Soil Organic Carbon (SOC)

AUS-AIF-FOR-SOC General Moderate confidence

Benchmark Value

No specific value — see range
Range: 1 to 2 %
Thresholds: Lower: 1, Upper: 2
Optimal Range: 1 to 2
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 13 benchmarks together — the OptimalRange form drives the primary score, while 12 guard(s) constrain the result.

Contributing Benchmarks

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

Evidence & Context

An organic carbon threshold (varying with soil type but usually 1-2% in surface layers) below which physical and chemical fertility effectively collapse.

Metric Definition:

Soil Organic Carbon (SOC) critical lower threshold in surface soil layers

Benchmark Definition:

This benchmark defines the critical lower threshold range of Soil Organic Carbon in surface soils below which soil physical and chemical fertility collapse, indicating severe degradation of soil function.

Justification:

This threshold is supported by strong consensus in scientific and governmental literature indicating that below 1-2% SOC, soil fertility and function are severely compromised.

Sources (1)

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, Journal

Maintaining groundcover to reduce erosion and sustain production - NSW Department of Primary Industries

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Supporting Sources (20)

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

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

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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

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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 ...

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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

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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

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

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

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

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

FOREST CARBON MARKETS - Forestry Australia, accessed July 21, 2025

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

pmc.ncbi.nlm.nih.gov

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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

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

The six rights of how and when to test for soil C saturation - Copernicus.org

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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

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

(PDF) Mapping soil organic carbon fractions for Australia, their stocks, and uncertainty

View Source
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,
Contextual Support Government

Soils and carbon for reduced emissions - Agriculture Victoria, accessed July 21, 2025,

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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

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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?

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Context

  • Region Australia
  • Biome Arid Inland Floodplains & Ephemeral River Systems
  • Land Use Production Forestry
  • Assessment Pristine Reference
  • Evidence Type DegradationThreshold

Lifecycle

  • Status Active
  • Version 1
  • Effective From 18 Mar 2026

Notes

Below this level, soil physical and chemical fertility collapses, leading to impaired structure and function. Recovery from this state can take decades.

Related Benchmarks

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

4.5 % Moderate
Production Forestry · Pristine Reference
Point Active v1