Understanding Solonetz Soil

Solonetz soil is a type of soil that is characterized by a high concentration of sodium ions, particularly in the B horizon (subsoil). This high sodium content leads to specific physical and chemical properties that distinguish it from other soil types.

Alternative Terminology: Black Alkali Soil

Solonetz soil is commonly known by another name: Black alkali soil.

This alternative name comes from certain characteristics associated with high sodium levels:

• High sodium causes clay particles and organic matter to disperse.
• Dispersed organic matter can move down the soil profile and accumulate in the B horizon.
• The presence of dispersed organic matter in the B horizon often results in a dark or "black" appearance when the soil is wet, especially on the surface of structural units.
• The term "alkali" refers to the high pH that often develops in these soils due to the accumulation of sodium carbonate, which is a strong alkali.

In contrast, "white alkali soil" typically refers to saline soils where the dominant salts are neutral salts like sodium chloride or sodium sulfate, which tend to form a white crust on the surface when the soil dries.

Highly saline soil refers to soils with a high total concentration of soluble salts, which might or might not have high sodium relative to other cations (as is the case with sodic or alkali soils like Solonetz).

Non-saline soil has low levels of soluble salts.

Therefore, based on the soil characteristics, Solonetz soil aligns with the description of Black alkali soil due to its high sodium content leading to alkalinity and the potential for a dark appearance from dispersed organic matter.

Summary of Soil Types

Here is a brief comparison of related soil terms:

Thus, Solonetz soil is correctly termed as Black alkali soil.