BASES OF PRODUCTION, EXAMINATION AND USE OF GROWTH MEDIA
The conception ‘growth media’ includes as well the long time known horticultural soils obtained through composting and decomposition of organic matter (leaf soil, pine soil, bog soil, moor soil, compost and so on), as the peaty substrates which became more and more important since World War II, for instance the in Germany used standard soil (Einheitserde) and the horticultural peat substrate (Torfkultursubstrat), and last but not least the artificial substrates, which form the special topic of our symposium containing foam plastics, perlite, vermiculite, pumice, brick fragments, lava-ash, peat, coal, sand etc., and mixtures with them.
Common to all these materials is the property, that they make plant-growing independent of local soil fertility and give the chance to produce more and to have better quality. Comparing the use of these substrates in the different branches of horticulture, we find a close correlation between the utilization of substrates and the intensity of crop production. So there is no substrate used in extensive agriculture, but increasingly in fruit growing, in vegetable growing, in tree nursery, in cut flower growing and in pot plant growing. In the same succession more money will