EVALUATION OF SOIL ENZYME ACTIVITIES UNDER DIFFERENT CROPLANDS

Soil enzyme activities play key roles in the biochemical functioning of soils, nutrient cycling, and in the degradation of litter and artificial substances. Knowledge of soil enzyme activities can provide information on changes in soil quality due to land use management. In this study, we report the actual and potential dehydrogenase and catalase activities involved in intracellular metabolism and phosphatases (phosphomonoesterases) activities involved in phosphorus metabolism under different croplands. Soil was sampled from the 0- 10-, 10-20- and 20-30-cm depths from typical clay soil at Livada (Satu Mare County), and from typical chernozem and histosol at Berveni (Satu Mare County). Significant and unsignificant differences were registered in the soil enzymatic activities depending on the kind of enzymatic activity and the type of soil. All enzymatic activities studied were greater in typical chernozem compared to the typical clay soil and histosol. Based on the absolute values of the enzymatic activities, the enzymatic indicator of soil quality (EISQ) was calculated. The EISQ values ranged between 0.605 and 0.989 indicating an appreciable intensity of the enzymatic activities. These values mean that by determination of soil enzyme activities valuable information can be obtained regarding fertility status of soils. The enzyme activities were significantly intercorrelated with r values from 0.814 to 0.989 (p<0.05). A perfect positive correlation between enzymatic indicator of soil quality and grain yield was establish.