Soil pH

AUS-TMS-AGR-SPH General Moderate confidence

Benchmark Value

No specific value — see range
Range: 5.8 to 6.8 pH
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 4 benchmarks together — the OptimalRange form drives the primary score, while 3 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 nutrient availability, microbial activity, and overall ecosystem health.

Justification:

This range balances the need to avoid toxicity and nutrient deficiencies while supporting sustainable agricultural production and ecological functions.

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 literature and expert synthesis

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Context

  • Region Australia
  • Biome Tropical Monsoonal Savannas
  • Land Use Agricultural Crop Production
  • Assessment Agricultural Biodiversity Target
  • Evidence Type HealthyOperationalRange

Lifecycle

  • Status Active
  • Version 2
  • Effective From 10 Jun 2026

Notes

No upper detrimental threshold — higher values are always better up to natural saturation. Supports good Cation Exchange Capacity and diverse microbial communities essential for nutrient cycling and disease suppression.