Silver-white, very brittle heavy metal or element (Mn). In nature, it often occurs in combination with iron in many minerals. These are e.g. manganite, manganese dioxide, manganite and iron ore (picture left). For the vine, manganese is important as a nutrient in small quantities. It is involved in carbohydrate and protein metabolism, as well as in the formation of cell membranes and supports photosynthesis. There are close interrelationships between manganese and iron in the metabolism of plants. Alkaline soils with high pH values are most likely to be deficient in plant-available manganese. Similarly, high levels of calcium also inhibit uptake and transport in the plant. The picture on the left (cube) shows a 99.9% pure manganese, the picture on the right rhodochrosite (rose spar) a frequently occurring manganese carbonate.
Serious sources on the internet are rare - and Wine lexicon from wein.plus is one such source. When researching for my articles, I regularly consult the wein.plus encyclopaedia. There I get reliable and detailed information.Thomas Götz
Weinberater, Weinblogger und Journalist; Schwendi