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 7 benchmarks together — the OptimalRange form drives the primary score, while 6 guard(s) constrain the result.
Contributing Benchmarks
Evidence & Context
The benchmark of 400 mg/kg represents a 'best available condition' for sustainable cropping in Australia's arid and semi-arid zones.
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 the best available condition for sustainable cropping in Australia's arid and semi-arid zones, reflecting a high level of soil microbial biomass carbon indicative of healthy soil biological function.
This value is synthesized from multiple sources. It is positioned above the regional average of 338 mg/kg reported by Gupta et al. (2024) for low-rainfall cropping systems, reflecting the positive influence of best-practice management. It also aligns with the transition point from soils considered 'typically cultivated' (<400 mg/kg) to those with enhanced biological function.
Sources (1)
Soil and fertilizer phosphorus: Effects on plant P supply and mycorrhizal development - Canadian Science Publishing, accessed August 28, 2025
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