Soil pH

AUS-TMS-AGR-SPH General Moderate confidence

Benchmark Value

No specific value — see range
Range: 5.8 to 6.8 pH (CaCl₂)
Optimal Range: 5.8 to 6.8
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 10 benchmarks together — the OptimalRange form drives the primary score, while 9 guard(s) constrain the result.

Evidence & Context

Synthesizing the information from the benchmark discussion and the lower critical threshold, an Optimal Soil pH Range of pH (CaCl₂) 5.8 to 6.8 is proposed for agricultural crop production systems in Australian Tropical Monsoonal Savannas aiming for high ecological health and sustainability.

Metric Definition:

Optimal soil pH range measured in 0.01M CaCl₂ supporting ecological integrity and sustainable crop production.

Benchmark Definition:

Range of soil pH values that support good nutrient availability, avoid major toxicities, foster beneficial microbial activity, and maintain good CEC in agricultural systems of the Tropical Monsoonal Savannas biome.

Justification:

This range supports multiple facets of soil health and sustainable production, balancing nutrient availability and toxicity risks in tropical savanna soils.

Sources (1)

Preview of Cotton Production and Sustainability in the Northern Territory: A Comprehensive Analysis of Yield, Soil Properties, and Cover Crops (Mwando et al., 2024, In: Proceedings of the 21st Australian Agronomy Conference)
Cotton Production and Sustainability in the Northern Territory: A Comprehensive Analysis of Yield, Soil Properties, and Cover Crops (Mwando et al., 2024, In: Proceedings of the 21st Australian Agronomy Conference) Journal

Cotton Production and Sustainability in the Northern Territory: A Comprehensive Analysis of Yield, Soil Properties, and Cover Crops (Mwando et al., 2024, In: Proceedings of the 21st Australian Agronomy Conference)

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Supporting Sources (1)

Additional references from the underlying research that informed this benchmark.

Preview of Effects of agricultural management on soil carbon and pH in the Douglas Daly region of the Northern Territory - NT (Book), accessed on June 7, 2025
Effects of agricultural management on soil carbon and pH in the Douglas Daly region of the Northern Territory - NT (Book), accessed on June 7, 2025
Contextual Support Journal

General soil science principles and reviewed literature

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Context

  • Region Australia
  • Biome Tropical Monsoonal Savannas
  • Land Use Agricultural Crop Production
  • Assessment Pristine Reference
  • Evidence Type TargetCondition

Lifecycle

  • Status Active
  • Version 2
  • Effective From 25 Mar 2026

Notes

Managing soil pH within this optimal range aims to support crop productivity and broader ecological functions, contributing to agroecosystem resilience.