Soil Microbial Structure and Activity As Affected By Lead (Pb) Contamination.

Lead is a nearly ubiquitous contaminant of urban soils. Children are particularly sensitive to Pb, and lowering the risk to Pb exposure is a high priority. Recent research has found that organic matter can reduce the Pb bioavailability. Soil microorganisms are crucial to soil organic matter cycling in soils, yet little is known about how elevated soil Pb affects soil microorganisms. This research project investigated how three soil amendments influenced soil microbial structure and activity on Pb contaminated soil in southeastern Wisconsin. The plots were sown with grasses following incorporation of municipal compost, fish bone meal, and triple super phosphate fertilizer. Soils were sampled prior to amendment application and 45 and 90 days after application. Soil physical and chemical soil characteristics were quantified in addition to microbial analysis using DNA sequencing and operation taxonomic unit classification. Results are forthcoming and expected to identify the best in situ Pb remediation methods for decreasing bioavailability of lead and optimizing microbial health and plant production.