Carbon Source Utilization by Microbial Communities in Soils under Organic and Conventional Farming Practice

Summary

In a long-term field trial in which organic and conventional agricultural systems were compared since 1978 we analyzed soil microbial biomass, microbial activity and substrate utilization patterns by the Biolog GN microplates. Microbial biomass and the Cmic -to-Corg ratio was distinctly higher in organic plots whilst the metabolic quotient qCO2 as an indicator of the energy requirement of soil microorganisms was lower. Substrate utilization profiles were affected by the different lon-term treatments, but also indicated differences of short-term effects like crop and soil management steps.