Soil Potassium

AUS-ASC-FOR-SOK General Low confidence

Benchmark Value

700 mg/kg

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

Contributing Benchmarks

OptimalRange Primary Point Guard Point Guard MinimumOnly Guard Point 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:

This benchmark represents a reference value for extractable soil potassium indicating high environmental health in Australian alpine and subalpine production forestry ecosystems.

Justification:

Derived from mean values for K-replete Organosols in natural Australian alpine ecosystems, 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) Journal

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)

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

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

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

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

www.nrc.nsw.gov.au, accessed on May 27, 2025

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

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 - BioOne Complete

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

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

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

Potassium | Fact Sheets | soilquality.org.au

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 Acidity, Phosphorus, and Potassium Nutrient Levels: Key to Forage Nutrient Management Planning | Mississippi State University Extension Service, accessed on May 27, 2025

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

SFI 2015-2019 STANDARDS AND RULES - Sustainable Forestry Initiative, accessed on May 27, 2025

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

Preview of theaustralianalpsnationalparks.org, accessed on May 25, 2025,

theaustralianalpsnationalparks.org, accessed on May 25, 2025,

Contextual Support Journal

Phosphorus Nutrition of Proteaceae in Severely Phosphorus-Impoverished Soils: Are There Lessons To Be Learned for Future Crops? - PubMed Central

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

Agriculture Victoria. (2025). Understanding soil tests for pastures. Farm Management.

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 9 Jun 2026

Notes

Lower Critical Threshold: Indicatively <150−200 mg⋅kg−1 (further research needed). Optimal Range: Indicatively 300−800 mg⋅kg−1 (based on healthy natural alpine systems on fertile soils). 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−1 are not considered detrimental in situ.