Vershinin A.A., Petrov A.M., Zaynulgabidinov E.R., Karimullin L.K.
OIL POLLUTION AND MICROBIAL BIOMASS IN DIFFERENT TYPES OF SOILS ^{[№ 3 ' 2018]}
Content of microbial biomass carbon (Cmic) in light-grey forest medium loamy soil, grey forest light loamy soil, dark-grey forest light loamy soil, sod-podzolic sandy loamy soil and sod-podzolic medium loamy soil under different levels of residual content of oil products was studied. The nature of change of microbe biomass carbon and share of microbial carbon in organic substance of soil (Cmic/Corg) dependent on soil type, granulometric composition and residual content of oil. Increase of non-polar hydrocarbons concentration led to decrease both microbial biomass carbon and Cmic/Corg. Among the soils studied microbiota of sod-podzolic sabulous soil appeared to be the most sensitive to oil pollution. Carbone content of dark-grey forest light loamy soil remained at high level and virtually unchanged even high doses of pollutant. The lack of inhibitory effect on the basal respiration of studied soils within the using range of pollutant concentrations indicates sufficiently intensive degradation of oil hydrocarbons. Against the background of absence of influence of pollutant concentration on the speed of basal respiration, increase in content of oil products led to a increase in the speed of substrate-induced respiration. This effect is most pronounced in the experimental varianrs of light sod-podzolic sandy loamy soil. The decrease in activity of substrate-induced respiration of dark-grey forest light loamy soil in 10 % is registered only in variants containing 4,94 and 6,45 g/kg of oil products. Practically in all variants of experiment the inhibitory effect of oil pollution on the growth of wheat roots was recorded. Sod-podzolic sandy loamy soil was most exposed to the negative influence of the pollutant. In other soils, phytoeffect is determinate by the residual oil content in soil. In the course of conducted researches somt interrelation between microbial potential (Cmic and Cmic/Corg ) and toxicity of oil polluted soils was found. The maximum toxicity for higher plants were identified in the sod-podzolic sandy loamy soil, with a minimum reserve of microbial carbon.