EN
The aim of the study has been to determine the effect of soil contamination with zinc on the activity of soil enzymes. The study consisted of two laboratory experiments. Same, light loamy soil of pH 7.1, was used in both experiments. The variables in the first experiment were: a degree of soil contamination with zinc in mg Zn kg-1 d.m. of soil: 0, 5, 500, 1000, 1500 and 2000; dose of cellulose in g kg-1 d.m. of soil: 0, 15, and time of soil incubation (15 – 120 days). In the second experiment the following variables were tested: the degree of soil contamination with zinc in mg Zn kg-1 d.m. of soil: 0, 1000 and 2000; soil pH: 7.1, 6.4 and 5.5, and the time of soil incubation (15 – 120 days). The results of the experiments demonstrated that contamination of soil with zinc led to depressed activity of dehydrogenases, urease, acid phosphatase and alkaline phosphatase. Dehydrogenases and urease appeared to be more vulnerable to zinc contamination than phosphatases. The soil enzymes were adversely affected not only by zinc contamination but also by increasing soil acidity. According to their vulnerability to soil acidity the soil enzymes can be ordered as follows: dehydrogenases > urease > alkaline phosphatase > acid phosphatase. Cellulose added to soil (15 g kg-1) proved to be a good factor in the improvement of soil biochemical properties, although it did not limit the effects produced by zinc.