Biological properties of south Russian soils: Tolerance to oil pollution

Abstract

Oil pollution of south Russian soils usually leads to reduction in the abundance of ammonifying bacteria, microscopic fungi, and bacteria of the genus Azotobacter , as well as in enzyme (catalase and invertase) and cellulolytic activities. By the criterion of biological tolerance to oil pollution, these soils can be arranged in the following series: ordinary chernozems >= soddy calcareous soils = southern chernozems >= leached chernozems > brown forest soils >= gray sand soils. A regional scheme of ecological safety standards for oil contents in these soil types is proposed.