Characterization and evaluation of the potential irrigable lands between elkawa town and essireha village along the eastern bank of the White Nile, Sudan

This study (about 65000 ha) was on the characterization and land evaluation of irrigable soils between Elkawa town and Essireha village on the eastern bank of the White Nile. Soil Characterization and land evaluation processes were used as per the FAO system of land evaluation which was adapted to suit our local conditions. Both field and laboratory methods were considered for mapping different soils in the field. The GPS Garmin 12 Model was utilized and field observations were located using Adindan Sudan, UTM system. Ten soil profiles and more than 5000 soil samples were analyzed to characterize the soil series and to study the salinity and the sodicity of the area. From the study, six different soil series (four were Vertisols and two Aridisols) were identified based on their position on the landscape, soil texture, soil reaction and vertisolic characteristics. The current land suitability for irrigated agriculture of the identified land units, ranged from moderately suitable (56.1% of the total area) to marginally suitable lands (43.99%). The dominant limitations that hinder the agricultural production in these lands include the high smectitic content of clays (vertisolic limitations), soil salinity, and soil sodicity and wetness conditions. These were associated with the relatively lowlying areas on which two main soil mapping units were identified. The study also revealed that the soluble salts were mainly concentrated on the top 30 cm of the soil and constituted more than 50% of the total area. The salinity classes in the area were mainly slight to moderate, whereas the strongly saline classes were of a limited extent (1%) and mostly associated with lowlying areas. Soil sodicity of the top soil (0-30cm) occupies about 30.4% of the total area and increased with depth to account to 32.4% of it, while the strongly sodic soils comprised about 5% of the total area