Soil Organic Carbon (SOC)

AUS-TSR-AGR-SOC General Moderate confidence

Benchmark Value

No specific value — see range

Range: 1.9 to 2.2 %

Optimal Range: 1.9 to 2.2

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 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

The study predicted that the optimal SOC concentration for achieving the highest yields and best nitrogen use efficiency was in the range of 1.9% to 2.2%.

Metric Definition:

Optimal functional range of Soil Organic Carbon for peak crop productivity and nutrient use efficiency.

Benchmark Definition:

Range of SOC concentration associated with maximum crop productivity and nutrient use efficiency.

Justification:

This range is a strong, evidence-based guideline for peak ecosystem function in tropical cropping systems.

Sources (1)

critical soil organic carbon range for optimal crop response to mineral fertiliser nitrogen on a ferralsol - ResearchGate, accessed August 3, 2025,

CRITICAL SOIL ORGANIC CARBON RANGE FOR OPTIMAL CROP ...

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Supporting Sources (2)

Additional references from the underlying research that informed this benchmark.

Addressing the rundown of nitrogen and soil organic carbon - GRDC, accessed July 25, 2025,

Direct Evidence Journal

CRITICAL SOIL ORGANIC CARBON RANGE FOR OPTIMAL CROP RESPONSE TO MINERAL FERTILISER NITROGEN ON A FERRALSOL | Experimental Agriculture - Cambridge University Press

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Preview of Farming system legacy impacts on the storage and persistence of soil organic carbon and understanding the different types carbon in northern cropping systems

Farming system legacy impacts on the storage and persistence of soil organic carbon and understanding the different types carbon in northern cropping systems

Direct Evidence Journal

Farming system legacy impacts on the storage and persistence of soil organic carbon and understanding the different types carbon in northern cropping systems

View Source

Context

Region Australia
Biome Tropical & Subtropical Rainforests
Land Use Agricultural Crop Production
Assessment Pristine Reference
Evidence Type HealthyOperationalRange

Lifecycle

Status Active
Version 1
Effective From 19 Mar 2026

Notes

This range should be interpreted as a guideline rather than an absolute value applicable to all soil types and conditions in Australia. No upper detrimental threshold — higher values are always better up to natural saturation.

Related Benchmarks

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