Soils of different riverine deposits in arid land
Clay type and content in soil are not only factors but also key determinants of soil quality and sustainability, the understanding of their nature, and potential productivity is an essential need for the sustainable utilization of agroecosystems. Despite their agricultural and economical importance in Sudan, clays and qoz landscape until recently their nature and mineralogical components have been largely ignored. This study was conducted in the Western sides of the White Nile and Blue Nile rivers in three different physiographic positions of each site. The aim of the first part of this study was to
characterize and analyse the morphological, physical and chemical properties of the soil collected from different physiographic positions at various soil genetic horizons in order to better understand the drivers influencing soil diversity within the soil profile and to determine the soil properties affected with the physiographic positions, especially in the context of soil
texture. The second aim of the study was to characterize the clay mineralogy and heavy minerals in these soils as a function of soil depth and properties (collected from fixed depths) in order to elucidate the deposition and accumulation processes, as well as the soil mineralogical characteristics in relation to their paleo depositional environment and origin of source rocks. A third objective of this study was to assess the effect of the different physiographic positions on the morphological, physical, chemical and mineralogical properties. Soil morphological characteristics, profiles description, particle size distribution, chemical analysis, heavy minerals separation and X-ray diffraction analyses have been used. The origin
of source rocks, weathering process, transportation and paleo depositional environment significantly affect soils. The first terraces and colluviums soil in the White Nile and Blue Nile are significantly different in their morphology, properties and mineralogical characteristics, while soils from the second terraces of both rivers slightly differ. The variations in soil properties in the White Nile and Blue Nile area significantly depend on the
physiographic position, clay content and mineralogical components.