Changes in the Physical and Chemical Properties of an Ultisol in Response to Short Term Fertilizer Management

The study investigated the short term effects of organomineral and inorganic fertilizers on the physicochemical properties of an Ultisol. The experimental site is a maize plantation of the Teaching and Research Farm, Obafemi Awolowo University, Ile – Ife, Nigeria that received mineral fertilizers applied as 400 kg NPK ha-1, 1300 kg Urea ha-1 and 680 kg SSP ha-1 and organomineral fertilizer applied as 1700 kg OF ha-1 arranged in a Randomized Complete Block Design with five replicates. Surface soil was sampled from 0-15 cm and 15-30 cm soil depth for laboratory analyses and selected soil properties were determined while the hydraulic conductivity and the soil strength were determined in-situ. Data obtained were subjected to analysis of variance; Duncan’s New Multiple Range Test was used to separate significant means at p < 0.05. The results indicated high significant difference for organomineral fertilizer treatment on the bulk density at the topsoil. Organomineral fertilizer also had significant effect on soil hydraulic conductivity at the topsoil (2.2 x 10-7) compared with control plot. Combined application of organomineral fertilizer and urea significantly increased the nitrogen content of the topsoil. It was concluded that the Organomineral fertilizer improved the fertility status and hydraulic property of the soil