Physiochemical Characteristics and Lead Concentrations in the Inland Valleys of Ishiagu, Southeastern Nigeria

The research work was conducted at two locations in 2012, 100 meters away from mining pits to determine the effects of lead, slope position and depth on the variation of soil chemical properties. Random sampling method was used to collect soil samples from the study area. Samples were collected from upper-slope, middle-slope and bottom slope positions at depths 0 – 15 cm and 15 – 30 cm. Results indicated that the soils are generally clayey to clay loam and poorly drained in all the depths. The upper slope position in the two locations gave the highest contents of sand, while the highest percent of clay and silt were obtained from the bottom slope position in both Amaeze and Ihietutu locations. Results showed a significant difference among the chemical properties of upper, middle and bottom slope soils. Soil pH of the upper-slope (6.2) was the highest followed by middle (5.9) and bottom slopes (5.8). Soil pH in 15 – 30 cm depth gave the highest significant (P = 0.05) value (6.2) than the 0 – 15 cm depth (5.8).Exchangeable calcium and magnesium were highest at bottom slope followed by middle and upper-slopes. The results indicated that soil pH, CEC and available phosphorous increased as lead concentrations increases, total nitrogen decreases with increase in Pb, especially in Amaeze location. The soil in all the locations sampled is marginally fertile, as organic carbon and nitrogen of the fertility parameters are within the low- medium range when compared with the standard values. Exchangeable Mg, Ca and CEC are within medium and high range compared with the standard values.