Silver-white shiny, medium-soft metal (Fe = ferrum), which is the fourth most common element of the earth's crust with a share of just under 5%. In the soil it is seldom dignified, but mostly in the bound form of sulfidic and oxidic iron minerals. These include magnetic iron stone, red iron stone, brown iron stone and spatula stone. Iron is present in large quantities in many soils. The frequently occurring iron oxides give floors the characteristic reddish color. Such soil types are used in viticulture as Rotliegendes (Rotliegend) or Terra Rossa designated. Among other things, the Australian wine region draws Coonawarra such a soil type. Even the single layer Scharlachberg in Rheinhessen got its name from the color.
All vertebrate beings need iron as a component of hemoglobin (red blood cell dye). Iron favors plant growth photosynthesis the formation of chlorophyll without it being incorporated, and of protein and nucleic acid. Iron is an essential nutrient for the healthy Rebstock growth, Excessive proportions of calcium. copper and phosphorus in the soil, as well as cool soil temperatures in connection with moisture have a negative effect on the iron metabolism. In this case, the iron cannot be absorbed by the roots. This leads to acute chlorophyll deficiency and yellowish discoloration of the leaves respectively. chlorosis (Iron deficiency or bad weather chlorosis). In extreme cases, it comes to Verrieseln of banknotes and even death of the vine. A fertilization must be in the form of organic compounds (gel). Also through contact with corridible devices in the basement at the winemaking too much iron can get into the wine, which is caused by cloudiness and metallic - bitter Taste and the wine error Black break manifests. The Perceptual threshold is around 10 mg / l.