Soil Potassium

AUS-AIF-LVG-SOK General Moderate confidence

Benchmark Value

120 mg/kg

Thresholds: Lower: 120, Upper: —

Direction: Higher is desirable ↑

Form: LowerThreshold

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 2 benchmarks together — the LowerThreshold form drives the primary score, while 1 guard(s) constrain the result.

Contributing Benchmarks

LowerThreshold Primary UpperThreshold Guard

Evidence & Context

a Colwell K value of approximately 120 mg/kg is a scientifically defensible critical lower threshold for the clay-dominated soils of Australia's Arid Inland Floodplains.

Metric Definition:

Colwell-extractable potassium in the top 10 cm of soil.

Benchmark Definition:

Critical lower threshold below which ecosystem function is compromised due to potassium deficiency.

Justification:

This threshold is based on agronomic minimums for improved pastures on heavy soils and is used as a proxy for native rangeland health.

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,

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

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

Preview of After record harvests, how much nitrogen will be tied-up in high ..., accessed August 13, 2025,

After record harvests, how much nitrogen will be tied-up in high ..., accessed August 13, 2025,

Contextual Support Journal

Queensland Soil and Land Resource Survey Information Guideline, accessed July 17, 2025,

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,

Methodology Source Government

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

Preview of Australian Soils and Landscapes | Monitoring & Data | TERN - esoil.io, accessed July 30, 2025,

Australian Soils and Landscapes | Monitoring & Data | TERN - esoil.io, accessed July 30, 2025,

Contextual Support Government

Australian Soils and Landscapes | Monitoring & Data | TERN - esoil.io, accessed July 17, 2025,

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,

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 - ResearchGate, accessed July 19, 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 - ResearchGate, accessed July 19, 2025,

Contextual Support Journal

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 - ResearchGate, accessed July 17, 2025,

Preview of Ecosystem Processes – Environmental Data Collection Methods - TERN Australia

Ecosystem Processes – Environmental Data Collection Methods - TERN Australia

Methodology Source Government

TERN Surveillance monitoring program: Soil vis-NIR spectral library with accompanying soil measurement data for 367 specimens - CSIRO Data Access Portal, accessed July 17, 2025,

Preview of Grazing support programs | Environment, land and water - Queensland Government, accessed August 8, 2025

Grazing support programs | Environment, land and water - Queensland Government, accessed August 8, 2025

Contextual Support Government

Response of Grazing Land Soil Health to Management Strategies: A Summary Review, accessed July 17, 2025,

Preview of Hydrological assessment and analysis of the Cooper Creek Catchment, South Australia - Department for Environment and Water, accessed July 21, 2025,

Hydrological assessment and analysis of the Cooper Creek Catchment, South Australia - Department for Environment and Water, accessed July 21, 2025,

Contextual Support Journal

Riparian vegetation of a permanent waterhole on Cooper Creek, southwest Queensland, accessed July 17, 2025,

Preview of Impacts of Agricultural Management Practices on Soil Health - NCBI, accessed May 11, 2025

Impacts of Agricultural Management Practices on Soil Health - NCBI, accessed May 11, 2025

Contextual Support

Grazing support programs | Environment, land and water - Queensland Government, accessed July 17, 2025,

Preview of Nutrient cycling in the Southern Coorong - Department for Environment and Water, accessed July 17, 2025,

Nutrient cycling in the Southern Coorong - Department for Environment and Water, accessed July 17, 2025,

Contextual Support Journal

Nutrient cycling in the Southern Coorong - Department for Environment and Water, accessed July 17, 2025,

Preview of Potassium | Fact Sheets | soilquality.org.au, accessed August 11, 2025,

Potassium | Fact Sheets | soilquality.org.au, accessed August 11, 2025,

Direct Evidence Government

Soil fertility in grazing systems: Manage potassium to manage nitrogen - Crops and Soils, accessed July 28, 2025,

Preview of Response of Grazing Land Soil Health to Management Strategies: A Summary Review, accessed August 5, 2025,

Response of Grazing Land Soil Health to Management Strategies: A Summary Review, accessed August 5, 2025,

Contextual Support Journal

Response of Grazing Land Soil Health to Management Strategies: A Summary Review

Preview of Soil carbon sequestration in rangelands: A critical review of the impacts of major management strategies - ResearchGate, accessed August 5, 2025,

Soil carbon sequestration in rangelands: A critical review of the impacts of major management strategies - ResearchGate, accessed August 5, 2025,

Contextual Support Journal

final repport - Department of Primary Industries, Queensland, accessed July 17, 2025,

Preview of The dirt on our soils - Curious - Australian Academy of Science, accessed July 13, 2025

The dirt on our soils - Curious - Australian Academy of Science, accessed July 13, 2025

Contextual Support GreyLiterature

1301.0 - ABS Feature Articles, 1966 - Australian Bureau of Statistics, accessed July 28, 2025,

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

Understanding soil tests for pastures

Context

Region Australia
Biome Arid Inland Floodplains & Ephemeral River Systems
Land Use Livestock Grazing & Pasture
Assessment Pristine Reference
Evidence Type DegradationThreshold

Lifecycle

Status Active
Version 1
Effective From 25 Mar 2026

Notes

Below this level, native pasture response to flood events is impaired, increasing erosion risk and reducing pasture quality.

Related Benchmarks

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