Microbial Respiration

AUS-TDG-AGR-SMR General Moderate confidence

Benchmark Value

5.8 mg/kg/day

Range: 5.8 to 5.8 mg/kg/day

Optimal Range: 5.8 to 5.8

Direction: Higher is desirable ↑

Form: Point

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 7 benchmarks together — the OptimalRange form drives the primary score, while 6 guard(s) constrain the result.

Contributing Benchmarks

OptimalRange Primary Point Guard Point Guard LowerThreshold Guard UpperThreshold Guard UpperThreshold Guard Point Guard

Evidence & Context

The benchmark value is derived from the NT+SR+N0 treatment in the Li et al. (2022) study. This treatment represents the pinnacle of sustainable management within the experimental design, characterized by maximum carbon input (stubble retention) and minimum soil disturbance (no-till). Source Data: The study reports that the cumulative microbial respiration for the NT+SR+N0 treatment was the lowest among the NT systems, measuring approximately 528 mg CO₂-C/kg of soil. This measurement was taken over an incubation period of 91 days (the experiment ran for 98 days, but the authors excluded the first 7 days of data to avoid the initial flush effect from re-wetting of air-dried soil, a standard practice for measuring basal respiration). The incubation was conducted under controlled laboratory conditions at 25°C and 60% water-holding capacity, representing near-optimal conditions for mesophilic microbial activity.

Metric Definition:

Basal microbial respiration rate measured as mg CO2-C released per kg of soil per day under standardized laboratory conditions (25°C, 60% water-holding capacity).

Benchmark Definition:

Basal microbial respiration rate measured under standardized lab conditions as an indicator of soil biological function in temperate dry woodlands and native grasslands under agricultural crop production.

Justification:

This value originates from a 50-year no-till, stubble-retained, zero-N fertilizer cropping system representing a mature, stabilized regenerative system. It is interpreted as a state of high carbon use efficiency and sustainable biological function.

Sources (1)

Preview of How to determine an OPTIMAL soil respiration (or microbial respiration)? - ResearchGate, accessed August 5, 2025,

How to determine an OPTIMAL soil respiration (or microbial respiration)? - ResearchGate, accessed August 5, 2025, GreyLiterature

Soil Health Testing - Agronomic Insights, accessed August 13, 2025,

Supporting Sources (16)

Additional references from the underlying research that informed this benchmark.

Preview of Comparison of temperature effects on soil respiration and bacterial and fungal growth rates | FEMS Microbiology Ecology | Oxford Academic, accessed July 30, 2025,

Comparison of temperature effects on soil respiration and bacterial and fungal growth rates | FEMS Microbiology Ecology | Oxford Academic, accessed July 30, 2025,

Contextual Support Journal

Quantifying thermal adaptation of soil microbial respiration - PMC - PubMed Central, accessed August 13, 2025,

Preview of Haney Test Interpretation Guide v1.0, accessed August 9, 2025

Haney Test Interpretation Guide v1.0, accessed August 9, 2025

Contextual Support

Sustainable Land Use Enhances Soil Microbial Respiration Responses to Experimental Heat Stress - PMC - PubMed Central, accessed August 13, 2025,

Preview of Inherent Factors Affecting Soil Respiration - USDA, accessed July 30, 2025,

Inherent Factors Affecting Soil Respiration - USDA, accessed July 30, 2025,

Contextual Support Journal

Twenty years of progress, challenges, and opportunities in measuring and understanding soil respiration, accessed August 13, 2025,

Preview of Is there any harmful effect of agrochemicals use on soil microorganisms? - ResearchGate

Is there any harmful effect of agrochemicals use on soil microorganisms? - ResearchGate

Contextual Support GreyLiterature

Starting / Enhancing Your Regenerative Agriculture Journey, accessed August 13, 2025,

Preview of Microbiological Indicators for Assessing the Effects of Agricultural Practices on Soil Health: A Review - MDPI, accessed on June 5, 2025

Microbiological Indicators for Assessing the Effects of Agricultural Practices on Soil Health: A Review - MDPI, accessed on June 5, 2025

Contextual Support Journal

Microbiological Indicators for Assessing the Effects of Agricultural Practices on Soil Health: A Review - MDPI, accessed August 13, 2025,

Preview of Regenerative Agriculture - a literature review on the practices and mechanisms used to improve soil health - DPIRD's Digital library, accessed August 5, 2025,

Regenerative Agriculture - a literature review on the practices and mechanisms used to improve soil health - DPIRD's Digital library, accessed August 5, 2025,

Contextual Support

Regenerative Land Management - HEALTHY SOILS AUSTRALIA

Preview of Regenerative agriculture in Australia: the changing face of farming - Frontiers, accessed August 4, 2025

Regenerative agriculture in Australia: the changing face of farming - Frontiers, accessed August 4, 2025

Contextual Support Journal

NCC: Regenerative Agriculture and Soil Health - Wet Tropics Plan, accessed July 27, 2025,

Preview of Regenerative Agriculture—A Literature Review on the Practices and Mechanisms Used to Improve Soil Health - MDPI, accessed August 5, 2025,

Regenerative Agriculture—A Literature Review on the Practices and Mechanisms Used to Improve Soil Health - MDPI, accessed August 5, 2025,

Contextual Support Journal

Regenerative Agriculture—A Literature Review on the Practices and Mechanisms Used to Improve Soil Health - MDPI, accessed August 28, 2025,

Preview of Soil carbon - Department for Environment and Water, accessed August 5, 2025,

Soil carbon - Department for Environment and Water, accessed August 5, 2025,

Contextual Support Journal

Soil carbon - Department for Environment and Water, accessed August 13, 2025,

Preview of Soil Carbon Sequestration Potential: A review for Australian agriculture - MLA, accessed August 5, 2025,

Soil Carbon Sequestration Potential: A review for Australian agriculture - MLA, accessed August 5, 2025,

Contextual Support Journal

Spatial distribution of soil microbial activity and soil properties ..., accessed August 13, 2025,

Preview of Soil organic carbon thresholds control fertilizer effects on carbon accrual in croplands worldwide - PMC, accessed August 13, 2025,

Soil organic carbon thresholds control fertilizer effects on carbon accrual in croplands worldwide - PMC, accessed August 13, 2025,

Contextual Support Journal

Soil organic carbon thresholds control fertilizer effects on carbon accrual in croplands worldwide - PMC, accessed August 13, 2025,

Preview of Soil respiration - Wikipedia, accessed July 30, 2025,

Soil respiration - Wikipedia, accessed July 30, 2025,

Contextual Support

Soil respiration - Wikipedia, accessed August 13, 2025,

Preview of Soil Respiration in Semiarid Temperate Grasslands under Various Land Management | PLOS One - Research journals, accessed August 12, 2025,

Soil Respiration in Semiarid Temperate Grasslands under Various Land Management | PLOS One - Research journals, accessed August 12, 2025,

Contextual Support Journal

Threshold Limits of Soil in Relation to Various Soil Functions and Crop Productivity, accessed August 13, 2025,

Preview of Soil respiration rate and its sensitivity to temperature in pasture systems of dry-tropics - Taylor & Francis Online, accessed July 30, 2025,

Soil respiration rate and its sensitivity to temperature in pasture systems of dry-tropics - Taylor & Francis Online, accessed July 30, 2025,

Contextual Support Journal

Soil respiration rate and its sensitivity to temperature in pasture systems of dry-tropics - Taylor & Francis Online, accessed August 13, 2025,

Preview of Temperature sensitivity of soil respiration rates enhanced by microbial community response - PubMed, accessed July 30, 2025,

Temperature sensitivity of soil respiration rates enhanced by microbial community response - PubMed, accessed July 30, 2025,

Contextual Support Journal

Temperature sensitivity of soil respiration rates enhanced by microbial community response - PubMed, accessed August 13, 2025,

Preview of Understanding the impacts of farming practices on the soil microbiome as a sustainable approach to crop production. - CSIRO Research, accessed July 9, 2025

Understanding the impacts of farming practices on the soil microbiome as a sustainable approach to crop production. - CSIRO Research, accessed July 9, 2025

Contextual Support Government

Growing-season soil microbial respiration response to long-term no ..., accessed August 13, 2025,

Context

Region Australia
Biome Temperate Dry Woodlands & Native Grasslands
Land Use Agricultural Crop Production
Assessment Pristine Reference
Evidence Type ReferenceCondition

Lifecycle

Status Superseded
Version 1
Effective From 24 Mar 2026
Effective To 24 Mar 2026

Notes

Measured under controlled conditions (25°C, 60% WHC). Represents a mature, high-functioning regenerative agricultural system. Confidence is Moderate due to subtropical study location but long-term nature and ideal management practices provide strong justification.

Related Benchmarks

Other benchmarks in the AUS-TDG-AGR-SMR family.