Microbial biomass versus soil fertility in forest sites

Soil chemistry, soil microbial biomass and mineralization rate of organic matter (OM) were estimated on plots, which were set up in Scots pine and Norway spruce forests in southern Poland. The aim of the study was to assess the relations between soil microbial biomass and chemical parameters associated with soil fertility. The size of microbial biomass was found to be significantly correlated with chemical parameters reflecting soil nutritional status (content of base cations, cation exchange capacity, base saturation) and organic matter quality (C[org] to macronutrients ratios). In addition, soil microbial biomass appeared to be strongly correlated with OM mineralization rate. These findings point out a distinct relationship between soil fertility and soil microbial biomass, suggesting that microbial biomass measurements provide a valid estimate of soil quality.