Assessment of L-cysteine Reductase Activity as an Indicator of Soil Health in Different Climatic Zones After Pollution by Oil

The sulfur cycle in the soil regulates many vital processes in plants since it enters the composition of amino acids, vitamins, phytochelatins, and other substances. Soils of different climatic zones have different physicochemical properties and sulfur reserves, which, therefore, stipulates various activities of soil enzymes. The aim of the study was the assessment of L-cysteine reductase activity as an indicator of soil health in different climatic zones after oil pollution: semi-desert types, steppe types and forest types of soils. A model experiment was based on the pollution of 12 types of soil by oil (1%, 5%, and 10%) followed by the determination of the L-cysteine reductase activity in the soils after 30 days from the start of the experiment. The highest activity of L-cysteine ​​reductase in soils contaminated with oil was found in semi-desert (Haplic Solonchaks Aridic, Haplic Kastanozems Chromic) and forest (Luvic Phaeozems Albic and Luvic Stagnosols Dystric (Illuvial-Ferrugenous)) soils. The greatest sensitivity and informative content by oil pollution, assessed by the activity of L-cysteine reductase, were found in Haplic Kastanozems Chromic (semi-desert types of soils), Voronic Chernozems Pachic (ordinary) and Luvic Phaeozems Albic (steppe types of soils) and Luvic Stagnosols Dystric and Luvic Stagnosols Dystric (Illuvial-Ferrugenous) (forest types of soil). The results obtained can be used in diagnosing and assessing the ecological state and health of soils contaminated by petroleum hydrocarbons.