Pict. 10.7. kép: Traces of wind erosion Pict. 10.8. Ripplemarks on sand surface
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10.2.2. Secondary salinization
Worldwide, the major factor in the development of saline soils is a lack of precipitation. Most naturally saline soils are found in (semi)arid regions and climates of the globe.
Salinization has a direct effect on both plant growth and the structure of the soil. If the soil is saline a plant will have to expend energy bringing water into it's cells because it is forced to work against osmotic potential. The cation exchange complex (CEC) effects the stability of colloid size particles in the soil. The cation's positive charge will be attracted to the negative charge found on clay particles which make up most of the colloid fraction. Di-valiant cations (Ca, Mg) will allow the colloidal particle to get close enough together that Van Dehr Wahls forces will cause the clays to flocculate, or form stable aggregates. Sodic soils, whose CEC is dominated by mono-valiant sodium cations, will tend to be dispersed and not form stable aggregates. Sodium is mono-valiant and can not pull the colloid particles close enough together for the short range Van Dehr Wahls forces to act. Sodic soils will tend to have a dark, organic appearance due to the dispersion of clay and organic particles while saline soils will tend to have a white crusty surface due to the precipitation of salts. Both of these effects will lead to decreased permeability and hydraulic conductivity (Pict. 10.9.).
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