Soil Organic Carbon (SOC)

AUS-AMR-CON-SOC General Moderate confidence

Benchmark Value

1.26 %

Range: 1 to 1.5 %

Thresholds: Lower: 1, Upper: —

Optimal Range: 1 to 1.5

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 6 benchmarks together — the OptimalRange form drives the primary score, while 5 guard(s) constrain the result.

Contributing Benchmarks

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

Evidence & Context

Benchmark Reference Value: A reference value of 1.26% SOC is established for the topsoil (0–10 cm).

Metric Definition:

Soil Organic Carbon (SOC) concentration in the topsoil (0–10 cm) layer under conservation management in Australia's Arid Mountain Ranges & Uplands biome.

Benchmark Definition:

SOC concentration representing a high state of ecological health and function in conservation areas.

Justification:

It is a direct field measurement of total organic carbon from a well-documented study in a comparable Australian semi-arid ecosystem, representing a functional and aspirational target for conservation landscapes.

Sources (1)

The relationship between soil organic carbon and soil surface characteristics in the semi-arid rangelands of southern Australia Journal

The relationship between soil organic carbon and soil surface characteristics in the semi-arid rangelands of southern Australia

View Source

Supporting Sources (1)

Additional references from the underlying research that informed this benchmark.

Is there a critical level of organic matter in the agricultural soils of temperate regions: A review | Request PDF - ResearchGate

Contextual Support

Is there a critical level of organic matter in the agricultural soils of temperate regions: A review | Request PDF - ResearchGate

View Source

Context

Region Australia
Biome Arid Mountain Ranges & Uplands
Land Use Conservation / Protected Natural Areas
Assessment Conservation Target
Evidence Type ReferenceCondition

Lifecycle

Status Active
Version 1
Effective From 19 Mar 2026

Notes

Lower Critical Threshold: 1 %. No upper detrimental threshold — higher values are always better up to natural saturation. Functional Range: A critical lower threshold for ecosystem function is identified at ~1.0% SOC. The optimal range for ecosystem health is ~1.0% to 1.5%. SOC levels are highly texture-dependent, with sandy soils typically having lower values (e.g., ~0.6−1.0%) and loamy soils supporting the benchmark level.

Related Benchmarks

Other benchmarks in the AUS-AMR-CON-SOC family.