Silvery white, very brittle heavy metal or element (Mn). In nature, it often occurs with iron in many minerals. These are brownite, brown stone, hausmannite and manganite as well as iron ores. For the Rebstock is manganese as nutrient important in small quantities. It is involved in the carbohydrate and protein metabolism, as well as in the formation of cell membranes and also supports them photosynthesis, Close interrelationships are suspected in the metabolism of plants between manganese and iron. On alkaline Soils with high PH value is most likely to be deficient in plant-available manganese. High levels also inhibit calcium the uptake and transport in the plant.
Chalky, black or humus sandy soils in particular tend to lack manganese, which leads to a reduction in green and yellow leaf pigments. This is expressed by small pale to yellow-green, spot-shaped chlorosis, There is enough manganese, especially in clayey soils. On moist soils or when irrigated for a long time, the levels available are usually higher. Manganese deficiency is therefore more common in dry years than in wet years. Enrichment takes place e.g. B. with the manganese-containing fertilizers cottage lime and Thomas flour. An excess of manganese arises especially on acidic soils with a low pH and has a negative effect on growth and yield.