Microbial Biomass Carbon (MBC)

AUS-TGP-AGR-SMB General Moderate confidence

Benchmark Value

No specific value — see range

Range: 200 to 600 mg/kg

Optimal Range: 200 to 600

Direction: Higher is desirable ↑

Form: OptimalRange

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

OptimalRange Primary Point Guard OptimalRange Guard Point Guard OptimalRange Guard Point Guard LowerThreshold Guard

Evidence & Context

A defensible optimal range for a high-functioning cropping system in the Temperate Grassy Woodlands biome can be proposed as 200 mg/kg to 600 mg/kg.

Metric Definition:

Optimal functional range of Microbial Biomass Carbon (MBC) concentration in topsoil (0-10 cm) for agroecosystem health.

Benchmark Definition:

Range within which Microbial Biomass Carbon supports efficient ecosystem services without negative consequences in temperate grassy woodlands agricultural crop production.

Justification:

Anchored by best-practice continuous cropping benchmark and upper bound informed by diverse perennial systems.

Sources (1)

Soil microbial biomass—Interpretation and consideration for soil monitoring

View Source

Supporting Sources (3)

Additional references from the underlying research that informed this benchmark.

Altered soil microbial community at elevated CO2 leads to loss of soil carbon | PNAS, accessed August 5, 2025

Direct Evidence

Altered soil microbial community at elevated CO2 leads to loss of soil carbon - PNAS, accessed July 28, 2025,

View Source

Soil microbial biomass—what do the numbers really mean? - ResearchGate, accessed August 28, 2025,

Direct Evidence

Soil microbial biomass carbon and CO2? - ResearchGate, accessed July 18, 2025,

View Source

Soil microbial biomass, activity and nutrient cycling as indicators of soil health.

Contextual Support GreyLiterature

Soil microbial biomass, activity and nutrient cycling as indicators of soil health., accessed August 5, 2025

View Source

Context

Region Australia
Biome Temperate Grassy Woodlands & Plains
Land Use Agricultural Crop Production
Assessment Pristine Reference
Evidence Type HealthyOperationalRange

Lifecycle

Status Retired
Version 1
Effective From 17 Mar 2026
Effective To 24 Mar 2026

Notes

Represents a dynamic state of ecological and agronomic balance with robust biological activity and resilience. Retired via Evidence Integrity Review on 2026-03-24 09:41 UTC — all DirectEvidence sources confirmed dead or inaccessible.

Related Benchmarks

Other benchmarks in the AUS-TGP-AGR-SMB family.