Soil Phosphorus

AUS-TSR-FOR-SOP General Moderate confidence

Benchmark Value

6 mg/kg
Direction: Lower is desirable ↓
Form: MaximumOnly

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 14 benchmarks together — the OptimalRange form drives the primary score, while 13 guard(s) constrain the result.

Contributing Benchmarks

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

Evidence & Context

Upper Detrimental Threshold: >6 mg/kg

Metric Definition:

Available Phosphorus refers to a suite of chemical extraction methods designed to estimate the portion of soil P that is readily available for plant uptake during a growing season.

Benchmark Definition:

This benchmark marks the upper detrimental threshold of available soil phosphorus above which ecological harm and biodiversity loss may occur in tropical rainforest production forestry soils.

Justification:

Conservatively set based on evidence from rehabilitated sites where available P levels approaching and exceeding this value were directly associated with negative impacts on native plant community composition.

Sources (1)

Preview of Too much of a good thing: phosphorus over-fertilisation in rehabilitated landscapes of high biodiversity value
Too much of a good thing: phosphorus over-fertilisation in rehabilitated landscapes of high biodiversity value Journal

Too much of a good thing: phosphorus over-fertilisation in rehabilitated landscapes of high biodiversity value, accessed May 7, 2026

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Supporting Sources (19)

Additional references from the underlying research that informed this benchmark.

Preview of (PDF) A review of the effects of forest fire on soil properties - ResearchGate, accessed July 19, 2025
(PDF) A review of the effects of forest fire on soil properties - ResearchGate, accessed July 19, 2025
Contextual Support GreyLiterature

(PDF) A review of the effects of forest fire on soil properties - ResearchGate, accessed July 19, 2025

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Preview of (PDF) Soil phosphorus transformations along two long-term chronosequences with contrasting climate in south-western Australia - ResearchGate, accessed July 19, 2025
(PDF) Soil phosphorus transformations along two long-term chronosequences with contrasting climate in south-western Australia - ResearchGate, accessed July 19, 2025
Contextual Support GreyLiterature

Organic phosphorus speciation in Australian Red Chromosols: stoichiometric control, accessed July 19, 2025

View Source
Preview of A Critical Review on Soil Chemical Processes that Control How Soil pH Affects Phosphorus Availability to Plants - MDPI, accessed July 19, 2025
A Critical Review on Soil Chemical Processes that Control How Soil pH Affects Phosphorus Availability to Plants - MDPI, accessed July 19, 2025
Contextual Support Journal

A Critical Review on Soil Chemical Processes that Control How Soil pH Affects Phosphorus Availability to Plants - MDPI, accessed July 19, 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 Browsing Smithsonian Tropical Research Institute by Title, accessed July 19, 2025
Browsing Smithsonian Tropical Research Institute by Title, accessed July 19, 2025
Contextual Support Journal

Soil phosphorus responses to chronic nutrient fertilisation and seasonal drought in a humid lowland forest, Panama - CSIRO Publishing, accessed July 19, 2025

View Source
Preview of Critical phosphorus values from the Better Fertiliser Decisions for Pastures project: early insights from validation trials - BioOne Complete, accessed July 28, 2025,
Critical phosphorus values from the Better Fertiliser Decisions for Pastures project: early insights from validation trials - BioOne Complete, accessed July 28, 2025,
Contextual Support Journal

Soil nutrient critical limits | MBFP | More Beef from Pastures - MLA

View Source
Preview of Different profiles of soil phosphorous compounds depending on tree species and availability of soil phosphorus in a tropical rainforest in French Guiana - PubMed Central, accessed July 19, 2025
Different profiles of soil phosphorous compounds depending on tree species and availability of soil phosphorus in a tropical rainforest in French Guiana - PubMed Central, accessed July 19, 2025
Contextual Support Journal

Soil phosphorus fractions and their relation to leaf litterfall in a central Amazonian terra firme rainforest - SciELO, accessed July 19, 2025

View Source
Preview of Impacts of Logging-Associated Compaction on Forest Soils: A Meta-Analysis - Frontiers, accessed July 11, 2025,
Impacts of Logging-Associated Compaction on Forest Soils: A Meta-Analysis - Frontiers, accessed July 11, 2025,
Contextual Support Journal

Impacts of Logging-Associated Compaction on Forest Soils: A Meta-Analysis - Frontiers, accessed July 19, 2025

View Source
Preview of Maycock, Colin Rulzion (1998) Plant-soil nutrient relationships in ...
Maycock, Colin Rulzion (1998) Plant-soil nutrient relationships in ...
Contextual Support Journal

Australian Journal of Botany - CSIRO PUBLISHING, accessed July 19, 2025

View Source
Preview of Phosphorus buffering determines how soil properties and rainfall influence wheat (Triticum aestivum) yield response to - CSIRO Publishing, accessed July 19, 2025
Phosphorus buffering determines how soil properties and rainfall influence wheat (Triticum aestivum) yield response to - CSIRO Publishing, accessed July 19, 2025
Contextual Support Journal

Phosphorus buffering determines how soil properties and rainfall influence wheat (Triticum aestivum) yield response to - CSIRO Publishing, accessed July 19, 2025

View Source
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
Direct Evidence Journal

(PDF) Sensitivity of seedling growth to phosphorus supply in six tree ...

View Source
Preview of Phosphorus nutrition of phosphorus-sensitive Australian native plants: threats to plant communities in a global biodiversity hotspot | Conservation Physiology | Oxford Academic, accessed August 4, 2025
Phosphorus nutrition of phosphorus-sensitive Australian native plants: threats to plant communities in a global biodiversity hotspot | Conservation Physiology | Oxford Academic, accessed August 4, 2025
Contextual Support Journal

Phosphorus nutrition of phosphorus-sensitive Australian native plants: threats to plant communities in a global biodiversity hotspot | Conservation Physiology | Oxford Academic, accessed July 7, 2025,

View Source
Preview of Phosphorus Nutrition of Proteaceae in Severely Phosphorus-Impoverished Soils: Are There Lessons To Be Learned for Future Crops? - PubMed Central, accessed August 4, 2025
Phosphorus Nutrition of Proteaceae in Severely Phosphorus-Impoverished Soils: Are There Lessons To Be Learned for Future Crops? - PubMed Central, accessed August 4, 2025
Direct Evidence Journal

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

View Source
Preview of Phosphorus Transformation in Soils Following Co-Application of Charcoal and Wood Ash, accessed July 19, 2025
Phosphorus Transformation in Soils Following Co-Application of Charcoal and Wood Ash, accessed July 19, 2025
Contextual Support Journal

Phosphorus Transformation in Soils Following Co-Application of Charcoal and Wood Ash, accessed July 19, 2025

View Source
Preview of Soil condition | NSW State of the Environment, accessed August 10, 2025,
Soil condition | NSW State of the Environment, accessed August 10, 2025,
Contextual Support Government

Analysing water sensitive urban design options - Australian Water Association

View Source
Preview of Soil condition | NSW State of the Environment, accessed July 16, 2025
Soil condition | NSW State of the Environment, accessed July 16, 2025
Contextual Support GreyLiterature

Soil condition | NSW State of the Environment, accessed July 16, 2025,

View Source
Preview of Soil organic phosphorus dynamics following perturbation of litter cycling in a tropical moist forest, accessed July 19, 2025
Soil organic phosphorus dynamics following perturbation of litter cycling in a tropical moist forest, accessed July 19, 2025
Methodology Source Journal

Chronosequences, succession and soil development - Research Commons - University of Waikato, accessed July 19, 2025

View Source
Preview of Soil phosphorus transformations along a 500,000-year coastal dune chronosequence under subtropical rainforest in Australia
Soil phosphorus transformations along a 500,000-year coastal dune chronosequence under subtropical rainforest in Australia
Direct Evidence Journal

Soil Development and Nutrient Availability Along a 2 Million-Year Coastal Dune Chronosequence Under Species-Rich Mediterranean - Smithsonian Institution, accessed July 19, 2025

View Source
Preview of Wildfire effects on soils and soil processes - CSIRO Publishing, accessed July 24, 2025,
Wildfire effects on soils and soil processes - CSIRO Publishing, accessed July 24, 2025,
Contextual Support GreyLiterature

The dynamics of microbial biomass C [MBC (a, b)] and N [MBN (c, d)]...

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Context

  • Region Australia
  • Biome Tropical & Subtropical Rainforests
  • Land Use Production Forestry
  • Assessment Not Stated
  • Vegetation Forest
  • Evidence Type DegradationThreshold

Lifecycle

  • Status Active
  • Version 1
  • Effective From 26 May 2026

Notes

Levels above this are demonstrably harmful, causing P-toxicity in native flora, loss of biodiversity, and increased risk of waterway eutrophication. AssessmentContext defaulted to 'Not Stated' because the source document did not state one.

Related Benchmarks

Other benchmarks in the AUS-TSR-FOR-SOP family.

— mg/kg High
Production Forestry · Pristine Reference · Forest
OptimalRange Active v1
2 mg/kg Moderate
Production Forestry · Not Stated · Forest
MinimumOnly Active v1