Soil Phosphorus

AUS-AIF-CON-SOP General High confidence

Benchmark Value

No specific value — see range

Range: 10 to 120 mg/kg

Optimal Range: 10 to 120

Direction: Higher is desirable ↑

Form: OptimalRange

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

Contributing Benchmarks

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

Evidence & Context

These ranges represent the "safe operating space" for conservation management in this biome.

Metric Definition:

Available soil phosphorus measured by the Colwell P test, stratified by soil Phosphorus Buffering Index (PBI)

Benchmark Definition:

This benchmark defines the optimal range of available soil phosphorus (measured by the Colwell P test) that supports native plant communities in Australian arid inland floodplains, stratified by soil Phosphorus Buffering Index (PBI). It represents the safe operating space for conservation management in this biome.

Justification:

The value is a range and must be stratified by the soil's Phosphorus Buffering Index (PBI) as P availability and ecological impact are highly soil-dependent.

Sources (1)

Preview of (PDF) Soil phosphorus—crop response calibration relationships and ..., accessed August 4, 2025

(PDF) Soil phosphorus—crop response calibration relationships and ..., accessed August 4, 2025

Soil phosphorus—crop response calibration relationships and criteria for oilseeds, grain legumes and summer cereal crops grown in Australia - ResearchGate

Supporting Sources (21)

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

Preview of Ecological mechanisms underpinning climate adaptation ... - SciSpace, accessed July 21, 2025,

Ecological mechanisms underpinning climate adaptation ... - SciSpace, accessed July 21, 2025,

Contextual Support Journal

A simple phosphorus buffering index for Australian soils - University of Tasmania Open Access Repository Cover sheet, accessed July 21, 2025,

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

Preview of Guidance document for assessing and managing water quality in temporary waters, accessed July 21, 2025,

Guidance document for assessing and managing water quality in temporary waters, accessed July 21, 2025,

Contextual Support Journal

Guidance document for assessing and managing water quality in temporary waters, accessed July 21, 2025,

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 Marine and Freshwater Research - CSIRO PUBLISHING, accessed July 21, 2025,

Marine and Freshwater Research - CSIRO PUBLISHING, accessed July 21, 2025,

Contextual Support Journal

Marine and Freshwater Research - CSIRO PUBLISHING, accessed July 21, 2025,

Preview of Phosphorus - WA | Fact Sheets | soilquality.org.au, accessed July 21, 2025,

Phosphorus - WA | Fact Sheets | soilquality.org.au, accessed July 21, 2025,

Contextual Support GreyLiterature

Phosphorus - Qld | Fact Sheets | soilquality.org.au, accessed July 18, 2025

Preview of Phosphorus and Iron Nutrition in Australian Native Plants, accessed July 21, 2025,

Phosphorus and Iron Nutrition in Australian Native Plants, accessed July 21, 2025,

Contextual Support Journal

Phosphorus speciation and release from different plant litters on a River Murray (Australia) floodplain | Request PDF - ResearchGate, accessed July 21, 2025,

Preview of Phosphorus Dynamics in an Ephemeral Wetland Ecosystem after Re-Flooding | Request PDF - ResearchGate, accessed July 21, 2025,

Phosphorus Dynamics in an Ephemeral Wetland Ecosystem after Re-Flooding | Request PDF - ResearchGate, accessed July 21, 2025,

Contextual Support GreyLiterature

Hydrological characteristics of selected flood events on the Cooper Creek floodplain, downstream of the junction of the Thomson and Barcoo rivers, Australia. (Source: Queensland Department of Natural Resources, 1998). - ResearchGate, accessed July 21, 2025,

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 Nutrition of Proteaceae in Severely Phosphorus-Impoverished Soils: Are There Lessons To Be Learned for Future Crops? - PubMed Central, accessed July 21, 2025,

Phosphorus Nutrition of Proteaceae in Severely Phosphorus-Impoverished Soils: Are There Lessons To Be Learned for Future Crops? - PubMed Central, accessed July 21, 2025,

Contextual Support

Sorption of phosphorus by soils : how it is measured in Western Australia - DPIRD's Digital library, accessed July 21, 2025,

Preview of Phosphorus speciation and dynamics in river sediments, floodplain soils and leaf litter from the Lower Murray River region - CSIRO Publishing, accessed July 21, 2025,

Phosphorus speciation and dynamics in river sediments, floodplain soils and leaf litter from the Lower Murray River region - CSIRO Publishing, accessed July 21, 2025,

Contextual Support Journal

Phosphorus speciation and dynamics in river sediments, floodplain soils and leaf litter from the Lower Murray River region - CSIRO Publishing, accessed July 21, 2025,

Preview of Phosphorus speciation and dynamics in river sediments, floodplain soils and leaf litter from the Lower Murray River region | Request PDF - ResearchGate, accessed July 21, 2025,

Phosphorus speciation and dynamics in river sediments, floodplain soils and leaf litter from the Lower Murray River region | Request PDF - ResearchGate, accessed July 21, 2025,

Contextual Support

Phosphorus speciation and dynamics in river sediments, floodplain soils and leaf litter from the Lower Murray River region | Request PDF - ResearchGate, accessed July 21, 2025,

Preview of Response of a perennial grassland to nitrogen and phosphorus additions in sub-tropical, semi-arid Australia | Request PDF - ResearchGate, accessed July 21, 2025,

Response of a perennial grassland to nitrogen and phosphorus additions in sub-tropical, semi-arid Australia | Request PDF - ResearchGate, accessed July 21, 2025,

Contextual Support Journal

Response of a perennial grassland to nitrogen and phosphorus additions in sub-tropical, semi-arid Australia | Request PDF - ResearchGate, accessed July 21, 2025,

Preview of Soil Carbon Sequestration Potential: A review for Australian agriculture - MLA, accessed July 19, 2025

Soil Carbon Sequestration Potential: A review for Australian agriculture - MLA, accessed July 19, 2025

Contextual Support Government

Victorian Grain Cropping Soils - Ferrosols | VRO | Agriculture Victoria, accessed July 21, 2025,

Preview of The dirt on our soils - Curious - Australian Academy of Science, accessed July 13, 2025

The dirt on our soils - Curious - Australian Academy of Science, accessed July 13, 2025

Contextual Support GreyLiterature

The dirt on our soils - Curious - Australian Academy of Science

Preview of The incidence of low phosphorus soils in Australia | Request PDF - ResearchGate, accessed July 21, 2025,

The incidence of low phosphorus soils in Australia | Request PDF - ResearchGate, accessed July 21, 2025,

Contextual Support Journal

Survival of native plants of Hawkesbury Sandstone communities with additional nutrients: effect of plant age and habitat - ResearchGate

Preview of The phosphorus concentration of common rocks—a potential driver of ecosystem P status - Brown University, accessed July 21, 2025,

The phosphorus concentration of common rocks—a potential driver of ecosystem P status - Brown University, accessed July 21, 2025,

Contextual Support Journal

The phosphorus concentration of common rocks—a potential driver of ecosystem P status - Brown University, accessed July 22, 2025

Preview of Too much of a good thing: phosphorus over-fertilisation in rehabilitated landscapes of high biodiversity value - Australian Centre for Geomechanics, accessed August 11, 2025

Too much of a good thing: phosphorus over-fertilisation in rehabilitated landscapes of high biodiversity value - Australian Centre for Geomechanics, accessed August 11, 2025

Contextual Support Journal

Too much of a good thing: phosphorus over-fertilisation in rehabilitated landscapes of high biodiversity value - Australian Centre for Geomechanics

Preview of Too much of a good thing: phosphorus over-fertilisation in rehabilitated landscapes of high biodiversity value - Australian Centre for Geomechanics, accessed July 21, 2025,

Too much of a good thing: phosphorus over-fertilisation in rehabilitated landscapes of high biodiversity value - Australian Centre for Geomechanics, accessed July 21, 2025,

Contextual Support

Too much of a good thing: phosphorus over-fertilisation in rehabilitated landscapes of high biodiversity value - Australian Centre for Geomechanics, accessed July 21, 2025,

Preview of Validation of critical soil-test phosphorus values from the Better Fertiliser Decisions for Pastures meta-analysis - CSIRO Publishing, accessed July 21, 2025,

Validation of critical soil-test phosphorus values from the Better Fertiliser Decisions for Pastures meta-analysis - CSIRO Publishing, accessed July 21, 2025,

Contextual Support

Validation of critical soil-test phosphorus values from the Better Fertiliser Decisions for Pastures meta-analysis - CSIRO Publishing, accessed July 21, 2025,

Context

Region Australia
Biome Arid Inland Floodplains & Ephemeral River Systems
Land Use Conservation / Protected Natural Areas
Assessment Conservation Target
Evidence Type ReferenceCondition

Lifecycle

Status Active
Version 1
Effective From 8 Jun 2026

Notes

Lower Critical Threshold: The lower value of the PBI-specific range (e.g., 10 mg/kg for low PBI soils) represents a management floor to ensure basic ecosystem function. Upper Detrimental Threshold: The upper value of the PBI-specific range (e.g., 20 mg/kg for low PBI soils) is a critical ecological ceiling. Levels exceeding this threshold are strongly associated with the displacement of native perennial grasses by invasive annuals and potential P-toxicity to adapted native flora.

Related Benchmarks

Other benchmarks in the AUS-AIF-CON-SOP family.