Soil Potassium

AUS-AMR-FOR-SOK General Moderate confidence

Benchmark Value

No specific value — see range

Range: 120 to 200 mg/kg

Thresholds: Lower: 50, Upper: 250

Optimal Range: 120 to 200

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 10 benchmarks together — the OptimalRange form drives the primary score, while 9 guard(s) constrain the result.

Contributing Benchmarks

OptimalRange Primary OptimalRange Guard Point Guard MaximumOnly Guard UpperThreshold Guard OptimalRange Guard LowerThreshold Guard Point Guard MinimumOnly Guard OptimalRange Guard

Evidence & Context

Based on the preceding synthesis of the best available analogue data, the following benchmark for soil potassium is proposed for production forestry in Australia's Arid Mountain Ranges & Uplands biome, representing a state of high environmental health and sustainable productivity.

Metric Definition:

Available potassium (Colwell K or equivalent method) in the topsoil (0-10 cm)

Benchmark Definition:

This benchmark represents a target for available potassium (Colwell K or equivalent method) in the topsoil (0-10 cm) that balances productivity with ecological sustainability in Australia's Arid Mountain Ranges & Uplands biome under production forestry.

Justification:

This benchmark is derived by synthesis due to a lack of direct studies for the specified context. It balances productivity with ecological sustainability and accounts for nutrient export in production forestry.

Sources (2)

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 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.

View Source

Understanding soil tests for pastures | Soil | Farm management ..., accessed May 12, 2025 Government

Understanding soil tests for pastures

View Source

Supporting Sources (1)

Additional references from the underlying research that informed this benchmark.

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

Direct Evidence 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

View Source

Context

Region Australia
Biome Arid Mountain Ranges & Uplands
Land Use Production Forestry
Assessment Pristine Reference
Evidence Type ReferenceCondition

Lifecycle

Status Active
Version 1
Effective From 25 Mar 2026

Notes

The specific value within the range should be interpreted based on soil texture: aim for the lower end (~120 mg/kg) for sandy soils and the upper end (~200 mg/kg) for loamy to clay soils. Lower Critical Threshold: 50 mg/kg. Upper Detrimental Threshold: 250 mg/kg.

Related Benchmarks

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