Soil Potassium

AUS-AIF-FOR-SOK General Moderate confidence

Benchmark Value

No specific value — see range
Range: 100 to 150 mg/kg
Thresholds: Lower: 80, Upper: 150
Optimal Range: 100 to 150
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.

Evidence & Context

An optimal range of 100 – 150 mg/kg is therefore proposed for sandy soils within this biome.

Metric Definition:

Available potassium concentration in sandy soils measured as exchangeable K or equivalent method.

Benchmark Definition:

Optimal available potassium range for sandy soils to ensure sufficiency for native ecosystems.

Justification:

Derived from Western Australian DPI sufficiency levels for pasture legumes (>100 mg/kg).

Sources (2)

Preview of Crop and Pasture Science - CSIRO PUBLISHING, accessed July 10, 2025
Crop and Pasture Science - CSIRO PUBLISHING, accessed July 10, 2025 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, accessed July 17, 2025,

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Preview of Potassium for crop production | UMN Extension
Potassium for crop production | UMN Extension Government

Potassium for crop production | UMN Extension, accessed July 28, 2025,

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Supporting Sources (3)

Additional references from the underlying research that informed this benchmark.

Preview of NSW Department of Primary Industries
NSW Department of Primary Industries
Contextual Support GreyLiterature

NSW Department of Primary Industries

View Source
Preview of Potassium | Fact Sheets | soilquality.org.au, accessed August 11, 2025,
Potassium | Fact Sheets | soilquality.org.au, accessed August 11, 2025,
Direct Evidence Government

Soil fertility in grazing systems: Manage potassium to manage nitrogen - Crops and Soils, accessed July 28, 2025,

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Preview of Potassium limitation of forest productivity – Part 1: A mechanistic model simulating the effects of potassium availability on canopy carbon and water fluxes in tropical eucalypt stands - BG
Potassium limitation of forest productivity – Part 1: A mechanistic model simulating the effects of potassium availability on canopy carbon and water fluxes in tropical eucalypt stands - BG
Contextual Support GreyLiterature

Potassium limitation of forest productivity – Part 1: A mechanistic model simulating the effects of potassium availability on canopy carbon and water fluxes in tropical eucalypt stands - BG

View Source

Context

  • Region Australia
  • Biome Arid Inland Floodplains & Ephemeral River Systems
  • Land Use Production Forestry
  • Assessment Conservation Target
  • Evidence Type TargetCondition

Lifecycle

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

Notes

Lower Critical Threshold: 80 mg/kg. Upper Detrimental Threshold: 150 mg/kg. Levels above 150 mg/kg offer diminishing returns in low-CEC sandy soils.

Related Benchmarks

Other benchmarks in the AUS-AIF-FOR-SOK family.

500 mg/kg Moderate
Production Forestry · Conservation Target
Point Active v1
— mg/kg Moderate
Production Forestry · Conservation Target
OptimalRange Active v1