UNE-EN ISO 23611-4:2022

This document specifies a method for sampling and handling free-living nematodes from terrestrial field soils as a prerequisite for using them as bio-indicators (e.g. to assess the quality of a soil as a habitat for organisms).This document applies to all terrestrial biotopes in which nematodes occur. The sampling design of field studies in general is specified in ISO 18400-101.This document is not applicable to aquatic nematodes because of differences in the sample matrix (e.g. water column). Methods for some other soil organism groups such as earthworms, collembolans enchytraeids or macro-invertebrates are covered in ISO 23611-1, ISO 23611-2, ISO 23611-3 and ISO 23611-5.The nematodes that are characterized by the proposed procedure are all the free-living forms of nematodes found in soil. They include non-plant-feeding nematodes as well as ectoparasitic plant-feeding nematodes and free-living stage of endoparasitic nematodes. The quantification of obligate plant-feeding nematodes in roots requires specific methods.NOTE Basic information on the ecology of nematodes and their use as bio-indicators can be found in the bibliography.This document does not cover the pedological characterization of the site which is highly recommendable when sampling soil invertebrates. ISO 10390, ISO 10694, ISO 11272, ISO 11274, ISO 11277, ISO 11461 and ISO 11465 include suitable procedures for measuring pH, particle size distribution, C/N ratio, organic carbon content and water-holding capacity.