Soil Potassium
Benchmark Value
Scoring Curve
This curve shows how a field measurement for this indicator would score across all available benchmark forms in this context.
Evidence & Context
Based on this evidence, a proposed optimal range for soil potassium (Colwell K, 0-10 cm) in sustainable cropping systems within the target biome, adjusted for soil texture, is: Sands and Sandy Loams: Approximately 100–170 mg/kg. Clay Loams and Clays: Approximately 150–250 mg/kg.
Optimal range of soil potassium concentration measured as Colwell K in the 0-10 cm soil depth supporting robust plant health and sustainable productivity.
Optimal range supporting vigorous plant growth, health, and sustainable high yields.
This range is inferred from 'ideal' and 'adequate' ranges established for well-managed agricultural systems and aligns with K levels in less disturbed native temperate woodlands.
Sources (3)
Potassium | Fact Sheets | soilquality.org.au
View SourceAgriculture Victoria. (2025). Understanding soil tests for pastures. Farm Management.
View SourceWhat are the optimum nutrient targets for pastures? - Soil Health Knowledgebase, accessed July 18, 2025
View SourceSupporting Sources (2)
Additional references from the underlying research that informed this benchmark.
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
Soil management guides - NSW Department of Primary Industries
View Source