Soil Potassium

AUS-TCF-AGR-SOK General Moderate confidence

Benchmark Value

No specific value — see range
Range: 110 to 180 mg/kg
Optimal Range: 110 to 180
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.

Evidence & Context

For broadacre cropping systems cultivated on clay soils, which also occur within the biome, a slightly higher Colwell K range of 110-180 mg/kg might be more appropriate.

Metric Definition:

Soil Potassium (Colwell K)

Benchmark Definition:

This benchmark represents the target range of bicarbonate-extractable soil potassium (Colwell K) for broadacre cropping systems on clay soils in the Temperate Coastal Forests & Woodlands biome, aimed at supporting optimal crop yield.

Justification:

Based on Victorian pasture guidelines and the greater capacity of clay soils to hold and supply potassium.

Sources (1)

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 Government

Agriculture Victoria. (2025). Understanding soil tests for pastures. Farm Management.

View Source

Supporting Sources (5)

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,
Direct Evidence Journal

Nutrient Cycling in Australian Savannas on JSTOR - DOI

View Source
Preview of Crop and Pasture Science - CSIRO PUBLISHING, accessed July 10, 2025
Crop and Pasture Science - CSIRO PUBLISHING, 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, accessed July 17, 2025

View Source
Preview of Eastern Australian temperate forests - Wikipedia, accessed July 15, 2025
Eastern Australian temperate forests - Wikipedia, accessed July 15, 2025
Contextual Support

Eastern Australian temperate forests - Wikipedia

View Source
Preview of Potassium | Fact Sheets | soilquality.org.au, accessed July 10, 2025
Potassium | Fact Sheets | soilquality.org.au, accessed July 10, 2025
Direct Evidence Government

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 July 17, 2025

View Source
Preview of Southeast Australia Temperate Forests | One Earth
Southeast Australia Temperate Forests | One Earth
Contextual Support Journal

Southeast Australia Temperate Forests | One Earth

View Source

Context

  • Region Australia
  • Biome Temperate Coastal Forests & Woodlands
  • Land Use Agricultural Crop Production
  • Assessment Agricultural Biodiversity Target
  • Evidence Type ReferenceCondition

Lifecycle

  • Status Active
  • Version 1
  • Effective From 3 Jun 2026

Notes

Target for achieving approximately 90-95% of potential yield.

Related Benchmarks

Other benchmarks in the AUS-TCF-AGR-SOK family.

— mg/kg Moderate
Agricultural Crop Production · Agricultural Biodiversity Target
OptimalRange Active v1
200 mg/kg Moderate
Agricultural Crop Production · Agricultural Biodiversity Target
Point Active v1