Mineralogical characterization of soils in the Savanna ecosystem

Abstract

The mineralogical composition of soil plays a crucial role in determining soil fertility and agricultural potential. Given the highly weathered and nutrient-poor nature of Savanna soils, understanding their mineralogical composition is essential for developing sustainable land management strategies that enhance nutrient availability, support crop production, and improve long-term agricultural productivity in the region. This study investigates the mineralogical composition of soils in the Savanna region across three locations: Ikole (IK), Oye (OY), and Erinmope (ER). These locations have distinct climatic conditions that influence mineral weathering and soil properties. Fieldwork involved sampling from profile pits across these sites, followed by laboratory analyses, including particle size distribution, pH, organic carbon, and exchangeable cations. X-ray diffraction (XRD) analysis was used to determine the mineralogical composition. The primary minerals identified in all pedons included quartz, along with traces of orthoclase (K-feldspar), albite (Na-feldspar), and muscovite (mica), which varied across different soil profiles and depths. Kaolinite, a secondary mineral, was also present as a product of the weathering of feldspars and aluminosilicate minerals. The findings revealed that kaolinite dominates the soils in Ikole, indicating intense weathering and leaching typical of tropical climates, which contribute to moderate soil fertility. In contrast, Oye soils exhibited a higher presence of quartz, reflecting significant physical weathering. In Erinmope, quartz dominated the surface horizons, while kaolinite increased with depth, alongside iron oxides such as hematite and goethite, suggesting prolonged weathering processes. These variations in mineral composition significantly influence soil structure, nutrient-holding capacity, and response to agricultural practices. This study contributes to the development of sustainable agricultural practices, soil conservation strategies, and ecosystem sustainability.