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 6 benchmarks together — the OptimalRange form drives the primary score, while 5 guard(s) constrain the result.
Contributing Benchmarks
Evidence & Context
While values up to 250-300 mg/kg may be acceptable in high-CEC clay soils, any soil test showing results in this upper range should immediately trigger a more detailed assessment of the full cation balance.
Available soil potassium concentration in topsoil
Upper boundary for soil potassium based on nutrient imbalance risk, not toxicity, in production forestry soils of arid mountain biomes.
Excess potassium can induce magnesium deficiency; values exceeding 250-300 mg/kg require cation balance assessment.
Sources (1)
Little left to lose: deforestation and forest degradation in Australia since European colonization | Journal of Plant Ecology | Oxford Academic
View SourceSupporting Sources (3)
Additional references from the underlying research that informed this benchmark.
Soil Inorganic Carbon, the Other and Equally Important Soil Carbon Pool: Distribution, Controlling Factors, and the Impact of C
View Source
Long-term rundown of plant-available potassium in Western Australia requires a re-evaluation of potassium management for grain production: a review - BioOne Complete
View SourceAgriculture Victoria. (2025). Understanding soil tests for pastures. Farm Management.
View Source