Soil Phosphorus

AUS-TDG-FOR-SOP General Moderate confidence

Benchmark Value

No specific value — see range
Range: 3 to 8 mg/kg
Optimal Range: 3 to 8
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 16 benchmarks together — the OptimalRange form drives the primary score, while 15 guard(s) constrain the result.

Contributing Benchmarks

OptimalRange Primary Point Guard LowerThreshold Guard UpperThreshold Guard LowerThreshold Guard MinimumOnly Guard OptimalRange Guard LowerThreshold Guard OptimalRange Guard UpperThreshold Guard Point Guard OptimalRange Guard MinimumOnly Guard Point Guard LowerThreshold Guard OptimalRange Guard

Evidence & Context

This range (3-8 mg/kg available P, using Colwell P or Olsen P methods which are common for Australian soils) represents the best available condition for production forestry in Australian Temperate Dry Woodlands & Native Grasslands that prioritizes high environmental health, ecological functions, and biodiversity.

Metric Definition:

Available phosphorus in soil measured by Colwell P or Olsen P methods, representing best available condition under production forestry.

Benchmark Definition:

Available phosphorus in soil measured by Colwell P or Olsen P methods representing best available condition for production forestry in Australian Temperate Dry Woodlands & Native Grasslands.

Justification:

This range represents the best available condition for production forestry in Australian Temperate Dry Woodlands & Native Grasslands that prioritizes high environmental health, ecological functions, and biodiversity. It reflects the naturally P-impoverished status of these ancient, weathered Australian soils to which the native flora is highly adapted.

Sources (1)

Preview of Al-Beidh, S., & Al-Tawaha, A. R. M. (2023). Basic Properties and Mineralogy of Soils and Their Impact on the Growth of Jarrah Forest in Southwestern Australia. Land, 12(6), 1236.
Al-Beidh, S., & Al-Tawaha, A. R. M. (2023). Basic Properties and Mineralogy of Soils and Their Impact on the Growth of Jarrah Forest in Southwestern Australia. Land, 12(6), 1236. Journal

Soil Characteristics and Fertility of the Unique Jarrah Forest of Southwestern Australia, with Particular Consideration of Plant Nutrition and Land Rehabilitation - MDPI, accessed July 19, 2025,

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Supporting Sources (3)

Additional references from the underlying research that informed this benchmark.

Preview of Phosphorus fertiliser management for pastures based on native grasses in south-eastern Australia - CSIRO Publishing, accessed August 5, 2025,
Phosphorus fertiliser management for pastures based on native grasses in south-eastern Australia - CSIRO Publishing, accessed August 5, 2025,
Contextual Support Journal

Phosphorus nutrition of phosphorus-sensitive Australian native ..., accessed May 15, 2025,

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Preview of Phosphorus nutrition of phosphorus-sensitive Australian native plants: threats to plant communities in a global biodiversity hotspot - PMC
Phosphorus nutrition of phosphorus-sensitive Australian native plants: threats to plant communities in a global biodiversity hotspot - PMC
Contextual Support Journal

(PDF) Sensitivity of seedling growth to phosphorus supply in six tree ..., accessed May 15, 2025,

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Preview of Sensitivity of seedling growth to phosphorus supply in six tree species of the Australian Great Western Woodlands - ResearchGate, accessed August 11, 2025
Sensitivity of seedling growth to phosphorus supply in six tree species of the Australian Great Western Woodlands - ResearchGate, accessed August 11, 2025
Contextual Support Journal

Understanding soil tests for pastures | Soil | Farm management ..., accessed May 15, 2025,

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Context

  • Region Australia
  • Biome Temperate Dry Woodlands & Native Grasslands
  • Land Use Production Forestry
  • Assessment Pristine Reference
  • Evidence Type ReferenceCondition

Lifecycle

  • Status Active
  • Version 1
  • Effective From 25 Mar 2026

Notes

The benchmark aims to maintain conditions that support characteristic native plant communities and avoid P enrichment, which is known to be detrimental to many P-sensitive native species and overall ecosystem integrity.