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Classification, Properties, and Management of Aridisols

Sodic Soils and Saline-Sodic Soils

Aridisols Slide 80

Sorghum growth in the central portion of this field is poor because of sodic soil conditions. Sodic soils lack high concentrations of soluble salts but have problems associated with high sodium concentrations. These soils usually have unsatisfactory physical conditions because of the dispersing influence of sodium.

Aridisols Slide 81

Sodium affected soils can also be reclaimed for agriculture for leaching, with an important additional step. The sodium on the soil exchange complex must be replaced with calcium. One way to accomplish this is by applying gypsum to the soil. The calcium in the gypsum replaces the sodium on the soil exchange complex forming sodium sulfate which can be leached from the rooting zone.

Aridisols Slide 82

Sudan grass is being grown in this field with saline-sodic soil conditions. Saline-sodic soils have chemical properties of both saline and sodic soils. The exchangeable sodium percentage is greater than in saline soils while soluble salt concentrations remain high. Reclamation of saline-sodic soils requires that the amount of exchangeable sodium be decreased and excess salts be removed before satisfactory crop growth is realized.

Aridisols Slide 83

Many Aridisols have high soil pH's. Soil pH directly influences the availability of essential plant nutrients such as phosphorus, zinc and iron. In this illustration, nutrient availability is plotted against pH. The wider the bar, the greater the availability. Notice how the availability of iron decreases as soil pH rises.

Aridisols Slide 84

The yellowish color of the sorghum grown in this field with calcareous soil conditions is the result of iron deficiency. The addition of sulfur and sulfur compounds helps to lower soil pH and increase the availability of micronutrient elements. In some situations, micronutrient deficiencies may also be remedied by foliar fertilization.

Introduction to Aridic Soils | Soil Taxonomy | Introduction to Soil Horizons | The Horizons | Suborders and Great Groups | Argid Suborder | Orthid Suborder | Subgroups | Families | Non-Aridisols | Irrigation | Saline Soils | Sodic and Saline-Sodic Soils | Final Considerations

Last revised: 29 August 2001
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