Soil Potassium

AUS-AKW-CON-SOK General Moderate confidence

Benchmark Value

No specific value — see range

Range: 30 to 300 mg/kg

Optimal Range: 30 to 300

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 5 benchmarks together — the OptimalRange form drives the primary score, while 4 guard(s) constrain the result.

Contributing Benchmarks

OptimalRange Primary MaximumOnly Guard Point Guard MinimumOnly Guard MaximumOnly Guard

Evidence & Context

A broad "sufficient functional range" of 30-300 mg/kg is more appropriate for this stable, resilient ecosystem than a narrow "optimal" range focused on productivity.

Metric Definition:

Sufficient functional range of available soil potassium within which native flora function effectively and ecosystem resilience is maintained.

Benchmark Definition:

Broad sufficient functional range for soil potassium reflecting ecosystem resilience rather than production optimization in Arid Karstic Woodlands & Shrublands under conservation management.

Justification:

Reflects ecological adaptation to a wide nutrient spectrum and the absence of evidence for a narrow optimal range.

Sources (1)

Nullarbor Plains Xeric Shrublands | One Earth, accessed July 26, 2025,

Ecological literature on nutrient adaptation in arid ecosystems

View Source

Supporting Sources (3)

Additional references from the underlying research that informed this benchmark.

"Soil potassium-crop response calibration relationships and criteria for field crops grown in Australia"

Contextual Support Journal

"Soil Groups of Western Australia"

View Source

(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

Estimating woody vegetation cover in arid and semi-arid rangelands - Murdoch Research Portal, accessed July 12, 2025,

Contextual Support Journal

Agronomic and ecological studies on potassium excess effects

View Source

Context

Region Australia
Biome Arid Karstic Woodlands & Shrublands
Land Use Conservation / Protected Natural Areas
Assessment Pristine Reference
Evidence Type HealthyOperationalRange

Lifecycle

Status Active
Version 1
Effective From 10 Jun 2026

Notes

Native plants are adapted to function effectively across this broad range, with resilience maintained rather than maximized productivity.

Related Benchmarks

Other benchmarks in the AUS-AKW-CON-SOK family.