Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
9451949 | Chemosphere | 2005 | 7 Pages |
Abstract
A study was conducted to evaluate the effects of different concentrations of lead (Pb) and cadmium (Cd) applied as their nitrates on soil microbial biomass carbon (Cmic) and nitrogen (Nmic), and substrate utilization pattern of soil microbial communities. The Cmic and Nmic contents were determined at 0, 14, 28, 42 and 56 days after heavy metal application (DAA). The results showed a significant decline in the Cmic for all Pb and Cd amended soils from the start to 28 DAA. From 28 to 56 DAA, Cmic contents changed non-significantly for all other treatments except for 600 mg kgâ1 Pb and 100 mg kgâ1 Cd in which it declined significantly from 42 to 56 DAA. The Nmic contents also decreased significantly from start to 28 DAA for all other Pb and Cd treatments except for 200 mg kgâ1 Pb which did not show significant difference from the control. Control and 200 mg kgâ1 Pb had significantly lower soil microbial biomass C:N ratio as compared with other Pb treatments from 14 to 42 DAA, however at 56 DAA, only 1000 mg kgâ1 Pb showed significantly higher C:N ratio compared with other treatments. No significant difference in C:N ratio for all Cd treated soils was seen from start to 28 DAA, however from 42 to 56 DAA, 100 mg kgâ1 Pb showed significantly higher C:N ratio compared with other treatments. On 56 DAA, substrate utilization pattern of soil microbial communities was determined by inoculating Biolog ECO plates. The results indicated that Pb and Cd addition inhibited the functional activity of soil microbial communities as indicated by the intensity of average well color development (AWCD) during 168 h of incubation. Multivariate analysis of sole carbon source utilization pattern demonstrated that higher levels of heavy metal application had significantly affected soil microbial community structure.
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Environmental Science
Environmental Chemistry
Authors
Muhammad Akmal, Xu Jianming, Li Zhaojun, Wang Haizhen, Yao Huaiying,