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ARS Home » Southeast Area » Florence, South Carolina » Coastal Plain Soil, Water and Plant Conservation Research » Research » Publications at this Location » Publication #388508

Research Project: Innovative Manure Treatment Technologies and Enhanced Soil Health for Agricultural Systems of the Southeastern Coastal Plain

Location: Coastal Plain Soil, Water and Plant Conservation Research

Title: Microbial response to phytostabilization in mining impacted soils using maize in conjunction with biochar and compost

item Ducey, Thomas
item Sigua, Gilbert
item Novak, Jeffrey
item IPPOLITO, JAMES - Colorado State University
item Spokas, Kurt
item JOHNSON, MARK - Environmental Protection Agency (EPA)

Submitted to: Microorganisms
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/8/2021
Publication Date: 12/9/2021
Citation: Ducey, T.F., Sigua, G.C., Novak, J.M., Ippolito, J.A., Spokas, K.A., Johnson, M.G. 2021. Microbial response to phytostabilization in mining impacted soils using maize in conjunction with biochar and compost. Microorganisms. 9(12), Article 2545.

Interpretive Summary: Over the past century, the soils of the Oronogo-Duenweg Mining Belt in southwest Missouri, have been impacted by heavy mining activity. This activity has contaminated the soils with high concentrations of the heavy metals cadmium (Cd), lead, and zinc (Zn). These heavy metals pose a threat to both human health and the environment, and the contaminated lands were listed as a US EPA Superfund Site. As a consequence of remediation to remove the lead, the productive soil was removed, leaving a subsoil with poor soil fertility characteristics, as well as residual cadmium and zinc. To remove the cadmium and zinc, as well as allow the growth of corn - for use as a phytostabilizing treatment - we applied a combination of biochars and varying rates, with or without inclusion of compost. Our results indicate that both biochars utilized, as well as the addition of compost, result in improved soil microbial characteristics, bind cadmium and zinc, and support plant growth. This suggests that using biochar and compost can improve mine-impacted soil characteristics, helping future remediation efforts.

Technical Abstract: The Oronogo-Duenweg Mining Belt was home to one of the largest lead mining operations in the United States. Remediation has removed mining waste material, as well as the contaminated top-soil, leaving behind a landscape inhospitable to plant growth, while also containing residual amounts of cadmium and zinc. To gain a better understanding of how manure-derived biochars and compost impact microbial community structure and function during phytostabilization with maize, we utilized a combination of phospholipid fatty acid (PLFA) analysis, and enzymatic assays. Results indicate that microbial biomass is significantly increased, over untreated mining impacted soils, upon addition of compost and poultry litter biochar. Additionally, both biochar type, rate of application, and addition of compost had noticeable impacts on microbial community structure. These shifts in community structure correlated with pH, EC, and soil Mg concentrations. Lastly, poultry litter biochar at both application rates (2.5% and 5%), further amended with compost, had the highest esterase activity rates, while other enzyme activities varied based on biochar type, amendment rate, and compost addition. These results suggest that using a combination of biochar and compost can be utilized as a management tool to support phytoremediation efforts in mining impacted soils of the Oronogo-Duenweg Mining Belt.