Soil pH — Benchmark Detail

Benchmark Value

8 pH

Thresholds: Lower: —, Upper: 8

Direction: Lower is desirable ↓

Form: UpperThreshold

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

OptimalRange Primary OptimalRange Guard MinimumOnly Guard UpperThreshold Guard OptimalRange Guard LowerThreshold Guard OptimalRange Guard UpperThreshold Guard OptimalRange Guard LowerThreshold Guard UpperThreshold Guard MinimumOnly Guard LowerThreshold Guard OptimalRange Guard UpperThreshold Guard OptimalRange Guard LowerThreshold Guard UpperThreshold Guard OptimalRange Guard

Evidence & Context

pHCaCl2 values exceeding 8.0 - 8.5 can induce micronutrient deficiencies, limiting pasture productivity and diversity.

Metric Definition:

Topsoil pH measured in 0.01M CaCl2 solution

Benchmark Definition:

This benchmark sets the upper soil pH threshold in 0.01M CaCl2 solution above which micronutrient deficiencies and degradation risks increase in Temperate Semi-Arid Shrublands & Open Woodlands under livestock grazing and pasture.

Justification:

Values above 8.0 indicate nutrient deficiencies and potential degradation from overgrazing.

Sources (2)

Preview of Heavy grazing reduces soil bacterial diversity by increasing soil pH in a semi-arid steppe, accessed July 10, 2025,

Heavy grazing reduces soil bacterial diversity by increasing soil pH in a semi-arid steppe, accessed July 10, 2025, Journal

Soil Acidity in the Mallee - Department for Environment and Water, accessed July 7, 2025,

View Source

Preview of Soil Acidity - Ag Excellence Alliance, accessed July 10, 2025,

Soil Acidity - Ag Excellence Alliance, accessed July 10, 2025, GreyLiterature

Soil pH and Microbial Life - Number Analytics, accessed July 7, 2025,

View Source

Supporting Sources (5)

Additional references from the underlying research that informed this benchmark.

Preview of Effects of soil pH on the growth, soil nutrient composition, and rhizosphere microbiome of Ageratina adenophora - PMC - PubMed Central, accessed July 30, 2025,

Effects of soil pH on the growth, soil nutrient composition, and rhizosphere microbiome of Ageratina adenophora - PMC - PubMed Central, accessed July 30, 2025,

Direct Evidence Journal

Factors influencing decline in soil pH in Hawaiian Eucalyptus and Albizia plantations

View Source