Characterization of Some Selected "Gardud" Soils in Great Kordofan, Sudan

Page(s): 8 (1), 26-45,22 RefFour sites, representing a wide range of rainfall and ecological zones, were selected to study some physical, chemical and mineralogical characteristics of "Gardud" soils (hard non-cracking soils). Annual rainfall (mm) is 600-800 at Baradab, 400-600 at Umgamalla, 225-400 at El-Nihud and 100-225 at Sodari. "Gardud" soils undergo severe wind erosion in the north and water erosion in the south. Two pits were excavated and described in each of the four concave and convex sites. The soils exhibited differences in a number of chemical and physical properties, namely pH, electrical conductivity of the saturation extract, carbon nitrogen ratio (C/N), phosphorus, sodium adsorption ratio, soluble cations and anions, bulk density, texture and infiltration rate. The soil profiles of Baradab and Nihud were uniform in texture, and were clay and sandy clay loam, respectively. Umgamalla and Sodari surface soil was sandy loam, in texture, while their sub-surface soil was sandy clay loam and sandy loam, respectively. The dominant clay minerals in all sites were kaolinite, montmorillonite and illite. The soil of the concave sites were classified as kanhaplic Rhodustalfs (Baradab), rhodic Kandiustalfs (Nihud), ustic Haplustalfs (Umgamalla) and typic Camborthids (Sodari concave and convex sites). The convex sites classification for Baradab, Nihud and Umgamalla was Paleustalfs indicating an old or excessive development.Khartoum University Pres