Microbial Biomass Carbon (MBC)
Benchmark Value
Scoring Curve
This curve shows how a field measurement for this indicator would score across all available benchmark forms in this context. The scoring engine uses 16 benchmarks together — the OptimalRange form drives the primary score, while 15 guard(s) constrain the result.
Evidence & Context
The optimal range for MBC is not a static value but is dynamically linked to the carbon-carrying capacity of the soil. It is most effectively estimated on a site-specific basis as 2–5% of the total Soil Organic Carbon (SOC).
Microbial Biomass Carbon (MBC) is a measure of the carbon contained within the living component of soil organic matter (SOM), which is composed predominantly of bacteria and fungi.
This benchmark represents a dynamic optimal range for Microbial Biomass Carbon in agricultural soils, estimated as 2–5% of the total Soil Organic Carbon, tailored to local soil and climate conditions.
This approach provides land managers with a realistic and scalable target that is tailored to their local soil type and climatic potential.
Sources (1)
Regenerative opportunities for building soil biological resilience – a case study in the low-rainfall zone in Southern Australia - GRDC
View SourceSupporting Sources (2)
Additional references from the underlying research that informed this benchmark.
Regenerative agriculture in Australia: the changing face of farming - Frontiers, accessed July 8, 2025
View SourceProspects for summer cover crops in southern Australian semi-arid cropping systems | Request PDF - ResearchGate
View Source