Effect of different substances on some properties of soil contaminated with heating oil

The aim of the study was to determine the effect of the application of different substances (nitrogen, compost, bentonite, zeolite and calcium oxide) to soil on its selected properties after prior contamination with heating oil: 0, 5, 10, 15 and 20 g kg^-1 d.m. of soil. Heating oil contamination and the application of different substances had a significant effect on the tested soil properties. In the series without additives, heating oil caused an increase in soil pH and a decrease in hydrolytic acidity, the total exchange bases and cation exchange capacity. Bentonite and calcium oxide had the strongest effect of all the substances on soil properties. They induced a rise in soil pH, an increase in the total exchange bases and cation exchange capacity and a decrease in hydrolytic acidity. The effect of other substances, particularly nitrogen and compost, on the tested soil properties was significantly lower. On the soil contaminated with heating oil, the effect of individual substances on the degree of base saturation was relatively small because it did not exceed 8% in all of the test series.