As the word akali correspond to sodic, the notion alkali soil is, similar to the notion sodic soil, is not explicit.Alkali, or alkaline, soils are clay soils with a comparatively high exchangeable sodium percentage, a relative high pH (> 9), a poor soil arrangement and a little infiltration capacity. Frequently they have a hard calcareous layer at 0.5 to 1 m. depth in India this coating is called 'kankar'. Alkali soils owe their unfavorable physico-chemical properties mostly to the dominating presence of sodium carbonate. Akali soils are normally not saline, i.e. the some amount of soluble salts, particularly sodium chloride, is not extreme .
Alkali soils are also called sodic soils, since sodium is an alkali metal. This, however, does not distinguish alkali soils adequately from saline soils.
