Response of the Soil Microbial Community to Simultaneous Influence of Metals and Organic Substance
P. Yu. GALITSKAYA, A. A. SAVELIEV, S. Yu. SELIVANOVSKAYA
Institute of Environmental Sciences Kazan Federal University, 420008, Kazan, Kremlyovskaya str., 18
Keywords: soil, composts, microbial biomass, respiration, metabolic quotient, metals
Abstract
Organic substances and metals have multidirectional effects on soil microorganisms. The response of a soil microbial community to simultaneous introduction of an organic substance and metals was assessed (the metals were a part of a sewage sludge compost). The increase of Corg to 2,1 ± 0,4 % and mobile Cd, Cr, Cu, Ni, Pb and Zn forms to 1,1 ± 0,03, 3,8 ± 0,8, 6,0 ± 1,2, 2,1 ± 0,5, 3,2 ± 0,7 and 12,3 ± 2,7 ppm–1 correspondingly resulted in the growth of microbial biomass in comparison to the control soil, two seasons after soil treatment. Respiratory activity of the studied soils increased during the first season and decreased by the end of the second season to the level of control plots. The value of metabolic quotient did not exceed the control level. The principal components analysis of the obtained data revealed that the major factor defining variability of the microbial community was the content of organic substance in the soil.
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