Microbial Biomass Carbon (MBC)

AUS-AIF-LVG-SMB General Moderate confidence

Benchmark Value

585 mg/kg
Range: 585 to 1600 mg/kg
Optimal Range: 585 to 1600
Direction: Higher is desirable ↑
Form: Point

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 11 benchmarks together — the OptimalRange form drives the primary score, while 10 guard(s) constrain the result.

Contributing Benchmarks

OptimalRange Primary OptimalRange Guard MinimumOnly Guard Point Guard OptimalRange Guard MinimumOnly Guard Point Guard Point Guard MinimumOnly Guard OptimalRange Guard MinimumOnly Guard

Evidence & Context

The value of 585 mg/kg can be interpreted as a strong, credible baseline for a healthy, well-managed pasture system during a non-flooded or dry phase.

Metric Definition:

Microbial Biomass Carbon (MBC) as a measure of microbial carbon in soil.

Benchmark Definition:

This benchmark represents a baseline microbial biomass carbon value for healthy pasture conditions during dry phases in arid inland floodplains under livestock grazing.

Justification:

This value anchors the lower end of the optimal functional range and is based on data from well-managed pastures on fertile soils.

Sources (1)

Preview of Microbial biomass and microbial biodiversity in some soils from New South Wales, Australia | Request PDF - ResearchGate
Microbial biomass and microbial biodiversity in some soils from New South Wales, Australia | Request PDF - ResearchGate Journal

Microbial biomass and microbial biodiversity in some soils from New South Wales, Australia | Request PDF - ResearchGate, accessed July 8, 2025

View Source

Supporting Sources (2)

Additional references from the underlying research that informed this benchmark.

Preview of grazing impacts on the spatial distribution of soil microbial biomass around tussock grasses in a tropical grassland - Publication : USDA ARS
grazing impacts on the spatial distribution of soil microbial biomass around tussock grasses in a tropical grassland - Publication : USDA ARS
Direct Evidence Journal

Soil microbial community structure is unaltered by grazing intensity and plant species richness in a temperate grassland steppe in northern China - Publication : USDA ARS, accessed July 29, 2025

View Source
Preview of Loss of Soil Carbon Associated with a Short-Duration Flood in a Semi-Arid Lowland River Floodplain Forest
Loss of Soil Carbon Associated with a Short-Duration Flood in a Semi-Arid Lowland River Floodplain Forest
Contextual Support Journal

Loss of Soil Carbon Associated with a Short-Duration Flood in a Semi-Arid Lowland River Floodplain Forest

View Source

Context

  • Region Australia
  • Biome Arid Inland Floodplains & Ephemeral River Systems
  • Land Use Livestock Grazing & Pasture
  • Assessment Pristine Reference
  • Evidence Type HealthyOperationalRange

Lifecycle

  • Status Active
  • Version 2
  • Effective From 19 Mar 2026

Notes

Represents the lower bound of a dynamic optimal range for MBC in arid floodplain grazing systems. Accepted by operator on 2026-03-19 05:03 UTC — superseded v1 (#852)

Related Benchmarks

Other benchmarks in the AUS-AIF-LVG-SMB family.

250 mg/kg Moderate
Livestock Grazing & Pasture · Pristine Reference
MinimumOnly Active v1
1600 mg/kg High
Livestock Grazing & Pasture · Pristine Reference
Point Superseded v1