201. [Ecological effects of low dosage mixed rare earth elements accumulation on major soil microbial groups in a yellow cinnamon soil].
- Author
-
Tang X, Sun Y, Xia M, Wen C, and Zhang Z
- Subjects
- Soil analysis, Ecosystem, Fertilizers, Metals, Rare Earth analysis, Soil Microbiology, Soil Pollutants analysis
- Abstract
A combination of field plot experiment and simulated low dosage accumulation test was adopted to study the ecological effects of low dosage mixed rare earth elements (REE) accumulation on major soil microbial groups in a yellow cinnamon soil. The continuous accumulation of REE had the alternative effects of stimulation, inhibition and re-stimulation on soil bacteria and actinomycetes, and a continuous stimulation on soil fungi. The inhibitory intensity of REE on the three groups of soil microorganisms was in the order of bacteria > actinomycetes > fungi. At the accumulation of 150 mg x kg(-1) of REE, the population structure of three groups changed remarkably. The number of REE-tolerant microbes increased, with gram negative bacteria, white spore group and penicillium being predominant in bacteria, actinomycetes and fungi population, respectively. The median effect concentration (EC50) of REE was 24.1, 41.6-73.8 and 55.3-150.1 mg x kg(-1) for soil bacteria, actinomycetes and fungi, respectively. The EC50 value of 30 mg x kg(-1) might be taken as the critical value of mixed REE in yellow cinnamon soil.
- Published
- 2004