Researchers developed a method to measure soil microbial biomass C by examining the effects of fumigation on organic C in different soils. They found a strong relationship between microbial biomass C and the difference in organic C extracted from fumigated and non-fumigated soil. This relationship held across a wide range of soil pH levels. The study also showed that ATP and microbial biomass N concentrations were similar in different soils, indicating that both come from soil microbial biomass. Additionally, the C:N ratio of microbial biomass was higher in strongly acidic soil compared to less acidic soils. The method proposed can estimate soil microbial biomass C in both neutral and acid soils.