EFFECTS OF LIME AND NUTRIENT SALTS ON THE MICROBIOLOGICAL ACTIVITIES OF FOREST SOILS

In pot experiments, lime and mineral salts were applied to forest soils taken from three different sites. Microbial biomass, basal respiration, N turnover, and the activities of protease, phosphatase, and CM-cellulase were determined monthly. The fertilized soils showed a great increase in biomass, respiration and N turnover, and some increase in protease activity, whereas phosphatase activity decreased in comparison with the untreated soils. Estimates of the number of colony-forming units of different classes of microorganisms showed an increase in treated soils in most cases. The untreated soils had the lowest biological activity but the maximum application of lime and mineral salts did not automatically lead to maximum activity.