Analysis of Chemical and Biochemical Parameters of Petrol-Contaminated Soil after Biostimulation with an Enzyme Reagent

This study aimed to assess the effect of petrol and the Fyre Zyme reagent on selected chemical and biochemical properties of loamy sand. The experiment was conducted under laboratory conditions. First, petrol was introduced into the soil at doses of 0 and 50 g k(-1) dry matter (DM). Next, 6% Fyre-Zyme enzyme reagent solution was added to the samples contaminated and uncontaminated with petrol, in the following combinations: 0 (control), once at 40 cm(3)kg(-1) DM, twice at 20 cm(3)kg(-1) DM at two-week intervals, and four times at 10 cm(3)kg(-1)DM at weekly intervals. Contamination of loamy sand with petrol caused slight changes in the determined chemical parameters and stimulated dehydrogenase activities, but inhibited the activity of phosphatases. The introduction of the enzyme reagent into the soil increased the C-org and N-tot content. The greatest changes were observed in the activity of phosphatases. The receiver operating characteristic (ROC) curves revealed that the application of the enzyme reagent at the application of 4 x 10 cm(3)kg(-1) DM was the most beneficial. However, the results of the eta(2) analysis indicate that the greatest influence on the determined experimental parameters was found in the soil contaminated with petrol.