Soil physical control on saturated hydraulic conductivity across contrasting land use types in Imo State, southeastern Nigeria
Abstract
Saturated hydraulic conductivity (Ksat) is an important indicator of soil physical quality, influencing water infiltration, drainage, runoff, groundwater recharge, and nutrient movement. This study evaluated the effects of selected soil physical properties on Ksat under five contrasting land-use systems in Imo State, southeastern Nigeria. Five communities which includes, Agbala, IMSU, Orogwe, Umuelu Ohaji, and Umueze Ohaji were selected, with five land uses (cassava farmland, secondary forest, oil palm plantation, plantain plantation, and block industry) assessed in each community. Composite and undisturbed soil samples were collected at 0–15 and 15–30 cm depths using a Completely Randomized Design with three replications. Particle size distribution, bulk density, total porosity, moisture content, and Ksat were determined using standard laboratory procedures. Data were subjected to analysis of variance, Duncan’s Multiple Range Test, Pearson correlation, and regression analysis. Results showed significant (P < 0.05) variations in soil physical properties and Ksat across land uses and depths. Plantain plantations and secondary forests generally recorded higher moisture content, lower bulk density, greater porosity, and higher Ksat than oil palm plantations and block industry sites. Correlation results indicated weak to moderate relationships between Ksat and individual soil properties, suggesting that hydraulic conductivity was controlled by the combined effects of texture, bulk density, porosity, soil structure, and pore continuity. Vegetation-based land uses promoted better soil structure and water transmission, whereas intensive disturbance increased compaction and reduced hydraulic performance. The findings emphasize the need for sustainable land management practices that maintain vegetation cover, improve organic matter, and minimize soil disturbance to enhance soil hydraulic functioning and agricultural productivity in humid tropical environments.