Jordkvalitet. Pedologi

This document specifies a basic method of determining the particle size distribution applicable to a wide range of mineral soil materials, including the mineral fraction of organic soils. It also offers procedures to deal with the less common soils mentioned in the introduction. This document has been developed largely for use in the field of environmental science, and its use in geotechnical investigations is something for which professional advice might be required.

A major objective of this document is the determination of enough size fractions to enable the construction of a reliable particle-size-distribution curve.

This document does not apply to the determination of the particle size distribution of the organic components of soil, i.e. the more or less fragile, partially decomposed, remains of plants and animals. It is also realized that the chemical pre-treatments and mechanical handling stages in this document could cause disintegration of weakly cohesive particles that, from field inspection, might be regarded as primary particles, even though such primary particles could be better described as aggregates. If such disintegration is undesirable, then this document is not used for the determination of the particle size distribution of such weakly cohesive materials.

This document specifies a method for sampling and handling earthworms from field soils as a prerequisite for using these animals as bioindicators (e.g. to assess the quality of a soil as a habitat for organisms). This document applies to all terrestrial biotopes in which earthworms occur. The sampling design of field studies in general is given in ISO 18400‑101 and guidance on the determination of effects of pollutants on earthworms in field situations is given in ISO 11268‑3. These aspects can vary according to the national requirements or the climatic/regional conditions of the site to be sampled (see also Annex C). This document is not applicable for semi-terrestrial soils and it can be difficult to use under extreme climatic or geographical conditions (e.g. in high mountains). Methods for some other soil organism groups, such as collembolans, are covered in other parts of ISO 23611.