Location: Coastal Plain Soil, Water and Plant Conservation Research
Project Number: 6082-12630-002-004-I
Project Type: Interagency Reimbursable Agreement
Start Date: Apr 1, 2021
End Date: Mar 31, 2026
Objective:
This study seeks to address the challenges associated with the restoration of mine-impacted soils, as well as developing a risk assessment framework for future soil restorative efforts in degraded (agro)ecosystems. These goals will be pursued by accomplishing the following objectives:
1. Understanding the process by which locally effective microorganisms, in conjunction with other organic inputs (e.g., compost and biochar) and biostimulants (e.g., humic substances), stimulate soil formation in parent material impacted by mine-spoils.
2. Adapt and further develop currently existing soil health tests and their relevant matrices for the development of risk assessment frameworks to inform future remediation efforts.
Approach:
This project will be conducted using field plots and sites within the Oronogo-Duenweg Mining Belt Superfund located near Joplin, Missouri. Comparative analysis will be performed by looking at the following sites: pristine, sites with no documented mining impacts; remediated, sites that have had all lead contamination removed, generally resulting in an exposed C horizon; naturally revegetated, sites impacted by mining but with a naturally formed soil layer; restored, sites that have been remediated and receiving a newly constituted soil layer comprised of compost, locally effective microorganisms, and other soil amendments planted with native plant species with the aim of restoring wildlife habitat.
Locally Effective Microorganisms (LEM) will be produced from soil microorganisms collected from soils identified as free from mining impacts using a fermentation process. Microbial teas made from these fermented microbial populations will be used to inoculate composts produced by an EPA-built composting facility in Webb City, MO which will then be used to develop field plots for further analysis.
Soil Health - soil health measurements will be conducted using the SMAF framework, which is a combination of physical, chemical, and biological measures. Physical measurements include: water stable aggregates; bulk density; and aggregate stability. Chemical measurements include: pH, electrical conductivity, extractable phosphorus and potassium, and total organic carbon. Biological measurements include: microbial biomass carbon via fumigation-extraction; potentially mineralizable nitrogen; beta-glucosidase enzyme activity. Further assessments will be conducted by examination of microbial diversity as measured by deep 16S DNA sequencing.
Soil accumulation will be monitored by the use of calibrated metal rods and erosion pins. Additionally tracking of plot carbon balances will be monitored via examination of aboveground and belowground biomass measurements and decomposition rates via litter bag decomposition.
