Soil Phosphorus

AUS-TDG-AGR-SOP General Moderate confidence

Benchmark Value

5 mg/kg

Thresholds: Lower: 5, Upper: —

Direction: Higher is desirable ↑

Form: LowerThreshold

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

Contributing Benchmarks

OptimalRange Primary LowerThreshold Guard UpperThreshold Guard Point Guard LowerThreshold Guard OptimalRange Guard UpperThreshold Guard OptimalRange Guard OptimalRange Guard MinimumOnly Guard MaximumOnly Guard OptimalRange Guard

Evidence & Context

Considering these factors, a Lower Critical Threshold of approximately 5 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:

Lower critical threshold below which ecosystem integrity or sustainable crop resilience is compromised.

Justification:

Below this level, significant P deficiency is expected even in P-efficient sustainable cropping systems, impairing growth and ecosystem functions.

Sources (1)

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, Journal

Phosphorus nutrition of phosphorus-sensitive Australian native ..., accessed May 15, 2025,

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Supporting Sources (6)

Additional references from the underlying research that informed this benchmark.

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

Contextual Support Journal

Phosphorus Dynamics in the Soil–Plant–Environment Relationship in Cropping Systems: A Review - MDPI

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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

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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, accessed July 19, 2025,

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