University of Idaho College of Agricultural and Life Sciences Plant, Soil & Entomological Sciences Soil & Land Resources
Soil Orders
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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.

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<< back to Soil Orders list Oxisol example #1 >> 


1. Eutrotorrox landscape
2. Typic Eutrotorrox
3. Hapludox landscape
central Puerto Rico
4. Inceptic Hapludox
central Puerto Rico
5. Udox landscape
southwestern Nigeria
6. Humic Rhodic Eutrustox
7. Oxisol
If you have any comments, suggestions, or questions about the 12 Soil Orders web site,
please contact
Dr. Paul McDaniel  at the Soil Science Division,
University of Idaho, Moscow, ID 83844-2339.