Soil Phosphorus

AUS-AMR-LVG-SOP General Moderate confidence

Benchmark Value

15 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 10 benchmarks together — the OptimalRange form drives the primary score, while 9 guard(s) constrain the result.

Contributing Benchmarks

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

Evidence & Context

Therefore, a benchmark value of 15 mg/kg (Colwell P) is proposed.

Metric Definition:

Colwell P concentration in soil representing the best available ecological condition for native pastures under sustainable grazing.

Benchmark Definition:

This benchmark represents the optimal soil phosphorus level for productive native pastures in arid grazing systems, supporting groundcover for erosion control while avoiding ecological harm.

Justification:

Derived from ecological research linking soil P concentrations to native grass persistence and ecosystem stability, with a safe margin below the 20 mg/kg detrimental threshold.

Sources (2)

Preview of Phosphorus fertiliser management for pastures ... - CSIRO Publishing, accessed August 11, 2025
Phosphorus fertiliser management for pastures ... - CSIRO Publishing, accessed August 11, 2025 Journal

Phosphorus fertiliser management for pastures ... - CSIRO Publishing

View Source
Preview of Soil nutrient critical limits | MBFP | More Beef from Pastures
Soil nutrient critical limits | MBFP | More Beef from Pastures Journal

Soil nutrient critical limits | MBFP | More Beef from Pastures

View Source

Supporting Sources (30)

Additional references from the underlying research that informed this benchmark.

Preview of (PDF) Mineral Nutrition of Plants in Australia's Arid Zone - ResearchGate, accessed July 13, 2025
(PDF) Mineral Nutrition of Plants in Australia's Arid Zone - ResearchGate, accessed July 13, 2025
Contextual Support

Putting the P in Ptilotus: a phosphorus-accumulating herb native to Australia - PMC

View Source
Preview of (PDF) Mineral Nutrition of Plants in Australia's Arid Zone - ResearchGate, accessed July 23, 2025,
(PDF) Mineral Nutrition of Plants in Australia's Arid Zone - ResearchGate, accessed July 23, 2025,
Direct Evidence Journal

Ecology of Australia: The effects of nutrient-poor soils and intense fires - ResearchGate

View Source
Preview of Agricultural Phosphorus and Eutrophication - Second Edition - USDA ARS
Agricultural Phosphorus and Eutrophication - Second Edition - USDA ARS
Contextual Support Journal

Agricultural Phosphorus and Eutrophication - Second Edition - USDA ARS

View Source
Preview of Australian Soil Classification edition 3 - CALCAROSOLS, accessed July 26, 2025
Australian Soil Classification edition 3 - CALCAROSOLS, accessed July 26, 2025
Contextual Support

Distribution, characteristics and management of calcareous soils

View Source
Preview of Australian Soil: Definition, Classification, Types and Quality - Access EP, accessed July 30, 2025
Australian Soil: Definition, Classification, Types and Quality - Access EP, accessed July 30, 2025
Contextual Support GreyLiterature

Appendix H - Water Infiltration Modelling - NT EPA, accessed July 16, 2025,

View Source
Preview of Common soil types | Environment, land and water - Queensland Government, accessed August 9, 2025
Common soil types | Environment, land and water - Queensland Government, accessed August 9, 2025
Contextual Support Government

Sodic & Alkaline Soil - Soil Quality Knowledge Base

View Source
Preview of Crop NutritioN FACT SHEET - Grains Research and Development Corporation (GRDC)
Crop NutritioN FACT SHEET - Grains Research and Development Corporation (GRDC)
Contextual Support Journal

What are the optimum nutrient targets for pastures? - Soil Health Knowledgebase

View Source
Preview of Ecology of Australia: the effects of nutrient-poor soils and intense fires - PubMed, accessed August 11, 2025,
Ecology of Australia: the effects of nutrient-poor soils and intense fires - PubMed, accessed August 11, 2025,
Contextual Support Journal

A Study on Distribution of Forms of Phosphorus in Calcareous Soils ..., accessed July 22, 2025

View Source
Preview of Fertilisers and the environment - NSW Department of Primary Industries
Fertilisers and the environment - NSW Department of Primary Industries
Contextual Support Journal

Fertilisers and the environment - NSW Department of Primary Industries

View Source
Preview of Fertilisers and the environment, accessed August 4, 2025
Fertilisers and the environment, accessed August 4, 2025
Contextual Support Government

Phosphorus, Agriculture & The Environment | VCE Publications | Virginia Tech, accessed August 4, 2025

View Source
Preview of Field benchmarking of the critical external phosphorus requirements of pasture legumes for southern Australia - ResearchGate
Field benchmarking of the critical external phosphorus requirements of pasture legumes for southern Australia - ResearchGate
Direct Evidence Journal

Field benchmarking of the critical external phosphorus requirements of pasture legumes for southern Australia - ResearchGate

View Source
Preview of Find out the Different Types of Soil in Australia - Kelly Tillage AUS, accessed July 6, 2025,
Find out the Different Types of Soil in Australia - Kelly Tillage AUS, accessed July 6, 2025,
Contextual Support GreyLiterature

1301.0 - ABS Feature Articles, 1966 - Australian Bureau of Statistics

View Source
Preview of How to reduce Fertiliser Costs - Eco-logical Solutions - Learning from Nature
How to reduce Fertiliser Costs - Eco-logical Solutions - Learning from Nature
Contextual Support GreyLiterature

How to reduce Fertiliser Costs - Eco-logical Solutions - Learning from Nature

View Source
Preview of Phosphorus - WA | Fact Sheets | soilquality.org.au, accessed August 4, 2025
Phosphorus - WA | Fact Sheets | soilquality.org.au, accessed August 4, 2025
Contextual Support GreyLiterature

Phosphorus - Tas | Fact Sheets | soilquality.org.au, accessed August 11, 2025,

View Source
Preview of Phosphorus Buffering Capacity Indices as Related to Soil Properties and Plant Uptake
Phosphorus Buffering Capacity Indices as Related to Soil Properties and Plant Uptake
Contextual Support GreyLiterature

Phosphorus Buffering Capacity Indices as Related to Soil Properties and Plant Uptake

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
Contextual Support Journal

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

View Source
Preview of Phosphorus status and saturation in soils that drain into the Peel Inlet and Harvey Estuary of Western Australia - CSIRO Publishing, accessed August 28, 2025
Phosphorus status and saturation in soils that drain into the Peel Inlet and Harvey Estuary of Western Australia - CSIRO Publishing, accessed August 28, 2025
Contextual Support Journal

Phosphorus status and saturation in soils that drain into the Peel Inlet and Harvey Estuary of Western Australia - CSIRO Publishing

View Source
Preview of Plant mechanisms to optimise access to soil phosphorus - ResearchGate
Plant mechanisms to optimise access to soil phosphorus - ResearchGate
Contextual Support Journal

Plant mechanisms to optimise access to soil phosphorus - ResearchGate

View Source
Preview of Regenerative Grazing workshop proves popular despite the dust - Landscape SA
Regenerative Grazing workshop proves popular despite the dust - Landscape SA
Contextual Support Government

Regenerative Grazing workshop proves popular despite the dust - Landscape SA

View Source
Preview of Regenerative Grazing: 3 Different Approaches - Shorthandstories.com, accessed August 5, 2025,
Regenerative Grazing: 3 Different Approaches - Shorthandstories.com, accessed August 5, 2025,
Contextual Support GreyLiterature

Regenerative Grazing: 3 Different Approaches - Shorthandstories.com

View Source
Preview of Restoration of degraded grazing country in the semi-arid areas of ..., accessed July 10, 2025,
Restoration of degraded grazing country in the semi-arid areas of ..., accessed July 10, 2025,
Contextual Support Journal

Maintain and improve groundcover - Local Land Services

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 phosphorus-crop response calibration relationships and criteria for winter cereal crops grown in Australia
Soil phosphorus-crop response calibration relationships and criteria for winter cereal crops grown in Australia
Contextual Support

RCS Regenerative Grazing Principles - Resource Consulting Services

View Source
Preview of Soil phosphorus–crop response calibration ... - CSIRO Publishing, accessed May 11, 2025,
Soil phosphorus–crop response calibration ... - CSIRO Publishing, accessed May 11, 2025,
Contextual Support Journal

Soil phosphorus–crop response calibration relationships and criteria for winter cereal crops grown in Australia - CSIRO Publishing

View Source
Preview of The development and application of functions describing pasture yield responses to phosphorus, potassium and sulfur in Australia - DPIRD's Digital library
The development and application of functions describing pasture yield responses to phosphorus, potassium and sulfur in Australia - DPIRD's Digital library
Contextual Support

The development and application of functions describing pasture yield responses to phosphorus, potassium and sulfur in Australia - DPIRD's Digital library

View Source
Preview of theaustralianalpsnationalparks.org, accessed on May 25, 2025,
theaustralianalpsnationalparks.org, accessed on May 25, 2025,
Contextual Support Journal

Phosphorus Nutrition of Proteaceae in Severely Phosphorus-Impoverished Soils: Are There Lessons To Be Learned for Future Crops? - PubMed Central

View Source
Preview of Understanding Soil Phosphorus - Integrated Pest and Crop Management
Understanding Soil Phosphorus - Integrated Pest and Crop Management
Contextual Support Journal

Understanding Soil Phosphorus - Integrated Pest and Crop Management

View Source
Preview of Understanding soil tests for pastures | Soil | Farm management ...
Understanding soil tests for pastures | Soil | Farm management ...
Contextual Support Journal

Understanding soil tests for pastures | Soil | Farm management ...

View Source
Preview of Understanding soil tests for pastures | Soil | Farm management ..., accessed May 12, 2025
Understanding soil tests for pastures | Soil | Farm management ..., accessed May 12, 2025
Contextual Support Government

Agriculture Victoria. (2025). Understanding soil tests for pastures. Farm Management.

View Source
Preview of What are the optimum nutrient targets for pastures? - Soil Health Knowledgebase, accessed August 5, 2025,
What are the optimum nutrient targets for pastures? - Soil Health Knowledgebase, accessed August 5, 2025,
Contextual Support Government

What are the optimum nutrient targets for pastures? - Soil Health Knowledgebase, accessed July 18, 2025

View Source

Context

  • Region Australia
  • Biome Arid Mountain Ranges & Uplands
  • Land Use Livestock Grazing & Pasture
  • Assessment Not Stated
  • Evidence Type HealthyOperationalRange

Lifecycle

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

Notes

Upper Detrimental Threshold: 20 mg/kg. The benchmark balances supporting groundcover for erosion control and avoiding ecological regime shifts caused by excessive phosphorus. AssessmentContext defaulted to 'Not Stated' because the source document did not state one.

Related Benchmarks

Other benchmarks in the AUS-AMR-LVG-SOP family.

20 mg/kg Moderate
Livestock Grazing & Pasture · Not Stated
MaximumOnly Active v1