The effect of water quality on soil hydraulic conductivity in salt-affected soils of Sudan

Abstract EN

The effect of the concentration c and sodium adsorption ratio (SAR) of mixed-salt solutions composed of calcium and sodium chloride and hydraulic conductivity of two montmorillonitic soils from Khartoum state were studied.

Dispersion processes which may influence the movement of these mixed-salt solutions through the soils were also investigated.

For the two soils the result showed that K decreases as SAR increases and c decreases.

The two mortmorillonitic soils exhibited qualitatively similar dispersion characteristic.

The data showed that the dispersion index (DI) increases as SAR increases and c decreases.

Rapid increase in dispersion was found when soil ESP increased from zero to 49 in solutions of c<800 meq/1.

The Drushab (Aridisols) soil was found to be more dispersible than the Soba soil.

(Uertisols) The decrease in hydraulic conductivity with increase in SAR and decrease in c ١١١^}' be attributed to dispersion and migrationof colloidal particles.

The processes cause the reduction and partial or total plugging of macro and micropores and hence reduce hydraulic conductivity.

For reclamation of this type of soils, the research needs more investigation.