Soil Potassium

AUS-AMR-LVG-SOK General Moderate confidence

Benchmark Value

120 mg/kg
Range: 80 to 200 mg/kg
Thresholds: Lower: 80, Upper: 200
Optimal Range: 80 to 200
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 6 benchmarks together — the OptimalRange form drives the primary score, while 5 guard(s) constrain the result.

Evidence & Context

Therefore, a benchmark of 120 mg/kg (Colwell K) is proposed.

Metric Definition:

Colwell K (mg/kg) - a measure of plant-available soil potassium using sodium bicarbonate extractant.

Benchmark Definition:

A benchmark representing the best available condition for soil potassium in loamy soils of the Arid Mountain Ranges & Uplands biome under best-practice grazing management.

Justification:

This benchmark is based on synthesis of agronomic guidelines for temperate pastures and soil science principles adapted to arid ecosystems, reflecting a level sufficient to support drought resilience and pasture persistence.

Sources (1)

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, GreyLiterature

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

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Supporting Sources (31)

Additional references from the underlying research that informed this benchmark.

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(PDF) Long-term rundown of plant-available potassium in Western Australia requires a re-evaluation of potassium management for grain production: a review - ResearchGate, accessed July 28, 2025,
Contextual Support GreyLiterature

(PDF) Long-term rundown of plant-available potassium in Western Australia requires a re-evaluation of potassium management for grain production: a review - ResearchGate, accessed July 28, 2025,

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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

The Western Australian Rangeland Monitoring System (WARMS) – operating a regional scale monitoring system - ResearchGate, accessed July 24, 2025

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Preview of ARID LANDS OF AUSTRALIA - Open Research Repository, accessed July 28, 2025,
ARID LANDS OF AUSTRALIA - Open Research Repository, accessed July 28, 2025,
Contextual Support Journal

ARID LANDS OF AUSTRALIA - Open Research Repository, accessed July 28, 2025,

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Preview of AusPlots-Rangelands: survey progress in the Northern Territory - Ninti One, accessed July 28, 2025,
AusPlots-Rangelands: survey progress in the Northern Territory - Ninti One, accessed July 28, 2025,
Contextual Support Government

AusPlots surveys begin in the rangelands - TERN Australia, accessed July 28, 2025,

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Preview of Australian dryland soils are acidic and nutrient‐depleted, and have unique microbial communities compared with other drylands - Arid Ecology Lab, accessed August 3, 2025
Australian dryland soils are acidic and nutrient‐depleted, and have unique microbial communities compared with other drylands - Arid Ecology Lab, accessed August 3, 2025
Contextual Support Government

Beringer, J., et al. 2022. Carbon and water fluxes over a temperate Eucalyptus forest and a tropical wet/dry savanna in Australia. Agricultural and Forest Meteorology 129(3):151-173.

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Preview of Australian Soils and Landscapes | Monitoring & Data | TERN - esoil.io, accessed July 27, 2025,
Australian Soils and Landscapes | Monitoring & Data | TERN - esoil.io, accessed July 27, 2025,
Contextual Support Government

ausplotsR: quickstart guide to basic analysis of TERN AusPlots vegetation data, accessed July 28, 2025,

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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,

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Preview of Chemical fractions of potassium in arid region calcareous soils: The impact of microclimates and physiographic variability | PLOS One - Research journals, accessed July 28, 2025,
Chemical fractions of potassium in arid region calcareous soils: The impact of microclimates and physiographic variability | PLOS One - Research journals, accessed July 28, 2025,
Contextual Support Journal

Potassium's pivotal role - Agronomic Insights, accessed July 28, 2025,

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Preview of Do regenerative grazing management practices improve vegetation and soil health in grazed rangelands? Preliminary insights from a space for time study in the Great Barrier Reef catchments - CSIRO Research Publications Repository, accessed July 18, 2025,
Do regenerative grazing management practices improve vegetation and soil health in grazed rangelands? Preliminary insights from a space for time study in the Great Barrier Reef catchments - CSIRO Research Publications Repository, accessed July 18, 2025,
Contextual Support Journal

Do regenerative grazing management practices improve vegetation and soil health in grazed rangelands? - Great Barrier Reef Foundation, accessed July 28, 2025,

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Preview of Ecosystem Surveillance Monitoring - Confluence - atlassian, accessed July 27, 2025
Ecosystem Surveillance Monitoring - Confluence - atlassian, accessed July 27, 2025
Contextual Support GreyLiterature

Potassium fertility impacts hay and pasture performance during drought - Field Crops, accessed July 28, 2025,

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Preview of From the Ground Up - Department for Environment and Water, accessed July 28, 2025,
From the Ground Up - Department for Environment and Water, accessed July 28, 2025,
Contextual Support Journal

The Critical Role of Potassium in Plant Stress Response - PMC, accessed July 28, 2025,

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Preview of Location of AusPlots within Australia | Download Scientific Diagram - ResearchGate, accessed July 28, 2025,
Location of AusPlots within Australia | Download Scientific Diagram - ResearchGate, accessed July 28, 2025,
Contextual Support GreyLiterature

Location of AusPlots within Australia | Download Scientific Diagram - ResearchGate, accessed July 28, 2025,

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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 - CSIRO PUBLISHING | Crop and Pasture Science, accessed July 24, 2025

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Preview of MacDonnell Ranges - DCCEEW, accessed July 29, 2025,
MacDonnell Ranges - DCCEEW, accessed July 29, 2025,
Contextual Support Government

4.3 CLIMATE AND SOIL MOISTURE The West Macdonnell Ranges have a semi arid climate with low humidity and low but erratic annual r - AWS, accessed July 28, 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

Rangelands Living Skin | .Meat & Livestock Australia - MLA, accessed July 28, 2025,

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Preview of Plant nutrients in the soil - NSW Department of Primary Industries, accessed July 28, 2025,
Plant nutrients in the soil - NSW Department of Primary Industries, accessed July 28, 2025,
Contextual Support GreyLiterature

Plant nutrients in the soil - NSW Department of Primary Industries, accessed July 28, 2025,

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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,

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Preview of Potassium and Its Role in Sustainable Agriculture - ResearchGate, accessed August 9, 2025
Potassium and Its Role in Sustainable Agriculture - ResearchGate, accessed August 9, 2025
Contextual Support GreyLiterature

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

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

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Preview of Potassium for high-performing pastures
Potassium for high-performing pastures
Contextual Support GreyLiterature

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 28, 2025,

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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

What are the optimum nutrient targets for pastures? - Soil Health Knowledgebase, accessed July 28, 2025,

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Preview of Potassium In Soil Explained - Soil Quality Knowledge Base, accessed July 28, 2025,
Potassium In Soil Explained - Soil Quality Knowledge Base, accessed July 28, 2025,
Contextual Support Journal

Effect of water quality on the leaching of potassium from sandy soil - ResearchGate, accessed July 28, 2025,

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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 SciELO Brasil - Potassium chloride: impacts on soil microbial activity ...
SciELO Brasil - Potassium chloride: impacts on soil microbial activity ...
Contextual Support Journal

Potassium chloride: impacts on soil microbial activity and nitrogen mineralization - SciELO, accessed July 28, 2025,

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Preview of Soil condition | NSW State of the Environment, accessed August 10, 2025,
Soil condition | NSW State of the Environment, accessed August 10, 2025,
Contextual Support Government

The relationships between land management practices and soil condition and the quality of ecosystem services delivered from agri - DAFF, accessed July 28, 2025,

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

Soil health stocktake Queensland - GRDC, accessed July 28, 2025,

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Preview of Soil K rundown in the Western grains region – where, why and what does it mean for crop yields? - GRDC, accessed July 13, 2025
Soil K rundown in the Western grains region – where, why and what does it mean for crop yields? - GRDC, accessed July 13, 2025
Contextual Support GreyLiterature

Lime squeezes new life into perennial pastures | .Meat & Livestock Australia - MLA, accessed July 28, 2025,

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soils - of the australian alps, accessed July 28, 2025,
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The dirt on our soils - Curious - Australian Academy of Science, accessed July 13, 2025
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Preview of What are the optimum nutrient targets for pastures? - Soil Health Knowledgebase, accessed August 5, 2025,
What are the optimum nutrient targets for pastures? - Soil Health Knowledgebase, accessed August 5, 2025,
Contextual Support Government

Scanlan, C. A., et al. (2013). Soil Quality: 10 Plant Nutrition. CCMA Soil Health Knowledge Base.

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Preview of www.barrierreef.org, accessed on May 25, 2025,
www.barrierreef.org, accessed on May 25, 2025,
Contextual Support Journal

Potassium for high-performing pastures | Nutrient Advantage, accessed July 28, 2025,

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Context

  • Region Australia
  • Biome Arid Mountain Ranges & Uplands
  • Land Use Livestock Grazing & Pasture
  • Assessment Pristine Reference
  • Evidence Type TargetCondition

Lifecycle

  • Status Active
  • Version 1
  • Effective From 25 Mar 2026

Notes

Lower Critical Threshold: 80 mg/kg. Upper Detrimental Threshold: 200 mg/kg.