Soil Organic Carbon (SOC)

AUS-AIF-FOR-SOC General Moderate confidence

Benchmark Value

No specific value — see range
Range: 2 to 4.5 %
Thresholds: Lower: 2, Upper: —
Optimal Range: 2 to 4.5
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 6 benchmarks together — the OptimalRange form drives the primary score, while 5 guard(s) constrain the result.

Contributing Benchmarks

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

Evidence & Context

The optimal range can be understood as the broad span of SOC concentrations, well above the critical lower threshold, where soil-mediated ecosystem services are operating efficiently and are not limited by a lack of carbon.

Metric Definition:

Optimal functional range of Soil Organic Carbon (SOC) supporting ecosystem functions

Benchmark Definition:

This benchmark represents the optimal range of soil organic carbon in surface soils where ecosystem functions operate efficiently and soil-mediated services are robust.

Justification:

Defined as SOC levels above the critical threshold that sustain key soil functions such as nutrient cycling, water retention, and structural stability.

Sources (1)

Preview of Soils and carbon for reduced emissions - Agriculture Victoria, accessed July 6, 2025,
Soils and carbon for reduced emissions - Agriculture Victoria, accessed July 6, 2025, Government

Soils and carbon for reduced emissions - Agriculture Victoria, accessed July 26, 2025

View Source

Supporting Sources (21)

Additional references from the underlying research that informed this benchmark.

Preview of (PDF) Rivers in Australia - ResearchGate
(PDF) Rivers in Australia - ResearchGate
Contextual Support Journal

Fluvial Form Variability in Arid Central Australia - Smithsonian Institution, accessed July 19, 2025

View Source
Preview of (PDF) Rivers in Australia - ResearchGate, accessed July 16, 2025,
(PDF) Rivers in Australia - ResearchGate, accessed July 16, 2025,
Contextual Support

Modelling the flow regime of an arid zone floodplain river, Diamantina River, Australia | Request PDF - ResearchGate, accessed July 19, 2025

View Source
Preview of (PDF) Soil Organic Carbon for Enhancing Soil Health - ResearchGate
(PDF) Soil Organic Carbon for Enhancing Soil Health - ResearchGate
Contextual Support GreyLiterature

Soil Organic Carbon (SOC): Importance and Impacts on Soil Health, Plant Growth, Environment & More - Advance Pesticides, accessed July 19, 2025

View Source
Preview of (PDF) Sources, sinks and transformations of organic carbon in ...
(PDF) Sources, sinks and transformations of organic carbon in ...
Contextual Support Journal

(PDF) Sources, sinks and transformations of organic carbon in ..., accessed July 19, 2025

View Source
Preview of 4 reasons to measure Soil Organic Carbon | AgroCares
4 reasons to measure Soil Organic Carbon | AgroCares
Contextual Support GreyLiterature

4 reasons to measure Soil Organic Carbon | AgroCares, accessed July 19, 2025

View Source
Preview of Carbon storage in temperate and semi-arid Australian plant communities containing cotton
Carbon storage in temperate and semi-arid Australian plant communities containing cotton
Contextual Support Journal

Baseline map of organic carbon in Australian soil to support national carbon accounting and monitoring under climate change

View Source
Preview of How Much Carbon Can Soil Store | Fact Sheets | soilquality.org.au
How Much Carbon Can Soil Store | Fact Sheets | soilquality.org.au
Contextual Support Government

How Much Carbon Can Soil Store | Fact Sheets | soilquality.org.au, accessed July 19, 2025

View Source
Preview of Impacts of Soil Organic Carbon on Soil Physical Behavior - USDA ARS
Impacts of Soil Organic Carbon on Soil Physical Behavior - USDA ARS
Contextual Support Journal

Impacts of Soil Organic Carbon on Soil Physical Behavior - USDA ARS, accessed July 19, 2025

View Source
Preview of Impacts of Soil Organic Carbon on Soil Physical Behavior | Health & Environmental Research Online (HERO) | US EPA
Impacts of Soil Organic Carbon on Soil Physical Behavior | Health & Environmental Research Online (HERO) | US EPA
Contextual Support Government

Impacts of Soil Organic Carbon on Soil Physical Behavior | Health & Environmental Research Online (HERO) | US EPA, accessed July 19, 2025

View Source
Preview of Mapping soil organic carbon fractions for Australia, their stocks, and uncertainty - BG, accessed August 5, 2025,
Mapping soil organic carbon fractions for Australia, their stocks, and uncertainty - BG, accessed August 5, 2025,
Contextual Support Journal

Effect of fire and tree‐grass patches on soil nitrogen in Australian tropical savannas

View Source
Preview of Mean total organic carbon (TOC) distribution (AE1 s.e.m.) by vegetation... - ResearchGate
Mean total organic carbon (TOC) distribution (AE1 s.e.m.) by vegetation... - ResearchGate
Contextual Support GreyLiterature

Mean total organic carbon (TOC) distribution (AE1 s.e.m.) by vegetation... - ResearchGate, accessed July 19, 2025

View Source
Preview of ORGANIC CARBON IN FORESTED SANDY SOILS: PROPERTIES, PROCESSES, AND THE IMPACT OF FOREST MANAGEMENT - Scion
ORGANIC CARBON IN FORESTED SANDY SOILS: PROPERTIES, PROCESSES, AND THE IMPACT OF FOREST MANAGEMENT - Scion
Contextual Support Journal

ORGANIC CARBON IN FORESTED SANDY SOILS: PROPERTIES, PROCESSES, AND THE IMPACT OF FOREST MANAGEMENT - Scion, accessed July 19, 2025

View Source
Preview of pmc.ncbi.nlm.nih.gov
pmc.ncbi.nlm.nih.gov
Contextual Support Journal

pmc.ncbi.nlm.nih.gov, accessed July 19, 2025

View Source
Preview of Rivers, wetlands and floodplains | Murray–Darling Basin Authority
Rivers, wetlands and floodplains | Murray–Darling Basin Authority
Contextual Support Journal

Rivers, wetlands and floodplains | Murray–Darling Basin Authority, accessed July 19, 2025

View Source
Preview of Soil carbon saturation: Linking concept and measurable carbon pools
Soil carbon saturation: Linking concept and measurable carbon pools
Contextual Support Journal

Soil carbon saturation: Linking concept and measurable carbon pools, accessed July 19, 2025

View Source
Preview of Soil Carbon Saturation: Linking Concept and Measurable Carbon Pools - ResearchGate
Soil Carbon Saturation: Linking Concept and Measurable Carbon Pools - ResearchGate
Contextual Support Journal

Soil Carbon Saturation: Linking Concept and Measurable Carbon Pools - ResearchGate, accessed July 19, 2025

View Source
Preview of Soil Carbon Saturation: What Do We Really Know? (Journal Article) | OSTI.GOV, accessed August 3, 2025,
Soil Carbon Saturation: What Do We Really Know? (Journal Article) | OSTI.GOV, accessed August 3, 2025,
Contextual Support Journal

Mapping soil organic carbon fractions for Australia, their stocks, and uncertainty - BG, accessed July 19, 2025

View Source
Preview of The relationships between land management practices and soil condition and the quality of ecosystem services delivered from agri - DAFF, accessed July 22, 2025,
The relationships between land management practices and soil condition and the quality of ecosystem services delivered from agri - DAFF, accessed July 22, 2025,
Direct Evidence Journal

View of Efficacy of the Ecosystem Services Approach in Transitioning to Regenerative Agriculture in Australia | Reinvention, accessed July 27, 2025,

View Source
Preview of Too Much Organic Matter - Maine Organic Farmers and Gardeners Association
Too Much Organic Matter - Maine Organic Farmers and Gardeners Association
Contextual Support GreyLiterature

Too Much Organic Matter - Maine Organic Farmers and Gardeners Association, accessed July 19, 2025

View Source
Preview of Western Australia - Arid, Semi-arid, Mediterranean | Britannica, accessed July 13, 2025
Western Australia - Arid, Semi-arid, Mediterranean | Britannica, accessed July 13, 2025
Contextual Support GreyLiterature

Climate of South Australia - Britannica, accessed July 13, 2025

View Source
Preview of What Kind of Harm Can Come From Soil Organic Matter?
What Kind of Harm Can Come From Soil Organic Matter?
Contextual Support GreyLiterature

What Kind of Harm Can Come From Soil Organic Matter?, accessed July 19, 2025

View Source

Context

  • Region Australia
  • Biome Arid Inland Floodplains & Ephemeral River Systems
  • Land Use Production Forestry
  • Assessment Not Stated
  • Evidence Type HealthyOperationalRange

Lifecycle

  • Status Active
  • Version 1
  • Effective From 3 Jun 2026

Notes

Represents a state of high functionality with resilience, high productivity, and robust biodiversity support. The benchmark of ~4.5% represents the high end of this range. AssessmentContext defaulted to 'Not Stated' because the source document did not state one.

Related Benchmarks

Other benchmarks in the AUS-AIF-FOR-SOC family.

4.5 % Moderate
Production Forestry · Not Stated
Point Active v1