Long-term sludge experiments in Britain: the effects of heavy metals on soil microorganisms
The overall objective of this study is to evaluate the effects of an established range of soil heavy metal concentrations on soil microbial activity, the implications for agricultural productivity and long- term soil fertility. At nine sites with contrasting clay contents throughout Britain, selected metal-rich sludge cakes were applied over a four year period (1994-1997) to establish individual zinc (Zn), copper (Cu) and cadmium (Cd) metal dose-response treatments. Following these additions, effects of the established range of soil heavy metal concentrations on soil microbial processes and chemical properties are being examined, with particular reference to nitrogen fixing rhizobia, microbial respiration, biomass carbon and soil extractable metal concentrations. Metal-amended liquid sludges were also applied at three of the sites in England over a three year period (1995-1997) to establish individual Zn, Cu and Cd metal dose-response treatments, and to provide a contrast in the form of metal applied to the sludge cake treatments. The programme of soil microbial and chemical property determinations followed the same protocol as the sludge cake experiments. The soil microbial assays have measured decreases in rhizobia numbers on the Zn dose-response treatments at a number of the sludge cake sites (6 sites in 2003), and decreases in biornass carbon on both the Zn and Cu sludge cake dose-response treatments at some sites (six for Zn and three for Cu, in 2003). Notably, there have been no decreases in rhizobia numbers or biomass C on the Zn dose-response treatments at the associated metal-amended liquid sludge sites.
biosolids heavy metals Rhizobinm most probable numbers sewage sludge soil biomass C soil respiration
P. A. Gibbs B. J. Chambers A. M. Chaudri S. P. McGrath C. H. Carlton-Smith A. R. Godley J. R. Bacon C. D. Campbell A. H. Sinclair
ADAS Gleadthorpe, Meden Vale, Mansfield, NG20 9PF, UK Rothamsted Research, Harpenden, AL5 2JQ, UK WRc plc, Frankland Road, Swindon, Wiltshire, SN5 8YF, UK Macaulay Institute, Craigiebuclder, Aberdeen, AB15 8QH, UK SAC Environmental Group, Ferguson Building, Craibstone, Aberdeen, AB21 9YA
国际会议
第九届痕量元素生物地球化学国际会议(9th International Conference on the Biogeochemistry of Trace Elements)
北京
英文
526-527
2007-07-15（万方平台首次上网日期，不代表论文的发表时间）