are moderately leached soils that have relatively high native
fertility. These soils have mainly formed under forest and have a subsurface
horizon in which clays have accumulated. Alfisols are primarily found
in temperate humid and subhumid regions of the world.
Alfisols occupy ~10.1% of the global ice-free land area. In the
US, they account for ~13.9% of the land area. Alfisols support about
17% of the world's population.
The combination of generally favorable climate and high native fertility
allows Alfisols to be very productive soils for both agricultural
and silvicultural use.
Alfisols are divided into
5 suborders: Aqualfs, Cryalfs, Udalfs,
Ustalfs, and Xeralfs. Click
here for more information about these suborders. Click
here to view a map of their distribution in the US.