Soil Phosphorus

AUS-TSR-CON-SOP General Moderate confidence

Benchmark Value

No specific value — see range
Range: 10 to 60 mg/kg
Optimal Range: 10 to 60
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 5 benchmarks together — the OptimalRange form drives the primary score, while 4 guard(s) constrain the result.

Contributing Benchmarks

OptimalRange Primary MaximumOnly Guard MinimumOnly Guard OptimalRange Guard OptimalRange Guard

Evidence & Context

Indicator Name: Soil Phosphorus Reference Value: 10 - 60 Unit: mg/kg Source Title: Plant-soil nutrient relationships in the wet tropical rainforests of north Queensland, Australia (Maycock 1998); Nutrient relationships of tree species in a New South Wales Subtropical rainforest (Turner & Lambert 1990); Tool 2.8: Soil nutrient critical limits (Meat & Livestock Australia 2020) Source URL or DOI: (Maycock 1998); (Turner & Lambert 1990); (MLA 2020) Confidence Level: Moderate

Metric Definition:

Available Phosphorus (Colwell P or equivalent) measured or inferred in the topsoil (0-10 cm) of undisturbed, high-integrity rainforest conservation areas.

Justification:

The confidence is Moderate, as the value is based on high-quality field data but requires inference for some soil types due to data anomalies in primary sources.

Sources (2)

Preview of Nutrient relationships of tree species in a New South Wales Subtropical rainforest (Turner & Lambert 1990)
Nutrient relationships of tree species in a New South Wales Subtropical rainforest (Turner & Lambert 1990) GreyLiterature

Tool 2.8: Soil nutrient critical limits (Meat & Livestock Australia 2020)

View Source
Preview of Plant-soil nutrient relationships in the wet tropical rainforests of north Queensland, Australia (Maycock 1998)
Plant-soil nutrient relationships in the wet tropical rainforests of north Queensland, Australia (Maycock 1998) Journal

Maycock, Colin Rulzion (1998) Plant-soil nutrient relationships in ..., accessed July 22, 2025

View Source

Supporting Sources (15)

Additional references from the underlying research that informed this benchmark.

Preview of (PDF) Nutrient relationships of tree species in a New South Wales ..., accessed July 22, 2025
(PDF) Nutrient relationships of tree species in a New South Wales ..., accessed July 22, 2025
Contextual Support Journal

A Broad Approach to Abrupt Boundaries: Looking Beyond the Boundary at Soil Attributes within and Across Tropical Vegetation Types | PLOS One - Research journals, accessed July 22, 2025

View Source
Preview of A new detailed map of total phosphorus stocks in Australian soil - ResearchGate, accessed August 11, 2025
A new detailed map of total phosphorus stocks in Australian soil - ResearchGate, accessed August 11, 2025
Contextual Support GreyLiterature

(PDF) Strategies to acquire and use phosphorus in phosphorus-impoverished and fire-prone environments - ResearchGate, accessed July 22, 2025

View Source
Preview of A simple phosphorus buffering index for Australian soils - University of Tasmania Open Access Repository Cover sheet
A simple phosphorus buffering index for Australian soils - University of Tasmania Open Access Repository Cover sheet
Contextual Support GreyLiterature

Phosphorus - NSW | Fact Sheets | soilquality.org.au, accessed July 22, 2025

View Source
Preview of Australian Journal of Soil Research - CSIRO Publishing, accessed August 5, 2025
Australian Journal of Soil Research - CSIRO Publishing, accessed August 5, 2025
Contextual Support

Australian Journal of Soil Research - CSIRO Publishing, accessed July 22, 2025

View Source
Preview of ENV509 | Module 3: Australian rainforests - an overview - Learnline, accessed July 22, 2025,
ENV509 | Module 3: Australian rainforests - an overview - Learnline, accessed July 22, 2025,
Contextual Support GreyLiterature

ENV509 | Module 3: Australian rainforests - an overview - Learnline, accessed July 22, 2025

View Source
Preview of He, X., et al. (2021). Global distribution and influencing factors of plant‐available phosphorus in semi‐natural soils. Earth System Science Data.
He, X., et al. (2021). Global distribution and influencing factors of plant‐available phosphorus in semi‐natural soils. Earth System Science Data.
Contextual Support

Soil nutrient critical limits | MBFP | More Beef from Pastures, accessed July 22, 2025

View Source
Preview of How to organically fertilise phosphorus sensitive Australian native plants, accessed July 22, 2025
How to organically fertilise phosphorus sensitive Australian native plants, accessed July 22, 2025
Contextual Support GreyLiterature

The Big Phosphorus Issue - Australian Native Plants — The Gardeners Lodge, accessed July 22, 2025

View Source
Preview of Influence of environmental conditions and some soil chemical properties on the carbon and nitrogen contents of some tropical Australian rainforest soils - Bohrium, accessed August 28, 2025,
Influence of environmental conditions and some soil chemical properties on the carbon and nitrogen contents of some tropical Australian rainforest soils - Bohrium, accessed August 28, 2025,
Contextual Support Journal

Ecosystem dynamics of disturbed and undisturbed sites in north ..., accessed July 22, 2025

View Source
Preview of Nutrient distribution and cycling in a subtropical ... - CSIRO Publishing, accessed July 16, 2025,
Nutrient distribution and cycling in a subtropical ... - CSIRO Publishing, accessed July 16, 2025,
Contextual Support Journal

Nutrient distribution and cycling in a subtropical ... - CSIRO Publishing, accessed July 22, 2025

View Source
Preview of Phosphorus requirements of Australian native plants - ResearchGate, accessed August 4, 2025
Phosphorus requirements of Australian native plants - ResearchGate, accessed August 4, 2025
Contextual Support Journal

Australian dryland soils are acidic and nutrient-depleted, and have unique microbial communities compared with other drylands - PMC, accessed July 22, 2025

View Source
Preview of Rain forest nutrient cycling and productivity in response to large-scale litter manipulation - Organization for Tropical Studies
Rain forest nutrient cycling and productivity in response to large-scale litter manipulation - Organization for Tropical Studies
Contextual Support Journal

Plant litter decomposition and nutrient cycling in north Queensland tropical rain-forest communities of differing successional status - Cambridge University Press, accessed July 22, 2025

View Source
Preview of Repeated logging depletes soil, pushing forests to ecological limits, finds new study, accessed July 22, 2025
Repeated logging depletes soil, pushing forests to ecological limits, finds new study, accessed July 22, 2025
Contextual Support GreyLiterature

Is tree planting enough? Investigation of soil condition and composition of vegetation and invertebrate assemblages after ecological restoration in agricultural landscapes - Murdoch Research Portal, accessed July 22, 2025

View Source
Preview of Salt, Nutrient, Sediment and Interactions: Findings from the National River Contaminants Program - DBCA Library, accessed July 22, 2025
Salt, Nutrient, Sediment and Interactions: Findings from the National River Contaminants Program - DBCA Library, accessed July 22, 2025
Contextual Support Journal

Salt, Nutrient, Sediment and Interactions: Findings from the National River Contaminants Program - DBCA Library, accessed July 22, 2025

View Source
Preview of The phosphorus concentration of common rocks—a potential driver of ecosystem P status - Brown University, accessed July 21, 2025,
The phosphorus concentration of common rocks—a potential driver of ecosystem P status - Brown University, accessed July 21, 2025,
Contextual Support Journal

The phosphorus concentration of common rocks—a potential driver of ecosystem P status - Brown University, accessed July 22, 2025

View Source
Preview of Too much of a good thing: phosphorus over-fertilisation in rehabilitated landscapes of high biodiversity value - Australian Centre for Geomechanics, accessed August 1, 2025
Too much of a good thing: phosphorus over-fertilisation in rehabilitated landscapes of high biodiversity value - Australian Centre for Geomechanics, accessed August 1, 2025
Contextual Support GreyLiterature

Fertilisers for native plants in gardens - Australian Plants Society | SA Region Inc, accessed July 22, 2025

View Source

Context

  • Region Australia
  • Biome Tropical & Subtropical Rainforests
  • Land Use Conservation / Protected Natural Areas
  • Assessment Pristine Reference
  • Vegetation Forest
  • Evidence Type ReferenceCondition

Lifecycle

  • Status Active
  • Version 1
  • Effective From 10 Jun 2026

Notes

Lower Critical Threshold: 10 mg/kg. Upper Detrimental Threshold: 60 mg/kg. The range of 10-60 mg/kg is essential because the natural P status of Australian rainforests is fundamentally determined by soil parent material, creating a spectrum of fertility from oligotrophic to eutrophic systems. Levels significantly below 10 mg/kg indicate degradation, and levels above 60 mg/kg are considered detrimental to ecological integrity.