Soil Potassium

AUS-ASC-FOR-SOK General Moderate confidence

Benchmark Value

700 mg/kg
Range: 300 to 800 mg/kg
Thresholds: Lower: 150, Upper: —
Optimal Range: 300 to 800
Direction: Higher is desirable ↑
Form: Point

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 3 benchmarks together — the OptimalRange form drives the primary score, while 2 guard(s) constrain the result.

Contributing Benchmarks

OptimalRange Primary Point Guard MinimumOnly Guard

Evidence & Context

Therefore, a reference value of 700 mg⋅kg−1 for extractable soil potassium is proposed.

Metric Definition:

Extractable soil potassium concentration in mg⋅kg−1

Benchmark Definition:

Extractable soil potassium concentration indicative of high environmental health in alpine and subalpine production forestry soils.

Justification:

Benchmark derived from mean values for K-replete Organosols in natural Australian alpine ecosystems 13, representing high environmental health. Direct data from "best-practice" alpine production forestry is limited.

Sources (1)

Preview of Patterns of variation in Australian alpine soils and their relationships to parent material, vegetation formation, climate and topography (data derived from analysis of Organosol groups)
Patterns of variation in Australian alpine soils and their relationships to parent material, vegetation formation, climate and topography (data derived from analysis of Organosol groups)
View Source

Supporting Sources (14)

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 23, 2025,
(PDF) Mineral Nutrition of Plants in Australia's Arid Zone - ResearchGate, accessed July 23, 2025,
Contextual Support Journal

Ecology of Australia: The effects of nutrient-poor soils and intense fires - ResearchGate

View Source
Preview of Benchmarking the impact of traditional small-scale logging systems used in Mediterranean forestry | Request PDF - ResearchGate, accessed on May 27, 2025,
Benchmarking the impact of traditional small-scale logging systems used in Mediterranean forestry | Request PDF - ResearchGate, accessed on May 27, 2025,
Contextual Support Journal

Benchmarking the impact of traditional small-scale logging systems used in Mediterranean forestry | Request PDF - ResearchGate, accessed on May 27, 2025,

View Source
Preview of Crop Nutrient Requirements - UC Agriculture and Natural Resources, accessed on May 27, 2025,
Crop Nutrient Requirements - UC Agriculture and Natural Resources, accessed on May 27, 2025,
Contextual Support GreyLiterature

Crop Nutrient Requirements - UC Agriculture and Natural Resources, accessed on May 27, 2025,

View Source
Preview of Full article: Impacts of Road Disturbance on Soil Properties and on Exotic Plant Occurrence in Subalpine Areas of the Australian Alps - Taylor & Francis Online, accessed May 28, 2025
Full article: Impacts of Road Disturbance on Soil Properties and on Exotic Plant Occurrence in Subalpine Areas of the Australian Alps - Taylor & Francis Online, accessed May 28, 2025
Contextual Support Journal

Rehabilitation Field Guide | Australian Alps National Parks, accessed March 28, 2026,

View Source
Preview of Indicator 7.1a: Extent to which the legal framework supports the conservation and sustainable management of forests (2024), accessed on May 27, 2025,
Indicator 7.1a: Extent to which the legal framework supports the conservation and sustainable management of forests (2024), accessed on May 27, 2025,
Contextual Support Journal

Understorey plant community structure in lower montane and

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 Nutrient Cycling in Forest Ecosystems - MDPI, accessed on May 27, 2025,
Nutrient Cycling in Forest Ecosystems - MDPI, accessed on May 27, 2025,
Contextual Support

Nutrient Cycling in Forest Ecosystems - MDPI, accessed on May 27, 2025,

View Source
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
Contextual Support Journal

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

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

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

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 Sustainable Forestry – Protecting Australia's Forest Dwelling Wildlife, accessed July 12, 2025,
Sustainable Forestry – Protecting Australia's Forest Dwelling Wildlife, accessed July 12, 2025,
Contextual Support GreyLiterature

Sustainable Forest Management. (n.d.). Sustainable Forestry – Protecting Australia's Forest Dwelling Wildlife.

View Source
Preview of Sustainable Forestry – Protecting Australia's Forest Dwelling Wildlife, accessed on May 27, 2025,
Sustainable Forestry – Protecting Australia's Forest Dwelling Wildlife, accessed on May 27, 2025,
Contextual Support Journal

www.forestry.org.au, accessed on May 27, 2025,

View Source
Preview of theaustralianalpsnationalparks.org, accessed on May 25, 2025,
theaustralianalpsnationalparks.org, accessed on May 25, 2025,
Contextual Support Journal

theaustralianalpsnationalparks.org

View Source
Preview of Understanding soil tests for pastures | Soil | Farm management ..., accessed May 12, 2025
Understanding soil tests for pastures | Soil | Farm management ..., accessed May 12, 2025
Contextual Support Government

Understanding soil tests for pastures

View Source

Context

  • Region Australia
  • Biome Alpine and Subalpine Complex
  • Land Use Production Forestry
  • Assessment Conservation Target
  • Vegetation Forest
  • Evidence Type ReferenceCondition

Lifecycle

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

Notes

Lower Critical Threshold: 150 mg/kg. Optimal Range: 300-800 mg/kg. Upper Detrimental Threshold: Not defined by direct K toxicity; potential for nutrient imbalances if K is excessively high relative to other cations (e.g., >10% K saturation of CEC, or K:Mg > ~2:1). Natural levels up to ~800 mg/kg are not considered detrimental in situ.