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
The proposed benchmark for available soil potassium is >280 mg/kg (Colwell-K).
Available soil potassium measured by the Colwell-K method representing the plant-available fraction of potassium in soil.
This benchmark represents a natural potassium sufficiency state for Arid Karstic Woodlands & Shrublands, based on agronomic trials on Calcarosols where potassium was non-limiting for crop production.
This value is derived from agronomic trials on identical soil types (Calcarosols) where >280 mg/kg (Colwell-K) was the observed baseline at which potassium was non-limiting for crop production, serving as a scientifically quantified proxy for a healthy, non-degraded state, corroborated by the potassium-accumulating nature of the biome's dominant native flora.
Sources (1)
The Western Australian Rangeland Monitoring System (WARMS) – operating a regional scale monitoring system - ResearchGate, accessed July 24, 2025
View SourceSupporting Sources (22)
Additional references from the underlying research that informed this benchmark.
3 - Understand nutritional properties of major arid zone pasture plants - MBFP-Pastoral, accessed July 24, 2025
View SourceCalcareous Soils Initiative - GRDC, accessed July 24, 2025
View SourceChemical fractions of potassium in arid region calcareous soils: The ..., accessed July 24, 2025
View Source
(PDF) Monitoring changes in pastoral rangelands – the Western Australian Rangeland Monitoring System (WARMS) - ResearchGate, accessed July 24, 2025
View SourceFarm-scale nitrogen, phosphorus, potassium and sulfur balances and use efficiencies on Australian dairy farms - CSIRO Publishing, accessed July 24, 2025
View Source
Report 119: Cenozoic evolution of the Nullarbor Plain paleokarst, southern Australia - NET, accessed July 24, 2025
View SourceGood Pastoral Land Management Guidelines - Government of ..., accessed July 24, 2025
View SourceGeology of the Nullarbor Plain (Webb and James 2006; courtesy JA ..., accessed July 24, 2025
View Source
Long-term rundown of plant-available potassium in Western Australia requires a re-evaluation of potassium management for grain production: a review - CSIRO PUBLISHING | Crop and Pasture Science, accessed July 24, 2025
View SourceMaireana sedifolia - Botanic Gardens Plant Selector, accessed July 24, 2025
View Source
(PDF) Soil potassium—crop response calibration relationships and ..., accessed July 24, 2025
View SourceNullarbor Plain - Wikipedia, accessed July 24, 2025
View Source
Nutrient Composition of Atriplex Leaves Grown in Saudi Arabia - Journals, accessed July 24, 2025
View SourcePotassium in Soils - International Potash Institute, accessed July 24, 2025
View SourceSoil Testing and Interpretation for Vegetable Crops - AUSVEG, accessed July 24, 2025
View SourceSouth Australia | Flag, Facts, Maps, & Points of Interest | Britannica, accessed July 24, 2025
View Source
The dynamics of potassium in some Australian soils - Adelaide Research & Scholarship, accessed July 24, 2025
View Source
The Dynamics of Potassium in some Australian soils - CORE, accessed July 24, 2025
View SourceThe Dynamics of Potassium in some Australian soils - ResearchGate, accessed July 24, 2025
View SourceThe Ecograze Project - developing guidelines to better manage grazing country - FutureBeef, accessed July 24, 2025
View Source
Nullarbor plain | Article for mature travellers - Odyssey Traveller, accessed July 24, 2025
View SourceKarst features and remnant dune systems on the Nullarbor Plain, Australia, accessed July 24, 2025
View Source