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
A state of significant ecological dysfunction is indicated by MBC levels falling below approximately 150 mg/kg.
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 indicates the minimum Microbial Biomass Carbon level below which significant ecological dysfunction is likely in agricultural soils of Australia's Arid Mountain Ranges & Uplands.
This threshold is conditional on other soil stressors, especially soil pH below 5.0, where microbial biomass becomes a primary driver of overall ecosystem multifunctionality.
Sources (2)
Regenerative agriculture in Australia: the changing face of farming - Frontiers, accessed July 8, 2025
View SourceRegenerative opportunities for building soil biological resilience – a case study in the low-rainfall zone in Southern Australia - GRDC
View SourceSupporting Sources (1)
Additional references from the underlying research that informed this benchmark.
Prospects for summer cover crops in southern Australian semi-arid cropping systems | Request PDF - ResearchGate
View Source