Soil pH — Benchmark Detail

Benchmark Value

No specific value — see range

Range: 6.1 to 6.9 pH

Optimal Range: 6.1 to 6.9

Direction: Higher is desirable ↑

Form: OptimalRange

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 MinimumOnly Guard MaximumOnly Guard MinimumOnly Guard OptimalRange Guard MaximumOnly Guard OptimalRange Guard MinimumOnly Guard MaximumOnly Guard MinimumOnly Guard MaximumOnly Guard OptimalRange Guard OptimalRange Guard Point Guard OptimalRange Guard MinimumOnly Guard OptimalRange Guard MaximumOnly Guard MaximumOnly Guard

Evidence & Context

Recommended Benchmark Value: A range of 6.1–6.9, interpreted as pH(water).

Metric Definition:

Soil pH measured in water (pH(water)) representing the optimal soil acidity range for sustainable livestock grazing in the Tropical and Subtropical Maritime Islands biome.

Benchmark Definition:

The optimal soil pH range for managed, modified Ferrosol (volcanic) soils on Norfolk Island, serving as a proxy for high-health pasture systems in the Tropical & Subtropical Maritime Islands biome.

Justification:

This range is derived from the Norfolk Island Agricultural Audit, representing the best available condition for volcanic soils in the target biome, supported by mainland pasture targets and soil science literature.

Sources (1)

Preview of AGRICULTURAL AUDIT & LAND USE CAPABILITY ASSESSMENT ..., accessed July 30, 2025,

AGRICULTURAL AUDIT & LAND USE CAPABILITY ASSESSMENT ..., accessed July 30, 2025, Journal

VEGETATION 0}' LORD HOWE ISLAND - Botanic Gardens of Sydney

View Source

Context

Region Australia
Biome Tropical & Subtropical Maritime Islands
Land Use Livestock Grazing & Pasture
Assessment Not Stated
Evidence Type ReferenceCondition

Lifecycle

Status Active
Version 1
Effective From 10 Jun 2026

Notes

The benchmark is a proxy from vegetable crop data but is consistent with pasture requirements. The range is interpreted as pH(water) and aligns with mainland Australian pasture targets. Confidence is low due to proxy use and inferred measurement method. AssessmentContext defaulted to 'Not Stated' because the source document did not state one.

Related Benchmarks

Other benchmarks in the AUS-TMI-LVG-SPH family.