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 16 benchmarks together — the OptimalRange form drives the primary score, while 15 guard(s) constrain the result.
Contributing Benchmarks
Evidence & Context
Thus, for soils that are not naturally alkaline, pushing the pH above pH_CaCl2 7.0 - 7.5 (approximately pH_w 7.8 - 8.3) through management interventions is likely to be detrimental from an ecological balance perspective.
Soil pH measured in 0.01M calcium chloride (pH_CaCl2), above which ecological detriments occur on non-alkaline soils.
Upper detrimental soil pH threshold for non-alkaline soils beyond which nutrient imbalances and ecological harm occur.
Evidence indicates high pH reduces micronutrient availability and can negatively impact native flora adapted to acidic soils.
Sources (1)
Helyar & Porter (1989) Soil acidification, its measurement and the processes involved (in S8)
View SourceSupporting Sources (5)
Additional references from the underlying research that informed this benchmark.
(PDF) Soil acidification and natural resource management ..., accessed May 16, 2025
View SourceSoil pH | Environment, land and water - Queensland Government, accessed August 28, 2025,
View SourceMultiple soil element and pH interactions constrain plant performance on tropical soils with a long history of fire - CSIRO PUBLISHING | Soil Research, accessed July 20, 2025
View SourceHunt, L. P., Petty, S., Cowley, R., Fisher, A., Ash, A., & MacDonald, N. (2014). Principles and guidelines for managing cattle grazing in the grazing lands of northern Australia: stocking rates, pasture resting, prescribed fire, paddock size and water points – a review. Rangeland Journal, 36(2), 109-130.
View Source
Soils of Cape York Peninsula - Queensland Government publications, accessed May 11, 2025,
View Source