Soil Phosphorus

AUS-TDG-AGR-SOP General Moderate confidence

Benchmark Value

20 mg/kg
Direction: Higher 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 4 benchmarks together — the OptimalRange form drives the primary score, while 3 guard(s) constrain the result.

Contributing Benchmarks

OptimalRange Primary Point Guard MinimumOnly Guard MaximumOnly Guard

Evidence & Context

Therefore, an Upper Detrimental Threshold of >20 mg/kg Olsen P (0-10 cm) is proposed.

Metric Definition:

Soil phosphorus concentration measured as Olsen P in the 0-10 cm soil depth.

Benchmark Definition:

This benchmark marks the upper detrimental soil phosphorus threshold above which ecological harm and increased environmental risks occur in temperate dry woodlands and native grasslands.

Justification:

Based on evidence of increased risk of P loss, eutrophication, and negative impacts on native biodiversity beyond this level.

Sources (2)

Preview of (PDF) Phosphorus accumulation and other changes in soil ...
(PDF) Phosphorus accumulation and other changes in soil ... Journal

(PDF) Phosphorus accumulation and other changes in soil ...

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Preview of Why phosphorus is important - NSW Department of Primary Industries, accessed August 4, 2025
Why phosphorus is important - NSW Department of Primary Industries, accessed August 4, 2025 Government

Why phosphorus is important - NSW Department of Primary Industries

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Supporting Sources (5)

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,
Direct Evidence GreyLiterature

Phosphorus nutrition of phosphorus-sensitive Australian native ...

View Source
Preview of Phosphorus: a finite resource essential for life, critical for agriculture and food security
Phosphorus: a finite resource essential for life, critical for agriculture and food security
Contextual Support Journal

Phosphorus: a finite resource essential for life, critical for agriculture and food security

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
Preview of The phosphorus saturation degree as a universal agronomic and environmental soil P test
The phosphorus saturation degree as a universal agronomic and environmental soil P test
Contextual Support Journal

Soil | Australia state of the environment 2021

View Source
Preview of www.agric.wa.gov.au
www.agric.wa.gov.au
Contextual Support

Achievements and future development in soil and nutritional research

View Source

Context

  • Region Australia
  • Biome Temperate Dry Woodlands & Native Grasslands
  • Land Use Agricultural Crop Production
  • Assessment Conservation Target
  • Evidence Type DegradationThreshold

Lifecycle

  • Status Active
  • Version 1
  • Effective From 8 Jun 2026

Notes

Indicates a departure from high environmental health and increased environmental risk due to excessive soil P.

Related Benchmarks

Other benchmarks in the AUS-TDG-AGR-SOP family.

8 mg/kg Moderate
Agricultural Crop Production · Conservation Target
Point Active v1
5 mg/kg Moderate
Agricultural Crop Production · Conservation Target
MinimumOnly Active v1
— mg/kg Moderate
Agricultural Crop Production · Conservation Target
OptimalRange Active v1