Assessing the Impact of Gully Erosion on Soil Fertility in Ankpa Local Government Area of Kogi State

Abstract

This study explores the impact of gully erosion on soil fertility in Ankpa Local Government Area, Kogi State, Nigeria. A systematic sampling procedure was employed, involving composite soil samples collected at varying depths (0 – 15 cm, 15 – 30 cm, and 30 – 45 cm). Physical and chemical analyses were conducted on these samples, and statistical analysis, utilizing the coefficient of variation (CV), was applied to the data. Results revealed that sand fractions dominated the surface horizons in all pedons studied, ranging from 74.10% to 80.60%. Silt content showed irregular accumulation down the profile depth, ranging from 5.00% to 6.00%. Clay content, ranging from 14.40% to 20.40%, decreased down the profile depth, indicating potential illuviation and pedoturbation processes. Bulk density values within the rooting zone were optimal for plant production. Particle size distribution suggested that the studied soils fell within the sandy loam textural class, except for one profile identified as sandy clay loam. Soil pH (H2O) and pH (KCl) indicated highly acidic conditions. Organic carbon content was critically low, and total nitrogen levels were also critically low according to fertility ratings. Available phosphorus ranged from low to moderate levels, while calcium dominated the exchange complexes. Magnesium levels were high, potentially contributing to unstable soil structural arrangements. Potassium content was categorized as moderate, while sodium content was rated moderate with implications for soil fertility. Cation Exchange Capacity (CEC) was moderate, reflecting the general low organic matter content in the soil series. Base saturation indicated high values, suggesting minimal leaching of plant nutrients. In conclusion, the study identifies the complex interplay of soil properties affected by gully erosion, emphasizing the need for targeted interventions to improve soil fertility.