Adogo is located in Ajaokuta local Government Area of Kogi State, Nigeria. The study area is a farm land 50 meters from the Okene Ajaokuta road. It lies within longitude 7029’50.3'N and latitude 6 0 29’43.3'E . The control sample was collected from a farmland –one kilometre from the Okene Lokoja road lying within longitude 7 041.821'N and latitude 6 0 20.925'E. The soil samples (0-15 cm dept) were collected from the vicinity of the farms at 50 meters interval using a stainless steel knife. Sampling locations are shown in Figure 1. The collected soil samples were air–dried for seventy-two hours, ground in a mortar and passed through < 2 mm and 0.005 mm sieve and stored in clean acid treated polythene bags.