THE USEFULNESS OF ORGANIC SUBSTANCES AND PLANT GROWTH IN NEUTRALIZING THE EFFECTS OF ZINC ON THE BIOCHEMICAL PROPERTIES OF SOIL

摘要

A pot experiment was carried out to determine the effect of organic substances on the biochemical properties of soil contaminated with zinc. Soil samples were amended with zinc (ZnCl_2) at 0, 150, 300, 600, 1200 mg Zn~(2+)kg~(-1) and fertilized with: fermented bark, keratin and cellulose in doses of 0 and 10 g kg~(-1). On experimental days 30 and 60 (harvest), soil samples were collected to determine the activity of soil enzymes: dehydrogenases, urease, acid phos-phatase and alkaline phosphatase. The results of the study indicate that the tested enzymes are sensitive to zinc contamination. The activity of dehydrogenases, urease, acid phosphatase and alkaline phosphatase decreased with an increase in the applied zinc dose. The highest level of all enzymatic activities was observed in treatments fertilized with cellulose, followed by those fertilized with fermented bark, while the lowest levels were recorded for treatments fertilized with keratin. Keratin did not alleviate the adverse effects of soil contamination with zinc because it inhibited the activity of all investigated enzymes (dehydrogenases, urease, acid phosphatase and alkaline phosphatase). All of the tested enzymes showed higher levels of activity in soil sown with oats than in unsown soil.