Characterization and Classification of Soils in the Blue Nile Basin Forests: Case Studies of Lembwa and El-Gazair Forest Reserves, Sennar State, Sudan

Abstract

This study was conducted in Lembwa and El-Gazair reserved forests, located on the Blue Nile basin in Sennar State. The study aimed to characterize and classify the soils of the four basen zones, locally named Gerf, Maya, Karab and Dahara, and determine their fertility. Three profiles were dug in each of Gerif, Maya and Karab and one profile in Dahara. The soil profile in Gerif in the two forests was deep, with high silt content and silty clay texture, while in Maya and Dahara it had clay content and clayey soil texture. Karab zone in El-Gazair forest was characterized by high sand content and sandy loam texture. The pH was neutral to slightly alkaline and the soil was free from salinity in all zones, except Dahara. The cation exchange capacity (CEC) was medium in all zones, except in Karab where it was low. Regarding fertility, Gerif zone wase rich and fertile followed by Maya zones. Dahara zone contained small amounts of other nutrients in the two forests. The World Reference Base (WRB) 2006 and USDA 2010 systems were used for classification of the zones. Gerif and Maya zones in both forests and Karab in Lembwa forest were classified as Haplic Fluvisols clayic (WRB) and Entisols Typic Torrifluvents, Entisols Vertic Torrifluvents (U.S Taxonomy), respectively. Karab zone in El-Gazair forest was classified as Haplic Regosols Calcaric and Inceptisols Typic Torrifluvents. Dahara zones were classified as Haplic Vertisols Calcaric and Vertisols Typic Haplotorrets.