Soil Potassium

AUS-AMR-CON-SOK General Moderate confidence

Benchmark Value

No specific value — see range
Range: 160 to 300 mg/kg
Optimal Range: 160 to 300
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

Indicator Name: Soil Potassium Reference Value: 160 - 300 mg/kg (for Loamy and Clayey soils); 100 - 200 mg/kg (for Sandy and Sandy Loam soils) Unit: mg/kg

Metric Definition:

Available soil potassium measured as Colwell K, representing plant-available potassium in soil.

Benchmark Definition:

Optimal range for available potassium in loam, clay loam, and clay soils for conservation landscapes.

Justification:

This range is based on Victorian agricultural guides and supported by evidence showing significant K depletion when native vegetation is converted to agriculture.

Sources (1)

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.

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Supporting Sources (38)

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 13, 2025
(PDF) Mineral Nutrition of Plants in Australia's Arid Zone - ResearchGate, accessed July 13, 2025
Contextual Support

Putting the P in Ptilotus: a phosphorus-accumulating herb native to Australia - PMC

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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

Nutrient Cycling in Australian Savannas on JSTOR - DOI

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Preview of 15 fascinating facts about the Flinders Ranges - Department for Environment and Water, accessed August 2, 2025,
15 fascinating facts about the Flinders Ranges - Department for Environment and Water, accessed August 2, 2025,
Contextual Support Government

FLC Flinders Chase Land System

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Preview of Accessing disparate soil data | TERN Australia
Accessing disparate soil data | TERN Australia
Contextual Support Government

(PDF) Final report Scoping Study of Soil Management in Livestock Grazing Systems

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Alice Mulga SuperSite | Soil & Vegetation Monitoring - TERN Australia, accessed July 22, 2025,
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Great Western Woodlands, Ground Water Data, 2014 - TERN Data Discovery Portal, accessed July 10, 2025,

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Preview of Australia - Soils, Climate, Erosion | Britannica
Australia - Soils, Climate, Erosion | Britannica
Contextual Support GreyLiterature

SOIL TESTING

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Preview of Comment: Potassium in soil is running low, threatening global food security - study proposes way out | UCL News - UCL – University College London
Comment: Potassium in soil is running low, threatening global food security - study proposes way out | UCL News - UCL – University College London
Contextual Support GreyLiterature

Comment: Potassium in soil is running low, threatening global food security - study proposes way out | UCL News - UCL – University College London

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Preview of Comment: Potassium in soil is running low, threatening global food security - study proposes way out | UCL News - UCL – University College London, accessed August 11, 2025,
Comment: Potassium in soil is running low, threatening global food security - study proposes way out | UCL News - UCL – University College London, accessed August 11, 2025,
Contextual Support GreyLiterature

Living with high potassium: Balance between nutrient acquisition and K-induced salt stress signaling

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Preview of Comparison of soil analytical methods for estimating plant-available potassium in highly weathered soils - CSIRO Publishing
Comparison of soil analytical methods for estimating plant-available potassium in highly weathered soils - CSIRO Publishing
Methodology Source Journal

EFFECTS OF AGRICULTURAL MANAGEMENT ON SOIL CARBON AND pH IN THE DOUGLAS DALY REGION OF THE NORTHERN TERRITORY, accessed July 16, 2025,

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

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Preview of Digital soil mapping of key soil properties over New South Wales - NSW Government
Digital soil mapping of key soil properties over New South Wales - NSW Government
Contextual Support Government

Digital soil mapping of key soil properties over New South Wales - NSW Government

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Preview of Flinders Ranges - UNESCO World Heritage Centre, accessed July 29, 2025,
Flinders Ranges - UNESCO World Heritage Centre, accessed July 29, 2025,
Contextual Support Government

Flinders Ranges - UNESCO World Heritage Centre, accessed July 29, 2025

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Preview of Flinders Ranges - Wikipedia, accessed August 2, 2025,
Flinders Ranges - Wikipedia, accessed August 2, 2025,
Contextual Support GreyLiterature

Geol ogy ofth e Flin ders Rang es Nati onal Park

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Preview of Long-term rundown of plant-available potassium in Western Australia requires a re-evaluation of potassium management for grain p - Murdoch Research Portal
Long-term rundown of plant-available potassium in Western Australia requires a re-evaluation of potassium management for grain p - Murdoch Research Portal
Contextual Support Journal

What are the optimum nutrient targets for pastures? - Soil Health Knowledgebase

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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

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Preview of MacDonnell Ranges - Wikipedia
MacDonnell Ranges - Wikipedia
Contextual Support GreyLiterature

MacDonnell Ranges - Wikipedia, accessed July 31, 2025

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Preview of MacDonnell Ranges Geology - SciArt
MacDonnell Ranges Geology - SciArt
Contextual Support GreyLiterature

A Dive into the Geological History of the Red Centre - Tourism Central Australia

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Preview of MAGNESIUM - Incitec Pivot Fertilisers
MAGNESIUM - Incitec Pivot Fertilisers
Contextual Support Journal

Soil potassium relationships, uptake efficiency and availability for six distinctive soils in central and southern New South Wales, Australia - CSIRO PUBLISHING | Soil Research

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Preview of Monitoring and forecasting drought through the assimilation of satellite water observations Siyuan Tian - ANU Open Research
Monitoring and forecasting drought through the assimilation of satellite water observations Siyuan Tian - ANU Open Research
Contextual Support Government

Monitoring and forecasting drought through the assimilation of satellite water observations Siyuan Tian - ANU Open Research, accessed May 27, 2025

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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

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Preview of Plantation tree growth responses to P, N, K and minor and trace elements on low fertility savanna soils - CSIRO Publishing
Plantation tree growth responses to P, N, K and minor and trace elements on low fertility savanna soils - CSIRO Publishing
Contextual Support Journal

Plantation tree growth responses to P, N, K and minor and trace elements on low fertility savanna soils - CSIRO Publishing, accessed July 20, 2025,

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

Potassium | Fact Sheets | soilquality.org.au

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Preview of Potassium and sulphur - emerging deficiencies in the southern region - GRDC, accessed July 13, 2025
Potassium and sulphur - emerging deficiencies in the southern region - GRDC, accessed July 13, 2025
Contextual Support Government

Potassium and sulphur - emerging deficiencies in the southern region - GRDC

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Preview of Potassium to Magnesium Ratio - Plant Nutrition - Yara Canada
Potassium to Magnesium Ratio - Plant Nutrition - Yara Canada
Contextual Support GreyLiterature

Optimal potassium to magnesium ratio in soils ? | ResearchGate

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Preview of Potassium: A Vital Regulator of Plant Responses and Tolerance to Abiotic Stresses - MDPI
Potassium: A Vital Regulator of Plant Responses and Tolerance to Abiotic Stresses - MDPI
Contextual Support Journal

Potassium Control of Plant Functions: Ecological and Agricultural Implications - MDPI

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Preview of Potassium: A Vital Regulator of Plant Responses and Tolerance to Abiotic Stresses - MDPI, accessed July 13, 2025
Potassium: A Vital Regulator of Plant Responses and Tolerance to Abiotic Stresses - MDPI, accessed July 13, 2025
Contextual Support Journal

Potassium: A Vital Regulator of Plant Responses and Tolerance to Abiotic Stresses - MDPI, accessed July 28, 2025,

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Preview of SLGA: Soil and Landscape Grid of Australia (Soil Attributes) | Earth Engine Data Catalog
SLGA: Soil and Landscape Grid of Australia (Soil Attributes) | Earth Engine Data Catalog
Contextual Support Journal

Soil and Landscape Grid National Soil Attribute Maps - Total Nitrogen (3" resolution) - Release 2 - CSIRO Data Access Portal, accessed July 13, 2025,

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Preview of SLGA: Soil and Landscape Grid of Australia (Soil Attributes) | Earth Engine Data Catalog, accessed July 30, 2025,
SLGA: Soil and Landscape Grid of Australia (Soil Attributes) | Earth Engine Data Catalog, accessed July 30, 2025,
Contextual Support

Soil and Landscape Grid National Soil Attribute Maps - Cation Exchange Capacity (3" resolution) - Release 1 - Research Data Australia

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Preview of Soil and Landscape Grid of Australia - CSIRO, accessed July 30, 2025,
Soil and Landscape Grid of Australia - CSIRO, accessed July 30, 2025,
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Soil and Landscape Grid of Australia - CSIRO

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Preview of Soil Constraints in an Arid Environment—Challenges, Prospects, and Implications - MDPI, accessed July 6, 2025,
Soil Constraints in an Arid Environment—Challenges, Prospects, and Implications - MDPI, accessed July 6, 2025,
Contextual Support Journal

Soil Constraints in an Arid Environment—Challenges, Prospects, and Implications - MDPI

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Preview of Soil health stocktake Queensland - GRDC, accessed May 11, 2025,
Soil health stocktake Queensland - GRDC, accessed May 11, 2025,
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Soil health stocktake Queensland - GRDC, accessed May 11, 2025

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Preview of Soil nutrient critical limits | MBFP | More Beef from Pastures - MLA, accessed May 13, 2025,
Soil nutrient critical limits | MBFP | More Beef from Pastures - MLA, accessed May 13, 2025,
Contextual Support Government

Understanding soil tests for pastures | Soil | Farm management ..., accessed July 17, 2025

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Preview of Soil potassium—crop response calibration relationships and criteria for field crops grown in Australia - CSIRO PUBLISHING | Crop and Pasture Science
Soil potassium—crop response calibration relationships and criteria for field crops grown in Australia - CSIRO PUBLISHING | Crop and Pasture Science
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Review and Synthesis of Potassium Dynamics and Crop Response in Australian Agriculture

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Preview of Subsoil testing required to detect the rundown of soil potassium to deficient levels for wheat production on loam-textured soils - ResearchGate, accessed July 13, 2025
Subsoil testing required to detect the rundown of soil potassium to deficient levels for wheat production on loam-textured soils - ResearchGate, accessed July 13, 2025
Contextual Support Journal

Subsoil testing required to detect the rundown of soil potassium to deficient levels for wheat production on loam-textured soils - ResearchGate

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Preview of Terrestrial Ecosystem Research Network TERN Australia - Queensland science, accessed July 30, 2025,
Terrestrial Ecosystem Research Network TERN Australia - Queensland science, accessed July 30, 2025,
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Preview of The Dynamics of Potassium in some Australian soils - ResearchGate
The Dynamics of Potassium in some Australian soils - ResearchGate
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The Dynamics of Potassium in some Australian soils - ResearchGate, accessed July 24, 2025

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Preview of Under the radar: Potassium on loamy soil - SoilsWest
Under the radar: Potassium on loamy soil - SoilsWest
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Under the radar: Potassium on loamy soil - SoilsWest

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Preview of V*. Clearing and burning brigalow (Acacia harpophylla) in Queensland, Australia, temporarily increases surface soil fertility prior to nutrient decline under cropping or grazing, accessed August 11, 2025,
V*. Clearing and burning brigalow (Acacia harpophylla) in Queensland, Australia, temporarily increases surface soil fertility prior to nutrient decline under cropping or grazing, accessed August 11, 2025,
Contextual Support Journal

V*. Clearing and burning brigalow (Acacia harpophylla) in Queensland, Australia, temporarily increases surface soil fertility prior to nutrient decline under cropping or grazing - CSIRO Publishing, accessed July 18, 2025,

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Context

  • Region Australia
  • Biome Arid Mountain Ranges & Uplands
  • Land Use Conservation / Protected Natural Areas
  • Assessment Conservation Target
  • Evidence Type ReferenceCondition

Lifecycle

  • Status Active
  • Version 1
  • Effective From 8 Jun 2026

Notes

Lower Critical Threshold: 120 mg/kg. No upper detrimental threshold — higher values are always better up to natural saturation. The upper detrimental threshold is defined by nutrient imbalance indicators.