Soil Organic Carbon (SOC)

AUS-TMS-CON-SOC General Low confidence

Benchmark Value

2.1 %
Direction: Higher is desirable ↑
Form: MinimumOnly

Scoring Curve

This curve shows how a field measurement for this indicator would score across all available benchmark forms in this context.

Evidence & Context

SOC levels below approximately 1.4% for sandy soils or 2.1% for sandy loams (indicative values from SA guidelines for high rainfall zones), or where significant functional impairment (e.g., severe erosion, loss of perennial grass cover) is evident, likely signify a compromised state.

Metric Definition:

Soil Organic Carbon (SOC) percentage in the 0-10 cm soil depth

Benchmark Definition:

This benchmark represents the minimum Soil Organic Carbon percentage below which sandy loam soils are likely to be ecologically compromised in tropical monsoonal savannas under conservation management.

Justification:

Inferred from South Australian agricultural guidelines for high rainfall zones as a lower limit for sandy loams.

Sources (3)

Preview of Carbon and nitrogen stores in a savanna landscape in the Berrimah Agricultural Research Centre, northern Australia. CSIRO.
Carbon and nitrogen stores in a savanna landscape in the Berrimah Agricultural Research Centre, northern Australia. CSIRO. Journal

Davies, J. (2017). Carbon and water exchange in Australian tropical savannas. PhD Thesis, James Cook University.

View Source
Preview of PhD Thesis: Carbon dynamics in tropical savannas: from leaf to landscape (Davies, 2017)
PhD Thesis: Carbon dynamics in tropical savannas: from leaf to landscape (Davies, 2017) GreyLiterature

Chen, X., Hutley, L.B., Eamus, D., Beringer, J. (2003). Carbon balance of a tropical savanna of northern Australia. Oecologia, 137, 405-416.

View Source
Preview of Soil Organic Carbon Benchmarks by Rainfall and Texture
Soil Organic Carbon Benchmarks by Rainfall and Texture Journal

Blunden et al. (2024). Fire regime impacts on soil microbes, soil organic carbon and ground cover in an Australian tropical savanna.

View Source

Context

  • Region Australia
  • Biome Tropical Monsoonal Savannas
  • Land Use Conservation / Protected Natural Areas
  • Assessment Conservation Target
  • Evidence Type DegradationThreshold

Lifecycle

  • Status Active
  • Version 1
  • Effective From 9 Jun 2026

Notes

Values below this likely indicate a depleted SOC status and compromised ecological function.

Related Benchmarks

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

— % Moderate
Conservation / Protected Natural Areas · Conservation Target
OptimalRange Active v1
4.1 % Low
Conservation / Protected Natural Areas · Conservation Target
MaximumOnly Active v1
1.4 % Low
Conservation / Protected Natural Areas · Conservation Target
MinimumOnly Active v1