Soil Phosphorus

AUS-TMI-FOR-SOP General Moderate confidence

Benchmark Value

110 mg/kg
Direction: Higher is desirable ↑
Form: Point

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

Based on this analysis, the proposed benchmark for Soil Phosphorus representing the best available natural condition for production forestry on Australian Tropical Maritime Islands is 110 mg/kg (Total P).

Metric Definition:

Total Phosphorus concentration in the 0-30 cm soil layer

Benchmark Definition:

Median Total Phosphorus concentration representing the inherent phosphorus capital of the landscape in Tropical & Subtropical Maritime Islands production forestry soils.

Justification:

The median is selected as the most robust measure of central tendency, less sensitive to outliers, representing the natural state before intensive management.

Sources (1)

Preview of Soil and Landscape Grid National Soil Attribute Maps - Total Phosphorus (3" resolution) - Release 2 - CSIRO Data Access Portal
Soil and Landscape Grid National Soil Attribute Maps - Total Phosphorus (3" resolution) - Release 2 - CSIRO Data Access Portal Government

Soil and Landscape Grid National Soil Attribute Maps - Total Phosphorus (3" resolution) - Release 2

View Source

Supporting Sources (6)

Additional references from the underlying research that informed this benchmark.

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

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Preview of BIODIVERSITY CONSERVATION ON THE TIWI ISLANDS, NORTHERN TERRITORY: Part 1. Environments and plants, accessed July 30, 2025,
BIODIVERSITY CONSERVATION ON THE TIWI ISLANDS, NORTHERN TERRITORY: Part 1. Environments and plants, accessed July 30, 2025,
Contextual Support Journal

Plantation Forestry and Economic Development in the Tiwi Islands

View Source
Preview of Eucalyptus pellita substantially outperforms Acacia mangium in tropical savannah ecosystem of Australia, but strategies are needed to maintain soil nutrients - Find an Expert - The University of Melbourne
Eucalyptus pellita substantially outperforms Acacia mangium in tropical savannah ecosystem of Australia, but strategies are needed to maintain soil nutrients - Find an Expert - The University of Melbourne
Contextual Support Journal

Eucalyptus pellita substantially outperforms Acacia mangium in tropical savannah ecosystem of Australia, but strategies are needed to maintain soil nutrients - Find an Expert - The University of Melbourne

View Source
Preview of Norfolk Island Subtropical Forests | One Earth, accessed July 30, 2025,
Norfolk Island Subtropical Forests | One Earth, accessed July 30, 2025,
Contextual Support

Conservation | Norfolk Island National Park | Parks Australia, accessed August 2, 2025

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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 Phosphorus: a finite resource essential for life, critical for agriculture and food security - CSIRO, accessed August 11, 2025
Phosphorus: a finite resource essential for life, critical for agriculture and food security - CSIRO, accessed August 11, 2025
Contextual Support Government

Nitrogen and Phosphorus Retranslocation of Leaves and Stemwood in a Mature Eucalyptus Forest Exposed to 5 Years of Elevated CO2 - Frontiers

View Source

Context

  • Region Australia
  • Biome Tropical & Subtropical Maritime Islands
  • Land Use Production Forestry
  • Assessment Not Stated
  • Evidence Type ReferenceCondition

Lifecycle

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

Notes

No upper detrimental threshold — higher values are always better up to natural saturation. This benchmark represents the typical, inherent phosphorus capital of the Kandosol soils in the region and serves as a scientifically defensible reference for a state of high environmental health. AssessmentContext defaulted to 'Not Stated' because the source document did not state one.

Related Benchmarks

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

60 mg/kg Moderate
Production Forestry · Not Stated
MinimumOnly Active v1
— mg/kg Moderate
Production Forestry · Not Stated
OptimalRange Active v1
200 mg/kg Moderate
Production Forestry · Not Stated
MaximumOnly Active v1