ABSTRACT
A study was undertaken to determine the status of some heavy metals in soils in the citrus farm at the University of Benin and to show the relationship between these selected heavy metals and some soil properties. The sample area was 300m by 200m, the area was divided into 3 replicates and soil samples were obtained from each replicate at 0-15cm, 15-30cm and 30-45cm depths. A total of 36 soil samples were obtained, soil samples collected were analysed using standard laboratory technique. The sand and silt fraction of the soil decreased significantly with increased soil depths while the clay fraction significantly increased with an increased soil depth.
The pH was moderately acidic, total nitrogen, available phosphorus and organic matter were generally low. Exchangeable bases were relatively high except for Ca which was below the critical level values and Mg which fell within the critical values. The Cd, Cr, Ni, Pb, V ranged from 29.80-22.00 my/kg, 46.73-34.00 mg/kg, 16.47-11.70 mg/kg, 33.59-27.30 mg/kg, 10.73-7.70 mg/kg respectively. The soil pH positively significantly correlated with Cd, but significantly and negatively correlated with Cr, Ni, Pb and V. The Ec, Sand, Silt, Clay, Ca, K, Mg, Na, Available P, Total N and Organic carbon all significantly and negatively correlated with Cd, Cr, Ni, Pb and V . Generally the soil needs to be beefed up with organic matter in order to improve the fertility of the soil.
