Characteristics of some vertisols in Egypt [electronic resource].

Includes references.

Six soil profiles representative of some Vertisols in Egypt have been investigated to reveal their main characteristics of these soils. Five soil profiles (nos. 1-5) were taken from the cultivated soils of the Nile Valley and Delta and one profile was taken from the non cultivated ones in Kharga Depression. The results show that all the profiles have cracks when dry. The depth and width of the cracks varied from one location to another depending on the clay content, moisture condition and salinity. Gilgai microrelief was difficult to be recognized in the cultivated soils under study due to the leveling processes. In non irrigated soils, the gilgai is very common. Slickensides were present in the irrigated Vertisols of the Nile Valley and Delta at the depth between 30 and 80 cm however, in the non irrigated Vertisols of Kharga Depression, the slickensides are present throughout the whole profile to the depth of 110 cm. Soil structure was mainly granular in the surface layers and parallelepiped in the subsurface ones in the soils of the Nile deposits; the Vertisols of Kharga Depression have mainly parallelepiped structure. The data of mechanical analysis indicate that the studied soils have more than 30% clay. Some chemical properties were discussed. The cultivated clay soils of well drained conditions in the Nile Delta are classified as Torrerts. They belong to Haplotorrerts at the great group level. The non cultivated Vertisols are classified as Torrerts at the suborder level. They belong to the Calcitorrerts at the great group level.

Summary in Arabic.

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