Soil Potassium

AUS-TSR-FOR-SOK General Moderate confidence

Benchmark Value

No specific value — see range
Range: 100 to 150 mg/kg
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. 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

The benchmark represents an optimal range for available soil K (assumed equivalent to mg/dm³) in high-productivity forestry systems, directly linking soil nutrient status to sustainable biomass production.

Metric Definition:

Available soil potassium (K) concentration in soil, measured as mg/kg or mg/dm³, representing exchangeable potassium available for plant uptake.

Benchmark Definition:

Optimal range of available soil potassium supporting sustainable production and ecosystem function in tropical and subtropical rainforest production forestry.

Justification:

Derived from a multi-evidence synthesis including high-productivity forestry systems, ecological principles from Australian rainforests, and soil-specific agronomic guidelines.

Sources (2)

Preview of Establishment of critical nutrient levels in soil and plant for eucalyptus
Establishment of critical nutrient levels in soil and plant for eucalyptus Journal

Establishment of critical nutrient levels in soil and plant for eucalyptus

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 Government

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

View Source

Supporting Sources (14)

Additional references from the underlying research that informed this benchmark.

Preview of A Review of Potassium-Rich Crop Residues Used as Organic Matter Amendments in Tree Crop Agroecosystems - MDPI
A Review of Potassium-Rich Crop Residues Used as Organic Matter Amendments in Tree Crop Agroecosystems - MDPI
Contextual Support Journal

A Review of Potassium-Rich Crop Residues Used as Organic Matter Amendments in Tree Crop Agroecosystems - MDPI

View Source
Preview of Cation Exchange Capacity - Local Land Services
Cation Exchange Capacity - Local Land Services
Contextual Support Government

Cation exchange capacity - NSW Department of Primary Industries, accessed July 28, 2025,

View Source
Preview of Cation exchange capacity - NSW Department of Primary Industries
Cation exchange capacity - NSW Department of Primary Industries
Contextual Support Journal

Cation exchange capacity - NSW Department of Primary Industries

View Source
Preview of Cations and Cation Exchange Capacity - Tas | Fact Sheets | soilquality.org.au
Cations and Cation Exchange Capacity - Tas | Fact Sheets | soilquality.org.au
Contextual Support Government

Cations and Cation Exchange Capacity | Fact Sheets | soilquality.org.au

View Source
Preview of Common soil types | Environment, land and water - Queensland Government, accessed August 9, 2025
Common soil types | Environment, land and water - Queensland Government, accessed August 9, 2025
Contextual Support Government

Sodic & Alkaline Soil - Soil Quality Knowledge Base

View Source
Preview of Form and Availability | Soils - Part 6: Phosphorus and Potassium in the Soil - passel
Form and Availability | Soils - Part 6: Phosphorus and Potassium in the Soil - passel
Contextual Support Government

Form and Availability | Soils - Part 6: Phosphorus and Potassium in the Soil - passel

View Source
Preview of Hoop Pine - The Monarch of the Forest - Gympie District Landcare
Hoop Pine - The Monarch of the Forest - Gympie District Landcare
Contextual Support Journal

Relationships between soil nutrients and vegetation in a north coast forest, New South Wales - ResearchGate

View Source
Preview of Nutrient distribution and cycling in a subtropical ... - CSIRO Publishing, accessed July 16, 2025,
Nutrient distribution and cycling in a subtropical ... - CSIRO Publishing, accessed July 16, 2025,
Contextual Support Journal

Nutrient distribution and cycling in a subtropical ... - CSIRO Publishing, accessed July 22, 2025

View Source
Preview of Plant nutrients in the soil - NSW Department of Primary Industries
Plant nutrients in the soil - NSW Department of Primary Industries
Contextual Support Journal

Plant nutrients in the soil - NSW Department of Primary Industries

View Source
Preview of Plant nutrients in the soil - NSW Department of Primary Industries, accessed July 18, 2025,
Plant nutrients in the soil - NSW Department of Primary Industries, accessed July 18, 2025,
Contextual Support Government

Potassium In Soil Explained - Soil Quality Knowledge Base

View Source
Preview of Potassium | Fact Sheets | soilquality.org.au
Potassium | Fact Sheets | soilquality.org.au
Contextual Support Government

Potassium | Fact Sheets | soilquality.org.au

View Source
Preview of Potassium | Fact Sheets | soilquality.org.au, accessed July 18, 2025,
Potassium | Fact Sheets | soilquality.org.au, accessed July 18, 2025,
Contextual Support Government

Potassium | Fact Sheets | soilquality.org.au, accessed July 18, 2025

View Source
Preview of Potassium Considerations for Nutrient Management - Gov.bc.ca, accessed July 18, 2025,
Potassium Considerations for Nutrient Management - Gov.bc.ca, accessed July 18, 2025,
Contextual Support Journal

Soil Fertility and Pastures for High Quality Raw Milk, accessed July 18, 2025

View Source
Preview of Potassium In Soil Explained - Soil Quality Knowledge Base, accessed August 11, 2025,
Potassium In Soil Explained - Soil Quality Knowledge Base, accessed August 11, 2025,
Contextual Support GreyLiterature

Healthy soils and soil test interpretation - North Central Catchment Management Authority

View Source

Context

  • Region Australia
  • Biome Tropical & Subtropical Rainforests
  • Land Use Production Forestry
  • Assessment Conservation Target
  • Vegetation Forest
  • Evidence Type ReferenceCondition

Lifecycle

  • Status Active
  • Version 1
  • Effective From 10 Jun 2026

Notes

Lower Critical Threshold: 100 mg/kg. The range supports 90–100% of maximum productivity in Eucalyptus plantations and aligns with moderate to ideal sufficiency ranges for clay loam and clay soils in Australian guidelines. The upper detrimental threshold is defined by cation imbalance rather than direct toxicity, with a soil-specific range of 310–780 mg/kg depending on CEC.

Related Benchmarks

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

100 mg/kg Moderate
Production Forestry · Conservation Target · Forest
MinimumOnly Active v1