Soil pH
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 10 benchmarks together — the OptimalRange form drives the primary score, while 9 guard(s) constrain the result.
Evidence & Context
A critical lower threshold exists around pH < 5.0, where potential for aluminium toxicity increases.
Soil pH level below which aluminium toxicity risk increases, impairing ecosystem function.
This benchmark marks the lower soil pH limit below which aluminium toxicity stress begins, affecting ecosystem health in tropical rainforests.
Based on ecological studies and field data showing increased aluminium toxicity risk below pH 5.0.
Sources (1)
Soil and plant nutrient concentrations across a tropical forest-sclerophyll vegetation boundary in north-eastern Australia
View SourceSupporting Sources (2)
Additional references from the underlying research that informed this benchmark.
What are the optimum nutrient targets for pastures? - Soil Health Knowledgebase
View SourceGrowing up or growing out? How soil pH and light affect seedling growth of a relictual rainforest tree | AoB PLANTS | Oxford Academic
View Source