Soil Phosphorus

AUS-AIF-FOR-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 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

The reference value of 15 mg/kg is selected as the scientifically supported optimum within this range, as it corresponds to the soil P level where the growth of a representative native production species (Eucalyptus marginata) is maximized before declining due to P toxicity.

Metric Definition:

Soil phosphorus concentration representing the optimal point balancing ecological health and sustainable productivity in a P-limited native ecosystem.

Benchmark Definition:

This benchmark represents the optimal soil phosphorus level for balancing ecological health and sustainable productivity in the Arid Inland Floodplains & Ephemeral River Systems biome under production forestry land use.

Justification:

The benchmark is synthesized from multiple lines of evidence including productivity proxies in analogous systems, ecological impacts observed at higher phosphorus levels, and growth response of Eucalyptus marginata.

Sources (2)

Preview of Phosphorus sensitivity in seedlings of Eucalyptus marginata (Jarrah) in relation to mycorrhizal colonisation

Phosphorus sensitivity in seedlings of Eucalyptus marginata (Jarrah) in relation to mycorrhizal colonisation

Preview of Soil nutrient critical limits | MBFP | More Beef from Pastures - MLA, accessed May 13, 2025,

Soil nutrient critical limits | MBFP | More Beef from Pastures - MLA, accessed May 13, 2025, Government

Understanding soil tests for pastures | Soil | Farm management ..., accessed July 17, 2025

Supporting Sources (19)

Additional references from the underlying research that informed this benchmark.

Preview of 3. C THE LOCATION - Lockhart Shire Council - NSW Government, accessed July 19, 2025,

3. C THE LOCATION - Lockhart Shire Council - NSW Government, accessed July 19, 2025,

Contextual Support Journal

3. C THE LOCATION - Lockhart Shire Council - NSW Government

Preview of Al-Beidh, S., & Al-Tawaha, A. R. M. (2023). Basic Properties and Mineralogy of Soils and Their Impact on the Growth of Jarrah Forest in Southwestern Australia. Land, 12(6), 1236.

Al-Beidh, S., & Al-Tawaha, A. R. M. (2023). Basic Properties and Mineralogy of Soils and Their Impact on the Growth of Jarrah Forest in Southwestern Australia. Land, 12(6), 1236.

Contextual Support Journal

Soil Characteristics and Fertility of the Unique Jarrah Forest of Southwestern Australia, with Particular Consideration of Plant Nutrition and Land Rehabilitation - MDPI

Preview of Are Murray-Darling Basin rivers getting the water they need to stay healthy?, accessed July 19, 2025,

Are Murray-Darling Basin rivers getting the water they need to stay healthy?, accessed July 19, 2025,

Contextual Support Journal

Are Murray-Darling Basin rivers getting the water they need to stay healthy?

Preview of Arid Swamps | WetlandInfo, accessed August 1, 2025,

Arid Swamps | WetlandInfo, accessed August 1, 2025,

Contextual Support Journal

Arid Swamps | WetlandInfo

Preview of Changes in soil carbon in response to flooding of the floodplain of a semi-arid lowland river - Charles Sturt University Research Output, accessed July 19, 2025,

Changes in soil carbon in response to flooding of the floodplain of a semi-arid lowland river - Charles Sturt University Research Output, accessed July 19, 2025,

Contextual Support Journal

Changes in soil carbon in response to flooding of the floodplain of a semi-arid lowland river - Charles Sturt University Research Output

Preview of Coolibah-Black Box Woodlands - IUCN Ecosystems, accessed July 19, 2025,

Coolibah-Black Box Woodlands - IUCN Ecosystems, accessed July 19, 2025,

Contextual Support Journal

Coolibah-Black Box Woodlands - IUCN Ecosystems

Preview of Determining baselines, drivers and trends of soil health and stability ..., accessed July 12, 2025,

Determining baselines, drivers and trends of soil health and stability ..., accessed July 12, 2025,

Contextual Support Journal

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

Preview of Hydrological assessment and analysis of the Cooper Creek Catchment, South Australia - Department for Environment and Water, accessed July 21, 2025,

Hydrological assessment and analysis of the Cooper Creek Catchment, South Australia - Department for Environment and Water, accessed July 21, 2025,

Contextual Support Journal

Managing Our River Red Gums.pdf

Preview of Managing soils - Department of Primary Industries and Regional Development, accessed July 21, 2025,

Managing soils - Department of Primary Industries and Regional Development, accessed July 21, 2025,

Contextual Support Journal

Gilgai wetlands - WetlandInfo

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

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

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

Preview of Rangeland Soil Quality: Infiltration - Natural Resources ...

Rangeland Soil Quality: Infiltration - Natural Resources ...

Contextual Support Journal

RIvER RED guMs AND wooDLAND FoREsts - Natural Resources Commission

Preview of The-importance-of-inundation-to-floodplain-soil-fertility-in-an-large-semi-arid-river.pdf - ResearchGate, accessed July 19, 2025,

The-importance-of-inundation-to-floodplain-soil-fertility-in-an-large-semi-arid-river.pdf - ResearchGate, accessed July 19, 2025,

Contextual Support

The-importance-of-inundation-to-floodplain-soil-fertility-in-an-large-semi-arid-river.pdf - ResearchGate

Preview of to ensure you are making money from phosphorus fertiliser - MLA, accessed August 4, 2025

to ensure you are making money from phosphorus fertiliser - MLA, accessed August 4, 2025

Contextual Support Journal

Towards restoration of grassy White and Yellow Box woodlands - understanding soil changes associated with degradation - Virtual Herbarium

Preview of to ensure you are making money from phosphorus fertiliser - MLA, accessed July 19, 2025,

to ensure you are making money from phosphorus fertiliser - MLA, accessed July 19, 2025,

Contextual Support

to ensure you are making money from phosphorus fertiliser - MLA

Preview of Towards restoration of grassy White and Yellow Box woodlands ..., accessed August 11, 2025,

Towards restoration of grassy White and Yellow Box woodlands ..., accessed August 11, 2025,

Contextual Support GreyLiterature

(PDF) Soil and vegetation response to thinning White Cypress Pine ...

Preview of Tropical Grasslands (2000) Volume 34, 139–146 - Soil fertility and ..., accessed July 19, 2025,

Tropical Grasslands (2000) Volume 34, 139–146 - Soil fertility and ..., accessed July 19, 2025,

Contextual Support Journal

Tropical Grasslands (2000) Volume 34, 139–146 - Soil fertility and ...

Preview of Wetlands | Environment, land and water | Queensland Government, accessed July 19, 2025,

Wetlands | Environment, land and water | Queensland Government, accessed July 19, 2025,

Contextual Support Journal

Wetlands | Environment, land and water | Queensland Government

Context

Region Australia
Biome Arid Inland Floodplains & Ephemeral River Systems
Land Use Production Forestry
Assessment Not Stated
Evidence Type HealthyOperationalRange

Lifecycle

Status Active
Version 1
Effective From 10 Jun 2026

Notes

Lower Critical Threshold: 10 mg/kg. Upper Detrimental Threshold: 20 mg/kg. The optimal range is 10–20 mg/kg, with 15 mg/kg as the optimum balancing point. The benchmark is derived from multiple lines of evidence including productivity proxies and ecological impacts. AssessmentContext defaulted to 'Not Stated' because the source document did not state one.