Assessment of Heavy Metal Contents in Three Different Land used Soils in Ohaji/Egbema Imo State, Nigeria

Abstract

This assessment of some heavy metal contents in different land used soils in Ohaji/Egbema, Imo State was conducted between June, 2019 and May, 2020. Three land used soils namely; the grass land, continuously cropped and forest land were studied. Soil profile representations were established in each of the physiographic units and soil samples collected from the pedogenetic horizons for the analysis of some heavy metals like Lead (Pb), Copper (Cu), Manganese (Mn), Zinc (Zn), and Iron (Fe). The heavy metals observed in this study were Cu, Mn, Zn and Fe while Pb was not detected in this study. The results of this study showed that the grass land, continuously cropped and forest land had no Pb detected. The heavy metal contents(Cu, Mn, Zn and Fe) detected decreases with depth from 0.15cm depth to 60-90 cm depth in grass land and continuously cropped and forested land respectively. The occurrence of Fe was high in forested land which ranges from 7.8-6.3Mg/Kg with mean value of 7.0Mg/Kg than continuous cropped land and grass land with lower values. The forest land had high sodium content with mean value of 0.74 and high electrical conductivity with a mean 4.91 dsm-1. The results showed low to moderate heavy metal load in forest land and high to moderate load of heavy metals in the grass land and continuously cropped land.