i. Oxisols get their name from the oxic horizon, a diagnostic accumulation of iron and aluminum oxides.
ii. They form in climates that are usually frostless throughout the year and rainy for at least part of the year.
iii. The resistant oxides aje left in the upper layers of the soil after heat and moisture have destroyed or removed most of the salt, complex clay, organic material, and plant nutrients.
iv. Oxisols in seasonally dry climates are prone to harden into rocklike masses when exposed to the sun or subjected to alternate wetting and drying.
v. An oxisol in a continuously wet climate is usually soft but leached of most of its plant nutrients. The alternate hazards of leaching and hardening make oxisols very difficult to farm.