ISO 18311:2016

Overview

ISO 18311:2016 - "Soil quality - Method for testing effects of soil contaminants on the feeding activity of soil dwelling organisms - Bait‑lamina test" - specifies a standardized, field‑based technique to assess how anthropogenic impacts (for example chemical contaminants) affect the feeding activity of soil organisms. The method uses small perforated plastic strips (bait‑lamina) filled with organic bait; loss of bait during a defined exposure time is used as an indicator of soil faunal feeding activity and thus of soil biological functioning.

Key topics and technical requirements

• Principle: Insert bait‑filled strips into the soil; evaluate the number and vertical distribution of empty apertures after exposure to quantify feeding activity.
• Bait composition: Typical bait mixture example - 70% cellulose powder, 25% finely ground wheat bran, 5% activated carbon.
• Bait‑lamina strip geometry: PVC strips 120 × 6 × 1 mm with a pointed tip; lower 85 mm contains 16 bi‑conical apertures (1.5 mm diameter) spaced at 5 mm; apertures numbered from 1 (0.5 cm) to 16 (8.0 cm).
• Exposure time (examples): Temperate zones 10–20 days; tropical areas 4–8 days.
• Environmental constraints: Best applied where soil organisms are active (recommended soil temperature 5–15 °C, soil moisture sufficient - e.g., >20%). Not applicable to semi‑terrestrial or very shallow soils; challenging in extreme climates or high mountains.
• Reagents & equipment: Bait‑lamina strips (commercially available), a sharp tool for insertion, 10% HCl for cleaning strips at contaminated sites.
• Data & supporting measurements: The standard advises measuring site parameters in the uppermost 8 cm (pH, particle size, dry bulk density, organic carbon, nitrogen, soil moisture and water‑holding capacity) using referenced ISO methods (e.g., ISO 10390, ISO 11277, ISO 10694).
• Results & quality assurance: Results expressed as number/percentage of empty apertures and their depth distribution; validity criteria, statistical analysis and required test reporting elements are specified.

Practical applications and users

• Applications: Field ecotoxicology, site‑specific risk assessment, biological soil quality monitoring, evaluation of land‑use impacts, and comparison of contaminated vs reference areas. The method is suited for rapid, low‑cost, in‑situ functional assessment of soil fauna activity and decomposition processes.
• Who uses it: Environmental consultants, soil ecologists, government monitoring agencies, contaminated‑land assessors, research scientists, and remediation practitioners who require standardized, comparable field measures of soil biological function.

Related standards

• ISO 23611‑6: Guidance for design of sampling programmes with soil invertebrates (sampling design).
• ISO 11074: Soil quality - Vocabulary.
• Additional referenced ISO methods are cited for measuring supporting soil parameters (pH, particle size, organic carbon, moisture).

ISO 18311:2016 (bait‑lamina test) is a practical, standardized tool for integrating biological function into soil quality assessment and ecological risk evaluation. Keywords: ISO 18311:2016, bait‑lamina test, soil quality, soil contaminants, feeding activity, soil organisms, field method, soil monitoring.