ARS | Publication request: Effects of Organic Amendments on Microbial Properties in Lead-Contaminated Soils

Submitted to: Soil and Water Conservation Society
Publication Type: Abstract
Publication Acceptance Date: August 1, 2007
Publication Date: August 1, 2007
Citation: Hoilett, N., Yang, J., Kremer, R.J., Eivazi, F. 2007. Effects of organic amendments on microbial properties in lead-contaminated soils. Soil and Water Conservation Society Annual Meeting, July 21-25, 2007, Tampa, Florida.

Technical Abstract: The Environmental Protection Agency lists more than 17,000 contaminated sites in the United States, many of which are contaminated with heavy metals including lead (Pb) and zinc (Zn). Lead contamination in soil has been shown to be a threat to human health and ecosystem functioning through adverse effects on microbial activity and community structure. Soil amendments composed of organic materials can reduce the environmental impact of lead in mining wastes and associated soils. The objective of this study was to assess the effects of organic amendments used for remediating Pb-contaminated mining sites on soil microbial properties. Field plots, established in Pb mining waste sites near Joplin, MO in the Oronogo-Duenweg Mining Belt, were amended with various organic materials including composted sewage sludge, spent mushroom compost, composted chicken litter, and turkey house litter. Soil C, N, and various microbial properties were determined on samples retrieved periodically from the surface 10 cm of plots over a two-year period after amendment. Total soil C and N, microbial biomass and phosphatase activity were increased by all organic amendments. Molecular analysis revealed that organic amendments also increased bacterial diversity in soils. In addition to the ability of organic materials to complex with and reduce toxicity of Pb, soil microbial properties were also improved, which can be considered an initial step in the overall improvement of soil quality at these degraded sites.