Effect of fertilization practice on biological properties of crude oil-polluted soil

Abstract

Abstract Hydrocarbon soil pollution is widespread problem in many regions of the world, where oil is extracted and transported. Pollution with crude oil has numerous adverse impacts on the soil-microorganism-plant system. Although adding fertilizers has been shown to be essential to enhance remediation rate, excessive nutrients may exert toxicity for microorganisms and plants. Field test was conducted in the area previously subjected to several accidental oil spills in the central European Russia. The effects of fresh pig manure and/or conventional NPK fertilizers on plant growth, hydrocarbon content and activities of catalase, dehydrogenase, urease, sucrose, and phosphatase were evaluated depending on an application rate. Fertilizer application resulted in restoration of plant cover and reduction of hydrocarbons by 13 to 46%. Oil pollution reduced activities of catalase, dehydrogenase, sucrase and phosphatase and increased urease activity. Manure application was more effective in regard to plant growth, hydrocarbon removal and enzymatic activity in comparison with mineral fertilizers. The maximum positive effect on contaminated soil-microorganism-plant system was obtained under combined application of manure and NPK.