BIOCHEMICAL CHARACTERIZATION OF PODZOLIC SOIL UNDER WILLOW CULTURE AFTER THREE YEARS FRAON ITS AMENDMENT WITH SEW AGE SLUDGE

摘要

The study was conducted on apodzolic soil (originating from a field experiment), fertilized with various doses of municipal-industrial sewage sludge, i.e. 30 (1%), 75 (2.5%), 150 (5%), 300 (10%) and 600 Mg ha'1 (20%), and then planted with willow (Salix viminalis L.). In the third year from setting up the experiment, in two layers of the soil (0-20 and 20-40 cm) determinations were made on the effect of the applied sludge on the respiratory activity, cellulose mineralization rate, intensification ofammonification and nitrification, and on dehydrogenases and protease activity. The results obtained showed a positive effect of the sludge on almost all of the analysed biochemical parameters, both in the surface and in the deeper layers of the soil. Theeffect of the sludge in the Ap horizon was more pronounced and generally increased with increasing dosage. Only the process of ammonification was subject to inhibition that was stronger in the surface horizon of the soil.