Overview
ISO 17155:2012 specifies a standardized method for determining the activity and quantity of active aerobic, heterotrophic microbial biomass in soils by analyzing respiration curves. This standard supports the monitoring of soil quality and the evaluation of ecotoxic potential in both natural and contaminated soils. ISO 17155:2012 is applicable to soils collected along contamination gradients, as well as soils contaminated experimentally in the field or laboratory. The methodology offers an insight into soil microflora abundance and their response to environmental stressors, contributing to sustainable soil management and remediation efforts.
Key Topics
- Microbial Biomass Activity: The standard outlines procedures for measuring the activity of soil microflora-particularly the aerobic, heterotrophic component-by tracking changes in carbon dioxide (CO₂) evolution or oxygen (O₂) consumption.
- Respiration Curves: Analysis of respiration rates before and after the addition of an easily degradable substrate provides indicators such as basal respiration, substrate-induced respiration, respiratory activation quotient, specific growth rate, and time to peak maximum. These parameters reveal both the abundance and vitality of soil microorganisms.
- Ecotoxicity Assessment: The method is suitable for detecting changes in soil microbial activity caused by chemical contaminants, providing a robust tool for risk assessment and environmental monitoring.
- Sample Handling and Testing: The standard includes guidelines on soil sampling, storage, and preparation, ensuring repeatability and reliability in laboratory conditions.
Applications
- Environmental Monitoring: Used by laboratories and regulatory bodies to track and assess soil quality, especially in agricultural land, industrial sites, and areas affected by pollution.
- Ecotoxicological Risk Assessment: Facilitates determination of potential toxic effects of chemicals and pollutants on soil microbial communities, aiding in compliance with environmental protection regulations.
- Soil Remediation: Helps evaluate the effectiveness of soil remediation techniques by monitoring microbial activity recovery after treatment of contaminated soils.
- Research and Baseline Studies: Supports academic and industrial research in soil science, providing standardized data for studying microbial processes, soil health, and the impact of land-use changes.
- Comparative Studies: Enables meaningful comparisons across different soil types (mineral, organic, polluted, or unpolluted), geographies, and management practices.
Related Standards
Implementation of ISO 17155:2012 may reference or be complemented by the following ISO standards to ensure comprehensive soil quality assessment:
- ISO 10381-6: Guidance on collection, handling, and storage of soil for assessment of microbiological processes, biomass, and diversity.
- ISO 10390: Soil pH determination, which is important for interpreting microbial activity.
- ISO 10694: Determination of organic and total carbon after dry combustion, providing context for microbial measurements.
- ISO 11277: Determination of particle size distribution in mineral soil material by sieving and sedimentation.
- ISO 11465: Gravimetric method for determination of water content in soil.
- ISO 14238: Methods for nitrogen mineralization and nitrification, relevant for ecotoxicological assessments.
- ISO 14240-1: Substrate-induced respiration method for determining soil microbial biomass, offering a comparison with the respiration curve approach outlined in ISO 17155:2012.
By following ISO 17155:2012, laboratories and stakeholders can ensure consistent, reliable, and internationally recognized assessment of soil microbial activity, supporting soil health management and environmental protection efforts.