Final Report: Impact of Soil Microflora on Revegetation Efforts in Southeast Kansas

EPA Grant Number: R825549C033
Subproject: this is subproject number 033 , established and managed by the Center Director under grant R825549
(EPA does not fund or establish subprojects; EPA awards and manages the overall grant for this center).

Center: HSRC (1989) - Great Plains/Rocky Mountain HSRC
Center Director: Erickson, Larry E.
Title: Impact of Soil Microflora on Revegetation Efforts in Southeast Kansas
Investigators: Banks, M. Katherine , Hetrick, B. A. , Schwab, Arthur Paul
Institution: Kansas State University
EPA Project Officer: Hahn, Intaek
Project Period: February 1, 1991 through January 1, 1994
Project Amount: Refer to main center abstract for funding details.
RFA: Hazardous Substance Research Centers - HSRC (1989) RFA Text |  Recipients Lists
Research Category: Heavy Metal Contamination of Soil/Water , Land and Waste Management


The overall goal of the proposed research is to assess the impact of soil microflora on plants used to revegetate heavy metal contaminated soils. We hypothesize that revegetation success may be significantly enhanced in the presence of heavy metal resistant microbes. Our specific objectives are: 1) To explore the role of soil microorganisms in metal tolerance of plants. 2) To determine whether exposure to heavy metal-resistant soil microbes increases plant tolerance to heavy metals and improves revegetation success. 3) To determine the effectiveness of several chemical soil tests to evaluate the changes in plant availability of heavy metals induced by microbial activity. 4) To examine whether establishment of tolerant plant species in the presence of resistant soil microorganisms will improve simultaneous or subsequent establishment of less tolerant (but more economically important) plant species.

Summary/Accomplishments (Outputs/Outcomes):

Revegetation of heavy metal-contaminated soils is prevent pollution of surrounding land or groundwater, but it is often difficult to establish plant cover on these sites. Soil microorganisms may directly improve plant establishment on waste sites by mineralizing essential nutrients for plant growth, producing growth regulating substances, or immobilizing the heavy metals, thus reducing their plant availability. Some soil microorganisms, the mycorrhizal fungi, have even been shown to more directly alter heavy metal tolerance in plants.

Previous remediation strategies have not considered the role of soil microorganisms in revegetation. We believe that heavy metal resistant microflora may be as critical to plant establishment as the plant species used. The relationship between heavy metal resistance in the microflora and the heavy metal tolerance expressed by plants were studied, to evaluate whether the use of a microbial amendment increased revegetation success.

Greenhouse Studies. The importance of soil microbes to revegetation was evaluated in greenhouse studies. No plant growth occurred in chat, regardless of microbial treatment. Mycorrhizal fungi improved growth of plants in moderately contaminated soil, but the origin of the mycorrhizal fungi did not influence the results. Mycorrhizal fungi affected translocation patterns of zinc in the obligate but not the facultative mycotroph (Shetty et al., 1994b).

A phosphorus-zinc interaction study indicated that mycorrhizal fungi adapted to high Zn conditions affected greater plant biomass in contaminated than in uncontaminated soil, while mycorrhizal fungi from uncontaminated soil resulted in greater plant biomass in uncontaminated than contaminated soil. There were no differences in shoot Zn concentrations of mycorrhizal and nonmycorrhizal plants. Mycorrhizal plants had significantly higher shoot phosphorus concentrations than nonmycorrhizal plants at all Zn levels. As P level increased, the mycorrhizal effect diminished, and plant biomass production increased. At 1000 mg/kg of Zn, plant growth was suppressed regardless of fungus or P level. This study indicates that microbial amendments would be insufficient to support plant growth in chat containing high Zn levels (Shetty et al., 1994b).

The effect of organic amendments in conjunction with mycorrhizal fungus inoculation was evaluated. Manure, nitrogen, phosphorus, and calcined-montmorillonite (Turface) were added in various combinations to chat seeded with fescue. Plant growth was best when mycorrhizal inoculation was combined with nitrogen (either organic or inorganic) and phosphorus fertilization. The biomass produced in contaminated soil did not equal that of similarly fertilized uncontaminated soil (Hetrick et al., 1994; Figge et al., 1995).

The influence of mycorrhizal symbiosis on plant growth and Zn tolerance of 44 plant species was studied in mine spoil. More cool-season grasses survived and produced shoot biomass in chat than warm-season grasses. Mycorrhizal fungus inoculation was beneficial to creeping bent grass, crested wheat grass, western wheat grass, alkali sacaton, big bluestem, red clover and wild carrot, but not other species tested. Only "merlin" red fescue and silene plants had shoot Zn concentration below phytotoxic range. Among all the groups, 14 plant species had higher Zn concentration in root compared to the shoot. Leguminous and non-leguminous fortes established most quickly, followed by cool-season grasses and warm-season grasses (Shetty et al., 1994c).

Laboratory Studies. Laboratory research focused primarily on the mobility of heavy metals in the immediate zone of influence surrounding plant roots (rhizosphere). The lowest concentrations of leachate Zn were found from pots with or without plants but amended with soil microbes. The highest concentrations were observed in leachates from pots with plants or no microbial amendments. The presence of plants increased Zn leaching either by providing channels for macropore flow of the contaminant or solubilizing the metals by complexing with organics exuded from the roots or associated microflora (Banks et al., 1994).

In order to investigate the potential role of organic acids in altering the mobility of metals in the rhizosphere, geochemical modeling of the soil-organic system was coupled with laboratory verifications. Organic acids were chosen based on their detection in soils, and concentrations ranged from 0.1 to 10 times that typically found. Acids tested were formic, acetic, succinic, citric, oxalic, salicyclic acids (Burckhard et al., 1994; Waters et al., 1994). The chemical equilibrium model, MINTEQA2, was used to determine the aqueous phase speciation and solid phase precipitation/dissolution in mine tailings exposed to solutions of carboxylic acids. Formic, acetic, oxalic, and salicyclic acids did not impact Zn solubility at any of the tested concentrations. Large increases in Zn solubility were predicted with increasing concentrations of succinic and citric acids, and this was supported by the batch equilibrations. Similarly, formic, acetic, oxalic, and salicyclic acids were predicted to have no impact on Zn solubility, and this was supported by laboratory measurements (Schwab and Banks, 1993).

The results have been presented at several professional meetings. They have also been shared with professionals at EPA and the U.S. Bureau of Mines.

Journal Articles on this Report : 8 Displayed | Download in RIS Format

Other subproject views: All 31 publications 8 publications in selected types All 8 journal articles
Other center views: All 904 publications 230 publications in selected types All 182 journal articles
Type Citation Sub Project Document Sources
Journal Article Abdelsaheb I, Schwab AP, Banks MK, Hetrick BA. Chemical characterization of heavy-metal contaminated soil in southeast Kansas. Water Air and Soil Pollution 1994;78(1-2):73-82. R825549C033 (Final)
R825549C046 (Final)
not available
Journal Article Banks MK, Schwab AP, Fleming GR, Hetrick BA. Effects of plants and soil microflora on leaching of zinc from mine tailings. Chemosphere 1994;29(8):1691-1699. R825549C033 (Final)
not available
Journal Article Banks MK, Waters CY, Schwab AP. Influence of organic acids on leaching of heavy metals from contaminated mine tailings. Journal of Environmental Science and Health Part A - Environmental Science and Engineering & Toxic and Hazardous Substance Control 1994;A29(5):1045-1056. R825549C033 (Final)
not available
Journal Article Figge DAH, Hetrick BAD, Wilson GWT. Role of expanded clay and porous ceramic amendments on plant establishment in mine spoils. Environmental Pollution 1995;88(2):161-165. R825549C033 (Final)
not available
Journal Article Hetrick BAD, Wilson GWT, Figge DAH. The influence of mycorrhizal symbiosis and fertilizer amendments on establishment of vegetation in heavy-metal mine spoil. Environmental Pollution 1994;86(2):171-179 R825549C033 (Final)
not available
Journal Article Shetty KG, Banks MK, Hetrick BA, Schwab AP. Biological characterization of a southeast Kansas mining site. Water, Air, and Soil Pollution 1994;78(1-2):169-177. R825549C033 (Final)
not available
Journal Article Shetty KG, Hetrick BAD, Figge DAH, Schwab AP. Effects of mycorrhizae and other soil microbes on revegetation of heavy metal contaminated mine spoil. Environmental Pollution 1994;86(2):181-188. R825549C033 (Final)
not available
Journal Article Shetty KG, Hetrick BAD, Schwab AP. Effects of mycorrhizal and fertilizer amendments on zinc tolerance of plants. Environmental Pollution 1995;88(3):307-314. R825549C033 (Final)
not available

Supplemental Keywords:

heavy metals, mycorrhizal fungi, revegetation., Scientific Discipline, Waste, Water, Geographic Area, Ecosystem Protection/Environmental Exposure & Risk, Contaminated Sediments, Environmental Chemistry, Geochemistry, State, Fate & Transport, Bioremediation, Ecology and Ecosystems, fate and transport, migration, contaminant transport, revegetation, biodegradation, contaminated sediment, pesticides, adsorption, microflora, bioremediation of soils, biotechnology, contaminants in soil, Zinc, chemical kinetics, Kansas (KS), phytoremediation, heavy metal contamination, contaminated soils, Pentachlorophenol

Relevant Websites: Exit

Progress and Final Reports:

Original Abstract
  • 1991
  • 1992

  • Main Center Abstract and Reports:

    R825549    HSRC (1989) - Great Plains/Rocky Mountain HSRC

    Subprojects under this Center: (EPA does not fund or establish subprojects; EPA awards and manages the overall grant for this center).
    R825549C006 Fate of Trichloroethylene (TCE) in Plant/Soil Systems
    R825549C007 Experimental Study of Stabilization/Solidification of Hazardous Wastes
    R825549C008 Modeling Dissolved Oxygen, Nitrate and Pesticide Contamination in the Subsurface Environment
    R825549C009 Vadose Zone Decontamination by Air Venting
    R825549C010 Thermochemical Treatment of Hazardous Wastes
    R825549C011 Development, Characterization and Evaluation of Adsorbent Regeneration Processes for Treament of Hazardous Waste
    R825549C012 Computer Method to Estimate Safe Level Water Quality Concentrations for Organic Chemicals
    R825549C013 Removal of Nitrogenous Pesticides from Rural Well-Water Supplies by Enzymatic Ozonation Process
    R825549C014 The Characterization and Treatment of Hazardous Materials from Metal/Mineral Processing Wastes
    R825549C015 Adsorption of Hazardous Substances onto Soil Constituents
    R825549C016 Reclamation of Metal and Mining Contaminated Superfund Sites using Sewage Sludge/Fly Ash Amendment
    R825549C017 Metal Recovery and Reuse Using an Integrated Vermiculite Ion Exchange - Acid Recovery System
    R825549C018 Removal of Heavy Metals from Hazardous Wastes by Protein Complexation for their Ultimate Recovery and Reuse
    R825549C019 Development of In-situ Biodegradation Technology
    R825549C020 Migration and Biodegradation of Pentachlorophenol in Soil Environment
    R825549C021 Deep-Rooted Poplar Trees as an Innovative Treatment Technology for Pesticide and Toxic Organics Removal from Soil and Groundwater
    R825549C022 In-situ Soil and Aquifer Decontaminaiton using Hydrogen Peroxide and Fenton's Reagent
    R825549C023 Simulation of Three-Dimensional Transport of Hazardous Chemicals in Heterogeneous Soil Cores Using X-ray Computed Tomography
    R825549C024 The Response of Natural Groundwater Bacteria to Groundwater Contamination by Gasoline in a Karst Region
    R825549C025 An Electrochemical Method for Acid Mine Drainage Remediation and Metals Recovery
    R825549C026 Sulfide Size and Morphology Identificaiton for Remediation of Acid Producing Mine Wastes
    R825549C027 Heavy Metals Removal from Dilute Aqueous Solutions using Biopolymers
    R825549C028 Neutron Activation Analysis for Heavy Metal Contaminants in the Environment
    R825549C029 Reducing Heavy Metal Availability to Perennial Grasses and Row-Crops Grown on Contaminated Soils and Mine Spoils
    R825549C030 Alachlor and Atrazine Losses from Runoff and Erosion in the Blue River Basin
    R825549C031 Biodetoxification of Mixed Solid and Hazardous Wastes by Staged Anaerobic Fermentation Conducted at Separate Redox and pH Environments
    R825549C032 Time Dependent Movement of Dioxin and Related Compounds in Soil
    R825549C033 Impact of Soil Microflora on Revegetation Efforts in Southeast Kansas
    R825549C034 Modeling the use of Plants in Remediation of Soil and Groundwater Contaminated by Hazardous Organic Substances
    R825549C035 Development of Electrochemical Processes for Improved Treatment of Lead Wastes
    R825549C036 Innovative Treatment and Bank Stabilization of Metals-Contaminated Soils and Tailings along Whitewood Creek, South Dakota
    R825549C037 Formation and Transformation of Pesticide Degradation Products Under Various Electron Acceptor Conditions
    R825549C038 The Effect of Redox Conditions on Transformations of Carbon Tetrachloride
    R825549C039 Remediation of Soil Contaminated with an Organic Phase
    R825549C040 Intelligent Process Design and Control for the Minimization of Waste Production and Treatment of Hazardous Waste
    R825549C041 Heavy Metals Removal from Contaminated Water Solutions
    R825549C042 Metals Soil Pollution and Vegetative Remediation
    R825549C043 Fate and Transport of Munitions Residues in Contaminated Soil
    R825549C044 The Role of Metallic Iron in the Biotransformation of Chlorinated Xenobiotics
    R825549C045 Use of Vegetation to Enhance Bioremediation of Surface Soils Contaminated with Pesticide Wastes
    R825549C046 Fate and Transport of Heavy Metals and Radionuclides in Soil: The Impacts of Vegetation
    R825549C047 Vegetative Interceptor Zones for Containment of Heavy Metal Pollutants
    R825549C048 Acid-Producing Metalliferous Waste Reclamation by Material Reprocessing and Vegetative Stabilization
    R825549C049 Laboratory and Field Evaluation of Upward Mobilization and Photodegradation of Polychlorinated Dibenzo-P-Dioxins and Furans in Soil
    R825549C050 Evaluation of Biosparging Performance and Process Fundamentals for Site Remediation
    R825549C051 Field Scale Bioremediation: Relationship of Parent Compound Disappearance to Humification, Mineralization, Leaching, Volatilization of Transformaiton Intermediates
    R825549C052 Chelating Extraction of Heavy Metals from Contaminated Soils
    R825549C053 Application of Anaerobic and Multiple-Electron-Acceptor Bioremediation to Chlorinated Aliphatic Subsurface Contamination
    R825549C054 Application of PGNAA Remote Sensing Methods to Real-Time, Non-Intrusive Determination of Contaminant Profiles in Soils
    R825549C055 Design and Development of an Innovative Industrial Scale Process to Economically Treat Waste Zinc Residues
    R825549C056 Remediation of Soils Contaminated with Wood-Treatment Chemicals (PCP and Creosote)
    R825549C057 Effects of Surfactants on the Bioavailability and Biodegradation of Contaminants in Soils
    R825549C058 Contaminant Binding to the Humin Fraction of Soil Organic Matter
    R825549C059 Identifying Ground-Water Threats from Improperly Abandoned Boreholes
    R825549C060 Uptake of BTEX Compounds by Hybrid Poplar Trees in Hazardous Waste Remediation
    R825549C061 Biofilm Barriers for Waste Containment
    R825549C062 Plant Assisted Remediation of Soil and Groundwater Contaminated by Hazardous Organic Substances: Experimental and Modeling Studies
    R825549C063 Extension of Laboratory Validated Treatment and Remediation Technologies to Field Problems in Aquifer Soil and Water Contamination by Organic Waste Chemicals