STANDARDISATION OF POTTING SOILS IN THE BENELUX
Potting soils are made from very different organic as well as inorganic materials. In the past, each gardener made hiw own potting soils. Nowadays there are specialized industries, manufacturing potting soils on a large scale. In the interest of the horticulture, the potting soils coming into the market, should meet certain minimum requirements. In the Benelux, therefore, a regulation was drafted, in which a number of minimum requirements for potting soils are given.
van Dijk, Dr. H. and van der Boon, Dr. J. (1971). STANDARDISATION OF POTTING SOILS IN THE BENELUX. Acta Hortic. 18, 110-123