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 5 benchmarks together — the OptimalRange form drives the primary score, while 4 guard(s) constrain the result.
Contributing Benchmarks
Evidence & Context
The primary evidence for this threshold is again drawn from the Lima Neto et al. (2020) study, which defined the critical level for achieving 90% of maximum productivity in Eucalyptus plantations as 100 mg/dm³ (assumed ≈ 100 mg/kg).
Critical lower threshold of available soil potassium below which forest productivity and health decline.
Lower critical threshold for available soil potassium indicating nutrient deficiency in tropical and subtropical rainforest production forestry.
Based on a forestry-specific study linking soil K levels to 90% of maximum productivity, representing a conservative and appropriate lower boundary for long-term forest health.
Sources (1)
Establishment of critical nutrient levels in soil and plant for eucalyptus
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 SourceSodic & Alkaline Soil - Soil Quality Knowledge Base
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, accessed July 22, 2025
View SourcePlant nutrients in the soil - NSW Department of Primary Industries
View SourcePotassium In Soil Explained - Soil Quality Knowledge Base
View SourcePotassium | Fact Sheets | soilquality.org.au
View SourcePotassium | Fact Sheets | soilquality.org.au, accessed July 18, 2025
View SourceSoil Fertility and Pastures for High Quality Raw Milk, accessed July 18, 2025
View SourceHealthy soils and soil test interpretation - North Central Catchment Management Authority
View SourceAgriculture Victoria. (2025). Understanding soil tests for pastures. Farm Management.
View Source