The effect of sewage water from an oil field on the properties and biological activity of typical Chernozem

The effect of different concentrations (0.5, 1.0, 2.0, and 4.0%) of salts, introduced into typical chernozem through sewage waters from an oil field on pH; the contents of exchangeable cations, total and labile humus, and nutrients (NPK); CO 2 emission; and the activity of hydrolytic and reduction-oxidation enzymes was studied in a laboratory experiment. Sixty days after contamination, no significant changes in the soil adsorption complex were registered. At the same time, changes in the soil agrochemical properties and, especially, enzymatic activity were obvious.