Translations:Benutzer:Arian/Klett-Mini-Test/831/en

The seedling grows from earthly substances and from forces of the cosmos that the mother plant deposited in the grain's floury body for the seed. This source is exhausted with the completion of the seedling plant. What source must now be freshly opened up? What nutrient tissue takes the place of the one consumed? It must be, like that one, a product of past life processes. It is the humus, which arises through the transformation of everything that plants leave behind as residues, apart from what has gone into seed formation. But how can the fully developed seedling plant open up this new source of nourishment — whether nutritive or fully ripened stable humus? Here the formation of the fibrous or crown roots comes first into consideration. They grow in spring from the lowest one or two nodes and multiply with increasing tillering. Compared to the primary seminal roots, the fibrous roots are secondary formations. They grow close to the surface and form a wreath of roots that permeates the topsoil in the finest branching. The actual unlocking of the humus, however, comes about through the root hairs already mentioned — through their dense covering on seminal and fibrous roots the root surface is enlarged many times over. Through the root hairs the sprouting plant enters into direct connection with the surrounding soil.