Soils contaminated with zinc from mining, refining, or fertilizing with zinc-bearing sludge can include many grams of zinc per kilogram of dry soil. Levels of zinc in excessive of 500 ppm in soil interfere with the flexibility of vegetation to absorb other crucial metals, like iron and manganese. Feature papers https://messiahzaptl.theideasblog.com/27175044/the-2-minute-rule-for-zinc-sulfide