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
A soil pH (CaCl₂) value below 4.8 is proposed as a lower critical threshold.
Soil pH measured in a 1:5 soil:0.01M CaCl₂ solution indicating the acidity level below which soil function and plant health are impaired.
This benchmark represents the critical lower soil pH threshold measured in CaCl₂ solution below which aluminium and manganese toxicity, nutrient deficiencies, and microbial impairment occur in Temperate Dry Woodlands & Native Grasslands under production forestry.
Below pHCa 4.8, detrimental effects on soil function and plant health become prevalent, including toxicity and nutrient unavailability, compromising ecosystem health and productivity.
Sources (1)
Soil acidity | Soil | Farm management - Agriculture Victoria, accessed August 28, 2025
View SourceSupporting Sources (2)
Additional references from the underlying research that informed this benchmark.
Prober, S.M., Thiele, K.R., & Lunt, I.D. (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 SourceManaging natural areas | City of Gold Coast, accessed May 19, 2025
View Source