Vines need water and minerals from the soil. Because of the deep roots, vines are able to supply themselves with water. A few dry weeks at the right time are even beneficial to the quality of the berries. However, in order to be able to provide the vine with nutrients, its fine roots need a loose soil and nitrogen-rich humus.
Above-ground, hardly anyone suspects anything of these exchanges: A vine does not use all the energy it obtains through photosynthesis to grow its leaves, fruits, branches and roots. Instead, a part of it is released to the soil via the roots and supplies up to five trillion microorganisms in its immediate environment. In exchange the vine receives important mineral nutrients, water and protection against parasites of the more than 50.000 different bacteria, fungi, threadworms and unicellular organisms that live in the so-called rhizosphere. However, these useful micro-organisms prefer to work where the soil is well aerated and rich in oxygen. Chemical-synthetic sprays and fertilizers and inappropriate tillage weaken or destroy them.
Therefore the quality of the soil is of great importance in organic vineyards. Legumes such as clover, lupins or vetches are among the best partners of the vines. Their strong, deep roots stabilize and loosen the soil, provide good aeration and direct the activity of microorganisms far into the subsoil. Furthermore legumes and other accompanying plants improve the soils water retention capacity and their lush leaves and stems contribute to the creation of hummus. They provide earthworms, arthropod, bacteria and fungi with a constant supply of organic substance that they decompose, store and distribute in the soil. In organic vineyards, the quality of the soil is therefore of great importance. Leguminous plants such as clover, lupin or vetches are among the best partners of the vines. Its strong, deep roots stabilize and loosen the soil, provide good aeration and direct the activity of the microorganisms far into the subsoil. In addition, legumes and other accompanying plants improve the soil's water retention capacity and its lush leaves and stems contribute to humus growth. They provide earthworms, arthropods, bacteria and fungi with a constant supply of organic matter that they decompose, store and distribute in the soil.
The very special connection of legumes with a so-called root tubercle gives the vines a further growth boost: The bacteria live in thickened root nodules of the legumes and are supplied by the plant with sugar and a constant living environment. The bacteria return the favor by withdraw the nitrogen in the air and making it available to the plants. The incorporation of this greening also benefits the vines, which urgently need nitrogen for their growth.