ARE MICROBIAL BIOMASS ESTIMATIONS EQUALLY VALID WITH ARABLE SOILS AND FOREST SOILS

The respiration and microbial biomass were calculated for 58 arable and forest soils. Both methods show that arable soils and forest soils do not stem from the same population. They have to be examined separately. A regression between respiration and microbial biomass for arable soils may be possible, but the slope seems to be less than stated by Anderson and Domsch. The subsample of the microbial biomasses calculated for forest soils appears to be rather heterogeneous. This may be due to well-known methodological problems with the fumigation-incubation-method and a regression equation could not be calculated. An overall conversion factor from respiration to biomass for all types of soil seems to be questionable.