Soil Potassium

AUS-TMS-CON-SOK General Moderate confidence

Benchmark Value

45.7 mg/kg
Direction: Higher is desirable ↑
Form: Point

Scoring Curve

Scoring curve unavailable

The scoring engine could not generate a curve for this benchmark context. The primary form is Point, but the benchmark data may be missing required fields (e.g., optimal range bounds for an OptimalRange benchmark). This is typically a data quality issue in the benchmark pipeline.

Evidence & Context

Based on available peer-reviewed data from an undisturbed native forest site on Melville Island (Red Kandosol soil), a mean exchangeable potassium value of 45.7 mg/kg (with an observed range of 35.2 – 450.0 mg/kg) is proposed as a reference point.

Metric Definition:

Available soil potassium, typically measured by methods such as Colwell K or exchangeable K, expressed in mg/kg.

Benchmark Definition:

This benchmark represents the available soil potassium level indicating high environmental health in Australian Tropical Monsoonal Savannas within Conservation / Protected Natural Areas, based on data from an undisturbed native forest site on Melville Island.

Justification:

The benchmark is based on peer-reviewed data from a single undisturbed native forest site on Melville Island (Red Kandosol soil), representing a best available natural condition. Moderate confidence is assigned due to the single site origin and wide observed range indicating heterogeneity or potential outliers.

Sources (2)

Preview of industry.nt.gov.au
industry.nt.gov.au Journal

industry.nt.gov.au, accessed May 20, 2025,

View Source
Preview of Plantation tree growth responses to P, N, K and minor and trace elements on low fertility savanna soils (data from undisturbed native forest comparison site on Red Kandosol)
Plantation tree growth responses to P, N, K and minor and trace elements on low fertility savanna soils (data from undisturbed native forest comparison site on Red Kandosol) Journal

Plantation tree growth responses to P, N, K and minor and trace elements on low fertility savanna soils (data from undisturbed native forest comparison site on Red Kandosol)

View Source

Supporting Sources (1)

Additional references from the underlying research that informed this benchmark.

Preview of Soil Research - CSIRO PUBLISHING, accessed May 16, 2025,
Soil Research - CSIRO PUBLISHING, accessed May 16, 2025,
Contextual Support Journal

Litchfield Savanna BASE Contextual, Soil Physico-Chemical Data ..., accessed May 20, 2025,

View Source

Context

  • Region Australia
  • Biome Tropical Monsoonal Savannas
  • Land Use Conservation / Protected Natural Areas
  • Assessment Pristine Reference
  • Evidence Type ReferenceCondition

Lifecycle

  • Status Active
  • Version 1
  • Effective From 10 Jun 2026

Notes

Lower Critical Threshold: Literature for pastures suggests <80 mg/kg K is low; for native savanna on Red Kandosols, levels consistently near or below the lower observed range of ~35 mg/kg may indicate significant stress. No specific optimal range is defined; the naturally functioning range observed in healthy, undisturbed sites is the best current guide. No evidence for an upper detrimental threshold; the upper observed value of 450 mg/kg suggests natural systems can accommodate high K locally.