Effect of heating oil on the activity of soil enzymes and the yield of yellow lupine

The aim of the study was to determine the response of soil enzymes such as dehydrogenases, urease and acid and alkaline phosphatases to heating oil contaminating (0.0, 0.25, 0.5, 0.75, 1.0, 1.5% of soil) the experimental soil supplemented with lime and used for cultivation of yellow lupine of the Markiz variety. An increasing contamination of soil with heating oil stimulated the activity of dehydrogenases and acid and alkaline phosphatases but had a toxic effect on yellow lupine. Lime supplements did not have a significant effect on an average activity of soil dehydrogenases. However, such soil treatment had a significant effect on urease. Increasing heating oil doses in lime-supplemented soil stimulated urease activity, whereas in lime-free soil urease activity was inhibited. The activity of acid and alkaline phosphatase was lower in limed soil than in lime-free soil. The activity of dehydrogenases, urease and alkaline phosphatase in the soil with lupine cultivation was significantly higher than in the unsown soil.