Environmental pollution concern of cocoa pod husk on soils in cocoa plantations within Ekiti State, Nigeria

The accelerated production of cocoa would result in a pileup of cocoa pod husk (CPH) within the plantation. Decomposition, which would enhance soil fertility and cause environmental pollution. This study evaluated the CPH piles influence on heavy metal status, contamination potentials, and selected soil properties in the cocoa plantations in Ekiti State. Surface (0-15 cm), sub-surface (15-30 cm), and undisturbed soil core samples were taken at 0, 5, 10, 20, and 50 m from the CPH piles in three cocoa plantations of over 20 years, each in Afolu-Ekiti, Ifaki-Ekiti, and Aare-Ekiti, and analyzed. The soils were loamy sand at both depths, with an average bulk density of 1.34 g cm⁻³ on the surface compared to 1.51 g cm⁻³ in the control. The soil chemical properties decreased with distance from the CPH pile (0 m), and values at the surface depth were significantly higher than the control except for the exchangeable bases. Heavy metals content were generally below the maximum permissible limits. The pollution indices imply varying degrees of heavy metals contamination in the cocoa plantations’ soils with an overall moderate contamination. Hence, cocoa pod husk is of potential to improve soil health with minimal environmental concern that could be averted by proper management.