5.5 - Aridisols

Dry soils with CaCO₃ (lime) accumulations, common in desert regions. The extent of Aridisol occurrence throughout the world is widespread, second in total ice-free land area only to the Entisols. Extensive areas of Aridisols occur in the major deserts of the world, as well as in Southwestern North America , Australia , and many Middle Eastern locations. Aridisols are commonly light in color, and low in organic matter content. Lime and salt accumulations are common in the subsurface horizons. (For details on horizon development see Lesson 3.3 and Lesson 4.2.) Some Aridisols have an argillic (clay accumulation) B horizon, likely formed during a period with a wetter climate.  Water deficiency is the dominant characteristic of Aridisols with adequate moisture for plant growth present for no more than 90 days at a time. Crops cannot be grown in these soils without irrigation. Productivity of Aridisols is generally low, and there is potential for land degradation due to overgrazing by livestock. If irrigation water is available, Aridisols can be made productive through use of fertilizers and proper management.

Key Characteristics:  Aridisols

• Soils of arid, desert climates
• Varied parent materials
• Often have accumulations of lime (CaCO₃), sodium, or salts.
• Can be made productive if irrigation water is available.
• Found extensively in tropical latitudes, rainshadows, and arid climates.
• Extent of world ice-free land area: 12%