By oxidation luminous element (P), whose name is derived from Phosphoros (Greek light bearer). In nature, it occurs mostly bound, mostly in the form of phosphates. Typical minerals are apatite, phosphorite, turquoise and wavellite. It is also contained in guano (bird excrement) and is used as fertilizer in this form. Pure, white phosphorus creates caustic wounds and is very toxic; as little as 50 mg is fatal to humans. Phosphorus compounds are essential for all living things and in central areas like that DNA as part of the nucleic acids and cellular energy supply. In the metabolism of the vine, phosphorus fulfills a variety of functions. It plays a central role in the energy balance in which photosynthesis as well as a component of proteins and enzymes. The proportion in the vine seeds is particularly high. To put it very simply, it can be expressed that phosphorus, especially Blossoms- and fruiting serves.
In the case of strongly acidic and also alkaline soils, phosphorus can be fixed (bound) and is therefore no longer available to plants. A phosphorus deficiency manifests itself in the vine through blue-red-green to violet discoloration of the leaves and weak bloom and fruit formation. Most of the soils used for viticulture have been supplied with large quantities of phosphorus fertilizers since the end of the 19th century. Inadequate supply of the vine is therefore not basically due to a lack in the ground, but often due to low availability. The phosphates tend to form poorly soluble and therefore difficult to obtain compounds. Only a small proportion of the phosphorus in the soil is in water-soluble, absorbable form. A fertilization using phosphates must therefore depend exactly on the soil PH value be coordinated. Phosphates are also called insecticides used for pest control.