Soil pH

Benchmark Value

5 pH

Direction: Lower is desirable ↓

Form: MinimumOnly

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 2 benchmarks together — the OptimalRange form drives the primary score, while 1 guard(s) constrain the result.

Contributing Benchmarks

OptimalRange Primary MinimumOnly Guard

Evidence & Context

Lower Critical Threshold: A soil pHw below 5.0 (approximately pHCaCl 2 < 4.5) is considered critically low for most savanna soils.

Metric Definition:

Soil pH measured in a 1:5 soil:water suspension (pHw)

Benchmark Definition:

This benchmark marks the critical lower soil pH threshold below which ecosystem health in tropical monsoonal savannas under livestock grazing is significantly impaired.

Justification:

Below this pH, nutrient availability is severely compromised and toxicities increase, impairing ecosystem function.

Sources (1)

Preview of Soil nutrient critical limits | MBFP | More Beef from Pastures - MLA, accessed May 13, 2025,

Soil nutrient critical limits | MBFP | More Beef from Pastures - MLA, accessed May 13, 2025, GreyLiterature

Understanding soil tests for pastures | Soil | Farm management ..., accessed July 17, 2025,

View Source

Supporting Sources (37)

Additional references from the underlying research that informed this benchmark.

S11

Direct Evidence

S11

S11

Direct Evidence

S11

S11

Direct Evidence

S11

S11

Direct Evidence

S11

S11

Direct Evidence

S11

S11

Direct Evidence

S11

S11

Direct Evidence

S11

S11, S8

Direct Evidence

S11, S8

S11, S8

Direct Evidence

S11, S8

S11, S8

Direct Evidence

S11, S8

S11, S8

Direct Evidence

S11, S8

S11, S8

Direct Evidence

S11, S8

S11, S8

Direct Evidence

S11, S8

S2, S8

Direct Evidence

S2, S8

S2, S8

Direct Evidence

S2, S8

S2, S8

Direct Evidence

S2, S8

S2, S8

Direct Evidence

S2, S8

S2, S8

Direct Evidence

S2, S8

S2, S8

Direct Evidence

S2, S8

S46, S25

Direct Evidence

S46, S25

S46, S25

Direct Evidence

S46, S25

S46, S25

Direct Evidence

S46, S25

S46, S25

Direct Evidence

S46, S25

S46, S25

Direct Evidence

S46, S25

S46, S25

Direct Evidence

S46, S25

S7, S25

Direct Evidence

S7, S25

S7, S25

Direct Evidence

S7, S25

S7, S25

Direct Evidence

S7, S25

S7, S25

Direct Evidence

S7, S25

S7, S25

Direct Evidence

S7, S25

S7, S25

Direct Evidence

S7, S25

S7, S25

Direct Evidence

S7, S25

Preview of Soil health: looking for suitable indicators. What should be considered to assess the effects of use and management on soil heal - alice Embrapa, accessed July 28, 2025,

Soil health: looking for suitable indicators. What should be considered to assess the effects of use and management on soil heal - alice Embrapa, accessed July 28, 2025,

Contextual Support Journal

www.barenbrug.com.au, accessed May 13, 2025,

View Source

Preview of Soil organic carbon content at a range of north Australian tropical savannas with contrasting site histories - OPUS at UTS, accessed May 16, 2025,

Soil organic carbon content at a range of north Australian tropical savannas with contrasting site histories - OPUS at UTS, accessed May 16, 2025,

Contextual Support Journal

opus.lib.uts.edu.au, accessed May 13, 2025,

View Source

Soil Quality and Its Management in Humid Subtropical and Tropical Environments - UKnowledge, accessed May 15, 2025,

Contextual Support

a comparisonof the soils of tropical latin america ano tropical australia, accessed May 13, 2025,

View Source

Preview of Soil surface pH DSM data of the Southern Gulf catchments (NT and Qld) generated by the Southern Gulf Water Resource Assessment - CSIRO Data Access Portal, accessed May 13, 2025,

Soil surface pH DSM data of the Southern Gulf catchments (NT and Qld) generated by the Southern Gulf Water Resource Assessment - CSIRO Data Access Portal, accessed May 13, 2025,

Contextual Support Government

Categories - Soil pH - CSIRO Data Access Portal, accessed May 13, 2025,

View Source

Tropical Pasture - Barenbrug Australia, accessed July 18, 2025,

Direct Evidence Journal

Soils of the Koolpinyah Surface (Chen et al., 2005)

View Source

Benchmark Value

Scoring Curve

Contributing Benchmarks

Evidence & Context

Sources (1)

Supporting Sources (37)

Context

Lifecycle

Notes

Related Benchmarks