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. The scoring engine uses 3 benchmarks together — the OptimalRange form drives the primary score, while 2 guard(s) constrain the result.
Contributing Benchmarks
Evidence & Context
The upper detrimental threshold is a range from approximately 310 mg/kg in lower-CEC clay loams to over 780 mg/kg in higher-CEC clays.
Upper detrimental threshold for soil potassium based on cation imbalance and soil CEC.
This benchmark defines the upper detrimental threshold for soil potassium in production forestry soils, where excess potassium can cause cation imbalance and magnesium deficiency.
Defined by cation imbalance where excess potassium induces magnesium deficiency, dependent on soil CEC.
Sources (1)
Understanding soil tests for pastures
View SourceSupporting Sources (15)
Additional references from the underlying research that informed this benchmark.
A Review of Potassium-Rich Crop Residues Used as Organic Matter Amendments in Tree Crop Agroecosystems - MDPI
View SourceCation exchange capacity - NSW Department of Primary Industries, accessed July 28, 2025,
View SourceCation exchange capacity - NSW Department of Primary Industries
View SourceCations and Cation Exchange Capacity | Fact Sheets | soilquality.org.au
View SourceAustralian Soil Classification edition 3 - CALCAROSOLS
View SourceEstablishment of critical nutrient levels in soil and plant for eucalyptus
View SourceForm and Availability | Soils - Part 6: Phosphorus and Potassium in the Soil - passel
View SourceRelationships between soil nutrients and vegetation in a north coast forest, New South Wales - ResearchGate
View SourceNutrient distribution and cycling in a subtropical ... - CSIRO Publishing
View SourcePlant nutrients in the soil - NSW Department of Primary Industries
View SourceRangelands Living Skin | .Meat & Livestock Australia - MLA, accessed July 28, 2025,
View SourcePotassium | Fact Sheets | soilquality.org.au
View SourcePlant nutrients 101 | Sustainable Gardening Australia
View SourceEssential Role of Potassium in Apple and Its Implications for Management of Orchard Fertilization - PubMed Central
View SourceWhat are the optimum nutrient targets for pastures? - Soil Health Knowledgebase, accessed July 28, 2025,
View Source