DIN EN 16086-2:2012-01

This European Standard describes a method for the routine determination of the effect of soil improvers and growing media or constituents thereof on the germination and early root development of cress. After cress seeds have been exposed to the test material for a few days under controlled conditions, the germination and growth of young roots are measured and compared with a control sample. The inhibition of germination and growth of young roots may be caused by phytotoxic substances. If the electrical conductivity (EC) in the diluted material is greater than 80 × mS m ^-1 according to EN 13038, the sample shall be mixed with sphagnum peat. In this case, the test does not measure the adverse effect of high EC of materials on germination and root development. In the case of composted materials, these phytotoxic substances can be for instance ammonia, ethylene oxide or short chain fatty acids. The test can also be used as an indication of the instability and "immaturity" of the material. If required (for example, to fulfil certain quality certification requirements or legislation), materials can be tested without checking the EC. For testing of specific effects, the use of additional plant species such as Chinese cabbage or lettuce may be considered. The Committee responsible for this standard is NA 057-03-01 AA "Bodenverbesserungsmittel und Kultursubstrate" ("Soil improvers and growing media") at DIN.