Soil Organic Carbon (SOC)

AUS-TSW-AGR-SOC General Moderate confidence

Benchmark Value

No specific value — see range

Range: 0.66 to 0.9 %

Thresholds: Lower: 0.7, Upper: —

Optimal Range: 0.66 to 0.9

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 10 benchmarks together — the OptimalRange form drives the primary score, while 9 guard(s) constrain the result.

Contributing Benchmarks

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

Evidence & Context

A critical threshold of <0.9% SOC (0-10 cm) is identified, below which soil function is significantly compromised, particularly in low-rainfall cropping zones. For plains cropping on sandier soils, this can be as low as <0.66%.

Metric Definition:

Soil Organic Carbon (SOC) content in the 0-10 cm soil layer

Benchmark Definition:

Lower critical threshold range for Soil Organic Carbon in the 0-10 cm soil layer below which soil function is impaired in temperate semi-arid shrublands and open woodlands under agricultural cropping.

Justification:

Below this range, soil function is significantly compromised, particularly in low-rainfall cropping zones.

Sources (1)

Thinking about a soil carbon project? Understand soil data first ... GreyLiterature

Thinking about a soil carbon project? Understand soil data first ...

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Supporting Sources (4)

Additional references from the underlying research that informed this benchmark.

Can soil organic matter be increased in a continuous cropping system in the low to medium rainfall zone? | Birchip Cropping Group

Contextual Support

(PDF) Soil carbon dynamics under different cropping and pasture management in temperate Australia: Results of three long-term experiments - ResearchGate, accessed August 4, 2025,

View Source

Organic Carbon Storage - WA | Fact Sheets | soilquality.org.au, accessed July 6, 2025,

Contextual Support Government

Organic Carbon Storage - WA | Fact Sheets | soilquality.org.au

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Soil Carbon Saturation: What Do We Really Know? - PMC - PubMed Central

Contextual Support Journal

Soil Carbon Saturation: What Do We Really Know? - PMC - PubMed Central

View Source

Thinking about a soil carbon project? Understand soil data first ..., accessed August 5, 2025,

Contextual Support GreyLiterature

Challenging claimed benefits of soil carbon sequestration for mitigating climate change and increasing crop yields: Heresy or sober realism? - PubMed Central

View Source

Context

Region Australia
Biome Temperate Semi-Arid Shrublands & Open Woodlands
Land Use Agricultural Crop Production
Assessment Pristine Reference
Evidence Type DegradationThreshold

Lifecycle

Status Superseded
Version 1
Effective From 20 Mar 2026
Effective To 20 Mar 2026

Notes

Critical threshold range of 0.7% to 0.9% SOC is scientifically defensible for this system.

Related Benchmarks

Other benchmarks in the AUS-TSW-AGR-SOC family.