Oxisols
(from French oxide, "oxide") are very highly weathered soils that are found primarily in the
intertropical regions of the world. These soils contain few weatherable
minerals and are often rich in Fe and Al oxide minerals.
Oxisols occupy ~7.5% of the global ice-free land area. In the US,
they only occupy ~0.02% of the land area and are restricted to Hawaii.
Most of these soils are characterized by extremely low native fertility,
resulting from very low nutrient reserves, high phosphorus retention
by oxide minerals, and low cation exchange capacity (CEC). Most
nutrients in Oxisol ecosystems are contained in the standing vegetation
and decomposing plant material. Despite low fertility, Oxisols can
be quite productive with inputs of lime and fertilizers.
Oxisols
are divided into 5 suborders: Aquox, Torrox, Ustox,
Perox, and Udox. Click
here for more information about these suborders. Click
here to view a map of their distribution in the US. |
