Geochemical Characteristics of Gully Impacted Soils in Southeast Nigeria

Gully erosion remains a critical environmental issue in Southeast Nigeria, threatening land productivity, infrastructure, and ecological balance. This study investigates the geochemical characteristics of gullyimpacted soils in order to identify the underlying factors contributing to erosion susceptibility and to inform effective mitigation strategies. Soil samples were collected from three erosion-prone states—Imo, Abia, and Anambra—representing Southeast Nigeria, while control samples were obtained from the three senatorial districts of Rivers State, a relatively stable area. Heavy metal analysis revealed elevated concentrations of manganese (Mn) and nickel (Ni) in the gully-affected soils, with values reaching 46.05 mg/kg and 15.71 mg/kg, respectively—significantly higher than those found in the control. Conversely, the control soils exhibited higher levels of iron (Fe), lead (Pb), copper (Cu), and zinc (Zn), which are essential for plant growth, microbial activity, and soil structural integrity. Notably, cadmium (Cd) and arsenic (As) were present in all test samples, but undetected in the control, highlighting potential toxicity concerns. Mineralogical analysis using X-ray diffraction identified quartz, albite, orthoclase, and vermiculite as the dominant minerals. Quartz appeared in 10 samples (9.90–96.00%), albite in 9 samples (0.80–13.00%), orthoclase in 6 (0.30–23.00%), and vermiculite in 3 (0.07–5.00%). The control soils were characterized to be predominantly coarse, erosion-resistant minerals—such as quartz and orthoclase—which enhance structural resilience. The findings suggest that both heavy metal contamination and mineral composition significantly influence soil stability and erosion potential. It is recommended that policymakers and land managers adopt soil-specific management strategies, including integrated conservation practices, to mitigate erosion and promote sustainable land use in Southeast Nigeria