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 19 benchmarks together — the OptimalRange form drives the primary score, while 18 guard(s) constrain the result.
Contributing Benchmarks
Evidence & Context
A soil pH(CaCl₂) above 8.0 is increasingly likely to be detrimental to many non-specialized native plant communities and their associated soil biota due to severe micronutrient deficiencies and, if the alkalinity is driven by sodium, potential issues related to sodicity and soil structural degradation.
Upper detrimental threshold for soil pH indicating severe ecological harm.
This benchmark defines the upper detrimental soil pH threshold indicating severe micronutrient deficiencies and sodicity-related soil degradation.
Above this pH, severe micronutrient deficiencies and sodicity-related soil degradation are likely.
Sources (1)
Working with bio-amendments: Insights from cropping farmers - Soils For Life, accessed July 7, 2025,
View SourceSupporting Sources (3)
Additional references from the underlying research that informed this benchmark.
Soil acidity | Soil | Farm management - Agriculture Victoria, accessed August 28, 2025
View SourceSoil acidity - Department for Environment and Water, accessed July 30, 2025,
View SourceProber, S. M., Lunt, I. D., & Thiele, K. R. (2002). Determining reference conditions for management and restoration of temperate grassy woodlands: relationships among trees, topsoils and understorey flora in little-grazed remnants. Australian Journal of Botany, 50(6), 687–697.
View Source