Soil enzyme activities after application of fungicide QuadrisR at increasing concentration rates

The study aimed to assess the effects of fungicide QuadrisR on activities of soil enzymes contributed to soil nutrient turnover. A batch laboratory experiment with QuadrisR-amended (0 mg/kg ds (dry soil) - 35.00 mg/kg ds) loamy sand soil was conducted, and shifts in soil physical environments and enzyme activities (beta-glucosidase, urease, acid and alkaline phosphatases, arylsulfatase and dehydrogenase) were evaluated on experimental days 1, 30, 60, 90 and 120. The results indicated that QuadrisR changed both soil properties and enzyme activities. The most sensitive environmental parameter to fungicide input was soil pH. The most suscaptable to QuadrisR enzymes were dehydrogenase and arylsulfatase, and the most resistant - urease. The mean overall dehydrogenase activity decreased by 33%, whereas the profile of arylsulfatase activity tended to permanent decrease over time. The general pattern of enzyme responses to QuadrisR was an immediate-early (days 1 - 30) decline of enzyme activities after fungicide application, except that of arylsulfatase. Beta-glucosidase manifested a temporal profile of steady-state stimulation under the lowest (2.90 mg/kg ds) and low sensitivity to the higher (14.65 mg/kg ds and 35.00 mg/kg ds) fungicide concentrations.