MICROBIAL ACTIVITY MEASUREMENT IN SOIL - A COMPARISON OF METHODS

The applicability of microbiological soil analyses for quantification Of soil activity was investigated. Activity measurements were performed with noncontaminated and with fuel oil contaminated soil. The glucose-induced respiration seems to be an inappropiate method for activity determination, because different soils show only slight differences in their initial reaction to glucose. It indicated no increase in activity of the contaminated soil (gradient k = 0.965; k indicates the sensitivity of the method). Because of the low sensitivity of CO2 determination according to Isermeyer [1] the soil respiration (k = 1.425) is not such a good indicator of activity as the TTC method, which exhibits the best result (k = 2.464). Although the INT method is based upon the same principles as the TTC method and comparably exhibits higher sensitivity, it might fail because of the small solubility of substrate and product. The INT method indicates a higher activity, almost-equal-to 1.458-fold. According to the evaluation of the experiment the DMSO reduction is also less appropriate for the determination of soil activity (k = 1.228).