Author) 39 refs

Soil Properties Database of Spanish Soils. Volume XV.- Aragon

International Nuclear Information System (INIS)

Trueba, C; Millan, R.; Schmid, T.; Lago, C.; Roquero, C; Magister, M.

1999-01-01

The soil vulnerability determines the sensitivity of the soil after an accidental radioactive contamination due to Cs-137 and Sr-90. The Departamento de Impacto Ambiental de la Energia of CIEMAT is carrying out an assessment of the radiological vulnerability of the different Spanish soils found on the Iberian Peninsula. This requires the knowledge of the soil properties for the various types of existing soils. In order to achieve this aim, a bibliographical compilation of soil profiles has been made to characterize the different soil types and create a database of their properties. Depending on the year of publication and the type of documentary source, the information compiled from the available bibliography is very heterogeneous. Therefore, an important effort has been made to normalize and process the information prior to its incorporation to the database. This volume presents the criteria applied to normalize and process the data as well as the soil properties of the various soil types belonging to the Comunidad Autonoma of Aragon. (Author) 47 refs

Soil Properties Database of Spanish Soils. Volume XIV.- Cataluna

International Nuclear Information System (INIS)

Trueba, C; Millan, R.; Schmid, T.; Lago, C.; Roquero, C; Magister, M.

1999-01-01

The soil vulnerability determines the sensitivity of the soil after an accidental radioactive contamination due to Cs-137 and Sr-90. The Departamento de Impacto Ambiental de la Energia of CIEMAT is carrying out an assessment of the radiological vulnerability of the different Spanish soils found on the Iberian Peninsula. This requires the knowledge of the soil properties for the various types of existing soils. In order to achieve this aim, a bibliographical compilation of soil profiles has been made to characterize the different soil types and create a database of their properties. Depending on the year of publication and the type of documentary source, the information compiled from the available bibliography is very heterogeneous. Therefore, an important effort has been made to normalize and process the information prior to its incorporation to the database. This volume presents the criteria applied to normalize and process the data as well as the soil properties of the various soil types belonging to the Comunidad Autonoma of Cataluna. (Author) 57 refs

Soil degradation effect on biological activity in Mediterranean calcareous soils

Science.gov (United States)

Roca-Pérez, L.; Alcover-Sáez, S.; Mormeneo, S.; Boluda, R.

2009-04-01

Soil degradation processes include erosion, organic matter decline, compaction, salinization, landslides, contamination, sealing and biodiversity decline. In the Mediterranean region the climatological and lithological conditions, together with relief on the landscape and anthropological activity are responsible for increasing desertification process. It is therefore considered to be extreme importance to be able to measure soil degradation quantitatively. We studied soil characteristics, microbiological and biochemical parameters in different calcareous soil sequences from Valencia Community (Easter Spain), in an attempt to assess the suitability of the parameters measured to reflect the state of soil degradation and the possibility of using the parameters to assess microbiological decline and soil quality. For this purpose, forest, scrubland and agricultural soil in three soil sequences were sampled in different areas. Several sensors of the soil biochemistry and microbiology related with total organic carbon, microbial biomass carbon, soil respiration, microorganism number and enzyme activities were determined. The results show that, except microorganism number, these parameters are good indicators of a soil biological activity and soil quality. The best enzymatic activities to use like indicators were phosphatases, esterases, amino-peptidases. Thus, the enzymes test can be used as indicators of soil degradation when this degradation is related with organic matter losses. There was a statistically significant difference in cumulative O2 uptake and extracellular enzymes among the soils with different degree of degradation. We would like to thank Spanish government-MICINN for funding and support (MICINN, project CGL2006-09776).

A soil mechanics approach to study soil compaction and traffic effect on the preconsolidation pressure of tropical soils

International Nuclear Information System (INIS)

Dias Junior, Moacir de Souza

2004-01-01

Several researchers have already demonstrated the causes and the effects of soil compaction. These studies showed that the soil compaction is a limiting factor in the agricultural production. The attributes of the soil conventionally monitored has not been capable to quantify the load support capacity of the soil, not allowing to foresee the levels of pressures that can be applied to the soils at different moisture conditions without additional soil compaction (structure degradation) happens. The researches done in the soil compressive behaviour of some tropical soils indicate that the pre-compression stress may be used as an alternative measure of the load support capacity and as a quantitative indicator of the structure sustainability of the tropical soils

Relationships between soil erosion risk, soil use and soil properties in Mediterranean areas. A comparative study of three typical sceneries

Science.gov (United States)

Gil, Juan; Priego-Navas, Mercedes; Zavala, Lorena M.; Jordán, Antonio

2013-04-01

Generally, literature shows that the high variability of rainfall-induced soil erosion is related to climatic differences, relief, soil properties and land use. Very different runoff rates and soil loss values have been reported in Mediterranean cropped soils depending on soil management practices, but also in soils under natural vegetation types. OBJECTIVES The aim of this research is to study the relationships between soil erosion risk, soil use and soil properties in three typical Mediterranean areas from southern Spain: olive groves under conventional tillage, minimum tillage and no-till practices, and soils under natural vegetation. METHODS Rainfall simulation experiments have been carried out in order to assess the relationship between soil erosion risk, land use, soil management and soil properties in olive-cropped soils under different types of management and soils under natural vegetation type from Mediterranean areas in southern Spain RESULTS Results show that mean runoff rates decrease from 35% in olive grove soils under conventional tillage to 25% in olive (Olea europaea) grove soils with minimum tillage or no-till practices, and slightly over 22% in soils under natural vegetation. Moreover, considering the different vegetation types, runoff rates vary in a wide range, although runoff rates from soils under holm oak (Quercus rotundifolia), 25.70%, and marginal olive groves , 25.31%, are not significantly different. Results from soils under natural vegetation show that the properties and nature of the organic residues play a role in runoff characteristics, as runoff rates above 50% were observed in less than 10% of the rainfall simulations performed on soils with a organic layer. In contrast, more than half of runoff rates from bare soils reached or surpassed 50%. Quantitatively, average values for runoff water losses increase up to 2.5 times in unprotected soils. This is a key issue in the study area, where mean annual rainfall is above 600 mm

Soil color - a window for public and educators to understands soils

Science.gov (United States)

Libohova, Zamir; Beaudette, Dylan; Wills, Skye; Monger, Curtis; Lindbo, David

2017-04-01

Soil color is one of the most visually striking properties recorded by soil scientists around the world. Soil color is an important characteristic related to soil properties such organic matter, parent materials, drainage. It is a simplified way for the public and educators alike to understand soils and their functions. Soil color is a quick measurement that can be recorded by people using color charts or digital cameras, offering an opportunity for the citizen science projects to contribute to soil science. The US Soil Survey has recorded soil colors using Munsell color system for over 20,000 soil types representing a wide range of conditions throughout the Unites States. The objective of this research was to generate a US soil color map based on color descriptions from the Official Series Descriptions (OSDs). A color calculator developed in R and ArcMap were used to spatially display the soil colors. Soil colors showed vertical trends related to soil depth and horizontal trends related to parent material and climate. Soil colors represent development processes depending upon environment and time that have influenced their appearance and geographic distribution. Dark colors represent soils that are rich in organic matter, such as the soils of the Midwest USA, which are some of the most fertile soils in the world. These soils are relatively "young" in that they developed over the last 20,000 years in materials left behind after continental Glaciers retreated and reflect long- term prairie vegetation that dominated this area prior to European settlements. Dark soils of the Pacific Northwest reflect the influence of forests (and volcanic activity) but are shallower and less fertile than the deep dark Midwest soils. Soils of the eastern and southern Coastal Plains are older and are enriched with iron oxides ('rust') which gives them their red coloring. Soils of flood plains, like the broad Mississippi Valley, have multi-colored soils that reflect the process of

Developing and using artificial soils to analyze soil microbial processes

Science.gov (United States)

Gao, X.; Cheng, H. Y.; Boynton, L.; Masiello, C. A.; Silberg, J. J.

2017-12-01

Microbial diversity and function in soils are governed by soil characteristics such as mineral composition, particles size and aggregations, soil organic matter (SOM), and availability of nutrients and H2O. The spatial and temporal heterogeneity of soils creates a range of niches (hotspots) differing in the availability of O2, H2O, and nutrients, which shapes microbial activities at scales ranging from nanometer to landscape. Synthetic biologists often examine microbial response trigged by their environment conditions in nutrient-rich aqueous media using single strain microbes. While these studies provided useful insight in the role of soil microbes in important soil biogeochemical processes (e.g., C cycling, N cycling, etc.), the results obtained from the over-simplified model systems are often not applicable natural soil systems. On the contrary, soil microbiologists examine microbial processes in natural soils using longer incubation time. However, due to its physical, chemical and biological complexity of natural soils, it is often difficult to examine soil characteristics independently and understand how each characteristic influences soil microbial activities and their corresponding soil functioning. Therefore, it is necessary to bridge the gap and develop a model matrix to exclude unpredictable influences from the environment while still reliably mimicking real environmental conditions. The objective of this study is to design a range of ecologically-relevant artificial soils with varying texture (particle size distribution), structure, mineralogy, SOM content, and nutrient heterogeneity. We thoroughly characterize the artificial soils for pH, active surface area and surface morphology, cation exchange capacity (CEC), and water retention curve. We demonstrate the effectiveness of the artificial soils as useful matrix for microbial processes, such as microbial growth and horizontal gene transfer (HGT), using the gas-reporting biosensors recently developed in

Effect of soil solarization on soil-borne pathogens

International Nuclear Information System (INIS)

Sobh, Hana

1995-01-01

Author.Soil solarization was conducted at three locations on the Lebanese coast. Maximum soil temperatures recorded were 53 and 48 celsius degrees at Jiyeh, 48.9, 46 and 43 celsius degrees at Naameh and 48, 45 and 43.5 celsius degrees at Khaldeh at 5, 15 and 25cm soil depths respectively. Mean soil temperatures recorded at 3pm were at Jiyeh 51.6, 47 and 46 celsius degrees compared to Naameh 47, 45 and 41 celsius degrees and Khaldeh 44, 42 and 41 celsius degrees at 5, 15 and 25 cm respectively. The mean temperature in solarized soils were 7.3 to 15 celsius degrees higher than those of the nonsolarized soils indicating a sustained increase of soil temperature in the solarized soils. The effect of soil solarization on artificially introduced fungal pathogens in the soil at Khaldeh, resulted in complete destruction of sclerotia of Sclerotinia spp. at three depths studied. However, with respect to the two other pathogens tested, solarization resulted in reduction of the viability of microsclerotia of Verticillium spp. by 99-79% and of Fusarium oxysporum f. sp. melonis inoculum by 88-54% at 5 and 15 cm respectively, but only by 45% and 14% reduction at 25 cm. This level of control is significant when it is compared to the percentage of control where the level of reduction of inoculum viability did not exceed 10% at any soil depth. As there were contradicting reports in the literature on nematodes, two field trials in greenhouses were conducted to study the possibility of integrating 2 methods for management on nematodes. Soil solarization alone or in combination with biological control of nematodes using Arthrobotrys spp. and Dactyl ella brocophaga to control the root-knot nematodes on two crops, tomato at Naameh and cucumber at Jiyeh were compared to Methyl Bromide treatment. It was evident that, even on a very susceptible crop like cucumber, the integration of biological control and soil solarization gave a good level of control similar to methyl bromide. Neither root

Modelling soil anaerobiosis from water retention characteristics and soil respiration

NARCIS (Netherlands)

Schurgers, G.; Dörsch, P.; Bakken, L.; Leffelaar, P.A.; Egil Haugen, L.

2006-01-01

Oxygen is a prerequisite for some and an inhibitor to other microbial functions in soils, hence the temporal and spatial distribution of oxygen within the soil matrix is crucial in soil biogeochemistry and soil biology. Various attempts have been made to model the anaerobic fraction of the soil

Soil gas radon response to environmental and soil physics variables

International Nuclear Information System (INIS)

Thomas, D.M.; Chen, C.; Holford, D.

1991-01-01

During the last three years a field study of soil gas radon activities conducted at Poamoho, Oahu, has shown that the primary environmental variables that control radon transport in shallow tropical soils are synoptic and diurnal barometric pressure changes and soil moisture levels. Barometric pressure changes drive advective transport and mixing of soil gas with atmospheric air; soil moisture appears to control soil porosity and permeability to enhance or inhibit advective and diffusive radon transport. An advective barrier test/control experiment has shown that advective exchange of soil gas and air may account for a substantial proportion of the radon loss from shallow soils but does not significantly affect radon activities at depths greater than 2.3 m. An irrigation test/control experiment also suggests that, at soil moisture levels approaching field capacity, saturation of soil macroporosity can halt all advective transport of radon and limit diffusive mobility to that occurring in the liquid phase. The results of the authors field study have been used to further refine and extend a numerical model, RN3D, that has been developed by Pacific Northwest Laboratories to simulate subsurface transport of radon. The field data have allowed them to accurately simulate the steady state soil gas radon profile at their field site and to track transient radon activities under the influence of barometric pressure changes and in response to changes in soil permeability that result from variations in soil moisture levels. Further work is continuing on the model to enable it to properly account for the relative effects of advective transport of soil gas through cracks and diffusive mobility in the bulk soils

SoilEffects – start characterization of the experimental soil

OpenAIRE

Løes, Anne-Kristin; Johansen, Anders; Pommeresche, Reidun; Riley, Hugh

2013-01-01

This report describes the establishment, experimental plan and initial soil characteristics of the field experiment linked to the project “Effects of anaerobically digested manure on soil fertility - establishment of a long-term study under Norwegian conditions” (SoilEffects, 2010-14). The aim of the SoilEffects project is to identify potential risks and benefits for soil fertility when animal manure is anaerobically digested for biogas production. The field experiment was established on...

Water repellent soils: the case for unsaturated soil mechanics

Directory of Open Access Journals (Sweden)

Beckett Christopher

2016-01-01

Full Text Available Water repellent (or “hydrophobic” or “non-wetting” soils have been studied by soil scientists for well over a century. These soils are typified by poor water infiltration, which leads to increased soil erosion and poor crop growth. However, the importance of water repellence on determining soil properties is now becoming recognised by geotechnical engineers. Water repellent soils may, for example, offer novel solutions for the design of cover systems overlying municipal or mine waste storage facilities. However, investigations into factors affecting their mechanical properties have only recently been initiated. This purpose of this paper is to introduce geotechnical engineers to the concept of water repellent soils and to discuss how their properties can be evaluated under an unsaturated soils framework. Scenarios in which water repellent properties might be relevant in geotechnical applications are presented and methods to quantify these properties in the laboratory and in the field examined.

On the assessment of root and soil respiration for soils of different textures: interactions with soil moisture contents and soil CO2 concentrations

NARCIS (Netherlands)

Bouma, T.J.; Bryla, D.R.

2000-01-01

Estimates of root and soil respiration are becoming increasingly important in agricultural and ecological research, but there is little understanding how soil texture and water content may affect these estimates. We examined the effects of soil texture on (i) estimated rates of root and soil

Dependence of Soil Respiration on Soil Temperature and Soil Moisture in Successional Forests in Southern China

Institute of Scientific and Technical Information of China (English)

Xu-Li Tang; Guo-Yi Zhou; Shu-Guang Liu; De-Qiang Zhang; Shi-Zhong Liu; Jiong Li; Cun-Yu Zhou

2006-01-01

The spatial and temporal variations in soil respiration and its relationship with biophysical factors in forests near the Tropic of Cancer remain highly uncertain. To contribute towards an improvement of actual estimates, soil respiration rates, soil temperature, and soil moisture were measured in three successional subtropical forests at the Dinghushan Nature Reserve (DNR) in southern China from March 2003 to February 2005. The overall objective of the present study was to analyze the temporal variations of soil respiration and its biophysical dependence in these forests. The relationships between biophysical factors and soil respiration rates were compared in successional forests to test the hypothesis that these forests responded similarly to biophysical factors. The seasonality of soil respiration coincided with the seasonal climate pattern, with high respiration rates in the hot humid season (April-September) and with low rates in the cool dry season (October-March). Soil respiration measured at these forests showed a clear increasing trend with the progressive succession. Annual mean (± SD) soil respiration rate in the DNR forests was (9.0±4.6) Mg CO2-C/hm2 per year, ranging from (6.1±3.2) Mg CO2-C/hm2 per year in early successional forests to (10.7±4.9) Mg CO2-C/hm2 per year in advanced successional forests. Soil respiration was correlated with both soil temperature and moisture. The T/M model, where the two biophysical variables are driving factors, accounted for 74%-82% of soil respiration variation in DNR forests. Temperature sensitivity decreased along progressive succession stages, suggesting that advanced-successional forests have a good ability to adjust to temperature. In contrast, moisture increased with progressive succession processes. This increase is caused, in part, by abundant respirators in advanced-successional forest, where more soil moisture is needed to maintain their activities.

Dependence of soil respiration on soil temperature and soil moisture in successional forests in Southern China

Science.gov (United States)

Tang, X.-L.; Zhou, G.-Y.; Liu, S.-G.; Zhang, D.-Q.; Liu, S.-Z.; Li, Ji; Zhou, C.-Y.

2006-01-01

The spatial and temporal variations in soil respiration and its relationship with biophysical factors in forests near the Tropic of Cancer remain highly uncertain. To contribute towards an improvement of actual estimates, soil respiration rates, soil temperature, and soil moisture were measured in three successional subtropical forests at the Dinghushan Nature Reserve (DNR) in southern China from March 2003 to February 2005. The overall objective of the present study was to analyze the temporal variations of soil respiration and its biophysical dependence in these forests. The relationships between biophysical factors and soil respiration rates were compared in successional forests to test the hypothesis that these forests responded similarly to biophysical factors. The seasonality of soil respiration coincided with the seasonal climate pattern, with high respiration rates in the hot humid season (April-September) and with low rates in the cool dry season (October-March). Soil respiration measured at these forests showed a clear increasing trend with the progressive succession. Annual mean (±SD) soil respiration rate in the DNR forests was (9.0 ± 4.6) Mg CO2-C/hm2per year, ranging from (6.1 ± 3.2) Mg CO2-C/hm2per year in early successional forests to (10.7 ± 4.9) Mg CO2-C/hm2 per year in advanced successional forests. Soil respiration was correlated with both soil temperature and moisture. The T/M model, where the two biophysical variables are driving factors, accounted for 74%-82% of soil respiration variation in DNR forests. Temperature sensitivity decreased along progressive succession stages, suggesting that advanced-successional forests have a good ability to adjust to temperature. In contrast, moisture increased with progressive succession processes. This increase is caused, in part, by abundant respirators in advanced-successional forest, where more soil moisture is needed to maintain their activities.

ROMANIAN SOIL RESOURCES - “HEALTHY SOILS FOR A HEALTHY LIFE”

Directory of Open Access Journals (Sweden)

Mircea MIHALACHE

2015-10-01

Full Text Available After nearly three years of intensive consultations, 2015 has been declared the International Year of Soils by the 68th UN General Assembly (A/RES/68/232. The International Years of Soil is to be a major platform for raising awareness of the importance of soils for food security and nutrition and essential eco-system functions. Key objectives of the International Years of Soil have been identified as follows: to create full awareness of all stakeholders about the fundamental roles of soils for human life; to achieve full recognition of the prominent contributions of soils to food security and nutrition, climate change adaptation and mitigation, essential ecosystem services, poverty alleviation and sustainable development; to promote effective policies and actions for the sustainable management and protection of soil resources; to sensitize decision-makers about the need for robust investment in sustainable soil management activities, to ensure healthy soils for different land users and population groups; to catalyze initiatives in connection with the Sustainable Development Goal process and Post-2015 agenda; to advocate rapid enhancement of capacities and systems for soil information collection and monitoring at all levels (global, regional and national (http://www.fao.org/soils-2015. Applying a proper management of the recovery and conservation of soil resources is a major goal for every nation. The development of a country depends on the production potential of own soil resources. Soil degradation is a serious problem in Europe an also in Romania. It is caused or exacerbated by human activity such as inadequate agricultural and forestry practices, industrial activities, tourism, urban and industrial expansion etc. Soil Quality Monitoring in Romania revealed a number of problems concerning land use in Romania following the manifestation of one or more limiting factors such as: moisture deficit, salinization and alkalization, soil erosion

Quicklime-induced changes of soil properties: Implications for enhanced remediation of volatile chlorinated hydrocarbon contaminated soils via mechanical soil aeration.

Science.gov (United States)

Ma, Yan; Dong, Binbin; He, Xiaosong; Shi, Yi; Xu, Mingyue; He, Xuwen; Du, Xiaoming; Li, Fasheng

2017-04-01

Mechanical soil aeration is used for soil remediation at sites contaminated by volatile organic compounds. However, the effectiveness of the method is limited by low soil temperature, high soil moisture, and high soil viscosity. Combined with mechanical soil aeration, quicklime has a practical application value related to reinforcement remediation and to its action in the remediation of soil contaminated with volatile organic compounds. In this study, the target pollutant was trichloroethylene, which is a volatile chlorinated hydrocarbon pollutant commonly found in contaminated soils. A restoration experiment was carried out, using a set of mechanical soil-aeration simulation tests, by adding quicklime (mass ratios of 3, 10, and 20%) to the contaminated soil. The results clearly indicate that quicklime changed the physical properties of the soil, which affected the environmental behaviour of trichloroethylene in the soil. The addition of CaO increased soil temperature and reduced soil moisture to improve the mass transfer of trichloroethylene. In addition, it improved the macroporous cumulative pore volume and average pore size, which increased soil permeability. As soil pH increased, the clay mineral content in the soils decreased, the cation exchange capacity and the redox potential decreased, and the removal of trichloroethylene from the soil was enhanced to a certain extent. After the addition of quicklime, the functional group COO of soil organic matter could interact with calcium ions, which increased soil polarity and promoted the removal of trichloroethylene. Copyright © 2017 Elsevier Ltd. All rights reserved.

Thermal-treated soil for mercury removal: Soil and phytotoxicity tests

Energy Technology Data Exchange (ETDEWEB)

Roh, Y.; Edwards, N.T.; Lee, S.Y.; Stiles, C.A.; Armes, S.; Foss, J.E.

2000-04-01

Mercury (Hg) contamination of soils and sediments is one of many environmental problems at the Oak Ridge Reservation, Oak Ridge, TN. Mercury-contaminated soil from the Lower East Fork Poplar Creek (LEFPC) at the Oak Ridge Reservation was treated thermally to reduce Hg concentration to a below target level (20 mg kg{sup {minus}1}) as a pilot scale thermal treatment demonstration. As a part of performance evaluation, the soil characteristics and plant growth response of the untreated and treated soil were examined. The soil treated at 350 C retained most of its original soil properties, but the soil treated at 600 C exhibited considerable changes in mineralogical composition and physicochemical characteristics. Growth and physiological response of the three plant species radish (Raphanus sativus L.), fescue (Festuca arundinacea Schreb.), and oat (Avena sativa L.) indicated adverse effects of the thermal treatment. The addition of N fertilizer had beneficial effects in the 350 C treated soil, but had little beneficial effect in the 600 C treated soil. Some changes of soil characteristics induced by thermal treatment cannot be avoided. Soil characteristics and phytotoxicity test results strongly suggest that changes occurring following the 350 C treatment do not limit the use of the treated soil to refill the excavated site for full-scale remediation. The only problem with the 350 C treatment is that small amounts of Hg compounds (<15 mg kg{sup {minus}1}) remain in the soil and a processing cost of $45/Mg.

Soils in art as a teaching tool in soil science

Science.gov (United States)

Poch, Rosa M.

2017-04-01

The representation of soils in the different artistic expressions occurs much less often than that of other naturalistic scientific disciplines, like botany or zoology, due to the minor perception of soils as a natural body since the humans started to express themselves through art. Nevertheless, painters, writers and even musicians and film directors have been forced to deal with soils in their works, as a component of the landscape and as the main actor of the various soil functions. Even if the artists are not aware of soils in the sense of soil science - a study object - their observation of nature invariably leads to express their properties, the problems due to their misuse or degradation and their management practices. These art works have a great value when teaching soil science to students, because the latter can learn to intepret and go beyond the artist's observation and therefore they can appreciate the perception of soils and soil properties along the history of humankind. Paintings from various periods can be used as exercises, mainly those depicting landscapes or agricultural works. Some examples are Dutch landscape painters, as Brueghel the Young showing detailed soil erosion features; or Wijnants (XVII century) depicting very clear podzols on sand dunes. Also the impressionists (Van Gogh, Cézanne, Gaugin), or the landscapes of the romantic nationalists (XIX- early XX century) show forest or agricultural soils that can be used either to deduce soil forming processes and describe horizons, or to discuss the effectivity of soil management practices (deforestation, burning, plowing, terracing). Also some pieces of literature can be used either for illustrating real soil landscapes and soil-water relationships (Steinbeck's "The Grapes of Wrath") or in case of fiction literature, as exercice for soil mapping (Tolkien's Middle Earth in "The Hobbit" and "The Lord of the Rings"). Films as "The field" (Jim Sheridan, 1990) or "Corn Island" (George Ovasvili

Basic Soils. Revision.

Science.gov (United States)

Montana State Univ., Bozeman. Dept. of Agricultural and Industrial Education.

This curriculum guide is designed for use in teaching a course in basic soils that is intended for college freshmen. Addressed in the individual lessons of the unit are the following topics: the way in which soil is formed, the physical properties of soil, the chemical properties of soil, the biotic properties of soil, plant-soil-water…

Cyanobacteria Inoculation Improves Soil Stability and Fertility on Different Textured Soils: Gaining Insights for Applicability in Soil Restoration

Directory of Open Access Journals (Sweden)

Sonia Chamizo

2018-06-01

Full Text Available Cyanobacteria are ubiquitous components of biocrust communities and the first colonizers of terrestrial ecosystems. They play multiple roles in the soil by fixing C and N and synthesizing exopolysaccharides, which increase soil fertility and water retention and improve soil structure and stability. Application of cyanobacteria as inoculants to promote biocrust development has been proposed as a novel biotechnological technique for restoring barren degraded areas and combating desertification processes in arid lands. However, previous to their widespread application under field conditions, research is needed to ensure the selection of the most suitable species. In this study, we inoculated two cyanobacterial species, Phormidium ambiguum (non N-fixing and Scytonema javanicum (N-fixing, on different textured soils (from silt loam to sandy, and analyzed cyanobacteria biocrust development and evolution of physicochemical soil properties for 3 months under laboratory conditions. Cyanobacteria inoculation led to biocrust formation in all soil types. Scanning electron microscope (SEM images showed contrasting structure of the biocrust induced by the two cyanobacteria. The one from P. ambiguum was characterized by thin filaments that enveloped soil particles and created a dense, entangled network, while the one from S. javanicum consisted of thicker filaments that grouped as bunches in between soil particles. Biocrust development, assessed by chlorophyll a content and crust spectral properties, was higher in S. javanicum-inoculated soils compared to P. ambiguum-inoculated soils. Either cyanobacteria inoculation did not increase soil hydrophobicity. S. javanicum promoted a higher increase in total organic C and total N content, while P. ambiguum was more effective in increasing total exopolysaccharide (EPS content and soil penetration resistance. The effects of cyanobacteria inoculation also differed among soil types and the highest improvement in soil

Effect of soil moisture on the temperature sensitivity of Northern soils

Science.gov (United States)

Minions, C.; Natali, S.; Ludwig, S.; Risk, D.; Macintyre, C. M.

2017-12-01

Arctic and boreal ecosystems are vast reservoirs of carbon and are particularly sensitive to climate warming. Changes in the temperature and precipitation regimes of these regions could significantly alter soil respiration rates, impacting atmospheric concentrations and affecting climate change feedbacks. Many incubation studies have shown that both temperature and soil moisture are important environmental drivers of soil respiration; this relationship, however, has rarely been demonstrated with in situ data. Here we present the results of a study at six field sites in Alaska from 2016 to 2017. Low-power automated soil gas systems were used to measure soil surface CO2 flux from three forced diffusion chambers and soil profile concentrations from three soil depth chambers at hourly intervals at each site. HOBO Onset dataloggers were used to monitor soil moisture and temperature profiles. Temperature sensitivity (Q10) was determined at each site using inversion analysis applied over different time periods. With highly resolved data sets, we were able to observe the changes in soil respiration in response to changes in temperature and soil moisture. Through regression analysis we confirmed that temperature is the primary driver in soil respiration, but soil moisture becomes dominant beyond a certain threshold, suppressing CO2 flux in soils with high moisture content. This field study supports the conclusions made from previous soil incubation studies and provides valuable insights into the impact of both temperature and soil moisture changes on soil respiration.

Effects of environmental factors and soil properties on topographic variations of soil respiration

Directory of Open Access Journals (Sweden)

K. Tamai

2010-03-01

Full Text Available Soil respiration rates were measured along different parts of a slope in (a an evergreen forest with common brown forest soil and (b a deciduous forest with immature soil. The effects of soil temperature, soil moisture and soil properties were estimated individually, and the magnitudes of these effects in the deciduous and evergreen forests were compared. In the evergreen forest with common brown forest soil, soil properties had the greatest effect on soil respiration rates, followed by soil moisture and soil temperature. These results may be explained by the fact that different soil properties matured within different environments. It can be argued that the low soil respiration rates in the low parts of the slope in the evergreen forest resulted from soil properties and not from wet soil conditions. In the deciduous forest, soil respiration rates were more strongly affected by soil moisture and soil temperature than by soil properties. These effects were likely due to the immaturity of the forest soil.

Wetting properties of fungi mycelium alter soil infiltration and soil water repellency in a γ-sterilized wettable and repellent soil.

Science.gov (United States)

Chau, Henry Wai; Goh, Yit Kheng; Vujanovic, Vladimir; Si, Bing Cheng

2012-12-01

Soil water repellency (SWR) has a drastic impact on soil quality resulting in reduced infiltration, increased runoff, increased leaching, reduced plant growth, and increased soil erosion. One of the causes of SWR is hydrophobic fungal structures and exudates that change the soil-water relationship. The objective of this study was to determine whether SWR and infiltration could be manipulated through inoculation with fungi. The effect of fungi on SWR was investigated through inoculation of three fungal strains (hydrophilic -Fusarium proliferatum, chrono-amphiphilic -Trichoderma harzianum, and hydrophobic -Alternaria sp.) on a water repellent soil (WR-soil) and a wettable soil (W-soil). The change in SWR and infiltration was assessed by the water repellency index and cumulative infiltration respectively. F. proliferatum decreased the SWR on WR-soil and slightly increased SWR in W-soil, while Alternaria sp. increased SWR in both the W-soil and the WR-soil. Conversely T. harzianum increased the SWR in the W-soil and decreased the SWR in the WR-soil. All strains showed a decrease in infiltration in W-soil, while only the F. proliferatum and T. harzianum strain showed improvement in infiltration in the WR-soil. The ability of fungi to alter the SWR and enmesh soil particles results in changes to the infiltration dynamics in soil. Copyright © 2012 The British Mycological Society. Published by Elsevier Ltd. All rights reserved.

Soil-Web: An online soil survey for California, Arizona, and Nevada

Science.gov (United States)

Beaudette, D. E.; O'Geen, A. T.

2009-10-01

Digital soil survey products represent one of the largest and most comprehensive inventories of soils information currently available. The complex structure of these databases, intensive use of codes and scientific jargon make it difficult for non-specialists to utilize digital soil survey resources. A project was initiated to construct a web-based interface to digital soil survey products (STATSGO and SSURGO) for California, Arizona, and Nevada that would be accessible to the general public. A collection of mature, open source applications (including Mapserver, PostGIS and Apache Web Server) were used as a framework to support data storage, querying, map composition, data presentation, and contextual links to related materials. Application logic was written in the PHP language to "glue" together the many components of an online soil survey. A comprehensive website ( http://casoilresource.lawr.ucdavis.edu/map) was created to facilitate access to digital soil survey databases through several interfaces including: interactive map, Google Earth and HTTP-based application programming interface (API). Each soil polygon is linked to a map unit summary page, which includes links to soil component summary pages. The most commonly used soil properties, land interpretations and ratings are presented. Graphical and tabular summaries of soil profile information are dynamically created, and aid with rapid assessment of key soil properties. Quick links to official series descriptions (OSD) and other such information are presented. All terminology is linked back to the USDA-NRCS Soil Survey Handbook which contains extended definitions. The Google Earth interface to Soil-Web can be used to explore soils information in three dimensions. A flexible web API was implemented to allow advanced users of soils information to access our website via simple web page requests. Soil-Web has been successfully used in soil science curriculum, outreach activities, and current research projects

Effects of natural and synthetic soil conditioners on soil moisture ...

African Journals Online (AJOL)

The efficacy of a natural soil conditioner, Coco-Peat (C-P), and synthetic soil conditioners, Terawet (T-200) and Teraflow (T-F), in improving soil moisture content were examined on five Ghanaian soil series (Akroso, Akuse, Amo, Hake and Oyarifa). In general, the water retention of T-200 and C-P treated soils were similar ...

Variability of the soil-to-plant radiocaesium transfer factor for Japanese soils predicted with soil and plant properties.

Science.gov (United States)

Uematsu, Shinichiro; Vandenhove, Hildegarde; Sweeck, Lieve; Van Hees, May; Wannijn, Jean; Smolders, Erik

2016-03-01

Food chain contamination with radiocaesium (RCs) in the aftermath of the Fukushima accident calls for an analysis of the specific factors that control the RCs transfer. Here, soil-to-plant transfer factors (TF) of RCs for grass were predicted from the potassium concentration in soil solution (mK) and the Radiocaesium Interception Potential (RIP) of the soil using existing mechanistic models. The mK and RIP were (a) either measured for 37 topsoils collected from the Fukushima accident affected area or (b) predicted from the soil clay content and the soil exchangeable potassium content using the models that had been calibrated for European soils. An average ammonium concentration was used throughout in the prediction. The measured RIP ranged 14-fold and measured mK varied 37-fold among the soils. The measured RIP was lower than the RIP predicted from the soil clay content likely due to the lower content of weathered micas in the clay fraction of Japanese soils. Also the measured mK was lower than that predicted. As a result, the predicted TFs relying on the measured RIP and mK were, on average, about 22-fold larger than the TFs predicted using the European calibrated models. The geometric mean of the measured TFs for grass in the affected area (N = 82) was in the middle of both. The TFs were poorly related to soil classification classes, likely because soil fertility (mK) was obscuring the effects of the soil classification related to the soil mineralogy (RIP). This study suggests that, on average, Japanese soils are more vulnerable than European soils at equal soil clay and exchangeable K content. The affected regions will be targeted for refined model validation. Copyright © 2015 Elsevier Ltd. All rights reserved.

Spatiotemporal Dynamics of Soil Penetration Resistance of Recultivated Soil

Directory of Open Access Journals (Sweden)

Zadorozhnaya Galina

2018-03-01

Full Text Available This article examines changes in the spatial distribution of soil penetration resistance in ordinary chernozem (Calcic Chernozem and in the recultivated soil in 2012 and 2014. The measurements were carried out in the field using an Eijkelkamp penetrometer on a regular grid. The depth of measurement was 50 cm, the interval was 5 cm. The indices of variation of soil penetration resistance in space and time have been determined. The degree of spatial dependence of soil penetration resistance has been determined layer by layer. The nature of temporal dynamics of soil penetration resistance of chernozem and technical soil has been described. A significant positive relationship of the structure of chernozem in the two years of the research has been shown. Significant correlations between the data of different years in the technical soil were found to be mostly negative.

Complex linkage between soil, soil water, atmosphere and Eucalyptus Plantations

Science.gov (United States)

Shukla, C.; Tiwari, K. N.

2017-12-01

Eucalyptus is most widely planted genus grown in waste land of eastern region of India to meet the pulp industry requirements. Sustainability of these plantations is of concern because in spite of higher demand water and nutrients of plantations, they are mostly planted on low-fertility soils. This study has been conducted to quantify effect of 25 years old, a fully established eucalyptus plantations on i.) Alteration in physico-chemical and hydrological properties of soil of eucalyptus plantation in comparison to soil of natural grassland and ii.) Spatio-temporal variation in soil moisture under eucalyptus plantations. Soil physico-chemical properties of two adjacent plots covered with eucatuptus and natural grasses were analyzed for three consecutive depths (i.e. 0-30 cm, 30-60 cm and 60-90 cm) with five replications in each plot. Soil infiltration rate and saturated hydraulic conductivity (Ks) were measured in-situ to incorporate the influence of macro porosity caused due to roots of plantations. Daily soil moisture at an interval of 10 cm upto 160 cm depth with 3 replications and Leaf Area Index (LAI) at an interval of 15 days with 5 replications were recorded over the year. Significant variations found at level of 0.05 between soil properties of eucalyptus and natural grass land confirm the effect of plantations on soil properties. Comparative results of soil properties show significant alteration in soil texture such as percent of sand, organic matter and Ks found more by 20%, 9% and 22% respectively in eucalyptus plot as compare to natural grass land. Available soil moisture (ASM) was found constantly minimum in top soil excluding rainy season indicate upward movement of water and nutrients during dry season. Seasonal variation in temperature (T), relative humidity (RH) and leaf area index (LAI) influenced the soil moisture extraction phenomenon. This study clearly stated the impact of long term establishment of eucalyptus plantations make considerable

Derivation of Soil Ecological Criteria for Copper in Chinese Soils.

Science.gov (United States)

Wang, Xiaoqing; Wei, Dongpu; Ma, Yibing; McLaughlin, Mike J

2015-01-01

Considerable information on copper (Cu) ecotoxicity as affected by biological species and abiotic properties of soils has been collected from the last decade in the present study. The information on bioavailability/ecotoxicity, species sensitivity and differences in laboratory and field ecotoxicity of Cu in different soils was collated and integrated to derive soil ecological criteria for Cu in Chinese soils, which were expressed as predicted no effect concentrations (PNEC). First, all ecotoxicity data of Cu from bioassays based on Chinese soils were collected and screened with given criteria to compile a database. Second, the compiled data were corrected with leaching and aging factors to minimize the differences between laboratory and field conditions. Before Cu ecotoxicity data were entered into a species sensitivity distribution (SSD), they were normalized with Cu ecotoxicity predictive models to modify the effects of soil properties on Cu ecotoxicity. The PNEC value was set equal to the hazardous concentration for x% of the species (HCx), which could be calculated from the SSD curves, without an additional assessment factor. Finally, predictive models for HCx based on soil properties were developed. The soil properties had a significant effect on the magnitude of HCx, with HC5 varying from 13.1 mg/kg in acidic soils to 51.9 mg/kg in alkaline non-calcareous soils. The two-factor predictive models based on soil pH and cation exchange capacity could predict HCx with determination coefficients (R2) of 0.82-0.91. The three-factor predictive models--that took into account the effect of soil organic carbon--were more accurate than two-factor models, with R2 of 0.85-0.99. The predictive models obtained here could be used to calculate soil-specific criteria. All results obtained here could provide a scientific basis for revision of current Chinese soil environmental quality standards, and the approach adopted in this study could be used as a pragmatic framework for

Courses for "Soil Practitioner" and other measures for raising soil awareness

Science.gov (United States)

Hartl, Wilfried

2014-05-01

Today, unfortunately, little use is made of the findings of rhizosphere research in practice. Therefore the author, together with the organic farmers` associations Distelverein and Bio Austria, developed the education programme "Soil Practitioner" for organic farmers. The 9-days` course focuses on the topics nutrient dynamics in soil, plant-root interactions, soil management, humus management and practical evaluation of soil functions. A second series of courses developed by Bio Forschung Austria aims at improving organic matter management on farm level. In order to enable the farmers to estimate if the humus content of their fields is increasing or decreasing, they are familiarized with the humus balancing method. In a second step, humus balances of farmers' fields are calculated and the results are discussed together. Another activity to raise soil awareness is the "Mobile Soil Laboratory", which is presented at various events. The soil functions are demonstrated to the public using special exhibits, which illustrate for example infiltration rate in soils with and without earthworms, or water holding capacity of soils with and without earthworms or erosion intensity on soil blocks from adjacent plots which had been cultivated with different crop rotations. The habitat function of soil is illustrated with portable rhizotrons, which show the ability of plants to root surprisingly deep and to penetrate compacted soil layers. Another exhibit shows a habitat preference test between differently fertilized soils with earthworms as indicator organisms. In the "Mobile Soil Laboratory", visitors are also invited to watch live soil animals through the binocular microscope. They are supplied with information on the soil animals` habitat and behaviour and on how agriculture benefits from biologically active soil. And last but not least, the "Root Demonstration Arena" at our institute features a 3-m-deep excavation lined with large viewing windows into the soil profile, where

Soil washing results for mixed waste pond soils at Hanford

International Nuclear Information System (INIS)

Gerber, M.A.; Freeman, H.D.; Baker, E.G.; Riemath, W.F.

1991-01-01

Soil washing technology was assessed as a means for remediating soil contaminated with mixed wastes primarily composed of heavy metals and radionuclides. The soils at the US Department of Energy's Hanford Site are considered suitable for soil washing because of their relatively low quantities of silt and clay. However, in a limited number of soil washing experiments using soils from different locations in the north pond of the 300 Area, the degree of decontamination achieved for the coarse fraction of the soil varied considerably. Part of this variation appears to be due to the presence of a discrete layer of contaminated sediment found in some of the samples

Effect of rainfall infiltration into unsaturated soil using soil column

Science.gov (United States)

Ibrahim, A.; Mukhlisin, M.; Jaafar, O.

2018-02-01

Rainfall especially in tropical region caused infiltration to the soil slope. The infiltration may change pore water pressure or matric suction of the soil. The event of rainfall infiltration into soil is a complex mechanism. Therefore, the main objectives of this research paper is to study the influence of rainfall intensity and duration that changed pore water pressure to soil. There are two types of soils used in this study; forest soil and kaolin. Soil column apparatus is used for experiments. Rainfall were applied to the soil and result for 3, 6, 12, 24, 72, 120 and 168 hours were retrieved. Result shows that for the both types of soil, the negative pore water pressures were increased during wetting process and gradually decreased towards drying process. The results also show that pore water pressure at top part was increased greatly as the wetting process started compared to the middle and bottom part of the column.

Metals in European roadside soils and soil solution--a review.

Science.gov (United States)

Werkenthin, Moritz; Kluge, Björn; Wessolek, Gerd

2014-06-01

This review provides a summary of studies analysing metal concentrations in soils and soil solution at European roadsides. The data collected during 27 studies covering a total of 64 sites across a number of European countries were summarised. Highest median values of Cr, Cu, Ni, Pb, and Zn were determined in the top soil layer at the first 5 m beside the road. Generally, the influence of traffic on soil contamination decreased with increasing soil depth and distance to the road. The concentration patterns of metals in soil solution were independent from concentrations in the soil matrix. At 10-m distance, elevated soil metal concentrations, low pH, and low percolation rates led to high solute concentrations. Directly beside the road, high percolation rates lead to high annual loadings although solute concentrations are comparatively low. These loadings might be problematic, especially in regions with acidic sandy soils and a high groundwater table. Copyright © 2014 Elsevier Ltd. All rights reserved.

Describing Soils: Calibration Tool for Teaching Soil Rupture Resistance

Science.gov (United States)

Seybold, C. A.; Harms, D. S.; Grossman, R. B.

2009-01-01

Rupture resistance is a measure of the strength of a soil to withstand an applied stress or resist deformation. In soil survey, during routine soil descriptions, rupture resistance is described for each horizon or layer in the soil profile. The lower portion of the rupture resistance classes are assigned based on rupture between thumb and…

Soil Plasticity Model for Analysis of Collapse Load on Layers Soil

Directory of Open Access Journals (Sweden)

Md Nujid Masyitah

2016-01-01

Full Text Available Natural soil consist of soil deposits which is a soil layer overlying a thick stratum of another soil. The bearing capacity of layered soil studies have been conducted using different approach whether theoretical, experimental and combination of both. Numerical method in computer programme has become a powerful tool in solving complex geotechnical problems. Thus in numerical modelling, stress-strain soil behaviour is well predicted, design and interpreted using appropriate soil model. It is also important to identify parameters and soil model involve in prediction real soil problem. The sand layer overlaid clay layer soil is modelled with Mohr-Coulomb and Drucker-Prager criterion. The bearing capacity in loaddisplacement analysis from COMSOL Multiphysics is obtained and presented. In addition the stress distribution and evolution of plastic strain for each thickness ratio below centre of footing are investigated. The results indicate the linear relation on load-displacement which have similar trend for both soil models while stress and plastic strain increase as thickness ratio increase.

Predicting radiocaesium sorption characteristics with soil chemical properties for Japanese soils.

Science.gov (United States)

Uematsu, Shinichiro; Smolders, Erik; Sweeck, Lieve; Wannijn, Jean; Van Hees, May; Vandenhove, Hildegarde

2015-08-15

The high variability of the soil-to-plant transfer factor of radiocaesium (RCs) compels a detailed analysis of the radiocaesium interception potential (RIP) of soil, which is one of the specific factors ruling the RCs transfer. The range of the RIP values for agricultural soils in the Fukushima accident affected area has not yet been fully surveyed. Here, the RIP and other major soil chemical properties were characterised for 51 representative topsoils collected in the vicinity of the Fukushima contaminated area. The RIP ranged a factor of 50 among the soils and RIP values were lower for Andosols compared to other soils, suggesting a role of soil mineralogy. Correlation analysis revealed that the RIP was most strongly and negatively correlated to soil organic matter content and oxalate extractable aluminium. The RIP correlated weakly but positively to soil clay content. The slope of the correlation between RIP and clay content showed that the RIP per unit clay was only 4.8 mmol g(-1) clay, about threefold lower than that for clays of European soils, suggesting more amorphous minerals and less micaceous minerals in the clay fraction of Japanese soils. The negative correlation between RIP and soil organic matter may indicate that organic matter can mask highly selective sorption sites to RCs. Multiple regression analysis with soil organic matter and cation exchange capacity explained the soil RIP (R(2)=0.64), allowing us to map soil RIP based on existing soil map information. Copyright © 2015 Elsevier B.V. All rights reserved.

Spatial patterns of soil organic carbon stocks in Estonian arable soils

Science.gov (United States)

Suuster, Elsa; Astover, Alar; Kõlli, Raimo; Roostalu, Hugo; Reintam, Endla; Penu, Priit

2010-05-01

Soil organic carbon (SOC) determines ecosystem functions, influencing soil fertility, soil physical, chemical and biological properties and crop productivity. Therefore the spatial pattern of SOC stocks and its appropriate management is important at various scales. Due to climate change and the contribution of carbon store in the soils, the national estimates of soil carbon stocks should be determined. Estonian soils have been well studied and mapped at a scale 1:10,000. Previous studies have estimated SOC stocks based on combinations of large groups of Estonian soils and the mean values of the soil profile database, but were not embedded into the geo-referenced databases. These studies have estimated SOC stocks of Estonian arable soils 122.3 Tg. Despite of available soil maps and databases, this information is still very poorly used for spatial soil modelling. The aim of current study is to assess and model spatial pattern of SOC stocks of arable soils on a pilot area Tartu County (area 3089 sq km). Estonian digital soil map and soil monitoring databases are providing a good opportunity to assess SOC stocks at various scales. The qualitative nature of the initial data from a soil map prohibits any straightforward use in modelling. Thus we have used several databases to construct models and linkages between soil properties that can be integrated into soil map. First step was to reorganize the soil map database (44,046 mapping units) so it can be used as an input to modelling. Arable areas were distinguished by a field layer of Agricultural Registers and Information Board, which provides precise information of current land use as it is the basis of paying CAP subsidies. The estimates of SOC content were found by using the arable land evaluation database of Tartu from the Estonian Land Board (comprising 950 sq km and 31,226 fields), where each soil type was assessed separately and average SOC content grouped by texture was derived. SOC content of epipedon varies in

Using Agricultural Residue Biochar to Improve Soil Quality of Desert Soils

Directory of Open Access Journals (Sweden)

Yunhe Zhang

2016-03-01

Full Text Available A laboratory study was conducted to test the effects of biochars made from different feedstocks on soil quality indicators of arid soils. Biochars were produced from four locally-available agricultural residues: pecan shells, pecan orchard prunings, cotton gin trash, and yard waste, using a lab-scale pyrolyzer operated at 450 °C under a nitrogen environment and slow pyrolysis conditions. Two local arid soils used for crop production, a sandy loam and a clay loam, were amended with these biochars at a rate of 45 Mg·ha−1 and incubated for three weeks in a growth chamber. The soils were analyzed for multiple soil quality indicators including soil organic matter content, pH, electrical conductivity (EC, and available nutrients. Results showed that amendment with cotton gin trash biochar has the greatest impact on both soils, significantly increasing SOM and plant nutrient (P, K, Ca, Mn contents, as well as increasing the electrical conductivity, which creates concerns about soil salinity. Other biochar treatments significantly elevated soil salinity in clay loam soil, except for pecan shell biochar amended soil, which was not statistically different in EC from the control treatment. Generally, the effects of the biochar amendments were minimal for many soil measurements and varied with soil texture. Effects of biochars on soil salinity and pH/nutrient availability will be important considerations for research on biochar application to arid soils.

Soil threats and soil protection: the role of biotechnology

International Nuclear Information System (INIS)

Rubio, J. L.

2009-01-01

The concept of soil conservation/soil protection in its wider sense has undergone important changes through history. Perceptions of soil as a crucial base of life in ancient cultures progressively evolved to a more pragmatic vision, with close connection to food production for survival. For centuries, agrarian production and the provision of food for humankind remained the main and crucial vision of the interaction of societies with soil. However, there are also some other new and important concepts related to soil which have progressively developed. (Author)

Underestimation of boreal soil carbon stocks by mathematical soil carbon models linked to soil nutrient status

Science.gov (United States)

Ťupek, Boris; Ortiz, Carina A.; Hashimoto, Shoji; Stendahl, Johan; Dahlgren, Jonas; Karltun, Erik; Lehtonen, Aleksi

2016-08-01

Inaccurate estimate of the largest terrestrial carbon pool, soil organic carbon (SOC) stock, is the major source of uncertainty in simulating feedback of climate warming on ecosystem-atmosphere carbon dioxide exchange by process-based ecosystem and soil carbon models. Although the models need to simplify complex environmental processes of soil carbon sequestration, in a large mosaic of environments a missing key driver could lead to a modeling bias in predictions of SOC stock change.We aimed to evaluate SOC stock estimates of process-based models (Yasso07, Q, and CENTURY soil sub-model v4) against a massive Swedish forest soil inventory data set (3230 samples) organized by a recursive partitioning method into distinct soil groups with underlying SOC stock development linked to physicochemical conditions.For two-thirds of measurements all models predicted accurate SOC stock levels regardless of the detail of input data, e.g., whether they ignored or included soil properties. However, in fertile sites with high N deposition, high cation exchange capacity, or moderately increased soil water content, Yasso07 and Q models underestimated SOC stocks. In comparison to Yasso07 and Q, accounting for the site-specific soil characteristics (e. g. clay content and topsoil mineral N) by CENTURY improved SOC stock estimates for sites with high clay content, but not for sites with high N deposition.Our analysis suggested that the soils with poorly predicted SOC stocks, as characterized by the high nutrient status and well-sorted parent material, indeed have had other predominant drivers of SOC stabilization lacking in the models, presumably the mycorrhizal organic uptake and organo-mineral stabilization processes. Our results imply that the role of soil nutrient status as regulator of organic matter mineralization has to be re-evaluated, since correct SOC stocks are decisive for predicting future SOC change and soil CO2 efflux.

Soil friability - Concept, Assessment and Effects of Soil Properties and Management

DEFF Research Database (Denmark)

Munkholm, Lars Juhl

Soil friability is a key soil physical property yielding valuable information on the ease of productin a favorable seed- and root beds during tillage operations. Therefore, soil friability is acrucial soil property in relation to the ability of soil to support plant growth and to minimzethe energy...... required for tillage. The topic has interested farmers and soil scientiest for centuries, but is was the paper by Utomo and Dexter (1981) that significantly put the topic on the soil science agenda. The awareness of soil friability is growing, both in practiceand in soil science. This must be viewed...... in the light of the present renewed focus on global food security together with a focus on fossil fuel consumption and greenhouse gas emissions in crop production. Certainly, the demand for well-functioning, arable soils is rising to meet the global challenges....

SoilGrids1km — Global Soil Information Based on Automated Mapping

Science.gov (United States)

Hengl, Tomislav; de Jesus, Jorge Mendes; MacMillan, Robert A.; Batjes, Niels H.; Heuvelink, Gerard B. M.; Ribeiro, Eloi; Samuel-Rosa, Alessandro; Kempen, Bas; Leenaars, Johan G. B.; Walsh, Markus G.; Gonzalez, Maria Ruiperez

2014-01-01

Background Soils are widely recognized as a non-renewable natural resource and as biophysical carbon sinks. As such, there is a growing requirement for global soil information. Although several global soil information systems already exist, these tend to suffer from inconsistencies and limited spatial detail. Methodology/Principal Findings We present SoilGrids1km — a global 3D soil information system at 1 km resolution — containing spatial predictions for a selection of soil properties (at six standard depths): soil organic carbon (g kg−1), soil pH, sand, silt and clay fractions (%), bulk density (kg m−3), cation-exchange capacity (cmol+/kg), coarse fragments (%), soil organic carbon stock (t ha−1), depth to bedrock (cm), World Reference Base soil groups, and USDA Soil Taxonomy suborders. Our predictions are based on global spatial prediction models which we fitted, per soil variable, using a compilation of major international soil profile databases (ca. 110,000 soil profiles), and a selection of ca. 75 global environmental covariates representing soil forming factors. Results of regression modeling indicate that the most useful covariates for modeling soils at the global scale are climatic and biomass indices (based on MODIS images), lithology, and taxonomic mapping units derived from conventional soil survey (Harmonized World Soil Database). Prediction accuracies assessed using 5–fold cross-validation were between 23–51%. Conclusions/Significance SoilGrids1km provide an initial set of examples of soil spatial data for input into global models at a resolution and consistency not previously available. Some of the main limitations of the current version of SoilGrids1km are: (1) weak relationships between soil properties/classes and explanatory variables due to scale mismatches, (2) difficulty to obtain covariates that capture soil forming factors, (3) low sampling density and spatial clustering of soil profile locations. However, as the Soil

Combination of soil classification and some selected soil properties ...

African Journals Online (AJOL)

The advantage in the combined use of soil classification and top soil analysis for explaining crop yield variation was examined. Soil properties and yields of maize (Zea mays L) on different soil types were measured on farmers' fields for 2 years. Yield prediction improved from 2 per cent at the Order and Association levels to ...

Metals in European roadside soils and soil solution – A review

International Nuclear Information System (INIS)

Werkenthin, Moritz; Kluge, Björn; Wessolek, Gerd

2014-01-01

This review provides a summary of studies analysing metal concentrations in soils and soil solution at European roadsides. The data collected during 27 studies covering a total of 64 sites across a number of European countries were summarised. Highest median values of Cr, Cu, Ni, Pb, and Zn were determined in the top soil layer at the first 5 m beside the road. Generally, the influence of traffic on soil contamination decreased with increasing soil depth and distance to the road. The concentration patterns of metals in soil solution were independent from concentrations in the soil matrix. At 10-m distance, elevated soil metal concentrations, low pH, and low percolation rates led to high solute concentrations. Directly beside the road, high percolation rates lead to high annual loadings although solute concentrations are comparatively low. These loadings might be problematic, especially in regions with acidic sandy soils and a high groundwater table. - Highlights: • Summary of studies analysing metals in soils and soil solution at European roadsides. • Metal concentrations in topsoil 5 m beside the road are influenced strongly by traffic. • Solute concentrations of metals are mostly independent from soil concentrations. • High percolation rates lead to high annual loadings directly beside the road. - Summarised data showed typical distance related metal patterns of European roadside soils; solute concentrations are mostly independent from soil matrix concentrations

Roles of soil biota and biodiversity in soil environment – A concise communication

Directory of Open Access Journals (Sweden)

Suleiman Usman

2016-10-01

Full Text Available Soil biota (the living organisms in soil plays an important role in soil development and soil formation. They are the most important component of soil organic matter decomposition and behave efficiently in the development and formation of soil structure and soil aggregate. Their biodiversity provides many functional services to soil and soil components. They help in dissolving verities of plant and animal materials, which could left as decayed organic matter at the surface soil. Understanding the vital role of soil organisms would undoubtedly helps to increase food production and reduces poverty, hunger and malnutrition. Soil biota and biodiversity research in sub-Saharan Africa would play an important role in sustaining food security, environmental health, water quality and forest regeneration. This paper, briefly highlighted some of the biological functions of soil biota and suggests that proper understandings of biota and their biodiversity in soil environment would provide ways to get better understanding of soil health, soil function, soil quality and soil fertility under sustainable soil management activities in agricultural production.

Soil Organic Matter and Soil Productivity: Searching for the Missing Link

Science.gov (United States)

Felipe G. Sanchez

1998-01-01

Soil-organic matter (SOM) is a complex array of components including soil fauna and flora at different stages of decomposition (Berg et al., 1982). Its concentration in soils can vary from 0.5% in mineral soils to almost 100% in peat soils (Brady, 1974). Organic matter (OM) in the surface mineral soil is considered a major determinant of forest ecosystem productivity...

Soil Spectroscopy: An Alternative to Wet Chemistry for Soil Monitoring

DEFF Research Database (Denmark)

Nocita, M.; Stevens, A.; van Wesemael, Bas

2015-01-01

The soil science community is facing a growing demand of regional, continental, and worldwide databases in order to monitor the status of the soil. However, the availability of such data is very scarce. Cost-effective tools to measure soil properties for large areas (e.g., Europe) are required....... Soil spectroscopy has shown to be a fast, cost-effective, envi-ronmental-friendly, nondestructive, reproducible, and repeatable analytical technique. The main aim of this paper is to describe the state of the art of soil spectroscopy as well as its potential to facilitating soil monitoring. The factors...... constraining the application of soil spectroscopy as an alternative to traditional laboratory analyses, together with the limits of the technique, are addressed. The paper also highlights that the widespread use of spectroscopy to monitor the status of the soil should be encouraged by (1) the creation...

Soil washing results for mixed waste pond soils at Hanford

International Nuclear Information System (INIS)

Gerber, M.A.

1991-09-01

Soil washing technology was assessed as a means for remediating soil contaminated with mixed wastes primarily composed of heavy metals and radionuclides. The soils at the US Department of Energy's Hanford Site are considered suitable for soil washing because of their relatively low quantities of silt and clay. However, in a limited number of soil washing experiments using soils from different locations in the north pond of the 300 Area, the degree of decontamination achieved for the coarse fraction of the soil varied considerably. Part of this variation appears to be due to the presence of a discrete layer of contaminated sediment found in some of the samples. 7 refs., 2 figs., 4 tabs

Soil washing and post-wash biological treatment of petroleum hydrocarbon contaminated soils

OpenAIRE

Bhandari, Alok

1992-01-01

A laboratory scale study was conducted to investigate the treatability of petroleum contaminated soils by soil washing and subsequent biological treatment of the different soil fractions. In addition to soils obtained from contaminated sites, studies were also performed on soils contaminated in the laboratory. Soil washing was performed using a bench-scale soil washing system. Washing was carried out with simultaneous fractionation of the bulk soil into sand, silt and clay fractions. Cl...

Soil friability

DEFF Research Database (Denmark)

Munkholm, Lars Juhl

2011-01-01

This review gathers and synthesizes literature on soil friability produced during the last three decades. Soil friability is of vital importance for crop production and the impact of crop production on the environment. A friable soil is characterized by an ease of fragmentation of undesirably large...... aggregates/clods and a difficulty in fragmentation of minor aggregates into undesirable small elements. Soil friability has been assessed using qualitative field methods as well as quantitative field and laboratory methods at different scales of observation. The qualitative field methods are broadly used...... by scientists, advisors and farmers, whereas the quantitative laboratory methods demand specialized skills and more or less sophisticated equipment. Most methods address only one aspect of soil friability, i.e. either the strength of unconfined soil or the fragment size distribution after applying a stress. All...

Soil Characteristics Driving Arbuscular Mycorrhizal Fungal Communities in Semiarid Mediterranean Soils.

Science.gov (United States)

Alguacil, Maria Del Mar; Torres, Maria Pilar; Montesinos-Navarro, Alicia; Roldán, Antonio

2016-06-01

We investigated communities of arbuscular mycorrhizal fungi (AMF) in the roots and the rhizosphere soil of Brachypodium retusum in six different natural soils under field conditions. We explored phylogenetic patterns of AMF composition using indicator species analyses to find AMF associated with a given habitat (root versus rhizosphere) or soil type. We tested whether the AMF characteristics of different habitats or contrasting soils were more closely related than expected by chance. Then we used principal-component analysis and multivariate analysis of variance to test for the relative contribution of each factor in explaining the variation in fungal community composition. Finally, we used redundancy analysis to identify the soil properties that significantly explained the differences in AMF communities across soil types. The results pointed out a tendency of AMF communities in roots to be closely related and different from those in the rhizosphere soil. The indicator species analyses revealed AMF associated with rhizosphere soil and the root habitat. Soil type also determined the distribution of AMF communities in soils, and this effect could not be attributed to a single soil characteristic, as at least three soil properties related to microbial activity, i.e., pH and levels of two micronutrients (Mn and Zn), played significant roles in triggering AMF populations. Communities of arbuscular mycorrhizal fungi (AMF) are main components of soil biota that can determine the productivity of ecosystems. These fungal assemblages vary across host plants and ecosystems, but the main ecological processes that shape the structures of these communities are still largely unknown. A field study in six different soil types from semiarid areas revealed that AMF communities are significantly influenced by habitat (soil versus roots) and soil type. In addition, three soil properties related to microbiological activity (i.e., pH and manganese and zinc levels) were the main factors

Soil Characteristics Driving Arbuscular Mycorrhizal Fungal Communities in Semiarid Mediterranean Soils

Science.gov (United States)

Torres, Maria Pilar; Montesinos-Navarro, Alicia; Roldán, Antonio

2016-01-01

ABSTRACT We investigated communities of arbuscular mycorrhizal fungi (AMF) in the roots and the rhizosphere soil of Brachypodium retusum in six different natural soils under field conditions. We explored phylogenetic patterns of AMF composition using indicator species analyses to find AMF associated with a given habitat (root versus rhizosphere) or soil type. We tested whether the AMF characteristics of different habitats or contrasting soils were more closely related than expected by chance. Then we used principal-component analysis and multivariate analysis of variance to test for the relative contribution of each factor in explaining the variation in fungal community composition. Finally, we used redundancy analysis to identify the soil properties that significantly explained the differences in AMF communities across soil types. The results pointed out a tendency of AMF communities in roots to be closely related and different from those in the rhizosphere soil. The indicator species analyses revealed AMF associated with rhizosphere soil and the root habitat. Soil type also determined the distribution of AMF communities in soils, and this effect could not be attributed to a single soil characteristic, as at least three soil properties related to microbial activity, i.e., pH and levels of two micronutrients (Mn and Zn), played significant roles in triggering AMF populations. IMPORTANCE Communities of arbuscular mycorrhizal fungi (AMF) are main components of soil biota that can determine the productivity of ecosystems. These fungal assemblages vary across host plants and ecosystems, but the main ecological processes that shape the structures of these communities are still largely unknown. A field study in six different soil types from semiarid areas revealed that AMF communities are significantly influenced by habitat (soil versus roots) and soil type. In addition, three soil properties related to microbiological activity (i.e., pH and manganese and zinc levels

Predicting soil particle density from clay and soil organic matter contents

DEFF Research Database (Denmark)

Schjønning, Per; McBride, R.A.; Keller, T.

2017-01-01

Soil particle density (Dp) is an important soil property for calculating soil porosity expressions. However, many studies assume a constant value, typically 2.65Mgm−3 for arable, mineral soils. Fewmodels exist for the prediction of Dp from soil organic matter (SOM) content. We hypothesized...

Effects of imidacloprid on soil microbial communities in different saline soils.

Science.gov (United States)

Zhang, Qingming; Xue, Changhui; Wang, Caixia

2015-12-01

The effects of imidacloprid in the soil environment are a worldwide concern. However, the impact of imidacloprid on soil microorganisms under salt stress is almost unknown. Therefore, an indoor incubation test was performed, and the denaturing gradient gel electrophoresis (DGGE) approach was used to determine the response of different saline soil bacterial and fungal community structures to the presence of imidacloprid (0.4, 2, 10 mg kg(-1)). The results showed that the soil bacterial diversity slightly declined with increasing imidacloprid concentration in soils with low salinity. In moderately saline soils, a new band in the DGGE profile suggested that imidacloprid could improve the soil bacterial diversity to some degree. An analysis of variance indicated that the measured soil bacterial diversity parameters were significantly affected by dose and incubation time. Compared with the control, the soil fungal community structure showed no obvious changes in low and moderately saline soils treated with imidacloprid. The results of these observations provide a basic understanding of the potential ecological effects of imidacloprid on different microorganisms in saline soils.

Soil and Pesticides

Science.gov (United States)

; Environment Human Health Animal Health Safe Use Practices Food Safety Environment Air Water Soil Wildlife Home Page Pesticides and the Environment Soil and Pesticides Related Topics: What Happens to Pesticides español Soil and Pesticides Soil can be degraded and the community of organisms living in the soil can

Decontamination by replacing soil and soil cover with deep-level soil in flower beds and vacant places in Northern Fukushima Prefecture

International Nuclear Information System (INIS)

Sugiura, Hiroyuki; Kawano, Keisuke; Kayama, Yukihiko; Koube, Nobuyuki

2012-01-01

Radioactivity decontamination by replacing soil and soil cover with deep-level soil and soil cover in flower beds and a vacant place in Northern Fukushima Prefecture were studied, which experienced radioactive contamination due to the accident at the TEPCO's Fukushima Daiichi Nuclear Power Plant. Radioactivity counting rate 1 cm above the soil surface after replacing surface soil with uncontaminated deep-level soil decreased to 13.7% of the control in gardens. The concentration of radioactive cesium in the cover soil increased after 132 days; however, it decreased in the old surface soil under the cover soil in flower beds. A 10 cm deep-level soil cover placed by heavy machinery decreased the radiation dose rate to 70.8% of the control and radioactivity counting rate to 24.6% in the vacant place. Replacing the radioactively contaminated surface soil and soil cover with a deep-level soil was a reasonable decontamination method for the garden and vacant place because it is quick, cost effective and labour efficient. (author)

know Soil Know Life - Getting Kids Excited About Soils

Science.gov (United States)

Lindbo, David L.; Robinson, Clay; Kozlowski, Deborah

2014-05-01

In the United States soils are often taught in primary school (grade 3-6) but with little excitement or passion. We have been working with schools and teachers to bring our passion about soils to this audience. The methods and message can be conveyed simply and effectively by engaging the students in a dialog and through kinematic learning. Our approach is to begin with a simple question - what are 4 things we cannot live without. The answer - Air, Water, Sunlight, and Soil. Most students say "food, shelter, clothing, plants, animals etc." so we then explain all of those come from soil. This leads us to a quick "dance" illustrating that without soils we would be 'Hungry. Homeless, and Naked". The results are that students and teachers remember this simple message. From this point it is our hope that students will continue to understand the importance of soils and stop treating soils like dirt. Other simple exercises for this younger audience will also be presented.

Evaluation of soil structure in the framework of an overall soil quality rating

DEFF Research Database (Denmark)

Mueller, L; Shepherd, T G; Schindler, U

2013-01-01

Soil structure is an important aspect of agricultural soil quality, and its preservation and improvement are key to sustaining soil functions. Methods of overall soil quality assessment which include visual soil structure information can be useful tools for monitoring and managing the global soil...... resource. The aim of the paper is: (i) to demonstrate the role of visual quantification of soil structure within the procedure of the overall soil quality assessment by the Muencheberg Soil Quality Rating (M-SQR), (ii) to quantify the magnitude and variability of soil structure and overall M......-SQR on a number of agricultural research sites and (iii) to analyse the correlations of soil quality rating results with crop yields. We analysed visual soil structure and overall soil quality on a range of 20 experimental sites in seven countries. To assess visual soil structure we utilised the Visual Soil...

Soil Survey Geographic (SSURGO) - Kinds and Distribution of Soils

Data.gov (United States)

California Natural Resource Agency — This data set is a digital soil survey and generally is the most detailed level of soil geographic data developed by the National Cooperative Soil Survey. The...

Soil aggregate and organic carbon distribution at dry land soil and paddy soil: the role of different straws returning.

Science.gov (United States)

Huang, Rong; Lan, Muling; Liu, Jiang; Gao, Ming

2017-12-01

Agriculture wastes returning to soil is one of common ways to reuse crop straws in China. The returned straws are expected to improve the fertility and structural stability of soil during the degradation of straw it selves. The in situ effect of different straw (wheat, rice, maize, rape, and broad bean) applications for soil aggregate stability and soil organic carbon (SOC) distribution were studied at both dry land soil and paddy soil in this study. Wet sieving procedures were used to separate soil aggregate sizes. Aggregate stability indicators including mean weight diameter, geometric mean diameter, mean weight of specific surface area, and the fractal dimension were used to evaluate soil aggregate stability after the incubation of straws returning. Meanwhile, the variation and distribution of SOC in different-sized aggregates were further studied. Results showed that the application of straws, especially rape straw at dry land soil and rice straw at paddy soil, increased the fractions of macro-aggregate (> 0.25 mm) and micro-aggregate (0.25-0.053 mm). Suggesting the nutrients released from straw degradation promotes the growing of soil aggregates directly and indirectly. The application of different straws increased the SOC content at both soils and the SOC mainly distributed at  0.25 and 0.25-0.053 mm aggregates with dry land soil. Rape straw in dry land and rice straw in paddy field could stabilize soil aggregates and increasing SOC contents best.

Relationship between soil erodibility and modeled infiltration rate in different soils

Science.gov (United States)

Wang, Guoqiang; Fang, Qingqing; Wu, Binbin; Yang, Huicai; Xu, Zongxue

2015-09-01

The relationship between soil erodibility, which is hard to measure, and modeled infiltration rate were rarely researched. Here, the soil erodibility factors (K and Ke in the USLE, Ki and K1 in the WEPP) were calculated and the infiltration rates were modeled based on the designed laboratory simulation experiments and proposed infiltration model, in order to build their relationship. The impacts of compost amendment on the soil erosion characteristics and relationship were also studied. Two contrasting agricultural soils (bare and cultivated fluvo-aquic soils) were used, and different poultry compost contents (control, low and high) were applied to both soils. The results indicated that the runoff rate, sediment yield rate and soil erodibility of the bare soil treatments were generally higher than those of the corresponding cultivated soil treatments. The application of composts generally decreased sediment yield and soil erodibility but did not always decrease runoff. The comparison of measured and modeled infiltration rates indicated that the model represented the infiltration processes well with an N-S coefficient of 0.84 for overall treatments. Significant negative logarithmic correlations have been found between final infiltration rate (FIR) and the four soil erodibility factors, and the relationship between USLE-K and FIR demonstrated the best correlation. The application of poultry composts would not influence the logarithmic relationship between FIR and soil erodibility. Our study provided a useful tool to estimate soil erodibility.

Testing of multistep soil washing for radiocesium-contaminated soil containing plant matter

International Nuclear Information System (INIS)

Funakawa, Masafumi; Tagawa, Akihiro; Okuda, Nobuyasu

2012-01-01

Decontamination work following radiocesium exposure requires a vast reduction in the amount of contaminated soil generated. The current study subjected 4 types of contaminated soil with different properties to multistep soil washing under the same conditions. This study also determined the effectiveness of radiocesium decontamination and the extent to which the amount of contaminated soil was reduced. In addition, the effectiveness of plant matter separation, adsorbent addition, and grinding as part of multistep soil washing was determined using the same contaminated soil. Results of testing indicated that the rate of radiocesium decontamination ranged from 73.6 to 89.2% and the recovery rate ranged from 51.5 to 84.2% for twice-treated soil, regardless of the soil properties or cesium level. Plant matter in soil had a high radiocesium level. However, there was little plant matter in our soil sample. Therefore, plant matter separation had little effect on the improvement in the percentage of radiocesium decontamination of twice-treated soil. Soil surface grinding improved the rate of radiocesium decontamination of twice-treated soil. However, radiocesium in soil tightly bound with minerals in the soil; thus, the addition of an adsorbent also failed to improve the rate of radiocesium decontamination. (author)

[Interrelationships between soil fauna and soil environmental factors in China: research advance].

Science.gov (United States)

Wang, Yi; Wei, Wei; Yang, Xing-zhong; Chen, Li-ding; Yang, Lei

2010-09-01

Soil fauna has close relations with various environmental factors in soil ecosystem. To explore the interrelationships between soil fauna and soil environmental factors is of vital importance to deep understand the dynamics of soil ecosystem and to assess the functioning of the ecosystem. The environmental factors affecting soil fauna can be classified as soil properties and soil external environment. The former contains soil basic physical and chemical properties, soil moisture, and soil pollution. The latter includes vegetation, land use type, landform, and climate, etc. From these aspects, this paper summarized the published literatures in China on the interrelationships between soil fauna and soil environmental factors. It was considered that several problems were existed in related studies, e.g., fewer researches were made in integrating soil fauna's bio-indicator function, research methods were needed to be improved, and the studies on the multi-environmental factors and their large scale spatial-temporal variability were in deficiency. Corresponding suggestions were proposed, i.e., more work should be done according to the practical needs, advanced experiences from abroad should be referenced, and comprehensive studies on multi-environmental factors and long-term monitoring should be conducted on large scale areas.

Soil carbon dynamics inferred from carbon isotope compositions of soil organic matter and soil respiration

International Nuclear Information System (INIS)

Koarashi, Jun; Asano, Tomohiro; Iida, Takao; Moriizumi, Jun

2004-01-01

To better understand 14 C cycling in terrestrial ecosystems, 14 C abundances were evaluated for fractionated soil organic matter (SOM) and soil respiration in an urban forest. In 2001 soil profile, Δ 14 C values of litter and bulk SOM increased rapidly from litter surface (62.7 per mille) to uppermost mineral soil layer (244.9 per mille), and then decreased sharply to 6 cm depth of mineral soil (125.0 per mille). Carbon enriched in 14 C by atmospheric nuclear weapons testing had penetrated to at least 16 cm depth of mineral soil. The average Δ 14 C in atmospheric CO 2 was 58.8 per mille in August 2001, suggesting recent carbon input to the topmost litter layer. Although a similar depth distribution was observed for Δ 14 C values of residual SOM after acid hydrolysis, the Δ 14 C values were slightly lower than those in bulk SOM. This indicates input of 'bomb' C into this organic fraction and higher 14 C abundance in acid-soluble SOM. The most of CO 2 may be derived from the microbial decomposition of the acid-soluble, or labile, SOM. Therefore, the labile SOM may become most influential pool for soil carbon cycling. In contrast, carbon in base-insoluble SOM remained considerably low in 14 C abundance at all depths, suggesting no or little incorporation of 'bomb' C to this fraction. Values of Δ 14 C in soil respiration ranged from 91.9 to 146.4 per mille in August 2001, showing a significant contribution from decomposition of SOM fixed over past 2-40 years. These results indicate that the use of bulk SOM as a representative of soil carbon pool would lead to severe misunderstand of the soil C dynamics on decadal and shorter time scales. (author)

The moisture response of soil heterotrophic respiration: interaction with soil properties

DEFF Research Database (Denmark)

Moyano, F E; Vasilyeva, N; Bouckaert, L

2012-01-01

the heterotrophic respiration response to moisture have limited empirical support and introduce an uncertainty of at least 4% in global soil carbon stock predictions by 2100. The necessity of improving the representation of this relationship in models has been highlighted in recent studies. Here we present a data......Soil moisture is of primary importance for predicting the evolution of soil carbon stocks and fluxes, both because it strongly controls organic matter decomposition and because it is predicted to change at global scales in the following decades. However, the soil functions used to model......-driven analysis of soil moisture-respiration relations based on 90 soils. With the use of linear models we show how the relationship between soil heterotrophic respiration and different measures of soil moisture is consistently affected by soil properties. The empirical models derived include main effects...

The Spatial Variability of Soil Dehydrogenase Activity: A Survey in Urban Soils

OpenAIRE

Kizilkaya, Ridvan; Aşkin, Tayfun

2007-01-01

Information on soil microorganisms and their activity used to determine microbiological characteristics are very important for soil quality and productivity. Studies of enzyme activities provide information on the biochemical processes occurring in soil. There is growing evidence that soil biological parameters may be potential and sensitive indicators of soil ecological conditions and soil management. Soil microbiological parameters may be evaluated statistically due to application of geosta...

Soil organic carbon dynamics jointly controlled by climate, carbon inputs, soil properties and soil carbon fractions.

Science.gov (United States)

Luo, Zhongkui; Feng, Wenting; Luo, Yiqi; Baldock, Jeff; Wang, Enli

2017-10-01

Soil organic carbon (SOC) dynamics are regulated by the complex interplay of climatic, edaphic and biotic conditions. However, the interrelation of SOC and these drivers and their potential connection networks are rarely assessed quantitatively. Using observations of SOC dynamics with detailed soil properties from 90 field trials at 28 sites under different agroecosystems across the Australian cropping regions, we investigated the direct and indirect effects of climate, soil properties, carbon (C) inputs and soil C pools (a total of 17 variables) on SOC change rate (r C , Mg C ha -1  yr -1 ). Among these variables, we found that the most influential variables on r C were the average C input amount and annual precipitation, and the total SOC stock at the beginning of the trials. Overall, C inputs (including C input amount and pasture frequency in the crop rotation system) accounted for 27% of the relative influence on r C , followed by climate 25% (including precipitation and temperature), soil C pools 24% (including pool size and composition) and soil properties (such as cation exchange capacity, clay content, bulk density) 24%. Path analysis identified a network of intercorrelations of climate, soil properties, C inputs and soil C pools in determining r C . The direct correlation of r C with climate was significantly weakened if removing the effects of soil properties and C pools, and vice versa. These results reveal the relative importance of climate, soil properties, C inputs and C pools and their complex interconnections in regulating SOC dynamics. Ignorance of the impact of changes in soil properties, C pool composition and C input (quantity and quality) on SOC dynamics is likely one of the main sources of uncertainty in SOC predictions from the process-based SOC models. © 2017 John Wiley & Sons Ltd.

Soil and soil cover changes in spruce forests after final logging

Directory of Open Access Journals (Sweden)

E. M. Lapteva

2015-10-01

Full Text Available Soil cover transformation and changes of morphological and chemical properties of Albeluvisols in clear-cuttings of middle taiga spruce forests were studied. The observed changes in structure and properties of podzolic texturally-differentiated soils at cuttings of spruce forests in the middle taiga subzone do not cause their transition to any other soil type. Soil cover of secondary deciduous-coniferous forests which replace cut forests are characterized with a varied soil contour and a combination of the main type of podzolic soils under undisturbed spruce forests. The increased surface hydromorphism in cut areas causes formation of complicated sub-types of podzolic texturally differentiated soils (podzolic surface-gley soils with microprofile of podzol and enlarges their ratio (up to 35–38 % in soil cover structure. Temporary soil over-wetting at the initial (5–10 years stage of after-cutting self-restoring vegetation succession provides for soil gleyzation, improves yield and segregation of iron compounds, increases the migratory activity of humic substances. Low content and resources of total nitrogen in forest litters mark anthropogenic transformation processes of podzolic soils at this stage. Later (in 30–40 years after logging, soils in cut areas still retain signs of hydromorphism. Forest litters are denser, less acidic and thick with a low weight ratio of organic carbon as compared with Albeluvisols of undisturbed spruce forest. The upper mineral soil horizons under secondary deciduous-coniferous forests contain larger amounts of total iron, its mobile (oxalate-dissolvable components, and Fe-Mn-concretions.

Bench Scale Treatability Studies of Contaminated Soil Using Soil Washing Technique

Directory of Open Access Journals (Sweden)

M. K. Gupta

2010-01-01

Full Text Available Soil contamination is one of the most widespread and serious environmental problems confronting both the industrialized as well as developing nations like India. Different contaminants have different physicochemical properties, which influence the geochemical reactions induced in the soils and may bring about changes in their engineering and environmental behaviour. Several technologies exist for the remediation of contaminated soil and water. In the present study soil washing technique using plain water with surfactants as an enhancer was used to study the remediation of soil contaminated with (i an organic contaminant (engine lubricant oil and (ii an inorganic contaminant (heavy metal. The lubricant engine oil was used at different percentages (by dry weight of the soil to artificially contaminate the soil. It was found that geotechnical properties of the soil underwent large modifications on account of mixing with the lubricant oil. The sorption experiments were conducted with cadmium metal in aqueous medium at different initial concentration of the metal and at varying pH values of the sorbing medium. For the remediation of contaminated soil matrices, a nonionic surfactant was used for the restoration of geotechnical properties of lubricant oil contaminated soil samples, whereas an anionic surfactant was employed to desorb cadmium from the contaminated soil matrix. The surfactant in case of soil contaminated with the lubricant oil was able to restore properties to an extent of 98% vis-à-vis the virgin soil, while up to 54% cadmium was desorbed from the contaminated soil matrix in surfactant aided desorption experiments.

Effects of Tillage Practices on Soil Organic Carbon and Soil Respiration

Science.gov (United States)

Rusu, Teodor; Ioana Moraru, Paula; Bogdan, Ileana; Ioan Pop, Adrian

2016-04-01

Soil tillage system and its intensity modify by direct and indirect action soil temperature, moisture, bulk density, porosity, penetration resistance and soil structural condition. Minimum tillage and no-tillage application reduce or completely eliminate the soil mobilization, due to this, soil is compacted in the first years of application. The degree of compaction is directly related to soil type and its state of degradation. All this physicochemical changes affect soil biology and soil respiration. Soil respiration leads to CO2 emissions from soil to the atmosphere, in significant amounts for the global carbon cycle. Soil respiration is one measure of biological activity and decomposition. Soil capacity to produce CO2 varies depending on soil, season, intensity and quality of agrotechnical tillage, soil water, cultivated plant and fertilizer. Our research follows the effects of the three tillage systems: conventional system, minimum tillage and no-tillage on soil respiration and finally on soil organic carbon on rotation soybean - wheat - maize, obtained on an Argic Faeoziom from the Somes Plateau, Romania. To quantify the change in soil respiration under different tillage practices, determinations were made for each crop in four vegetative stages (spring, 5-6 leaves, bean forming, harvest). Soil monitoring system of CO2 and O2 included gradient method, made by using a new generation of sensors capable of measuring CO2 concentration in-situ and quasi-instantaneous in gaseous phase. At surface soil respiration is made by using ACE Automated Soil CO2 Exchange System. These areas were was our research presents a medium multi annual temperature of 8.20C medium of multi annual rain drowns: 613 mm. The experimental variants chosen were: i). Conventional system: reversible plough (22-25 cm) + rotary grape (8-10 cm); ii). Minimum tillage system: paraplow (18-22 cm) + rotary grape (8-10 cm); iii). No-tillage. The experimental design was a split-plot design with three

Tropical Soil Chemistry

DEFF Research Database (Denmark)

Borggaard, Ole K.

and environmental protection. Tropical Soil Chemistry by Ole K. Borggaard provides an overview of the composition, occurrence, properties, processes, formation, and environmental vulnerability of various tropical soil types (using American Soil Taxonomy for classification). The processes and the external factors...... soil chemical issues are also presented to assess when, why, and how tropical soils differ from soils in other regions. This knowledge can help agricultural specialists in the tropics establish sustainable crop production. Readers are assumed to be familiar with basic chemistry, physics...

A long-term soil structure observatory for post-compaction soil structure evolution: design and initial soil structure recovery observations

Science.gov (United States)

Keller, Thomas; Colombi, Tino; Ruiz, Siul; Grahm, Lina; Reiser, René; Rek, Jan; Oberholzer, Hans-Rudolf; Schymanski, Stanislaus; Walter, Achim; Or, Dani

2016-04-01

Soil compaction due to agricultural vehicular traffic alters the geometrical arrangement of soil constituents, thereby modifying mechanical properties and pore spaces that affect a range of soil hydro-ecological functions. The ecological and economic costs of soil compaction are dependent on the immediate impact on soil functions during the compaction event, and a function of the recovery time. In contrast to a wealth of soil compaction information, mechanisms and rates of soil structure recovery remain largely unknown. A long-term (>10-yr) soil structure observatory (SSO) was established in 2014 on a loamy soil in Zurich, Switzerland, to quantify rates and mechanisms of structure recovery of compacted arable soil under different post-compaction management treatments. We implemented three initial compaction treatments (using a two-axle agricultural vehicle with 8 Mg wheel load): compaction of the entire plot area (i.e. track-by-track), compaction in wheel tracks, and no compaction. After compaction, we implemented four post-compaction soil management systems: bare soil (BS), permanent grass (PG), crop rotation without mechanical loosening (NT), and crop rotation under conventional tillage (CT). BS and PG provide insights into uninterrupted natural processes of soil structure regeneration under reduced (BS) and normal biological activity (PG). The two cropping systems (NT and CT) enable insights into soil structure recovery under common agricultural practices with minimal (NT) and conventional mechanical soil disturbance (CT). Observations include periodic sampling and measurements of soil physical properties, earthworm abundance, crop measures, electrical resistivity and ground penetrating radar imaging, and continuous monitoring of state variables - soil moisture, temperature, CO2 and O2 concentrations, redox potential and oxygen diffusion rates - for which a network of sensors was installed at various depths (0-1 m). Initial compaction increased soil bulk density

Soil organic carbon and nitrogen pools drive soil C-CO2 emissions from selected soils in Maritime Antarctica.

Science.gov (United States)

Pires, C V; Schaefer, C E R G; Hashigushi, A K; Thomazini, A; Filho, E I F; Mendonça, E S

2017-10-15

The ongoing trend of increasing air temperatures will potentially affect soil organic matter (SOM) turnover and soil C-CO 2 emissions in terrestrial ecosystems of Maritime Antarctica. The effects of SOM quality on this process remain little explored. We evaluated (i) the quantity and quality of soil organic matter and (ii) the potential of C release through CO 2 emissions in lab conditions in different soil types from Maritime Antarctica. Soil samples (0-10 and 10-20cm) were collected in Keller Peninsula and the vicinity of Arctowski station, to determine the quantity and quality of organic matter and the potential to emit CO 2 under different temperature scenarios (2, 5, 8 and 11°C) in lab. Soil organic matter mineralization is low, especially in soils with low organic C and N contents. Recalcitrant C form is predominant, especially in the passive pool, which is correlated with humic substances. Ornithogenic soils had greater C and N contents (reaching to 43.15gkg -1 and 5.22gkg -1 for total organic carbon and nitrogen, respectively). C and N were more present in the humic acid fraction. Lowest C mineralization was recorded from shallow soils on basaltic/andesites. C mineralization rates at 2°C were significant lower than at higher temperatures. Ornithogenic soils presented the lowest values of C-CO 2 mineralized by g of C. On the other hand, shallow soils on basaltic/andesites were the most sensitive sites to emit C-CO 2 by g of C. With permafrost degradation, soils on basaltic/andesites and sulfates are expected to release more C-CO 2 than ornithogenic soils. With greater clay contents, more protection was afforded to soil organic matter, with lower microbial activity and mineralization. The trend of soil temperature increases will favor C-CO 2 emissions, especially in the reduced pool of C stored and protected on permafrost, or in occasional Histosols. Copyright © 2016 Elsevier B.V. All rights reserved.

Soil water management

International Nuclear Information System (INIS)

Nielsen, D.R.; Cassel, D.K.

1984-01-01

The use of radiation and tracer techniques in investigations into soil water management in agriculture, hydrology etc. is described. These techniques include 1) neutron moisture gauges to monitor soil water content and soil water properties, 2) gamma radiation attenuation for measuring the total density of soil and soil water content, 3) beta radiation attenuation for measuring changes in the water status of crop plants and 4) radioactive and stable tracers for identifying pathways, reactions and retention times of the constituents in soils and groundwater aquifers. The number and spacing of soil observations that should be taken to represent the management unit are also considered. (U.K.)

Soils in Schools: Embedding Soil Science in STEM

Science.gov (United States)

Bryce, Alisa

2015-01-01

Soil science, though relevant to a variety of subjects including science, geography, mathematics, social sciences and history, is typically perceived as a subgenre of agriculture. With a global need for soil scientists, and declining numbers in university soil courses, there's a growing gap between science needs and providers. One way to promote…

Soil algae

African Journals Online (AJOL)

Timothy Ademakinwa

Also, the importance of algae in soil formation and soil fertility improvement cannot be over ... The presence of nitrogen fixing microalgae (Nostoc azollae) in the top soil of both vegetable ..... dung, fish food and dirty water from fish ponds on.

Effect of soil texture on phytoremediation of arsenic-contaminated soils

Science.gov (United States)

Pallud, C. E.; Matzen, S. L.; Olson, A.

2015-12-01

Soil arsenic (As) contamination is a global problem, resulting in part from anthropogenic activities, including the use of arsenical pesticides and treated wood, mining, and irrigated agriculture. Phytoextraction using the hyperaccumulating fern Pteris vittata is a promising new technology to remediate soils with shallow arsenic contamination with minimal site disturbance. However, many challenges still lie ahead for a global application of phytoremediation. For example, remediation times using P. vittata are on the order of decades. In addition, most research on As phytoextraction with P. vittata has examined As removal from sandy soils, where As is more available, with little research focusing on As removal from clayey soils, where As is less available. The objective of this study is to determine the effects of soil texture and soil fertilization on As extraction by P. vittata, to optimize remediation efficiency and decrease remediation time under complex field conditions. A field study was established 2.5 years ago in an abandoned railroad grade contaminated with As (average 85.5 mg kg-1) with texture varying from sandy loam to silty clay loam. Organic N, inorganic N, organic P, inorganic P, and compost were applied to separate sub-plots; control ferns were grown in untreated soil. In a parallel greenhouse experiment, ferns were grown in sandy loam soil extracted from the field (180 mg As kg-1), with similar treatments as those used at the field site, plus a high phosphate treatment and treatments with arbuscular mycorrhizal fungi. In the field study, fern mortality was 24% higher in clayey soil than in sandy soil due to waterlogging, while As was primarily associated with sandy soil. Results from the sandy loam soil indicate that soil treatments did not significantly increase As phytoextraction, which was lower in phosphate-treated ferns than in control ferns, both in the field and greenhouse study. Under greenhouse conditions, ferns treated with organic N were

Six-phase soil heating accelerates VOC extraction from clay soil

International Nuclear Information System (INIS)

Gauglitz, P.A.; Roberts, J.S.; Bergsman, T.M.; Caley, S.M.; Heath, W.O.; Miller, M.C.; Moss, R.W.; Schalla, R.; Jarosch, T.R.; Eddy-Dilek, C.A.

1994-08-01

Six-Phase Soil Heating (SPSH) was demonstrated as a viable technology for heating low permeability soils containing volatile organic contaminants. Testing was performed as part of the Volatile Organic Compounds in Non-Arid Soils Integrated Demonstration (VOC Non-Arid ID) at the Savannah River Site. The soil at the integrated demonstration site is contaminated with perchloroethylene (PCE) and trichloroethylene (TCE); the highest soil contamination occurs in clay-rich zones that are ineffectively treated by conventional soil vapor extraction due to the very low permeability of the clay. The SPSH demonstration sought to heat the clay zone and enhance the performance of conventional soil vapor extraction. Thermocouples at thirty locations quantified the areal and vertical heating within the treated zone. Soil samples were collected before and after heating to quantify the efficacy of heat-enhanced vapor extraction of PCE and TCE from the clay soil. Samples were taken (essentially every foot) from six wells prior to heating and adjacent to these wells after heating. Results show that contaminant removal from the clay zone was 99.7% (median) within the electrode array. Outside the array where the soil was heated, but to only 50 degrees C, the removal efficiency was 93%, showing that heating accelerated the removal of VOCs from the clay soil. The accelerated remediation resulted from effective heating of the contaminated clay zone by SPSH. The temperature of the clay zone increased to 100 degrees C after 8 days of heating and was maintained near 100 degrees C for 17 days. Electrical heating removed 19,000 gal of water from the soil as steam, with peak removal rate of 1,500 gpd of condensed steam

Soil compaction: Evaluation of stress transmission and resulting soil structure

Science.gov (United States)

Naveed, Muhammad; Schjønning, Per; Keller, Thomas; Lamande, Mathieu

2016-04-01

Accurate estimation of stress transmission and resultant deformation in soil profiles is a prerequisite for the development of predictive models and decision support tools for preventing soil compaction. Numerous studies have been carried out on the effects of soil compaction, whilst relatively few studies have focused on the cause (mode of stress transmission in the soil). We have coupled both cause and effects together in the present study by carrying out partially confined compression tests on (1) wet aggregates, (2) air dry aggregates, and (3) intact soils to quantify stress transmission and compaction-resulted soil structure at the same time. Stress transmission was quantified using both X-ray CT and Tactilus sensor mat, and soil-pore structure was quantified using X-ray CT. Our results imply that stress transmission through soil highly depends on the magnitude of applied load and aggregate strength. As soon as the applied load is lower than the aggregate strength, the mode of stress transmission is discrete as stresses were mainly transmitted through chain of aggregates. With increasing applied load soil aggregates start deforming that transformed heterogeneous soil into homogenous, as a result stress transmission mode was shifted from discrete towards more like a continuum. Continuum-like stress transmission mode was better simulated with Boussinesq (1885) model based on theory of elasticity compared to discrete. The soil-pore structure was greatly affected by increasing applied stresses. Total porosity was reduced 5-16% and macroporosity 50-85% at 620 kPa applied stress for the intact soils. Similarly, significant changes in the morphological indices of the macropore space were also observed with increasing applied stresses.

The effect of intrinsic soil properties on soil quality assessments

Directory of Open Access Journals (Sweden)

Alessandro Samuel-Rosa

2013-10-01

Full Text Available The assessment of soil quality is based on indicators and indices derived from soil properties. However, intrinsic soil properties may interfere with other soil properties that vary under different land uses and are used to calculate the indices. The aim of this study was to assess the extent to which intrinsic soil properties (clay and iron oxide contents explain variable soil properties (sum of bases, potential acidity, organic carbon, total porosity, and bulk density under different land uses (native forest, no-tillage and conventional agriculture on small family farms in Southern Brazil. The results showed that the five properties evaluated can be included in soil quality assessments and are not influenced by the clay and iron oxide contents. It was concluded that for little weathered 1:1 and 2:1 phyllosilicate rich-soils, if the difference between the maximum and the minimum clay content under the different land uses is less than about 200 g kg-1 and the iron oxide content less than about 15 g kg-1, the physico-chemical soil properties in the surface layer are determined mostly by the land use.

Soil Microbes and soil microbial proteins: interactions with clay minerals

International Nuclear Information System (INIS)

Spence, A.; Kelleher, B. P.

2009-01-01

Bacterial enumeration in soil environments estimates that the population may reach approximately 10 1 0 g - 1 of soil and comprise up to 90% of the total soil microbial biomass. Bacteria are present in soils as single cells or multicell colonies and often strongly adsorb onto mineral surfaces such as sand and clay. The interactions of microbes and microbial biomolecules with these minerals have profound impacts on the physical, chemical and biological properties of soils. (Author)

Continuous soil monitoring and inventory of soils as part of the soil information system

International Nuclear Information System (INIS)

Schilling, B.

1993-01-01

The Bavarian Geological State office conducted a soil inventory and continuous soil monitoring programme. In order to make permanent monitoring feasible the Bavarian Geological State office developed a special concept. This concept of site selection, commissioning, sampling and analysis is described in this paper. The results of first studies of the three permanent soil monitoring areas in the Alpine region shows that only on the Gotzenalm in the national park in Berchtegaden there are significant accumulations of Cs-137 and of some other typically anthropogenic heavy metals in the top soil. Organic pollution is small in all three areas. (orig./EW) [de

Soil Functional Mapping: A Geospatial Framework for Scaling Soil Carbon Cycling

Science.gov (United States)

Lawrence, C. R.

2017-12-01

Climate change is dramatically altering biogeochemical cycles in most terrestrial ecosystems, particularly the cycles of water and carbon (C). These changes will affect myriad ecosystem processes of importance, including plant productivity, C exports to aquatic systems, and terrestrial C storage. Soil C storage represents a critical feedback to climate change as soils store more C than the atmosphere and aboveground plant biomass combined. While we know plant and soil C cycling are strongly coupled with soil moisture, substantial unknowns remain regarding how these relationships can be scaled up from soil profiles to ecosystems. This greatly limits our ability to build a process-based understanding of the controls on and consequences of climate change at regional scales. In an effort to address this limitation we: (1) describe an approach to classifying soils that is based on underlying differences in soil functional characteristics and (2) examine the utility of this approach as a scaling tool that honors the underlying soil processes. First, geospatial datasets are analyzed in the context of our current understanding of soil C and water cycling in order to predict soil functional units that can be mapped at the scale of ecosystems or watersheds. Next, the integrity of each soil functional unit is evaluated using available soil C data and mapping units are refined as needed. Finally, targeted sampling is conducted to further differentiate functional units or fill in any data gaps that are identified. Completion of this workflow provides new geospatial datasets that are based on specific soil functions, in this case the coupling of soil C and water cycling, and are well suited for integration with regional-scale soil models. Preliminary results from this effort highlight the advantages of a scaling approach that balances theory, measurement, and modeling.

Effects of soil management techniques on soil water erosion in apricot orchards.

Science.gov (United States)

Keesstra, Saskia; Pereira, Paulo; Novara, Agata; Brevik, Eric C; Azorin-Molina, Cesar; Parras-Alcántara, Luis; Jordán, Antonio; Cerdà, Artemi

2016-05-01

Soil erosion is extreme in Mediterranean orchards due to management impact, high rainfall intensities, steep slopes and erodible parent material. Vall d'Albaida is a traditional fruit production area which, due to the Mediterranean climate and marly soils, produces sweet fruits. However, these highly productive soils are left bare under the prevailing land management and marly soils are vulnerable to soil water erosion when left bare. In this paper we study the impact of different agricultural land management strategies on soil properties (bulk density, soil organic matter, soil moisture), soil water erosion and runoff, by means of simulated rainfall experiments and soil analyses. Three representative land managements (tillage/herbicide/covered with vegetation) were selected, where 20 paired plots (60 plots) were established to determine soil losses and runoff. The simulated rainfall was carried out at 55mmh(-1) in the summer of 2013 (soil moisture) for one hour on 0.25m(2) circular plots. The results showed that vegetation cover, soil moisture and organic matter were significantly higher in covered plots than in tilled and herbicide treated plots. However, runoff coefficient, total runoff, sediment yield and soil erosion were significantly higher in herbicide treated plots compared to the others. Runoff sediment concentration was significantly higher in tilled plots. The lowest values were identified in covered plots. Overall, tillage, but especially herbicide treatment, decreased vegetation cover, soil moisture, soil organic matter, and increased bulk density, runoff coefficient, total runoff, sediment yield and soil erosion. Soil erosion was extremely high in herbicide plots with 0.91Mgha(-1)h(-1) of soil lost; in the tilled fields erosion rates were lower with 0.51Mgha(-1)h(-1). Covered soil showed an erosion rate of 0.02Mgha(-1)h(-1). These results showed that agricultural management influenced water and sediment dynamics and that tillage and herbicide

Dynamics of soil organic carbon and microbial activity in treated wastewater irrigated agricultural soils along soil profiles

Science.gov (United States)

Jüschke, Elisabeth; Marschner, Bernd; Chen, Yona; Tarchitzky, Jorge

2010-05-01

Treated wastewater (TWW) is an important source for irrigation water in arid and semiarid regions and already serves as an important water source in Jordan, the Palestinian Territories and Israel. Reclaimed water still contains organic matter (OM) and various compounds that may effect microbial activity and soil quality (Feigin et al. 1991). Natural soil organic carbon (SOC) may be altered by interactions between these compounds and the soil microorganisms. This study evaluates the effects of TWW irrigation on the quality, dynamics and microbial transformations of natural SOC. Priming effects (PE) and SOC mineralization were determined to estimate the influence of TWW irrigation on SOC along soil profiles of agricultural soils in Israel and the Westbank. The used soil material derived from three different sampling sites allocated in Israel and The Palestinian Authority. Soil samples were taken always from TWW irrigated sites and control fields from 6 different depths (0-10, 10-20, 20-30, 30-50, 50-70, 70-100 cm). Soil carbon content and microbiological parameters (microbial biomass, microbial activities and enzyme activities) were investigated. In several sites, subsoils (50-160 cm) from TWW irrigated plots were depleted in soil organic matter with the largest differences occurring in sites with the longest TWW irrigation history. Laboratory incubation experiments with additions of 14C-labelled compounds to the soils showed that microbial activity in freshwater irrigated soils was much more stimulated by sugars or amino acids than in TWW irrigated soils. The lack of such "priming effects" (Hamer & Marschner 2005) in the TWW irrigated soils indicates that here the microorganisms are already operating at their optimal metabolic activity due to the continuous substrate inputs with soluble organic compounds from the TWW. The fact that PE are triggered continuously due to TWW irrigation may result in a decrease of SOC over long term irrigation. Already now this could be

Degradation kinetics of ptaquiloside in soil and soil solution.

Science.gov (United States)

Ovesen, Rikke Gleerup; Rasmussen, Lars Holm; Hansen, Hans Christian Bruun

2008-02-01

Ptaquiloside (PTA) is a carcinogenic norsesquiterpene glycoside produced in bracken (Pteridium aquilinum (L.) Kuhn), a widespread, aggressive weed. Transfer of PTA to soil and soil solution eventually may contaminate groundwater and surface water. Degradation rates of PTA were quantified in soil and soil solutions in sandy and clayey soils subjected to high natural PTA loads from bracken stands. Degradation kinetics in moist soil could be fitted with the sum of a fast and a slow first-order reaction; the fast reaction contributed 20 to 50% of the total degradation of PTA. The fast reaction was similar in all horizons, with the rate constant k(1F) ranging between 0.23 and 1.5/h. The slow degradation, with the rate constant k(1S) ranging between 0.00067 and 0.029/ h, was more than twice as fast in topsoils compared to subsoils, which is attributable to higher microbial activity in topsoils. Experiments with sterile controls confirmed that nonmicrobial degradation processes constituted more than 90% of the fast degradation and 50% of the slow degradation. The lower nonmicrobial degradation rate observed in the clayey compared with the sandy soil is attributed to a stabilizing effect of PTA by clay silicates. Ptaquiloside appeared to be stable in all soil solutions, in which no degradation was observed within a period of 28 d, in strong contrast to previous studies of hydrolysis rates in artificial aqueous electrolytes. The present study predicts that the risk of PTA leaching is controlled mainly by the residence time of pore water in soil, soil microbial activity, and content of organic matter and clay silicates.

Spectral Assessment of Soil Properties: Standoff Quantification of Soil Organic Matter Content in Surface Mineral Soils and Alaskan Peat

Science.gov (United States)

2017-08-01

Soil Properties Standoff Quantification of Soil Organic Matter Content in Surface Mineral Soils and Alaskan Peat En gi ne er R es ea rc h an d D...ERDC 6.2 GRE ARTEMIS STO-R DRTSPORE ERDC TR-17-9 August 2017 Spectral Assessment of Soil Properties Standoff Quantification of Soil Organic...Matter Content in Surface Mineral Soils and Alaskan Peat Stacey L. Jarvis, Karen L. Foley, Robert M. Jones, Stephen D. Newman, and Robyn A. Barbato

Soil management planning for military installations: Strategy for identifying contaminated soils

International Nuclear Information System (INIS)

Makdisi, R.S.; Baskin, D.A.; Downey, D.; Taffinder, S.A.

1992-01-01

Numerous federal and state regulations mandate the proper handling and disposal and/or treatment of contaminated soils. The Land Disposal Ban and the increasing lack of new or proximal land disposal facilities, coupled with the increasing liability of off-site disposal, have created a need for altering the traditional methods of managing contaminated sods. To delineate soil management decisions, a Soil Management Plan (SMP) was developed which incorporates the substantive requirements of CERCLA/SARA and RCRA into the ongoing base activities (i.e., construction projects, utility repairs and maintenance) and other environmental projects (i.e., underground storage tank removals) that may involve contaminated soils. The decision-making process is developed to guide base personnel in recognizing contamination, following proper sampling and temporary storage procedures, preventing unnecessary human exposure and isolating soils for removal off-site or treatment on-site. The SMP also contains a comprehensive review of soil remediation technologies, such as biological treatment, soil vapor extraction, soil washing, biofiltering, thermal desorption, soil stabilization/solidification, chemical/physical treatment and incineration. Contaminant types expected at the federal military facility are cross-referenced to the appropriate remediation technologies to determine the specific base needs for a soil treatment unit. An example of a conceptual design for a hydrocarbon-contaminated soil treatment unit is presented for a base where underground fuel tanks are the principal source of soil contamination

Effects of environmental factors and soil properties on topographic variations of soil respiration

OpenAIRE

Tamai, K.

2010-01-01

Soil respiration rates were measured along different parts of a slope in (a) an evergreen forest with common brown forest soil and (b) a deciduous forest with immature soil. The effects of soil temperature, soil moisture and soil properties were estimated individually, and the magnitudes of these effects in the deciduous and evergreen forests were compared. In the evergreen forest with common brown forest soil, soil properties had the greatest effect on soil respiration rates, followed by soi...

Modelling soil organic carbon concentration of mineral soils in arable lands using legacy soil data

DEFF Research Database (Denmark)

Suuster, E; Ritz, Christian; Roostalu, H

2012-01-01

is appropriate if the study design has a hierarchical structure as in our scenario. We used the Estonian National Soil Monitoring data on arable lands to predict SOC concentrations of mineral soils. Subsequently, the model with the best prediction accuracy was applied to the Estonian digital soil map...

Effects of Soil Oxygen Conditions and Soil pH on Remediation of DDT-contaminated Soil by Laccase from White Rot Fungi

Directory of Open Access Journals (Sweden)

Yuechun Zhao

2010-04-01

Full Text Available High residues of DDT in agricultural soils are of concern because they present serious threats to food security and human health. This article focuses on remediation of DDT-contaminated soil using laccase under different soil oxygen and soil pH conditions. The laboratory experiment results showed significant effects of soil oxygen conditions and soil pH on remediation of DDT-contaminated soil by laccase at the end of a 25-d incubation period. This study found the positive correlation between the concentration of oxygen in soil and the degradation of DDT by laccase. The residue of DDTs in soil under the atmosphere of oxygen decreased by 28.1% compared with the atmosphere of nitrogen at the end of the incubation with laccase. A similar pattern was observed in the remediation of DDT-contaminated soil by laccase under different flooding conditions, the higher the concentrations of oxygen in soil, the lower the residues of four DDT components and DDTs in soils. The residue of DDTs in the nonflooding soil declined by 16.7% compared to the flooded soil at the end of the incubation. The residues of DDTs in soils treated with laccase were lower in the pH range 2.5–4.5.

Soil microbial activities and its relationship with soil chemical ...

African Journals Online (AJOL)

The fields assessed are organically managed Soils (OMS), Inorganically Managed Soils (IMS) and an Uncultivated Land having grass coverage (ULS). Soil Microbial Respiration (SMR), Microbial Biomass Carbon (MBC), Microbial Biomass Nitrogen (MBN) and Microbial Biomass Phosphorus (MBP) were analyzed.

Organic components and plutonium and americium state in soils and soil solutions

International Nuclear Information System (INIS)

Sokolik, G.A.; Ovsyannikova, S.V.; Kimlenko, I.M.

2002-01-01

The fraction composition of humus substances of different type soils and soil solutions have been studied. A distribution of Pu 239, 240 and Am 241 between humus substances fractions of different dispersity and mobility in soil-vegetation cover has been established. It was shown that humus of organic soils fixes plutonium and americium in soil medium in greater extent than humus of mineral soils. That leads to lower migration ability of radionuclides in organic soils. The lower ability of americium to form difficultly soluble organic and organic-mineral complexes and predomination of its anion complexes in soil solutions may be a reason of higher mobility and biological availability of americium in comparison to plutonium during soil-plant transfer (authors)

[Effect of trampling disturbance on soil infiltration of biological soil crusts].

Science.gov (United States)

Shi, Ya Fang; Zhao, Yun Ge; Li, Chen Hui; Wang, Shan Shan; Yang, Qiao Yun; Xie, Shen Qi

2017-10-01

The effect of trampling disturbance on soil infiltration of biological soil crusts was investigated by using simulated rainfall. The results showed that the trampling disturbance significantly increased soil surface roughness. The increasing extent depended on the disturbance intensity. Soil surface roughness values at 50% disturbance increased by 91% compared with the undisturbed treatment. The runoff was delayed by trampling disturbance. A linear increase in the time of runoff yield was observed along with the increasing disturbance intensity within 20%-50%. The time of runoff yield at 50% disturbance increased by 169.7% compared with the undisturbed treatment. Trampling disturbance increased soil infiltration and consequently decreased the runoff coefficient. The cumulative infiltration amount at 50% disturbance increased by 12.6% compared with the undisturbed treatment. Soil infiltration significant decreased when biocrusts were removed. The cumulative infiltration of the treatment of biocrusts removal decreased by 30.2% compared with the undisturbed treatment. Trampling disturbance did not significantly increase the soil loss when the distur bance intensity was lower than 50%, while the biocrusts removal resulted in 10 times higher in soil erosion modulus. The trampling disturbance of lower than 50% on biocrusts might improve soil infiltration and reduce the risk of runoff, thus might improve the soil moisture without obviously increa sing the soil loss.

[Response of mineralization of dissolved organic carbon to soil moisture in paddy and upland soils in hilly red soil region].

Science.gov (United States)

Chen, Xiang-Bi; Wang, Ai-Hua; Hu, Le-Ning; Huang, Yuan; Li, Yang; He, Xun-Yang; Su, Yi-Rong

2014-03-01

Typical paddy and upland soils were collected from a hilly subtropical red-soil region. 14C-labeled dissolved organic carbon (14C-DOC) was extracted from the paddy and upland soils incorporated with 14C-labeled straw after a 30-day (d) incubation period under simulated field conditions. A 100-d incubation experiment (25 degrees C) with the addition of 14C-DOC to paddy and upland soils was conducted to monitor the dynamics of 14C-DOC mineralization under different soil moisture conditions [45%, 60%, 75%, 90%, and 105% of the field water holding capacity (WHC)]. The results showed that after 100 days, 28.7%-61.4% of the labeled DOC in the two types of soils was mineralized to CO2. The mineralization rates of DOC in the paddy soils were significantly higher than in the upland soils under all soil moisture conditions, owing to the less complex composition of DOC in the paddy soils. The aerobic condition was beneficial for DOC mineralization in both soils, and the anaerobic condition was beneficial for DOC accumulation. The biodegradability and the proportion of the labile fraction of the added DOC increased with the increase of soil moisture (45% -90% WHC). Within 100 days, the labile DOC fraction accounted for 80.5%-91.1% (paddy soil) and 66.3%-72.4% (upland soil) of the cumulative mineralization of DOC, implying that the biodegradation rate of DOC was controlled by the percentage of labile DOC fraction.

Clay minerals, metallic oxides and oxy-hydroxides and soil organic carbon distribution within soil aggregates in temperate forest soils

Science.gov (United States)

Gartzia-Bengoetxea, Nahia; Fernández-Ugalde, Oihane; Virto, Iñigo; Arias-González, Ander

2017-04-01

Soil mineralogy is of primary importance for key environmental services provided by soils like carbon sequestration. However, current knowledge on the effects of clay mineralogy on soil organic carbon (SOC) stabilization is based on limited and conflicting data. In this study, we investigated the relationship between clay minerals, metallic oxides and oxy-hydroxides and SOC distribution within soil aggregates in mature Pinus radiata D.Don forest plantations. Nine forest stands located in the same geographical area of the Basque Country (North of Spain) were selected. These stands were planted on different parent material (3 on each of the following: sandstone, basalt and trachyte). There were no significant differences in climate and forest management among them. Moreover, soils under these plantations presented similar content of clay particles. We determined bulk SOC storage, clay mineralogy, the content of Fe-Si-Al-oxides and oxyhydroxides and the distribution of organic C in different soil aggregate sizes at different soil depths (0-5 cm and 5-20 cm). The relationship between SOC and abiotic factors was investigated using a factor analysis (PCA) followed by stepwise regression analysis. Soils developed on sandstone showed significantly lower concentration of SOC (29 g C kg-1) than soils developed on basalts (97 g C kg-1) and trachytes (119 g C kg-1). The soils on sandstone presented a mixed clay mineralogy dominated by illite, with lesser amounts of hydroxivermiculite, hydrobiotite and kaolinite, and a total absence of interstratified chlorite/vermiculite. In contrast, the major crystalline clay mineral identified in the soils developed on volcanic rocks was interstratified chlorite/vermiculite. Nevertheless, no major differences were observed between basaltic and trachytic soils in the clay mineralogy. The selective extraction of Fe showed that the oxalate extractable iron was significantly lower in soils on sandstone (3.7%) than on basalts (11.2%) and

Synthesis of soil-hydraulic properties and infiltration timescales in wildfire-affected soils

Science.gov (United States)

Ebel, Brian A.; Moody, John A.

2017-01-01

We collected soil-hydraulic property data from the literature for wildfire-affected soils, ash, and unburned soils. These data were used to calculate metrics and timescales of hydrologic response related to infiltration and surface runoff generation. Sorptivity (S) and wetting front potential (Ψf) were significantly different (lower) in burned soils compared with unburned soils, whereas field-saturated hydraulic conductivity (Kfs) was not significantly different. The magnitude and duration of the influence of capillarity during infiltration was greatly reduced in burned soils, causing faster ponding times in response to rainfall. Ash had large values of S and Kfs but moderate values of Ψf, compared with unburned and burned soils, indicating ash has long ponding times in response to rainfall. The ratio of S2/Kfs was nearly constant (~100 mm) for unburned soils but more variable in burned soils, suggesting that unburned soils have a balance between gravity and capillarity contributions to infiltration that may depend on soil organic matter, whereas in burned soils the gravity contribution to infiltration is greater. Changes in S and Kfs in burned soils act synergistically to reduce infiltration and accelerate and amplify surface runoff generation. Synthesis of these findings identifies three key areas for future research. First, short timescales of capillary influences on infiltration indicate the need for better measurements of infiltration at times less than 1 min to accurately characterize S in burned soils. Second, using parameter values, such as Ψf, from unburned areas could produce substantial errors in hydrologic modeling when used without adjustment for wildfire effects, causing parameter compensation and resulting underestimation of Kfs. Third, more thorough measurement campaigns that capture soil-structural changes, organic matter impacts, quantitative water repellency trends, and soil-water content along with soil-hydraulic properties could drive the

Remediation of soils combining soil vapor extraction and bioremediation: benzene.

Science.gov (United States)

Soares, António Alves; Albergaria, José Tomás; Domingues, Valentina Fernandes; Alvim-Ferraz, Maria da Conceição M; Delerue-Matos, Cristina

2010-08-01

This work reports the study of the combination of soil vapor extraction (SVE) with bioremediation (BR) to remediate soils contaminated with benzene. Soils contaminated with benzene with different water and natural organic matter contents were studied. The main goals were: (i) evaluate the performance of SVE regarding the remediation time and the process efficiency; (ii) study the combination of both technologies in order to identify the best option capable to achieve the legal clean up goals; and (iii) evaluate the influence of soil water content (SWC) and natural organic matter (NOM) on SVE and BR. The remediation experiments performed in soils contaminated with benzene allowed concluding that: (i) SVE presented (a) efficiencies above 92% for sandy soils and above 78% for humic soils; (b) and remediation times from 2 to 45 h, depending on the soil; (ii) BR showed to be an efficient technology to complement SVE; (iii) (a) SWC showed minimum impact on SVE when high airflow rates were used and led to higher remediation times for lower flow rates; (b) NOM as source of microorganisms and nutrients enhanced BR but hindered the SVE due the limitation on the mass transfer of benzene from the soil to the gas phase. (c) 2010 Elsevier Ltd. All rights reserved.

Biochar has no effect on soil respiration across Chinese agricultural soils.

Science.gov (United States)

Liu, Xiaoyu; Zheng, Jufeng; Zhang, Dengxiao; Cheng, Kun; Zhou, Huimin; Zhang, Afeng; Li, Lianqing; Joseph, Stephen; Smith, Pete; Crowley, David; Kuzyakov, Yakov; Pan, Genxing

2016-06-01

Biochar addition to soil has been widely accepted as an option to enhance soil carbon sequestration by introducing recalcitrant organic matter. However, it remains unclear whether biochar will negate the net carbon accumulation by increasing carbon loss through CO2 efflux from soil (soil respiration). The objectives of this study were to address: 1) whether biochar addition increases soil respiration; and whether biochar application rate and biochar type (feedstock and pyrolyzing system) affect soil respiration. Two series of field experiments were carried out at 8 sites representing the main crop production areas in China. In experiment 1, a single type of wheat straw biochar was amended at rates of 0, 20 and 40 tha(-1) in four rice paddies and three dry croplands. In experiment 2, four types of biochar (varying in feedstock and pyrolyzing system) were amended at rates of 0 and 20 tha(-1) in a rice paddy under rice-wheat rotation. Results showed that biochar addition had no effect on CO2 efflux from soils consistently across sites, although it increased topsoil organic carbon stock by 38% on average. Meanwhile, CO2 efflux from soils amended with 40 t of biochar did not significantly higher than soils amended with 20 t of biochar. While the biochars used in Experiment 2 had different carbon pools and physico-chemical properties, they had no effect on soil CO2 efflux. The soil CO2 efflux following biochar addition could be hardly explained by the changes in soil physic-chemical properties and in soil microbial biomass. Thus, we argue that biochar will not negate the net carbon accumulation by increasing carbon loss through CO2 efflux in agricultural soils. Copyright © 2016. Published by Elsevier B.V.

Soil solid-phase controls lead activity in soil solution.

Science.gov (United States)

Badawy, S H; Helal, M I D; Chaudri, A M; Lawlor, K; McGrath, S P

2002-01-01

Lead pollution of the environment is synonymous with civilization. It has no known biological function, and is naturally present in soil, but its presence in food crops is deemed undesirable. The concern regarding Pb is mostly due to chronic human and animal health effects, rather then phytotoxicity. However, not much is known about the chemistry and speciation of Pb in soils. We determined the activity of Pb2+, in near neutral and alkaline soils, representative of alluvial, desertic and calcareous soils of Egypt, using the competitive chelation method. Lead activity ranged from 10(-6.73) to 10(-4.83) M, and was negatively correlated with soil and soil solution pH (R2 = -0.92, P soil solution from the equation: log(Pb2+) = 9.9 - 2pH. A solubility diagram for the various Pb minerals found in soil was constructed using published thermodynamic data obtained from the literature, and our measured Pb2+ activities compared with this information. The measured Pb2+ activities were undersaturated with regard to the solubility of PbSiO3 in equilibrium with SiO2 (soil). However, they were supersaturated with regard to the solubilities of the Pb carbonate minerals PbCO3 (cerussite) and Pb3(CO3)2(OH)2 in equilibrium with atmospheric CO2 and hydroxide Pb(OH)2. They were also supersaturated with regard to the solubilities of the Pb phosphate minerals Pb3(PO4)2, Pb5(PO4)3OH, and Pb4O(PO4)2 in equilibrium with tricalcium phosphate and CaCO3. The activity of Pb2+ was not regulated by any mineral of known solubility in our soils, but possibly by a mixture of Pb carbonate and phosphate minerals.

Stimulation of soil microorganisms in pesticide-contaminated soil using organic materials

Directory of Open Access Journals (Sweden)

Ima Yudha Perwira

2016-08-01

Full Text Available Agrochemicals such as pesticides have contributed to significant increases in crop yields; however, they can also be linked to adverse effects on human health and soil microorganisms. For efficient bioremediation of pesticides accumulated in agricultural fields, stimulation of microorganisms is necessary. In this study, we investigated the relationships between bacterial biomass and total carbon (TC and total nitrogen (TN in 427 agricultural soils. The soil bacterial biomass was generally positively correlated with TC and TN contents in the soil, but some soils had a low bacterial biomass despite containing high amounts of TC and TN. Soils of two fields (fields A and B with low bacterial biomass but high TC and TN contents were investigated. Long-term pesticide use (dichloropropane-dichloropropene and fosthiazate in field A and chloropicrin in field B appeared to have contributed to the low bacterial biomass observed in these soils. Soil from field A was treated with different organic materials and incubated for 1 month under laboratory conditions. The bacterial biomass in field A soil was enhanced in treatments containing organic materials rich in TN. Application of organic materials stimulated the growth of microorganisms with the potential to bioremediate pesticide-polluted soils.

Decreased Soil Nitrification Rate with Addition of Biochar to Acid Soils

Institute of Scientific and Technical Information of China (English)

Shiyu LI; Xiangshu DONG; Dandan LIU; Li LIU; Feifei HE

2017-01-01

This study was conducted to investigate the effects of mixed biochar on the nitrification rate in acidic soils. A 15N tracer experiment with (15NH4)2SO4 was conducted to determine the nitrification rates of 4 acidic agricultural soils with pH 4.03-6.02in Yunnan Province, Southern China. The accumulation of 15N-NO3 - and nitrification rates decreased with the addition of biochar at the end of incubation, suggesting that biochar could be a nitrification inhibitor in acidic fertilized soil. Nitrification rates in soil with pH 4.03 were evidently lower than those in soil with pH 4.81 -6.02 with or without biochar. Decreased nitrification rates were detected in the acidic soils with biochar. Soil pH controlled nitrification more than biochar in certain strongly acidic soils.

Microwave remote sensing of soil moisture for estimation of profile soil property

International Nuclear Information System (INIS)

Mattikalli, N.M.; Engman, E.T.; Ahuja, L.R.; Jackson, T.J.

1998-01-01

Multi-temporal microwave remotely-sensed soil moisture has been utilized for the estimation of profile soil property, viz. the soil hydraulic conductivity. Passive microwave remote sensing was employed to collect daily soil moisture data across the Little Washita watershed, Oklahoma, during 10-18 June 1992. The ESTAR (Electronically Steered Thin Array Radiometer) instrument operating at L -band was flown on a NASA C-130 aircraft. Brightness temperature (TB) data collected at a ground resolution of 200m were employed to derive spatial distribution of surface soil moisture. Analysis of spatial and temporal soil moisture information in conjunction with soils data revealed a direct relation between changes in soil moisture and soil texture. A geographical information system (GIS) based analysis suggested that 2-days initial drainage of soil, measured from remote sensing, was related to an important soil hydraulic property viz. the saturated hydraulic conductivity (Ksat). A hydrologic modelling methodology was developed for estimation of Ksat of surface and sub-surface soil layers. Specifically, soil hydraulic parameters were optimized to obtain a good match between model estimated and field measured soil moisture profiles. Relations between 2-days soil moisture change and Ksat of 0-5 cm, 0-30 cm and 0-60cm depths yielded correla tions of 0.78, 0.82 and 0.71, respectively. These results are comparable to the findings of previous studies involving laboratory-controlled experiments and numerical simulations, and support their extension to the field conditions of the Little Washita watershed. These findings have potential applications of microwave remote sensing to obtain 2-days of soil moisture and then to quickly estimate the spatial distribution of Ksat over large areas. (author)

Effect of integrating straw into agricultural soils on soil infiltration and evaporation.

Science.gov (United States)

Cao, Jiansheng; Liu, Changming; Zhang, Wanjun; Guo, Yunlong

2012-01-01

Soil water movement is a critical consideration for crop yield in straw-integrated fields. This study used an indoor soil column experiment to determine soil infiltration and evaporation characteristics in three forms of direct straw-integrated soils (straw mulching, straw mixing and straw inter-layering). Straw mulching is covering the land surface with straw. Straw mixing is mixing straw with the top 10 cm surface soil. Then straw inter-layering is placing straw at the 20 cm soil depth. There are generally good correlations among the mulch integration methods at p soil infiltration, followed by straw mulching. Due to over-burden weight-compaction effect, straw inter-layering somehow retarded soil infiltration. In terms of soil water evaporation, straw mulching exhibited the best effect. This was followed by straw mixing and then straw inter-layering. Straw inter-layering could have a long-lasting positive effect on soil evaporation as it limited the evaporative consumption of deep soil water. The responses of the direct straw integration modes to soil infiltration and evaporation could lay the basis for developing efficient water-conservation strategies. This is especially useful for water-scarce agricultural regions such as the arid/semi-arid regions of China.

Using USDA's National Cooperative Soil Survey Soil Characterization Data to detect soil change: A cautionary tale

Science.gov (United States)

Recently, the USDA-NRCS National Cooperative Soil Survey Soil Characterization Database (NSCD) was reported to provide evidence that total nitrogen (TN) stocks of agricultural soils have increased across the Mississippi basin since 1985. Unfortunately, due to omission of metadata from the NSCD, hist...

The UK Soil Observatory (UKSO) and mySoil app: crowdsourcing and disseminating soil information.

Science.gov (United States)

Robinson, David; Bell, Patrick; Emmett, Bridget; Panagos, Panos; Lawley, Russell; Shelley, Wayne

2017-04-01

Digital technologies in terms of web based data portals and mobiles apps offer a new way to provide both information to the public, and to engage the public in becoming involved in contributing to the effort of collecting data through crowdsourcing. We are part of the Landpotential.org consortium which is a global partnership committed to developing and supporting the adoption of freely available technology and tools for sustainable land use management, monitoring, and connecting people across the globe. The mySoil app was launched in 2012 and is an example of a free mobile application downloadable from iTunes and Google Play. It serves as a gateway tool to raise interest in, and awareness of, soils. It currently has over 50,000 dedicated users and has crowd sourced more than 4000 data records. Recent developments have expanded the coverage of mySoil from the United Kingdom to Europe, introduced a new user interface and provided language capability, while the UKSO displays the crowd-sourced records from across the globe. We are now trying to identify which industry, education and citizen sectors are using these platforms and how they can be improved. Please help us by providing feedback or taking the survey on the UKSO website. www.UKSO.org The UKSO is a collaboration between major UK soil-data holders to provide maps, spatial data and real-time temporal data from observing platforms such as the UK soil moisture network. Both UKSO and mySoil have crowdsourcing capability and are slowly building global citizen science maps of soil properties such as pH and texture. Whilst these data can't replace professional monitoring data, the information they provide both stimulates public interest and can act as 'soft data' that can help support the interpretation of monitoring data, or guide future monitoring, identifying areas that don't correspond with current analysis. In addition, soft data can be used to map soils with machine learning approaches, such as SoilGrids.

Implementing a physical soil water flow model with minimal soil characteristics and added value offered by surface soil moisture measurements assimilation.

Science.gov (United States)

Chanzy, André

2010-05-01

Soil moisture is a key variable for many soil physical and biogeochemical processes. Its dynamic results from water fluxes in soil and at its boundaries, as well as soil water storage properties. If the water flows are dominated by diffusive processes, modelling approaches based on the Richard's equation or the Philip and de Vries coupled heat and water flow equations lead to a satisfactory representation of the soil moisture dynamic. However, It requires the characterization of soil hydraulic functions, the initialisation and the boundary conditions, which are expensive to obtain. The major problem to assess soil moisture for decision making or for representing its spatiotemporal evolution over complex landscape is therefore the lack of information to run the models. The aim of the presentation is to analyse how a soil moisture model can be implemented when only climatic data and basic soil information are available (soil texture, organic matter) and what would be the added of making a few soil moisture measurements. We considered the field scale, which is the key scale for decision making application (the field being the management unit for farming system) and landscape modelling (field size being comparable to the computation unit of distributed hydrological models). The presentation is limited to the bare soil case in order to limit the complexity of the system and the TEC model based on Philip and De Vries equations is used in this study. The following points are addressed: o the within field spatial variability. This spatial variability can be induced by the soil hydraulic properties and/or by the amount of infiltrated water induced by water rooting towards infiltration areas. We analyse how an effective parameterization of soil properties and boundary conditions can be used to simulate the field average moisture. o The model implementation with limited information. We propose strategies that can be implemented when information are limited to soil texture and

An evaluation of different soil washing solutions for remediating arsenic-contaminated soils.

Science.gov (United States)

Wang, Yiwen; Ma, Fujun; Zhang, Qian; Peng, Changsheng; Wu, Bin; Li, Fasheng; Gu, Qingbao

2017-04-01

Soil washing is a promising way to remediate arsenic-contaminated soils. Most research has mostly focused on seeking efficient extractants for removing arsenic, but not concerned with any changes in soil properties when using this technique. In this study, the removal of arsenic from a heavily contaminated soil employing different washing solutions including H 3 PO 4 , NaOH and dithionite in EDTA was conducted. Subsequently, the changes in soil physicochemical properties and phytotoxicity of each washing technique were evaluated. After washing with 2 M H 3 PO 4 , 2 M NaOH or 0.1 M dithionite in 0.1 M EDTA, the soil samples' arsenic content met the clean-up levels stipulated in China's environmental regulations. H 3 PO 4 washing decreased soil pH, Ca, Mg, Al, Fe, and Mn concentrations but increased TN and TP contents. NaOH washing increased soil pH but decreased soil TOC, TN and TP contents. Dithionite in EDTA washing reduced soil TOC, Ca, Mg, Al, Fe, Mn and TP contents. A drastic color change was observed when the soil sample was washed with H 3 PO 4 or 0.1 M dithionite in 0.1 M EDTA. After adjusting the soil pH to neutral, wheat planted in the soil sample washed by NaOH evidenced the best growth of all three treated soil samples. These results will help with selecting the best washing solution when remediating arsenic-contaminated soils in future engineering applications. Copyright © 2017 Elsevier Ltd. All rights reserved.

Patterns and possible mechanisms of soil CO2 uptake in sandy soil.

Science.gov (United States)

Fa, Ke-Yu; Zhang, Yu-Qing; Wu, Bin; Qin, Shu-Gao; Liu, Zhen; She, Wei-Wei

2016-02-15

It has been reported that soils in drylands can absorb CO2, although the patterns and mechanisms of such a process remain under debate. To address this, we investigated the relationships between soil CO2 flux and meteorological factors and soil properties in Northwest China to reveal the reasons for "anomalous" soil CO2 flux in a desert ecosystem. Soil CO2 flux increased significantly and exponentially with surficial turbulence at the diel scale under dry conditions (Psoil CO2 flux demonstrated remarkable negative correlation with soil air pressure (Psoil water content was insufficient to dissolve the absorbed CO2 in dry conditions, but was sufficient in wet conditions. The concentration of soil HCO3(-) in the morning was higher than in the evening in dry conditions, but this pattern was reversed in wet conditions. These results imply that CO2 outgassing induced by turbulence, expansion of soil air, CO2 effusion from soil water, and carbonate precipitation during daytime can explain the abiotic diurnal CO2 release. Moreover, CO2 pumping from the atmosphere into the soil, caused mainly by carbonate dissolution, can account for nocturnal CO2 absorption in dry conditions. The abiotic soil CO2 flux pattern (CO2 absorption throughout the diel cycle) in wet conditions can be attributed to downward mass flow of soil CO2 and intensified soil air shrinkage, CO2 dissolving in soil water, and carbonate dissolution. These results provide a basis for determining the location of abiotic fixed carbon within soils in desert ecosystems. Copyright © 2015 Elsevier B.V. All rights reserved.

New perspectives on the soil erosion-soil quality relationship

International Nuclear Information System (INIS)

Pennock, D.J.

1998-01-01

The redistribution of soil has a profound impact on its quality (defined as its ability to function within its ecosystem and within adjacent ecosystems) and ultimately on its productivity for crop growth. The application of 137 Cs-redistribution techniques to the study of erosion has yielded major new insights into the soil erosion-soil quality relationship. In highly mechanized agricultural systems, tillage erosion can be the dominant cause of soil redistribution; in other agroecosystems, wind and water erosion dominate. Each causal factor results in characteristic landscape-scale patterns of redistribution. In landscapes dominated by tillage redistribution, highest losses occur in shoulder positions (those with convex downslope curvatures); in water-erosion-dominated landscapes, highest losses occur where slope gradient and length are at a maximum. Major impacts occur through the loss of organically-enriched surface material and through the incorporation of possibly yield-limiting subsoils into the rooting zone of the soil column. The potential impact of surface soil losses and concomitant subsoil incorporation on productivity may be assessed by examining the pedological nature of the affected soils and their position in the landscape. The development of sound conservation policies requires that the soil erosion-quality relationship be rigorously examined in the full range of pedogenic environments, and future applications of the 137 Cs technique hold considerable promise for providing this comprehensive global database. (author)

Development of soil-cement blocks with three interventions: natural soil, soil corrected with sand and soil more phase change materials (PCMs)

International Nuclear Information System (INIS)

Dantas, Valter Bezerra; Gomes, Uilame Umbelino; Reis, Edmilson Pedreira; Valcacer, Samara Melo; Silva, A.S.

2014-01-01

In this work, the results of characterization tests of soil samples collected in Mossoro-RN, UFERSA-RN Campus, located approximately 20 meters high, and "5 ° 12'34.68 south latitude and 37 ° 19'5.74 "west longitude, with the purpose of producing soil-cement for the manufacture of pressed blocks with good resistance to compression and thermal stability. The following tests were performed: granulometry, plasticity limit, liquidity limit, particle size correction, scanning electron microscopy (SEM), X-ray fluorescence. In this soil, based on the results of the granulometric analysis, 10% of medium sand with 3% and 5% of eicosane paraffin and 10% of medium sand with 3% and 5% of paraffin 120 / 125F were added, forming analysis compositions, standard soil-cement block and natural soil-cement block with addition of 10% medium sand and 0% paraffin. Paraffins are referred to as PCMs (Phase Change Material). The contrasting effect between the different dosages on the compressive strength values of the soil-cement blocks was observed. The objective is to create new materials that give the block quality equal to or higher than the recommendations of ABNT norms, and that offer greater thermal comfort in the constructions. Soil particles of different sizes were added to 8% (by weight) of cement, and about 9.20% of water added to the mixture

Global soil-climate-biome diagram: linking soil properties to climate and biota

Science.gov (United States)

Zhao, X.; Yang, Y.; Fang, J.

2017-12-01

As a critical component of the Earth system, soils interact strongly with both climate and biota and provide fundamental ecosystem services that maintain food, climate, and human security. Despite significant progress in digital soil mapping techniques and the rapidly growing quantity of observed soil information, quantitative linkages between soil properties, climate and biota at the global scale remain unclear. By compiling a large global soil database, we mapped seven major soil properties (bulk density [BD]; sand, silt and clay fractions; soil pH; soil organic carbon [SOC] density [SOCD]; and soil total nitrogen [STN] density [STND]) based on machine learning algorithms (regional random forest [RF] model) and quantitatively assessed the linkage between soil properties, climate and biota at the global scale. Our results demonstrated a global soil-climate-biome diagram, which improves our understanding of the strong correspondence between soils, climate and biomes. Soil pH decreased with greater mean annual precipitation (MAP) and lower mean annual temperature (MAT), and the critical MAP for the transition from alkaline to acidic soil pH decreased with decreasing MAT. Specifically, the critical MAP ranged from 400-500 mm when the MAT exceeded 10 °C but could decrease to 50-100 mm when the MAT was approximately 0 °C. SOCD and STND were tightly linked; both increased in accordance with lower MAT and higher MAP across terrestrial biomes. Global stocks of SOC and STN were estimated to be 788 ± 39.4 Pg (1015 g, or billion tons) and 63 ± 3.3 Pg in the upper 30-cm soil layer, respectively, but these values increased to 1654 ± 94.5 Pg and 133 ± 7.8 Pg in the upper 100-cm soil layer, respectively. These results reveal quantitative linkages between soil properties, climate and biota at the global scale, suggesting co-evolution of the soil, climate and biota under conditions of global environmental change.

Effects of soil amendment on soil characteristics and maize yield in Horqin Sandy Land

Science.gov (United States)

Zhou, L.; Liu, J. H.; Zhao, B. P.; Xue, A.; Hao, G. C.

2016-08-01

A 4-year experiment was conducted to investigate the inter-annual effects of sandy soil amendment on maize yield, soil water storage and soil enzymatic activities in sandy soil in Northeast China in 2010 to 2014. We applied the sandy soil amendment in different year, and investigated the different effects of sandy soil amendment in 2014. There were six treatments including: (1) no sandy soil amendment application (CK); (2) one year after applying sandy soil amendment (T1); (3) two years after applying sandy soil amendment(T2); (4) three years after applying sandy soil amendment(T3); (5)four years after applying sandy soil amendment(T4); (6) five years after applying sandy soil amendment (T5). T refers to treatment, and the number refers to the year after application of the sandy soil amendment. Comparing with CK, sandy soil amendments improved the soil water storage, soil urease, invertase, and catalase activity in different growth stages and soil layers, the order of soil water storage in all treatments roughly performed: T3 > T5 > T4 > T2 > T1 > CK. the order of soil urease, invertase, and catalase activity in all treatments roughly performed: T5 > T3 > T4 > T2 > T1 > CK. Soil application of sandy soil amendment significantly (p≤⃒0.05) increased the grain yield and biomass yield by 22.75%-41.42% and 29.92%-45.45% respectively, and maize yield gradually increased with the years go by in the following five years. Sandy soil amendment used in poor sandy soil had a positive effect on soil water storage, soil enzymatic activities and maize yield, after five years applied sandy soil amendment (T5) showed the best effects among all the treatments, and deserves further research.

Lability of soil organic carbon in tropical soils with different clay minerals

DEFF Research Database (Denmark)

Bruun, Thilde Bech; Elberling, Bo; Christensen, Bent Tolstrup

2010-01-01

Soil organic carbon (SOC) storage and turnover is influenced by interactions between organic matter and the mineral soil fraction. However, the influence of clay content and type on SOC turnover rates remains unclear, particularly in tropical soils under natural vegetation. We examined the lability...... of SOC in tropical soils with contrasting clay mineralogy (kaolinite, smectite, allophane and Al-rich chlorite). Soil was sampled from A horizons at six sites in humid tropical areas of Ghana, Malaysian Borneo and the Solomon Islands and separated into fractions above and below 250 µm by wet sieving....... Basal soil respiration rates were determined from bulk soils and soil fractions. Substrate induced respiration rates were determined from soil fractions. SOC lability was significantly influenced by clay mineralogy, but not by clay content when compared across contrasting clay minerals. The lability...

Sorters for soil cleanup

International Nuclear Information System (INIS)

Bramlitt, E.T.; Johnson, N.R.; Tomicich, M.J.

1991-01-01

A soil sorter is a system with conveyor, radiation detectors, and a gate. The system activates the gate based on radiation measurements to sort soil to either clean or contaminated paths. Automatic soil sorters have been perfected for use in the cleanup of plutonium contaminated soil at Johnston Atoll. The cleanup processes soil through a plant which mines plutonium to make soil clean. Sorters at various locations in the plant effectively reduce the volume of soil for mining and they aid in assuring clean soil meets guidelines

The World Soil Museum: education and advocacy on soils of the world

Science.gov (United States)

Mantel, Stephan; Land, Hiske

2013-04-01

The World Soil Museum (WSM) in Wageningen, is part of ISRIC World Soil Information and was founded in 1966 on request of the United Nations Educational, Scientific and Cultural Organization (UNESCO) and the International Soil Science Society. The World Soil Museum has a collection of over 1100 soil profiles from more than 70 countries. This soil profiles are vertical sections and show the composition, layering and structure of the soil. The collection is unique in the world and includes a significant number of soil profiles from the Netherlands. The Dutch soil collection is important for serving broader visitor groups, as some visitors, such as secondary school classes, are specifically interested in the Dutch landscape and soils. Broadly speaking, the World Soil Museum has five functions: (i) education and courses, (ii) research, (iii) information and edutainment, (iv) social function, and (v) a real museum function (Art). The World Soil Museum (World Soil Museum) is well known in national and international circles soil and the English name has almost 1,000 references on the Internet. The World Soil Museum is visited by about 1000 people a year, mainly university and college students from Western Europe. Other visitor groups that have found their way to the museum are students from disciplines broader then soil science, such as geography and rural development. Secondary school classes visit the museum for geography classes. The uniqueness and the value of the collection of soil profiles (soil monoliths) and associated collections, such as soil samples, hand pieces, thin sections, slides, is emphasized by the fact ISRIC is the only World Data Centre for Soils (WDC-Soils) within the World Data System of the International Council of Science (ICSU). The collection provides an insight in and overview of the diversity of soils in the world, their properties and their limitations and possibilities for use. A new building is under construction for the WSM, which is

Gap assessment in current soil monitoring networks across Europe for measuring soil functions

Science.gov (United States)

van Leeuwen, J. P.; Saby, N. P. A.; Jones, A.; Louwagie, G.; Micheli, E.; Rutgers, M.; Schulte, R. P. O.; Spiegel, H.; Toth, G.; Creamer, R. E.

2017-12-01

Soil is the most important natural resource for life on Earth after water. Given its fundamental role in sustaining the human population, both the availability and quality of soil must be managed sustainably and protected. To ensure sustainable management we need to understand the intrinsic functional capacity of different soils across Europe and how it changes over time. Soil monitoring is needed to support evidence-based policies to incentivise sustainable soil management. To this aim, we assessed which soil attributes can be used as potential indicators of five soil functions; (1) primary production, (2) water purification and regulation, (3) carbon sequestration and climate regulation, (4) soil biodiversity and habitat provisioning and (5) recycling of nutrients. We compared this list of attributes to existing national (regional) and EU-wide soil monitoring networks. The overall picture highlighted a clearly unbalanced dataset, in which predominantly chemical soil parameters were included, and soil biological and physical attributes were severely under represented. Methods applied across countries for indicators also varied. At a European scale, the LUCAS-soil survey was evaluated and again confirmed a lack of important soil biological parameters, such as C mineralisation rate, microbial biomass and earthworm community, and soil physical measures such as bulk density. In summary, no current national or European monitoring system exists which has the capacity to quantify the five soil functions and therefore evaluate multi-functional capacity of a soil and in many countries no data exists at all. This paper calls for the addition of soil biological and some physical parameters within the LUCAS-soil survey at European scale and for further development of national soil monitoring schemes.

Soil Properties Database of Spanish Soils Volume IV.- Valencia and Murcia

International Nuclear Information System (INIS)

Trueba, C.; Millan, R.; Schmid, T.; Roquero, C; Magister, M.

1998-01-01

The soil vulnerability determines the sensitivity of the soil after an accidental radioactive contamination due to Cs-137 and Sr-90. The Departamento de Impacto Ambiental de la Energia of CIEMAT is carrying out an assessment of the radiological vulnerability of the different Spanish soils found on the Iberian Peninsula. This requires the knowledge of the soil properties for the various types of existing soils. In order to achieve this aim, a bibliographical compilation of soil profiles has been made to characterize the different soil types and create a database of their properties. Depending on the year of publication and the type of documentary source, the information compiled from the available bibliography is very heterogeneous. Therefore, an important effort has been made to normalize and process the information prior to its incorporation to the database. This volume presents the criteria applied to normalize and process the data as well as the soil properties of the various soil types belonging to the Comunidades Autonomas de Valencia and Murcia. (Author) 63 refs

Soil fungi as indicators of pesticide soil pollution

Directory of Open Access Journals (Sweden)

Mandić Leka

2005-01-01

Full Text Available Soil fungi, with their pronounced enzymic activity and high osmotic potential, represent a significant indicator of negative effects of different pesticides on the agroecosystem as a whole. In that respect, a trial was set up on the alluvium soil type with the aim to investigate the effect of different herbicides (Simazine, Napropamid, Paraquat, fungicides (Captan and Mancozeb and insecticides (Fenitrothion and Dimethoate on a number of soil fungi under apple trees. The number of soil fungi was determined during four growing seasons by an indirect method of dilution addition on the Czapek agar. The study results indicate that the fungi belong to the group of microorganisms that, after an initial sensible response to the presence of pesticides in the soil, very rapidly establish normal metabolism enabling them even to increase their number. The fungicides and insecticides applied were found to be particularly effective in that respect.

Methodology to assess the radiological sensitivity of soils: Application to Spanish soils

International Nuclear Information System (INIS)

Trueba Alonso, C.

2005-01-01

A methodology, based on standard physical and chemical soil properties, has been developed to estimate the radiological sensitivity of soils to a 137 C s and 90 S r contamination. In this framework, the soil radiological sensitivity is defined as the soil capability to mobilise or to retain these radionuclides. The purpose of this methodology is to assess, in terms of radiological sensitivity indexes, the behaviour of 137 C s and 90 S r in soils and their fluxes to man, considering two exposure pathways, the external irradiation exposure and the internal exposure from ingestion. The methodology is applied to the great variety of soil types found in Spain, where the soil profile is the reference unit for the assessment. The results for these soil types show, that their basic soil properties are the key to categorise the radiological sensitivity according to the risks considered. The final categorisation allows to identify soils specially sensible and improves the radiological impact assessment predictions. (Author)

Estimating respiration of roots in soil: interactions with soil CO2, soil temperature and soil water content

NARCIS (Netherlands)

Bouma, T.J.; Nielsen, K.F.; Eissenstat, D.M.; Lynch, J.P.

1997-01-01

Little information is available on the variability of the dynamics of the actual and observed root respiration rate in relation to abiotic factors. In this study, we describe I) interactions between soil CO2 concentration, temperature, soil water content and root respiration, and II) the effect of

Understanding and Enhancing Soil Biological Health: The Solution for Reversing Soil Degradation

Directory of Open Access Journals (Sweden)

R. Michael Lehman

2015-01-01

Full Text Available Our objective is to provide an optimistic strategy for reversing soil degradation by increasing public and private research efforts to understand the role of soil biology, particularly microbiology, on the health of our world’s soils. We begin by defining soil quality/soil health (which we consider to be interchangeable terms, characterizing healthy soil resources, and relating the significance of soil health to agroecosystems and their functions. We examine how soil biology influences soil health and how biological properties and processes contribute to sustainability of agriculture and ecosystem services. We continue by examining what can be done to manipulate soil biology to: (i increase nutrient availability for production of high yielding, high quality crops; (ii protect crops from pests, pathogens, weeds; and (iii manage other factors limiting production, provision of ecosystem services, and resilience to stresses like droughts. Next we look to the future by asking what needs to be known about soil biology that is not currently recognized or fully understood and how these needs could be addressed using emerging research tools. We conclude, based on our perceptions of how new knowledge regarding soil biology will help make agriculture more sustainable and productive, by recommending research emphases that should receive first priority through enhanced public and private research in order to reverse the trajectory toward global soil degradation.

Development of generic soil profiles and soil data development for SSI analyses

Energy Technology Data Exchange (ETDEWEB)

Parker, Josh, E-mail: jparker@nuscalepower.com [NuScale Power, 1000 NE Circle Boulevard, Suite 10310, Corvallis, OR 97330 (United States); Khan, Mohsin; Rajagopal, Raj [ARES Corporation, 1990N California Boulevard, Suite 500, Walnut Creek, CA 94596 (United States); Groome, John [NuScale Power, 1000 NE Circle Boulevard, Suite 10310, Corvallis, OR 97330 (United States)

2014-04-01

This paper presents the approach to developing generic soil profiles for the design of reactor building for small modular reactor (SMR) nuclear power plant developed by NuScale Power. The reactor building is a deeply embedded structure. In order to perform soil structure interaction (SSI) analyses, generic soil profiles are required to be defined for the standardized Nuclear Power Plant (NPP) designs for the United States Nuclear Regulatory Commission (NRC) in a design control document (DCD). The development of generic soil profiles is based on utilization of information on generic soil profiles from the new standardized nuclear power plant designs already submitted to the NRC for license certification. Eleven generic soil profiles have been recommended, and those profiles cover a wide range of parameters such as soil depth, shear wave velocity, unit weight, Poisson's ratio, water table, and depth to rock strata. The soil profiles are developed for a range of shear wave velocities between bounds of 1000 fps and 8000 fps as inferred from NRC Standard Review Plan (NUREG 0800) Sections 3.7.1 and 3.7.2. To account for the soil degradation due to seismic events, the strain compatible soil properties are based on the EPRI generic soil degradation curves. In addition, one dimensional soil dynamic response analyses were performed to study the soil layer input motions for performing the SSI analyses.

The effect of soil type on the bioremediation of petroleum contaminated soils.

Science.gov (United States)

Haghollahi, Ali; Fazaelipoor, Mohammad Hassan; Schaffie, Mahin

2016-09-15

In this research the bioremediation of four different types of contaminated soils was monitored as a function of time and moisture content. The soils were categorized as sandy soil containing 100% sand (type I), clay soil containing more than 95% clay (type II), coarse grained soil containing 68% gravel and 32% sand (type III), and coarse grained with high clay content containing 40% gravel, 20% sand, and 40% clay (type IV). The initially clean soils were contaminated with gasoil to the concentration of 100 g/kg, and left on the floor for the evaporation of light hydrocarbons. A full factorial experimental design with soil type (four levels), and moisture content (10 and 20%) as the factors was employed. The soils were inoculated with petroleum degrading microorganisms. Soil samples were taken on days 90, 180, and 270, and the residual total petroleum hydrocarbon (TPH) was extracted using soxhlet apparatus. The moisture content of the soils was kept almost constant during the process by intermittent addition of water. The results showed that the efficiency of bioremediation was affected significantly by the soil type (Pvalue soil with the initial TPH content of 69.62 g/kg, and the lowest for the clay soil (23.5%) with the initial TPH content of 69.70 g/kg. The effect of moisture content on bioremediation was not statistically significant for the investigated levels. The removal percentage in the clay soil was improved to 57% (within a month) in a separate experiment by more frequent mixing of the soil, indicating low availability of oxygen as a reason for low degradation of hydrocarbons in the clay soil. Copyright © 2016 Elsevier Ltd. All rights reserved.

Diurnal hysteresis between soil CO2 and soil temperature is controlled by soil water content

Science.gov (United States)

Diego A. Riveros-Iregui; Ryan E. Emanuel; Daniel J. Muth; L. McGlynn Brian; Howard E. Epstein; Daniel L. Welsch; Vincent J. Pacific; Jon M. Wraith

2007-01-01

Recent years have seen a growing interest in measuring and modeling soil CO2 efflux, as this flux represents a large component of ecosystem respiration and is a key determinant of ecosystem carbon balance. Process-based models of soil CO2 production and efflux, commonly based on soil temperature, are limited by nonlinearities such as the observed diurnal hysteresis...

Anaerobic N mineralization in paddy soils in relation to inundation management, physicochemical soil fractions, mineralogy and soil properties

Science.gov (United States)

Sleutel, Steven; Kader, Mohammed Abdul; Ara Begum, Shamim; De Neve, Stefaan

2013-04-01

Anaerobic N mineralization measured from (saturated) repacked soil cores from 25 paddy fields in Bangladesh and was previously found to negatively related to soil N content on a relative basis. This suggests that other factors like soil organic matter (SOM) quality or abiotic factors instead control the anaerobic N mineralization process. We therefore assessed different physical and chemical fractions of SOM, management factors and various soil properties as predictors for the net anaerobic N mineralization. 1° First, we assessed routinely analyzed soil parameters (soil N and soil organic carbon, texture, pH, oxalate- and pyrophosphate-extractable Fe, Al, and Mn, fixed-NH4 content). We found no significant influences of neither soil mineralogy nor the annual length of inundation on soil N mineralization. The anaerobic N mineralization correlated positively with Na-pyrophosphate-extractable Fe and negatively with pH (both at Presistant OM fraction, followed by extraction of mineral bound OM with 10%HF thereby isolating the HF-resistant OM. None of the physicochemical SOM fractions were found useful predictors anaerobic N mineralization. The linkage between these chemical soil N fractions and N supplying processes actually occurring in the soil thus appears to be weak. Regardless, we hypothesize that variation in strength of N-mineral and N-OM linkages is likely to explain variation in bio-availability of organic N and proneness to mineralization. Yet, in order to separate kinetically different soil N fractions we then postulated that an alternative approach would be required, which instead isolates soil N fractions on the basis of bonding strength. In this respect bonding strength should be seen as opposite of proneness to dissolution of released N into water, the habitat of soil microorganisms mediating soil N mineralization. We hypothesize that soil N extracted by water at increasing temperatures would reflect such N fractions with increasing bonding strength, in

Soil stabilization 1982

Science.gov (United States)

Barenberg, E. J.; Thompson, M. R.; Tayabji, S. D.; Nussbaum, P. J.; Ciolko, A. T.

Seven papers cover the following areas: design, construction and performance of lime, fly ash, and slag pavement; evaluation of heavily loaded cement stabilized bases; coal refuse and fly ash compositions; potential highway base course materials; lime soil mixture design considerations for soils of southeastern United States; short term active soil property changes caused by injection of lime and fly ash; soil cement for use in stream channel grade stabilization structures; and reaction products of lime treated southeastern soils.

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

Effect of long-term farming strategies on soil microbiota and soil health

Science.gov (United States)

Sommermann, Loreen; Babin, Doreen; Sandmann, Martin; Smalla, Kornelia; Schellenberg, Ingo; Grosch, Rita; Geistlinger, Joerg

2017-04-01

Increasing food and energy demands have resulted in considerable intensification of farming practices, which brought about severe consequences for agricultural soils, e.g. loss of fertility, erosion and enrichment of soil-borne plant diseases. In order to maintain soil quality and health for the future, the development of more extensive and sustainable farming strategies is urgently needed. The soil microbiome is regarded as a key player in soil ecosystem functions, particularly the natural ability of soils to suppress plant pathogens (suppressiveness). Recent studies showed that soil microbial communities are influenced by agricultural management. To further analyze the effects of farming strategies on soil suppressiveness and plant performance, agricultural soils from three long-term field trials in Thyrow, Bernburg (both in Germany) and Therwil (Switzerland) were sampled and subjected to molecular profiling of soil bacteria and fungi using marker genes and high-throughput amplicon sequencing. Significant effects on bacterial as well as fungal community composition, including plant pathogenic and beneficial taxa, were observed among variants of tillage and crop rotation. The least effect on both communities had fertilization, with no significance between variants. Subsequently, the same soils were subjected to growth chamber pot experiments with lettuce as a model (Lactuca sativa). After a growth period of six weeks significant differences in lettuce shoot and soil microbial biomass were observed among soil samples of the different long-term trials. Furthermore, the lettuce rhizosphere exhibited diverse bacterial community compositions as observed by DGGE (denaturing gradient gel electrophoresis). Using group-specific PCR-DGGE fingerprints, bacterial responders to fertilization, soil management and crop rotation were identified among different taxonomic groups. Currently, bacterial and fungal amplicon sequencing of rhizosphere and bulk soil from these pot

Measuring Soil Moisture in Skeletal Soils Using a COSMOS Rover

Science.gov (United States)

Medina, C.; Neely, H.; Desilets, D.; Mohanty, B.; Moore, G. W.

2017-12-01

The presence of coarse fragments directly influences the volumetric water content of the soil. Current surface soil moisture sensors often do not account for the presence of coarse fragments, and little research has been done to calibrate these sensors under such conditions. The cosmic-ray soil moisture observation system (COSMOS) rover is a passive, non-invasive surface soil moisture sensor with a footprint greater than 100 m. Despite its potential, the COSMOS rover has yet to be validated in skeletal soils. The goal of this study was to validate measurements of surface soil moisture as taken by a COSMOS rover on a Texas skeletal soil. Data was collected for two soils, a Marfla clay loam and Chinati-Boracho-Berrend association, in West Texas. Three levels of data were collected: 1) COSMOS surveys at three different soil moistures, 2) electrical conductivity surveys within those COSMOS surveys, and 3) ground-truth measurements. Surveys with the COSMOS rover covered an 8000-h area and were taken both after large rain events (>2") and a long dry period. Within the COSMOS surveys, the EM38-MK2 was used to estimate the spatial distribution of coarse fragments in the soil around two COSMOS points. Ground truth measurements included coarse fragment mass and volume, bulk density, and water content at 3 locations within each EM38 survey. Ground-truth measurements were weighted using EM38 data, and COSMOS measurements were validated by their distance from the samples. There was a decrease in water content as the percent volume of coarse fragment increased. COSMOS estimations responded to both changes in coarse fragment percent volume and the ground-truth volumetric water content. Further research will focus on creating digital soil maps using landform data and water content estimations from the COSMOS rover.

From soil in art towards Soil Art

Science.gov (United States)

Feller, C.; Landa, E. R.; Toland, A.; Wessolek, G.

2015-02-01

The range of art forms and genres dealing with soil is wide and diverse, spanning many centuries and artistic traditions, from prehistoric painting and ceramics to early Renaissance works in Western literature, poetry, paintings, and sculpture, to recent developments in cinema, architecture and contemporary art. Case studies focused on painting, installation, and cinema are presented with the view of encouraging further exploration of art about, in, with, or featuring soil or soil conservation issues, created by artists, and occasionally scientists, educators or collaborative efforts thereof.

Mass Transport within Soils

Energy Technology Data Exchange (ETDEWEB)

McKone, Thomas E.

2009-03-01

Contaminants in soil can impact human health and the environment through a complex web of interactions. Soils exist where the atmosphere, hydrosphere, geosphere, and biosphere converge. Soil is the thin outer zone of the earth's crust that supports rooted plants and is the product of climate and living organisms acting on rock. A true soil is a mixture of air, water, mineral, and organic components. The relative proportions of these components determine the value of the soil for agricultural and for other human uses. These proportions also determine, to a large extent, how a substance added to soil is transported and/or transformed within the soil (Spositio, 2004). In mass-balance models, soil compartments play a major role, functioning both as reservoirs and as the principal media for transport among air, vegetation, surface water, deeper soil, and ground water (Mackay, 2001). Quantifying the mass transport of chemicals within soil and between soil and atmosphere is important for understanding the role soil plays in controlling fate, transport, and exposure to multimedia pollutants. Soils are characteristically heterogeneous. A trench dug into soil typically reveals several horizontal layers having different colors and textures. As illustrated in Figure 1, these multiple layers are often divided into three major horizons: (1) the A horizon, which encompasses the root zone and contains a high concentration of organic matter; (2) the B horizon, which is unsaturated, lies below the roots of most plants, and contains a much lower organic carbon content; and (3) the C horizon, which is the unsaturated zone of weathered parent rock consisting of bedrock, alluvial material, glacial material, and/or soil of an earlier geological period. Below these three horizons lies the saturated zone - a zone that encompasses the area below ground surface in which all interconnected openings within the geologic media are completely filled with water. Similarly to the unsaturated

On the role of soil fauna in providing soil functions - a meta study

Science.gov (United States)

Lang, Birgit; Russell, David J.; Vogel, Hans-Jörg; Wollschläger, Ute

2017-04-01

Fertile soils are fundamental for the production of biomass and therefore for the provision of goods such as food or fuel. However, soils are threatened by e.g. land degradation, but once lost their functionality cannot simply be replaced as soils are complex systems developed over long time periods. Thus, to develop strategies for sustainable soil use and management, we need a comprehensive functional understanding of soil systems. To this end, the interdisciplinary research program "Soil as a Natural Resource for the Bio-Economy - BonaRes" was launched by the German Federal Government in 2015. One part of this program is the development of a Knowledge Centre for soil functions and services. As part of the Knowledge Centre, we focus on the identification and quantification of biological drivers of soil functions. Based on a systematic review of existing literature, we assess the importance of different soil faunal groups for the soil functions and processes most relevant to agricultural production (i.e. decomposition, mineralization, soil structuring. Additionally, we investigate direct impacts of soil fauna on soil properties (e.g. aggregation, pore volume). As site specific conditions such as climate, soil type or management practices affect soil fauna and their performance, these responses must also be taken into account. In the end, our findings will be used in the development of modeling tools aiming to predict the impacts of different management measures on soil ecosystem services and functions.

Soil dynamics of the origination of soil tare during sugar beet lifting

NARCIS (Netherlands)

Vermeulen, G.D.; Koolen, A.J.

2002-01-01

High soil tare of sugar beet on wet clay soil after uprooting with share lifters is usually attributed to the fact that the soil becomes sticky due to mechanical impact during uprooting. Results of field experiments have shown good potential for obtaining low soil tare of sugar beet on wet clay soil

Soil heavy metals

Energy Technology Data Exchange (ETDEWEB)

Sherameti, Irena [Jena Univ. (Germany). Inst. fuer Allgemeine Botanik und Pflanzenphysiologie; Varma, Ajit (eds.) [Amity Univ., Uttar Pradesh (India). Amity Inst. of Microbial Technology; Amity Science, Technology and Innovation Foundation, Noida, UP (India)

2010-07-01

Human activities have dramatically changed the composition and organisation of soils. Industrial and urban wastes, agricultural application and also mining activities resulted in an increased concentration of heavy metals in soils. How plants and soil microorganisms cope with this situation and the sophisticated techniques developed for survival in contaminated soils is discussed in this volume. The topics presented include: the general role of heavy metals in biological soil systems; the relation of inorganic and organic pollutions; heavy metal, salt tolerance and combined effects with salinity; effects on abuscular mycorrhizal and on saprophytic soil fungi; heavy metal resistance by streptomycetes; trace element determination of environmental samples; the use of microbiological communities as indicators; phytostabilization of lead polluted sites by native plants; effects of soil earthworms on removal of heavy metals and the remediation of heavy metal contaminated tropical land. (orig.)

[Removal of volatile organic compounds in soils by soil vapor extraction (SVE)].

Science.gov (United States)

Yin, Fu-xiang; Zhang, Sheng-tian; Zhao, Xin; Feng, Ke; Lin, Yu-suo

2011-05-01

An experiment study has been carried out to investigate effects of the diameter of soil columns, the size of soil particulate and different contaminants on efficiency of simulated soil vapor extraction (SVE). Experiments with benzene, toluene, ethylbenzene and n-propylbenzene contaminated soils showed that larger bottom area/soil height (S/H) of the columns led to higher efficiency on removal of contaminants. Experiments with contaminated soils of different particulate size showed that the efficiency of SVE decreased with increases in soil particulate size, from 10 mesh to between 20 mesh and 40 mesh and removal of contaminants in soils became more difficult. Experiments with contaminated soils under different ventilation rates suggested that soil vapor extraction at a ventilation rate of 0.10 L x min(-1) can roughly remove most contaminants from the soils. Decreasing of contaminants in soils entered tailing stages after 12 h, 18 h and 48 h for benzene, toluene and ethylbenzene, respectively. Removal rate of TVOCs (Total VOCs) reached a level as high as 99.52%. The results of the experiment have indicated that molecule structure and properties of the VOCs are also important factors which have effects on removal rates of the contaminants. Increases in carbon number on the benzene ring, decreases in vapor pressure and volatile capability resulted in higher difficulties in soil decontamination. n-propylbenzene has a lower vapor pressure than toluene and ethylbenzene which led to a significant retard effect on desorption and volatilization of benzene and ethylbenzene.

Plant species influence on soil C after afforestation of Mediterranean degraded soils

Science.gov (United States)

Dominguez, Maria T.; García-Vargas, Carlos; Madejón, Engracia; Marañón, Teodoro

2015-04-01

Increasing C sequestration in terrestrial ecosystems is one of the main current environmental challenges to mitigate climate change. Afforestation of degraded and contaminated lands is one of the key strategies to achieve an increase in C sequestration in ecosystems. Plant species differ in their mechanisms of C-fixation, C allocation into different plant organs, and interaction with soil microorganisms, all these factors influencing the dynamics of soil C following the afforestation of degraded soils. In this work we examine the influence of different woody plant species on soil C dynamics in degraded and afforested Mediterranean soils. The soils were former agricultural lands that were polluted by a mining accident and later afforested with different native plant species. We analysed the effect of four of these species (Olea europaea var. sylvestris Brot., Populus alba L., Pistacia lentiscus L. and Retama sphaerocarpa (L.) Boiss.) on different soil C fractions, soil nutrient availability, microbial activity (soil enzyme activities) and soil CO2 fluxes 15 years after the establishment of the plantations. Results suggest that the influence of the planted trees and shrubs is still limited, being more pronounced in the more acidic and nutrient-poor soils. Litter accumulation varied among species, with the highest C accumulated in the litter under the deciduous species (Populus alba L.). No differences were observed in the amount of total soil organic C among the studied species, or in the concentrations of phenols and sugars in the dissolved organic C (DOC), which might have indicated differences in the biodegradability of the DOC. Microbial biomass and activity was highly influenced by soil pH, and plant species had a significant influence on soil pH in the more acidic site. Soil CO2 fluxes were more influenced by the plant species than total soil C content. Our results suggest that changes in total soil C stocks after the afforestation of degraded Mediterranean

Soil treatment engineering

Science.gov (United States)

Ivica, Kisic; Zeljka, Zgorelec; Aleksandra, Percin

2017-10-01

Soil is loose skin of the Earth, located between the lithosphere and atmosphere, which originated from parent material under the influence of pedogenetic processes. As a conditionally renewable natural resource, soil has a decisive influence on sustainable development of global economy, especially on sustainable agriculture and environmental protection. In recent decades, a growing interest prevails for non-production soil functions, primarily those relating to environmental protection. It especially refers to protection of natural resources whose quality depends directly on soil and soil management. Soil contamination is one of the most dangerous forms of soil degradation with the consequences that are reflected in virtually the entire biosphere, primarily at heterotrophic organisms, and also at mankind as a food consumer. Contamination is correlated with the degree of industrialization and intensity of agrochemical usage. It is typically caused by industrial activity, agricultural chemicals or improper disposal of waste. The negative effects caused by pollution are undeniable: reduced agricultural productivity, polluted water sources and raw materials for food are only a few of the effects of soil degradation, while almost all human diseases (excluding AIDS) may be partly related to the transport of contaminants, in the food chain or the air, to the final recipients - people, plants and animals. The remediation of contaminated soil is a relatively new scientific field which is strongly developing in the last 30 years and becoming a more important subject. In order to achieve quality remediation of contaminated soil it is very important to conduct an inventory as accurately as possible, that is, to determine the current state of soil contamination.

Comparison of Capability of Digitizing Methods to Predict Soil classification According to the Soil Taxonomy and World Reference Base for Soil Resources

Directory of Open Access Journals (Sweden)

zohreh mosleh

2017-02-01

Full Text Available Introduction: Soil classification generally aims to establish a taxonomy based on breaking the soil continuum into homogeneous groups that can highlight the essential differences in soil properties and functions between classes.The two most widely used modern soil classification schemes are Soil Taxonomy (ST and World Reference Base for Soil Resources (WRB.With the development of computers and technology, digital and quantitative approaches have been developed. These new techniques that include the spatial prediction of soil properties or classes, relies on finding the relationships between soil and the auxiliary information that explain the soil forming factors or processes and finally predict soil patterns on the landscape. These approaches are commonly referred to as digital soil mapping (DSM (14. A key component of any DSM mapping activity is the method used to define the relationship between soil observation and auxiliary information (4. Several types of machine learning approaches have been applied for digital soil mapping of soil classes, such as logistic and multinomial logistic regressions (10,12, random forests (15, neural networks (3,13 and classification trees (22,4. Many decisions about the soil use and management are based on the soil differences that cannot be captured by higher taxonomic levels (i.e., order, suborder and great group (4. In low relief areas such as plains, it is expected that the soil forming factors are more homogenous and auxiliary information explaining soil forming factors may have low variation and cannot show the soil variability. Materials and Methods: The study area is located in the Shahrekord plain of Chaharmahal-Va-Bakhtiari province. According tothe semi-detailed soil survey (16, 120 pedons with approximate distance of 750 m were excavated and described according to the “field book for describing and sampling soils” (19. Soil samples were taken from different genetic horizons, air dried and

Mobility of arsenic and its compounds in soil and soil solution: the effect of soil pretreatment and extraction methods.

Science.gov (United States)

Száková, J; Tlustos, P; Goessler, W; Frková, Z; Najmanová, J

2009-12-30

The effect of soil extraction procedures and/or sample pretreatment (drying, freezing of the soil sample) on the extractability of arsenic and its compounds was tested. In the first part, five extraction procedures were compared with following order of extractable arsenic portions: 2M HNO(3)>0.43 M CH(3)COOH>or=0.05 M EDTA>or=Mehlich III (0.2M CH(3)COOH+0.25 M NH(4)NO(3)+0.013 M HNO(3)+0.015 M NH(4)F+0.001 M EDTA) extraction>water). Additionally, two methods of soil solution sampling were compared, centrifugation of saturated soil and the use of suction cups. The results showed that different sample pretreatments including soil solution sampling could lead to different absolute values of mobile arsenic content in soils. However, the interpretation of the data can lead to similar conclusions as apparent from the comparison of the soil solution sampling methods (r=0.79). For determination of arsenic compounds mild extraction procedures (0.05 M (NH(4))(2)SO(4), 0.01 M CaCl(2), and water) and soil solution sampling using suction cups were compared. Regarding the real soil conditions the extraction of fresh samples and/or in situ collection of soil solution are preferred among the sample pretreatments and/or soil extraction procedures. However, chemical stabilization of the solutions should be allowed and included in the analytical procedures for determination of individual arsenic compounds.

Soil [N] modulates soil C cycling in CO2-fumigated tree stands

DEFF Research Database (Denmark)

Dieleman, W. I. J.; Luyssaert, S.; Rey, A.

2010-01-01

Under elevated atmospheric CO2 concentrations, soil carbon (C) inputs are typically enhanced, suggesting larger soil C sequestration potential. However, soil C losses also increase and progressive nitrogen (N) limitation to plant growth may reduce the CO2 effect on soil C inputs with time. We...... compiled a data set from 131 manipulation experiments, and used meta-analysis to test the hypotheses that: (1) elevated atmospheric CO2 stimulates soil C inputs more than C losses, resulting in increasing soil C stocks; and (2) that these responses are modulated by N. Our results confirm that elevated CO2...... induces a C allocation shift towards below-ground biomass compartments. However, the increased soil C inputs were offset by increased heterotrophic respiration (Rh), such that soil C content was not affected by elevated CO2. Soil N concentration strongly interacted with CO2 fumigation: the effect...

Grey water treatment by the slanted soil system with unsorted soil media.

Science.gov (United States)

Ushijima, Ken; Tanaka, Erina; Suzuki, Laís Yuko; Hijikata, Nowaki; Funamizu, Naoyuki; Ito, Ryusei

2015-01-01

This study evaluated the performance of unsorted soil media in the slanted soil treatment system, in terms of removal efficiency in suspended solids (SS), chemical oxygen demand (COD), linear alkylbenzene sulphonate (LAS) and Escherichia coli, and lifetime until clogging occurs. Unsorted soil performed longer lifetime until clogging than sorted fine soil. Removal of SS, COD, and LAS also performed same or better level in unsorted soil than fine soil. As reaction coefficients of COD and LAS were described as a function of the hydraulic loading rate, we can design a slanted soil system according to the expected hydraulic loading rate and the targeted level of COD or LAS in effluent. Regarding bacteria removal, unsorted soil performed sufficient reduction of E. coli for 5 weeks; however, the removal process occurred throughout all four chambers, while that of fine soil occurred in one to two chambers.

Radiocarbon enrichment of soil organic matter fractions in New Zealand soils

International Nuclear Information System (INIS)

Goh, K.M.; Stout, J.D.; Rafter, T.A.

1977-01-01

Soil organic matter was extracted using the classical procedure and fractionated into humin (nonextractable), humic acid, and fulvic acid. The masses of total organic carbon in the whole soil samples and in the fractions, together with their 14 C content and 13 C/ 12 C ratios, were also determined. The following New Zealand soils were studied: a Fluvaquent, with experimental pasture plots, formed from deeply mixing subsoils of low organic carbon content; a Typic Fragiaqualf and a Typic Dystrochrept with moderately productive pastures; and an Umbric Vitrandept at two sites under native tussock and under introduced grasses of low productivity. The degree of radiocarbon enrichment of the different fractions in both topsoil and subsoil samples was examined in relation to differences in soil type, soil biological activity, and vegetation history. There was variation in the distribution and enrichment of the organic matter fractions both within the same soil type and between soil types, as well as between the topsoil and subsoil of the same soil. Differences appeared to be primarily a function of the stage of decomposition and translocation of the fractions through the soil rather than due to vegetation differences

Effect of biosolid waste compost on soil respiration in salt-affected soils

Science.gov (United States)

Raya, Silvia; Gómez, Ignacio; García, Fuensanta; Navarro, José; Jordán, Manuel Miguel; Belén Almendro, María; Martín Soriano, José

2013-04-01

A great part of mediterranean soils are affected by salinization. This is an important problem in semiarid areas increased by the use of low quality waters, the induced salinization due to high phreatic levels and adverse climatology. Salinization affects 25% of irrigated agriculture, producing important losses on the crops. In this situation, the application of organic matter to the soil is one of the possible solutions to improve their quality. The main objective of this research was to asses the relation between the salinity level (electrical conductivity, EC) in the soil and the response of microbial activity (soil respiration rate) after compost addition. The study was conducted for a year. Soil samples were collected near to an agricultural area in Crevillente and Elche, "El Hondo" Natural Park (Comunidad de Regantes from San Felipe Neri). The experiment was developed to determine and quantify the soil respiration rate in 8 different soils differing in salinity. The assay was done in close pots -in greenhouse conditions- containing soil mixed with different doses of sewage sludge compost (2, 4 and 6%) besides the control. They were maintained at 60% of water holding capacity (WHC). Soil samples were analyzed every four months for a year. The equipment used to estimate the soil respiration was a Bac-Trac and CO2 emitted by the soil biota was measured and quantified by electrical impedance changes. It was observed that the respiration rate increases as the proportion of compost added to each sample increases as well. The EC was incremented in each sampling period from the beginning of the experiment, probably due to the fact that soils were in pots and lixiviation was prevented, so the salts couldńt be lost from soil. Over time the compost has been degraded and, it was more susceptible to be mineralized. Salts were accumulated in the soil. Also it was observed a decrease of microbial activity with the increase of salinity in the soil. Keywords: soil

Visual soil evaluation

DEFF Research Database (Denmark)

Visual Soil Evaluation (VSE) provides land users and environmental authorities with the tools to assess soil quality for crop performance. This book describes the assessment of the various structural conditions of soil, especially after quality degradation such as compaction, erosion or organic...... and nutrient leaching, and for diagnosing and rectifying erosion and compaction in soils....

Hysteresis of soil temperature under different soil moisture and ...

African Journals Online (AJOL)

... in a solar greenhouse. The objective of this study was to find a simple method to estimate the hysteresis of soil temperature under three soil moisture and two fertilizer levels in solar greenhouse conditions with tomato crop (Lycopersicon esculentum Mill). The results show that the soil moisture had no significant effects on ...

Feedbacks Between Soil Structure and Microbial Activities in Soil

Science.gov (United States)

Bailey, V. L.; Smith, A. P.; Fansler, S.; Varga, T.; Kemner, K. M.; McCue, L. A.

2017-12-01

Soil structure provides the physical framework for soil microbial habitats. The connectivity and size distribution of soil pores controls the microbial access to nutrient resources for growth and metabolism. Thus, a crucial component of soil research is how a soil's three-dimensional structure and organization influences its biological potential on a multitude of spatial and temporal scales. In an effort to understand microbial processes at scale more consistent with a microbial community, we have used soil aggregates as discrete units of soil microbial habitats. Our research has shown that mean pore diameter (x-ray computed tomography) of soil aggregates varies with the aggregate diameter itself. Analyzing both the bacterial composition (16S) and enzyme activities of individual aggregates showed significant differences in the relative abundances of key members the microbial communities associated with high enzyme activities compared to those with low activities, even though we observed no differences in the size of the biomass, nor in the overall richness or diversity of these communities. We hypothesize that resources and substrates have stimulated key populations in the aggregates identified as highly active, and as such, we conducted further research that explored how such key populations (i.e. fungal or bacterial dominated populations) alter pathways of C accumulation in aggregate size domains and microbial C utilization. Fungi support and stabilize soil structure through both physical and chemical effects of their hyphal networks. In contrast, bacterial-dominated communities are purported to facilitate micro- and fine aggregate stabilization. Here we quantify the direct effects fungal versus bacterial dominated communities on aggregate formation (both the rate of aggregation and the quality, quantity and distribution of SOC contained within aggregates). A quantitative understanding of the different mechanisms through which fungi or bacteria shape aggregate

Soil Response to Global Change: Soil Process Domains and Pedogenic Thresholds (Invited)

Science.gov (United States)

Chadwick, O.; Kramer, M. G.; Chorover, J.

2013-12-01

The capacity of soil to withstand perturbations, whether driven by climate, land use change, or spread of invasive species, depends on its chemical composition and physical state. The dynamic interplay between stable, well buffered soil process domains and thresholds in soil state and function is a strong determinant of soil response to forcing from global change. In terrestrial ecosystems, edaphic responses are often mediated by availability of water and its flux into and through soils. Water influences soil processes in several ways: it supports biological production, hence proton-donor, electron-donor and complexing-ligand production; it determines the advective removal of dissolution products, and it can promote anoxia that leads microorganisms to utilize alternative electron acceptors. As a consequence climate patterns strongly influence global distribution of soil, although within region variability is governed by other factors such as landscape age, parent material and human land use. By contrast, soil properties can vary greatly among climate regions, variation which is guided by the functioning of a suite of chemical processes that tend to maintain chemical status quo. This soil 'buffering' involves acid-base reactions as minerals weather and oxidation-reduction reactions that are driven by microbial respiration. At the planetary scale, soil pH provides a reasonable indicator of process domains and varies from about 3.5 to10, globally, although most soils lie between about 4.5 and 8.5. Those that are above 7.5 are strongly buffered by the carbonate system, those that are characterized by neutral pH (7.5-6) are buffered by release of non-hydrolyzing cations from primary minerals and colloid surfaces, and those that are buffered by hydrolytic aluminum on colloidal surfaces. Alkali and alkaline (with the exception of limestone parent material) soils are usually associated with arid and semiarid conditions, neutral pH soils with young soils in both dry and wet

Soil Diversity as Affected by Land Use in China: Consequences for Soil Protection

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Wei Shangguan

2014-01-01

Full Text Available Rapid land-use change in recent decades in China and its impact on terrestrial biodiversity have been widely studied, particularly at local and regional scales. However, the effect of land-use change on the diversity of soils that support the terrestrial biological system has rarely been studied. Here, we report the first effort to assess the impact of land-use change on soil diversity for the entire nation of China. Soil diversity and land-use effects were analyzed spatially in grids and provinces. The land-use effects on different soils were uneven. Anthropogenic soils occupied approximately 12% of the total soil area, which had already replaced the original natural soils. About 7.5% of the natural soil classes in China were in danger of substantial loss, due to the disturbance of agriculture and construction. More than 80% of the endangered soils were unprotected due to the overlook of soil diversity. The protection of soil diversity should be integrated into future conservation activities.

Soil Diversity as Affected by Land Use in China: Consequences for Soil Protection

Science.gov (United States)

Shangguan, Wei; Gong, Peng; Liang, Lu; Dai, YongJiu; Zhang, Keli

2014-01-01

Rapid land-use change in recent decades in China and its impact on terrestrial biodiversity have been widely studied, particularly at local and regional scales. However, the effect of land-use change on the diversity of soils that support the terrestrial biological system has rarely been studied. Here, we report the first effort to assess the impact of land-use change on soil diversity for the entire nation of China. Soil diversity and land-use effects were analyzed spatially in grids and provinces. The land-use effects on different soils were uneven. Anthropogenic soils occupied approximately 12% of the total soil area, which had already replaced the original natural soils. About 7.5% of the natural soil classes in China were in danger of substantial loss, due to the disturbance of agriculture and construction. More than 80% of the endangered soils were unprotected due to the overlook of soil diversity. The protection of soil diversity should be integrated into future conservation activities. PMID:25250394

Can we predict uranium bioavailability based on soil parameters? Part 1: Effect of soil parameters on soil solution uranium concentration

International Nuclear Information System (INIS)

Vandenhove, H.; Hees, M. van; Wouters, K.; Wannijn, J.

2007-01-01

Present study aims to quantify the influence of soil parameters on soil solution uranium concentration for 238 U spiked soils. Eighteen soils collected under pasture were selected such that they covered a wide range for those parameters hypothesised as being potentially important in determining U sorption. Maximum soil solution uranium concentrations were observed at alkaline pH, high inorganic carbon content and low cation exchange capacity, organic matter content, clay content, amorphous Fe and phosphate levels. Except for the significant correlation between the solid-liquid distribution coefficients (K d , L kg -1 ) and the organic matter content (R 2 = 0.70) and amorphous Fe content (R 2 = 0.63), there was no single soil parameter significantly explaining the soil solution uranium concentration (which varied 100-fold). Above pH = 6, log(K d ) was linearly related with pH [log(K d ) = - 1.18 pH + 10.8, R 2 = 0.65]. Multiple linear regression analysis did result in improved predictions of the soil solution uranium concentration but the model was complex. - Uranium solubility in soil can be predicted from organic matter or amorphous iron content and pH or with complex multilinear models considering several soil parameters

Soil compaction: Evaluation of stress transmission and resulting soil structure

DEFF Research Database (Denmark)

Naveed, Muhammad; Schjønning, Per; Keller, Thomas

strength. As soon as the applied load is lower than the aggregate strength, the mode of stress transmission is discrete as stresses were mainly transmitted through chain of aggregates. With increasing applied load soil aggregates start deforming that transformed heterogeneous soil into homogenous......, as a result stress transmission mode was shifted from discrete towards more like a continuum. Continuum-like stress transmission mode was better simulated with Boussinesq (1885) model based on theory of elasticity compared to discrete. The soil-pore structure was greatly affected by increasing applied...... and compaction-resulted soil structure at the same time. Stress transmission was quantified using both X-ray CT and Tactilus sensor mat, and soil-pore structure was quantified using X-ray CT. Our results imply that stress transmission through soil highly depends on the magnitude of applied load and aggregate...

Pedotransfer functions estimating soil hydraulic properties using different soil parameters

DEFF Research Database (Denmark)

Børgesen, Christen Duus; Iversen, Bo Vangsø; Jacobsen, Ole Hørbye

2008-01-01

Estimates of soil hydraulic properties using pedotransfer functions (PTF) are useful in many studies such as hydrochemical modelling and soil mapping. The objective of this study was to calibrate and test parametric PTFs that predict soil water retention and unsaturated hydraulic conductivity...... parameters. The PTFs are based on neural networks and the Bootstrap method using different sets of predictors and predict the van Genuchten/Mualem parameters. A Danish soil data set (152 horizons) dominated by sandy and sandy loamy soils was used in the development of PTFs to predict the Mualem hydraulic...... conductivity parameters. A larger data set (1618 horizons) with a broader textural range was used in the development of PTFs to predict the van Genuchten parameters. The PTFs using either three or seven textural classes combined with soil organic mater and bulk density gave the most reliable predictions...

Natural radionuclides in soils - relation between soil properties and the activities

International Nuclear Information System (INIS)

Fujiyoshi, Ryoko; Nakayama, Masashi; Sawamura, Sadashi

2000-01-01

Vertical profiles of natural radionuclides (K-40 and Ra-226) have been investigated in a soil core with 8 m in depth to elucidate its relation to the bed rock activity and to several soil properties. Pattern of the Ra-226 activity with soil depth suggests inhomogeneity of this nuclide during the accumulating process. Radiometric sorption experiments with Pb-210 as a tracer gave the result that almost all Pb(II) in the soil solution disappeared to be sorbed to the soil components

Measured and simulated soil water evaporation from four Great Plains soils

Science.gov (United States)

The amount of soil water lost during stage one and stage two soil water evaporation is of interest to crop water use modelers. The ratio of measured soil surface temperature (Ts) to air temperature (Ta) was tested as a signal for the transition in soil water evaporation from stage one to stage two d...

Microbial response of an acid forest soil to experimental soil warming

Science.gov (United States)

S.S. Arnold; I.J. Fernandez; L.E. Rustad; L.M. Zibilske

1999-01-01

Effects of increased soil temperature on soil microbial biomass and dehydrogenase activity were examined on organic (O) horizon material in a low-elevation spruce-fir ecosystem. Soil temperature was maintained at 5 °C above ambient during the growing season in the experimental plots, and soil temperature, moisture, microbial biomass, and dehydrogenase activity were...

Soil-restoration rate and initial soil formation trends on example of anthropogenically affected soils of opencast mine in Kursk region, Russian Federation

Science.gov (United States)

Pigareva, Tatiana

2015-04-01

The mining industry is one of the main factors which anthropogenically change the environment. Mining process results in removing of the rocks and mechanical changes of considerable amounts of ground. One of the main results of mining arising of antropic ecosystems as well as increasing of the new created soils total area is technosols. The main factor controlling the soil formation in postmining environment is the quality of spoiled materials. Initial soil formation has been investigated on spoils of the largest iron ore extraction complex in Russia - Mikhailovsky mining and concentration complex which is situated in Kursk region, Russia. Investigated soils are presented by monogenetic weak developed soils of different age (10-15-20 years). Young soils are formed on the loess parent materials (20 year-old soil), or on a mix of sand and clay overburdens (15 and 10-year-old soils). Anthropogenically affected soils are characterized by well-developed humus horizon which is gradually replaced by weakly changed soil-building rocks (profile type A-C for 10-, 15-years old soils, and A-AC-C for 20 years old soils). Gray-humus soils are characterized by presence of diagnostic humus horizon gradually replaced by soil-building rock. The maximum intensity of humus accumulation has been determined in a semi-hydromorphic 10-year-old soil developed on the mixed heaps which is connected with features of water-air conditions complicating mineralization of plant remnants. 20-year-old soil on loess is characterized by rather high rate of organic substances accumulation between all the automorphous soils. It was shown that one of the most effective restoration ways for anthropogenically affected soils is a biological reclamation. Since overburdens once appeared on a day surface are overgrown badly in the first years, they are subject to influence of water and wind erosion. Our researchers have found out that permanent grasses are able to grow quickly; they accumulate a considerable

Comparing organic versus conventional soil management on soil respiration [version 1; referees: 2 approved

Directory of Open Access Journals (Sweden)

Bence Mátyás

2018-03-01

Full Text Available Soil management has great potential to affect soil respiration. In this study, we investigated the effects of organic versus conventional soil management on soil respiration.  We measured the main soil physical-chemical properties from conventional and organic managed soil in Ecuador. Soil respiration was determined using alkaline absorption according to Witkamp.  Soil properties such as organic matter, nitrogen, and humidity, were comparable between conventional and organic soils in the present study, and in a further analysis there was no statically significant correlation with soil respiration. Therefore, even though organic farmers tend to apply more organic material to their fields, but this did not result in a significantly higher CO2 production in their soils in the present study.

The role of soil pH on soil carbonic anhydrase activity

Science.gov (United States)

Sauze, Joana; Jones, Sam P.; Wingate, Lisa; Wohl, Steven; Ogée, Jérôme

2018-01-01

Carbonic anhydrases (CAs) are metalloenzymes present in plants and microorganisms that catalyse the interconversion of CO2 and water to bicarbonate and protons. Because oxygen isotopes are also exchanged during this reaction, the presence of CA also modifies the contribution of soil and plant CO18O fluxes to the global budget of atmospheric CO18O. The oxygen isotope signatures (δ18O) of these fluxes differ as leaf water pools are usually more enriched than soil water pools, and this difference is used to partition the net CO2 flux over land into soil respiration and plant photosynthesis. Nonetheless, the use of atmospheric CO18O as a tracer of land surface CO2 fluxes requires a good knowledge of soil CA activity. Previous studies have shown that significant differences in soil CA activity are found in different biomes and seasons, but our understanding of the environmental and ecological drivers responsible for the spatial and temporal patterns observed in soil CA activity is still limited. One factor that has been overlooked so far is pH. Soil pH is known to strongly influence microbial community composition, richness and diversity in addition to governing the speciation of CO2 between the different carbonate forms. In this study we investigated the CO2-H2O isotopic exchange rate (kiso) in six soils with pH varying from 4.5 to 8.5. We also artificially increased the soil CA concentration to test how pH and other soil properties (texture and phosphate content) affected the relationship between kiso and CA concentration. We found that soil pH was the primary driver of kiso after CA addition and that the chemical composition (i.e. phosphate content) played only a secondary role. We also found an offset between the δ18O of the water pool with which CO2 equilibrates and total soil water (i.e. water extracted by vacuum distillation) that varied with soil texture. The reasons for this offset are still unknown.

The role of soil pH on soil carbonic anhydrase activity

Directory of Open Access Journals (Sweden)

J. Sauze

2018-01-01

Full Text Available Carbonic anhydrases (CAs are metalloenzymes present in plants and microorganisms that catalyse the interconversion of CO2 and water to bicarbonate and protons. Because oxygen isotopes are also exchanged during this reaction, the presence of CA also modifies the contribution of soil and plant CO18O fluxes to the global budget of atmospheric CO18O. The oxygen isotope signatures (δ18O of these fluxes differ as leaf water pools are usually more enriched than soil water pools, and this difference is used to partition the net CO2 flux over land into soil respiration and plant photosynthesis. Nonetheless, the use of atmospheric CO18O as a tracer of land surface CO2 fluxes requires a good knowledge of soil CA activity. Previous studies have shown that significant differences in soil CA activity are found in different biomes and seasons, but our understanding of the environmental and ecological drivers responsible for the spatial and temporal patterns observed in soil CA activity is still limited. One factor that has been overlooked so far is pH. Soil pH is known to strongly influence microbial community composition, richness and diversity in addition to governing the speciation of CO2 between the different carbonate forms. In this study we investigated the CO2–H2O isotopic exchange rate (kiso in six soils with pH varying from 4.5 to 8.5. We also artificially increased the soil CA concentration to test how pH and other soil properties (texture and phosphate content affected the relationship between kiso and CA concentration. We found that soil pH was the primary driver of kiso after CA addition and that the chemical composition (i.e. phosphate content played only a secondary role. We also found an offset between the δ18O of the water pool with which CO2 equilibrates and total soil water (i.e. water extracted by vacuum distillation that varied with soil texture. The reasons for this offset are still unknown.

ENZYME ACTIVITIES OF PADDY SOILS AND RELATIONSHIPS WITH THE SOIL PROPERTIES

Directory of Open Access Journals (Sweden)

Rıdvan KIZILKAYA

1998-03-01

Full Text Available This study was carried out to determine the effect of soil properties on enzyme activities of paddy soils, the sample of which were taken from Üçpınar, Harız, Doğancı, Kaygusuz, Emenli, Sarıköy and Gelemenağarı villages where rice cultivation is an intensive agricultural system. In this study, soil properties having effects on urease, phosphatase, ß-glucosidase and catalase enzyme activities were setforth. Urease enzyme activities of soil samples varied from 24.12 to 39.03 mg N 100 g dry soil -1 . Significant correlations were determined between urease enzyme activities and organic matter (r = 0.89**, extractable Mn (r = 0.74**, exchangable K (r = 0.73** and total P content of soil (r = 0.81*. Acid phosphatase enzyme activity varied between 3.00-17.44 mg phenol 100 g dry soil -1 , alkaline phosphatase enzyme activity between 12.00-25.53 mg phenol 100 g dry soil-1 . Exchangable Mg (r = 0.71* and extractable Cu (r = 0.74* were found to have positive effect on acid phosphatase enzyme activity and pH (r = 0.73*, exchangable Ca (r = 0.74*, exchangable Mg (r = 0.71*, exchangable total basic cations (r = 0.79* and extractable Cu (r = 0.70* had positive effects on alkaline phosphatase enzyme activity, whereas total P (r = - 0.84** affected the activity negatively. ß-glucosidase enzyme activity was measured to vary between 1.12-3.64 mg salingen 100 g dry soil -1 . It was also observed that extractable Zn content of soil samples (r = - 0.97** had negative effect on ß-glucosidase activity, wheras total exchangable acidic cations (r = 0.70* affected the activity positively. Catalase enzyme activities of soils changed between 5.25 - 9.00 mg O2 5 g dry soil -1 . Significant correlations were found between catalase activities and fraction of soils and extractable Fe content. Positive correlations, however, were determined between catalase activities and clay fraction (r = 0.82* and salt content (r = 0.83** of samples.

Deep horizons: Soil Carbon sequestration and storage potential in grassland soils

Science.gov (United States)

Torres-Sallan, Gemma; Schulte, Rogier; Lanigan, Gary J.; Byrne, Kenneth A.; Reidy, Brian; Creamer, Rachel

2016-04-01

Soil Organic Carbon (SOC) enhances soil fertility, holding nutrients in a plant-available form. It also improves aeration and water infiltration. Soils are considered a vital pool for C (Carbon) sequestration, as they are the largest pool of C after the oceans, and contain 3.5 more C than the atmosphere. SOC models and inventories tend to focus on the top 30 cm of soils, only analysing total SOC values. Association of C with microaggregates (53-250 μm) and silt and clay (40 °C. Through a wet sieving procedure, four aggregate sizes were isolated: large macroaggregates (>2000 μm); macroaggregates (250-2000 μm); microaggregates and silt & clay. Organic C associated to each aggregate fraction was analysed on a LECO combustion analyser. Sand-free C was calculated for each aggregate size. For all soil types, 84% of the SOC located in the first 30 cm was contained inside macroaggregates and large macroaggregates. Given that this fraction has a turnover time of 1 to 10 years, sampling at that depth only provides information on the labile fraction in soil, and does not consider the longer term C sequestration potential. Only when looking at the whole profile, two clear trends could be observed: 1) soils with a clay increase at depth had most of their C located in the silt and clay fractions, which indicate their enhanced C sequestration capacity, 2) free-draining soils had a bigger part of their SOC located in the macroaggregate fractions. These results indicate that current C inventories and models that focus on the top 30 cm, do not accurately measure soil C sequestration potential in soils, but rather the more labile fraction. However, at depth soil forming processes have been identified as a major factor influencing C sequestration potential in soils. This has a major impact in further quantifying and sustaining C sequestration into the future. Soils with a high sequestration potential at depth need to be managed to enhance the residence time to contribute to future

Long-term tobacco plantation induces soil acidification and soil base cation loss.

Science.gov (United States)

Zhang, Yuting; He, Xinhua; Liang, Hong; Zhao, Jian; Zhang, Yueqiang; Xu, Chen; Shi, Xiaojun

2016-03-01

Changes in soil exchangeable cations relative to soil acidification are less studied particularly under long-term cash crop plantation. This study investigated soil acidification in an Ali-Periudic Argosols after 10-year (2002-2012) long-term continuous tobacco plantation. Soils were respectively sampled at 1933 and 2143 sites in 2002 and 2012 (also 647 tobacco plants), from seven tobacco plantation counties in the Chongqing Municipal City, southwest China. After 10-year continuous tobacco plantation, a substantial acidification was evidenced by an average decrease of 0.20 soil pH unit with a substantial increase of soil sites toward the acidic status, especially those pH ranging from 4.5 to 5.5, whereas 1.93 kmol H(+) production ha(-1) year(-1) was mostly derived from nitrogen (N) fertilizer input and plant N uptake output. After 1 decade, an average decrease of 27.6 % total exchangeable base cations or of 0.20 pH unit occurred in all seven tobacco plantation counties. Meanwhile, for one unit pH decrease, 40.3 and 28.3 mmol base cations kg(-1) soil were consumed in 2002 and 2012, respectively. Furthermore, the aboveground tobacco biomass harvest removed 339.23 kg base cations ha(-1) year(-1) from soil, which was 7.57 times higher than the anions removal, leading to a 12.52 kmol H(+) production ha(-1) year(-1) as the main reason inducing soil acidification. Overall, our results showed that long-term tobacco plantation not only stimulated soil acidification but also decreased soil acid-buffering capacity, resulting in negative effects on sustainable soil uses. On the other hand, our results addressed the importance of a continuous monitoring of soil pH changes in tobacco plantation sites, which would enhance our understanding of soil fertility of health in this region.

Soil properties influence kinetics of soil acid phosphatase in response to arsenic toxicity.

Science.gov (United States)

Wang, Ziquan; Tan, Xiangping; Lu, Guannan; Liu, Yanju; Naidu, Ravi; He, Wenxiang

2018-01-01

Soil phosphatase, which plays an important role in phosphorus cycling, is strongly inhibited by Arsenic (As). However, the inhibition mechanism in kinetics is not adequately investigated. In this study, we investigated the kinetic characteristics of soil acid phosphatase (ACP) in 14 soils with varied properties, and also explored how kinetic properties of soil ACP changed with different spiked As concentrations. The results showed that the Michaelis constant (K m ) and maximum reaction velocity (V max ) values of soil ACP ranged from 1.18 to 3.77mM and 0.025-0.133mMh -1 in uncontaminated soils. The kinetic parameters of soil ACP in different soils changed differently with As contamination. The K m remained unchanged and V max decreased with increase of As concentration in most acid and neutral soils, indicating a noncompetitive inhibition mechanism. However, in alkaline soils, the K m increased linearly and V max decreased with increase of As concentration, indicating a mixed inhibition mechanism that include competitive and noncompetitive. The competitive inhibition constant (K ic ) and noncompetitive inhibition constant (K iu ) varied among soils and ranged from 0.38 to 3.65mM and 0.84-7.43mM respectively. The inhibitory effect of As on soil ACP was mostly affected by soil organic matter and cation exchange capacity. Those factors influenced the combination of As with enzyme, which resulted in a difference of As toxicity to soil ACP. Catalytic efficiency (V max /K m ) of soil ACP was a sensitive kinetic parameter to assess the ecological risks of soil As contamination. Copyright © 2017 Elsevier Inc. All rights reserved.

Mapping specific soil functions based on digital soil property maps

Science.gov (United States)

Pásztor, László; Fodor, Nándor; Farkas-Iványi, Kinga; Szabó, József; Bakacsi, Zsófia; Koós, Sándor

2016-04-01

Quantification of soil functions and services is a great challenge in itself even if the spatial relevance is supposed to be identified and regionalized. Proxies and indicators are widely used in ecosystem service mapping. Soil services could also be approximated by elementary soil features. One solution is the association of soil types with services as basic principle. Soil property maps however provide quantified spatial information, which could be utilized more versatilely for the spatial inference of soil functions and services. In the frame of the activities referred as "Digital, Optimized, Soil Related Maps and Information in Hungary" (DOSoReMI.hu) numerous soil property maps have been compiled so far with proper DSM techniques partly according to GSM.net specifications, partly by slightly or more strictly changing some of its predefined parameters (depth intervals, pixel size, property etc.). The elaborated maps have been further utilized, since even DOSoReMI.hu was intended to take steps toward the regionalization of higher level soil information (secondary properties, functions, services). In the meantime the recently started AGRAGIS project requested spatial soil related information in order to estimate agri-environmental related impacts of climate change and support the associated vulnerability assessment. One of the most vulnerable services of soils in the context of climate change is their provisioning service. In our work it was approximated by productivity, which was estimated by a sequential scenario based crop modelling. It took into consideration long term (50 years) time series of both measured and predicted climatic parameters as well as accounted for the potential differences in agricultural practice and crop production. The flexible parametrization and multiple results of modelling was then applied for the spatial assessment of sensitivity, vulnerability, exposure and adaptive capacity of soils in the context of the forecasted changes in

Refining soil survey information for a Dutch soil series using land use history

NARCIS (Netherlands)

Sonneveld, M.P.W.; Bouma, J.; Veldkamp, A.

2002-01-01

Differences in land-use history within soil series, although not influencing soil classification, lead to variability of non-diagnostic soil properties in soil databases. Regional studies that use soil databases are confronted with this considerable variability. This has, for example, been reported

Sorption of Cu and Zn in low organic matter-soils as influenced by soil properties and by the degree of soil weathering.

Science.gov (United States)

Antoniadis, V; Golia, E E