Soil Potassium

AUS-TSR-LVG-SOK General Moderate confidence

Benchmark Value

40 mg/kg

Direction: Higher is desirable ↑

Form: MinimumOnly

Scoring Curve

This curve shows how a field measurement for this indicator would score across all available benchmark forms in this context.

Evidence & Context

Lower Critical Threshold: Levels below 40-50 mg/kg (for sands/loams) indicate deficiency, compromising pasture persistence and ecosystem health.

Metric Definition:

Colwell K soil test measurement of plant-available potassium in soil.

Benchmark Definition:

This benchmark defines the critical lower threshold of plant-available potassium in sandy and silty loam soils below which pasture health and persistence decline in tropical and subtropical rainforests under livestock grazing.

Justification:

Based on synthesized guidelines and agronomic data indicating deficiency below this level.

Sources (1)

Preview of Potassium for high-performing pastures

Potassium for high-performing pastures GreyLiterature

Potassium for high-performing pastures | Nutrient Advantage

View Source

Supporting Sources (16)

Additional references from the underlying research that informed this benchmark.

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

View Source

Demonstrating productive, regenerative Burdekin grazing practices | Meat & Livestock Australia - MLA, accessed July 19, 2025,

Contextual Support GreyLiterature

Grazing intensity influence soil microbial communities and their ..., accessed July 19, 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, Australia - CSIRO Publishing, accessed August 5, 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, Australia - CSIRO Publishing, accessed August 5, 2025,

Contextual Support Journal

Ludwig, J.A., Bastin, G.N., Chewings, V.H., Eager, R.W., and Liedloff, A.C. (2005). Clearing savannas for use as rangelands in Queensland: Altered landscapes and water-erosion processes. Rangeland Journal, 27(2), 135-149.

View Source

Contextual Support Journal

View Source

Preview of Farm-scale nitrogen, phosphorus, potassium and sulfur balances and use efficiencies on Australian dairy farms - CSIRO Publishing, accessed July 18, 2025,

Farm-scale nitrogen, phosphorus, potassium and sulfur balances and use efficiencies on Australian dairy farms - CSIRO Publishing, accessed July 18, 2025,

Contextual Support Journal

Farm-scale nitrogen, phosphorus, potassium and sulfur balances and use efficiencies on Australian dairy farms - CSIRO Publishing

View Source

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

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

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 distribution in Ferrosols and its influence on rain-fed crop production in the South Burnett region of Queensland - UQ eSpace, accessed July 18, 2025,

Potassium distribution in Ferrosols and its influence on rain-fed crop production in the South Burnett region of Queensland - UQ eSpace, accessed July 18, 2025,

Contextual Support GreyLiterature

Potassium Considerations for Nutrient Management - Gov.bc.ca, accessed July 18, 2025

View Source

Potassium for high-performing pastures | Nutrient Advantage, accessed July 18, 2025,

Direct Evidence Journal

Potassium for high rainfall pastures - DPIRD's Digital library

View Source

Preview of Soil and tissue tests to predict pasture yield responses to applications of potassium fertiliser in high-rainfall areas of south-western Australia | Request PDF - ResearchGate, accessed July 18, 2025,

Soil and tissue tests to predict pasture yield responses to applications of potassium fertiliser in high-rainfall areas of south-western Australia | Request PDF - ResearchGate, accessed July 18, 2025,

Contextual Support Direct Evidence Journal

What are the optimum nutrient targets for pastures?, accessed July 18, 2025

View Source

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

Contextual Support GreyLiterature

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

View Source

The development and application of functions ... - CSIRO Publishing, accessed July 18, 2025,

Contextual Support Journal

The development and application of functions ... - CSIRO Publishing, accessed July 18, 2025

View Source

Preview of The impact of deforestation and pasture abandonment on soil properties in the wet tropics of Australia - ResearchGate, accessed July 18, 2025,

The impact of deforestation and pasture abandonment on soil properties in the wet tropics of Australia - ResearchGate, accessed July 18, 2025,

Contextual Support

Tool 6.7 Soil health benchmarks and guidelines for managing ..., accessed July 18, 2025,

View Source

What are the optimum nutrient targets for pastures? - Soil Health Knowledgebase, accessed August 5, 2025,

Contextual Support Government

What are the optimum nutrient targets for pastures? - Soil Health Knowledgebase, accessed July 18, 2025

View Source

www.dpi.nsw.gov.au, accessed on May 25, 2025,

Contextual Support Journal

Plant nutrients in the soil - NSW Department of Primary Industries, accessed July 18, 2025

View Source

Context

Region Australia
Biome Tropical & Subtropical Rainforests
Land Use Livestock Grazing & Pasture
Assessment Not Stated
Evidence Type DegradationThreshold

Lifecycle

Status Active
Version 1
Effective From 1 Jun 2026

Notes

Below 40-50 mg/kg for sandy and loamy soils indicates potassium deficiency compromising pasture persistence and ecosystem health. AssessmentContext defaulted to 'Not Stated' because the source document did not state one.

Related Benchmarks

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