| Abstract: | Correlations of Enzyme-Activities in Soil Enzyme-activities often have been used as indicators of the biological state of soil. In this connection some questions may be posed: Which enzyme is the best indicator of biological activities in soil, what is the relationship of enzyme-activities to other ecological parameters and what is the interdependency between different enzymes? To answer these questions we measured activities of amylase, catalase, invertase, pectinase, urease, xylanase and cellulase at nine alpine and subalpine sites. Furthermore the CO2-evolution, contens of nitrogen, carbon, organic matter, the soil density, total bacterial number and water capacity were determined. With these data correlation coefficients were calculated. The best relationships were found between cellulase-xylanase and amylase-invertase activities (Table 1). While catalase and pectinase are in the middle range, urease shows relatively low values. There are highly significant correlations between enzyme-activities and the content of nitrogen, carbon, organic matter, soil density or the CO2-evolution (number of samples used for calculations was 68). Almost no correlations were found with total bacterial count (Table 2). For these calculations 34 samples of each parameter were used. To prove that the lower number of samples is not the reason for low correlation coefficients we computed data of 17 samples (Table 3). The water capacity is depending on soil density and content of organic matter and the correlations are in the same range (Comparison Table 1 and 3). This means that 17 samples of each parameter are enough for these calculations. Enzyme-activities proof therefore to be good indicators of the biological state of soil. It is inappropriate to characterise biological activities of soil by total bacterial counts only. |
