Soil Potassium

AUS-ASC-CON-SOK General Low confidence

Benchmark Value

152 mg/kg
Direction: Higher is desirable ↑
Form: MinimumOnly

Scoring Curve

This curve shows how a field measurement for this indicator would score across all available benchmark forms in this context.

Evidence & Context

The lowest mean extractable potassium value reported by Kirkpatrick et al. (2014) for a classified alpine soil group (Rudosol, Group 7, from the nationwide sample) was 152 mg/kg.

Metric Definition:

Available soil potassium measured by bicarbonate extraction method.

Benchmark Definition:

Lowest mean available potassium observed in alpine soils supporting vegetation, indicating a potential lower threshold for ecological health.

Justification:

Represents the lowest potassium level observed in soils still supporting alpine vegetation, indicating a potential lower threshold for ecological health.

Sources (1)

Preview of Patterns of variation in Australian alpine soils and their relationships to parent material, vegetation formation, climate and t
Patterns of variation in Australian alpine soils and their relationships to parent material, vegetation formation, climate and t Journal

Patterns of variation in Australian alpine soils and their relationships to parent material, vegetation formation, climate and topography

View Source

Supporting Sources (5)

Additional references from the underlying research that informed this benchmark.

Preview of (PDF) Soil potassium—crop response calibration relationships and criteria for field crops grown in Australia - ResearchGate, accessed July 18, 2025,
(PDF) Soil potassium—crop response calibration relationships and criteria for field crops grown in Australia - ResearchGate, accessed July 18, 2025,
Contextual Support Journal

The Western Australian Rangeland Monitoring System (WARMS) – operating a regional scale monitoring system - ResearchGate, accessed July 24, 2025

View Source
Preview of Long-term rundown of plant-available potassium in Western Australia requires a re-evaluation of potassium management for grain production: a review - BioOne Complete, accessed July 10, 2025
Long-term rundown of plant-available potassium in Western Australia requires a re-evaluation of potassium management for grain production: a review - BioOne Complete, accessed July 10, 2025
Contextual Support Journal

Long-term rundown of plant-available potassium in Western Australia requires a re-evaluation of potassium management for grain production: a review - CSIRO PUBLISHING | Crop and Pasture Science, accessed July 24, 2025

View Source
Preview of Potassium Control of Plant Functions: Ecological and Agricultural Implications - PMC, accessed May 28, 2025,
Potassium Control of Plant Functions: Ecological and Agricultural Implications - PMC, accessed May 28, 2025,
Contextual Support GreyLiterature

Soil tests get K levels right - Agronomic Insights

View Source
Preview of Soil Acidity, Phosphorus, and Potassium Nutrient Levels: Key to Forage Nutrient Management Planning | Mississippi State University Extension Service, accessed on May 27, 2025,
Soil Acidity, Phosphorus, and Potassium Nutrient Levels: Key to Forage Nutrient Management Planning | Mississippi State University Extension Service, accessed on May 27, 2025,
Contextual Support Government

Soil Test Interpretation Guide - OSU Extension Service, accessed May 28, 2025,

View Source
Preview of theaustralianalpsnationalparks.org, accessed on May 29, 2025,
theaustralianalpsnationalparks.org, accessed on May 29, 2025,
Contextual Support Journal

Maximising Plant Growth: The Importance of Potassium Fertiliser - Plant Needs Pty. Ltd., accessed May 28, 2025,

View Source

Context

  • Region Australia
  • Biome Alpine and Subalpine Complex
  • Land Use Conservation / Protected Natural Areas
  • Assessment Pristine Reference
  • Evidence Type DegradationThreshold

Lifecycle

  • Status Active
  • Version 1
  • Effective From 24 Mar 2026

Notes

No upper detrimental threshold — higher values are always better up to natural saturation. Levels significantly below this might indicate ecological concern or potassium deficiency.