The bluish-silvery, soft alkali metal with around 2.5% is the seven most common element (K) in the crust. The name derives from the Arabic "al kalja" for "potash" (Pottassium), an old name for potassium carbonate obtained from wood ash. The responsive element occurs in nature only in a bound form. It is found in many minerals such as mica, feldspar, kainite, potassium salt, polyhalite and clay. Experiments with increased potassium fertilizers have shown that vines respond to it with increased production malic acid react. Potassium, along with other factors, has an impact on that acid in wine. Potassium-rich wines have a "buffered or incorporated acid", which as balanced is felt. Compared to other minerals, potassium is present in large quantities in must (up to 1.5 g / l) or wine.
Potassium is one of the most important nutrient for the growth and metabolism of the vine by activating numerous enzymes, To put it simply, it can be said that potassium strengthens wood formation and plant statics. The soil permeability is increased in detail photosynthesis, Flower and fruit formation, wood maturation and saccharification promoted, as well as the Protein metabolism and over the stomata of the leaves regulates the water balance. A high content of potassium gives the soil a permeable crumbly with good water discharge,
In heavy soils, potassium can be bound to clay minerals and is therefore no longer available to plants. Too low a potassium level leads to water loss due to evaporation. It is characterized by dark purple, dark brown or blackish leaf discolouration, wavy faults and an oily shine leaves, as well as strikingly small grapes. A fertilization takes the form of potassium salts (potassium chloride) and potassium sulfates. A balanced relationship to calcium and magnesium is of great importance and must therefore be taken into account. The potassium compound pyrosulphite is used in viticulture as an antioxidant.