The fungal/bacterial ratio is the ratio of fungal to bacterial biomass, expressed in mg C per kg of soil. Measure of soil disturbance.
In general, undisturbed ecosystems have a higher fungi/bacteria ratio than disturbed systems. Organic and low-input systems have a higher fungi/bacteria ratio compared to enriched conventional systems. Disturbances such as tillage and removal of crop residues can lower the fungi/bacteria ratio.