ABSTRACT:

This paper investigated heavy metals concentration in soils under selected Oil Palm (Elaeis guineensis) Plantations in Edo State, Nigeria. Eighteen soil samples (0-15cm and 15-30cm depths) were collected from three oil palm plantations. The selected heavy metals were analyzed using the digestion method and data analyzed using permissible limits and student t-test. Vanadium (V), nickel (Ni), cadmium (Cd), iron (Fe) and manganese (Mn) were deficient while Copper (Cu) and zinc (Zn) were sufficient for NIFOR and OPC farms but were deficient in Hartman farms. Student t-test revealed that there were significant (P<0.05) differences between control and treatment sites (NIFOR versus OPC farms and Hartman Farms respectively for Mn, Fe and Cd concentrations. However, V, Ni, Zn and Cu contents were significantly different between NIFOR and Hartman farms (P-value was lesser than 0.05). In general, all heavy metals were not at toxic levels regardless of site. This elucidates that inorganic fertilizers were not extremely applied on their soils. The study therefore recommended that inorganic fertilizers with trace elements be applied to increase any deficiencies observed on a case-by-case basis, using tissue analytical diagnostic methods for Oil palms.