This part of ISO 11269 describes a method for the determination of the effects of contaminated soils or contaminated samples on the root elongation of terrestrial plants. This method is applicable to soils, soil materials, compost, sludge, waste or chemical testing. It is applicable to the comparison of soils of known and unknown quality and to the measurement of effects of materials (compost, sludge, waste) or chemicals deliberately added to the soil. The method is not intended to be used as a measure of the ability of the soil to support sustained plant growth.