Alfisols are a soil order in USDA soil taxonomy. Alfisols form in semiarid to humid areas, typically under a hardwood forest cover. They've a clay-enriched subsoil and relatively high native fertility. "Alf" refers to Aluminium (Al) and Iron (Fe). Because of their productivity and abundance, the Alfisols represent one of the more important soil orders for food and fiber production. They're widely used both in agriculture and forestry and are generally easier to keep fertile than other humid-clim… (More on Alfisols)