ABSTRACT
This research was carried out at Green Hills Farm located at Ologbo, Ikpoba okha local government area , Edo State, Nigeria to determine the effect of inorganic fertilizer (NPK) on selected physical and chemical properties of the soil in an Ultisol. Control had no fertilizer applied and was not planted on, Treatment 1 had one dose of NPK 12:1:17 fertilizer applied at 4bags/hectare, Treatment 2 had double doses of NPK 12:12:17 fertilizer applied at 3 weeks interval at the rate of 4bags/hectare.
The results of this experiment showed that at (p<0.05) level of probability, there were no significant differences among the mean value of the treatments for bulk density(1.49-1.50kgm -3), saturated hydraulic conductivity(26.64-27.43), water holding capacity(0.21-0.24), total porosity(43.35-43.45%), aggregate stability(0.63-0.65m.m), permeability(rapid).
Chemical properties of the soil were also influenced by the application of inorganic fertilizer, indicating that at (p<0.05) level of probability, there were significant difference among the mean value of the treatments for organic carbon(3.5-8.5g/kg), organic matter(6.17-14.43g/g), total nitrogen(0.18-0.42g/kg) while there were no significant differences among the mean value of the treatments for pH (4.5-4.8), available phosphorus(72-144mg/kg), cation (CEC) (0.71-0.77), exchangeable acidity (0.20-0.24meq/100g), ECEC (0.90-1.30meq/100g), base saturation (74.42-80.31meq/100g) at (p<0.05) level of probability.
