Soil Organic Carbon (SOC)

AUS-AMR-AGR-SOC General Moderate confidence

Benchmark Value

No specific value — see range

Thresholds: Lower: 1, Upper: —

Direction: Higher is desirable ↑

Form: LowerThreshold

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

An SOC level of less than 1% is considered functionally impaired.

Metric Definition:

Lower critical threshold of Soil Organic Carbon (SOC) percentage below which soil function is impaired.

Benchmark Definition:

Critical lower threshold of SOC below which soil health and productivity are compromised in arid mountain ranges & uplands under agricultural crop production.

Justification:

This threshold is supported by extensive data and expert opinion indicating compromised soil structure, water retention, and nutrient cycling below this level.

Sources (1)

Soil Organic Carbon update 2022-2023 - Goulburn Broken Catchment Management Authority

Soil Organic Carbon update 2022-2023 - Goulburn Broken Catchment Management Authority

View Source

Supporting Sources (2)

Additional references from the underlying research that informed this benchmark.

Soil Organic Carbon - Southern Farming Systems, accessed August 5, 2025,

Direct Evidence Journal

Addressing the effects of soil organic carbon on water retention in US Pacific Northwest wheat–soil systems - Frontiers, accessed July 28, 2025,

View Source

Preview of The value of soil organic matter and how we can slow its decline under cropping systems: Data from 500 paired-site comparisons - Grains Research and Development Corporation (GRDC), accessed August 5, 2025,

The value of soil organic matter and how we can slow its decline under cropping systems: Data from 500 paired-site comparisons - Grains Research and Development Corporation (GRDC), accessed August 5, 2025,

Direct Evidence

Full article: Exploring the barriers to farmer participation in soil carbon projects under the Australian Carbon Credit Unit Scheme - Taylor & Francis Online

View Source

Context

Region Australia
Biome Arid Mountain Ranges & Uplands
Land Use Agricultural Crop Production
Assessment Pristine Reference
Evidence Type DegradationThreshold

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. Below this threshold, soils exhibit poor aggregate stability, low water infiltration, diminished nutrient supply, and low biological activity.

Related Benchmarks

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