Impact of Mining on Heavy Metal Concentration and Soil Chemical Properties in Soils Sorrounding a Mining Site in Ebonyi State⸴ Nigeria

Field and laboratory studies were done to evaluate the effect of land use types on selected physical and chemical properties of soils in Umudike, southeastern Nigeria. Five land use types were studied: rubber plantation, oil palm plantation, forest land, cassava farm land and pasture land. Under each land use system, 3 sampling points were located. Around each of the 3 sampling points, soil samples were collected at two depths (0 – 20 and 20 – 40 cm) using soil auger and core samplers. Samples collected with the auger were air-dried and sieved through 2mm sieve for determination of some physical and chemical properties. Results from the study showed that the textural class of the soils was sandy loam except in rubber plantation which was clay loam. Forest land recorded the lowest bulk density values (1.32 Mg/m3 and 1.49 Mg/m3 ) at 0-20 and 20-40 cm depths respectively. Forest land had the highest total porosity at the two depths and highest hydraulic conductivity, the bulk density of the soils increased with depth, whereas total porosity and the saturated hydraulic conductivity decreased with depth. Forest land was also observed to have higher exchangeable bases, organic matter, total nitrogen and available phosphorus. Cassava farm land was low in organic matter, total nitrogen, effective cation exchange capacity and exchangeable bases. Conclusively, it was observed that the use to which the land was put significantly affected the physical and chemical properties of the soil at different depths, land use had significant impact on soil physical and chemical properties.