Overview
EN ISO 16198:2015 (ISO 16198:2015) - titled Soil quality - Plant-based test to assess the environmental bioavailability of trace elements to plants - specifies a standardized plant-based biotest for estimating the environmental bioavailability of trace elements to plants. The standard describes a laboratory procedure in which roots are grown in contact with soil (without penetrating it) so that uptake into shoots and roots - or more integratively, the net uptake flux - can be quantified. Prepared by ISO/TC 190 and adopted by CEN as EN ISO 16198:2015, it supports consistent, comparable assessments of trace element bioavailability across soils.
Key topics and requirements
The standard covers technical and procedural elements needed to run the biotest, including:
- Principle of the plant-based biotest and rationale for root–soil contact design.
- Selection of plant species and seed handling (annexes list adapted species and seed densities).
- Biotest apparatus and technical drawings for test components.
- Composition of nutrient solutions, growth-chamber climatic conditions, and pre-culture hydroponic steps.
- Soil sample pre-treatment (size reduction, sample size) and required soil analyses.
- Experimental procedure: germination, incubation with soil or soil material, plant growth period, harvests, grinding, digestion and analytical determination of trace elements.
- Validity criteria and statistical analysis requirements for biomasses and bioavailability end points.
- Reporting requirements and annexed guidance on digestion, expected biomass ranges and ring-test procedures.
Applications and users
EN ISO 16198:2015 is useful for:
- Environmental laboratories performing soil quality and contamination assessments.
- Soil scientists and ecotoxicologists quantifying bioavailability of metals and trace elements to plants.
- Regulatory bodies and consultants assessing contaminated land, risk to vegetation, and remediation effectiveness.
- Agronomists and remediation specialists comparing bioavailability across different soils or monitoring post-remediation changes.
The method provides a biologically relevant complement to chemical extraction methods by accounting for rhizosphere processes and plant uptake behavior.
Related standards
Keywords: EN ISO 16198:2015, ISO 16198:2015, soil quality, plant-based biotest, bioavailability, trace elements, environmental bioavailability, soil assessment.
