Effect of Industrial Manufactured Organic and Organomineral Fertilizers on Soil pH, Major Nutrients and Their Interactions at 90 Days of Incubation

Abstract

Objective: Incubation study was carried out to determine the effect of organic fertilizer (OG) and organomineral fertilizer (OMF) on soil major nutrients in Ondo, South Western Nigeria. Design: Organic and organomineral fertilizers were separately applied to 100 g soil at the rate of 0.25 and 0.5 g. The treatments were arranged on completely randomized design with six replications in the laboratory and incubated for 90 days. Analysis: Data collected were subjected to analysis of variance and the means were separated with the use of Duncan Multiple Range Test (DMRT). Results: Compared with control, OG applied at 0.25 and 0.5 g/100 g soil increased soil pH by 5 and 8% respectively. Organic fertilizer (OG) and organomineral fertilizer (OMF) at all rates significantly increased OC, between 12 and 23%, total N between 39 and 108%, available P (35-84%) and exchangeable K (5-17%). Application of 0.25 g OG, 0.5 g OG and 0.25 g OMF increased exchangeable Ca by 6, 30, and 0.02% respectively while Mg was increased by 52, 17 and 9.1% respectively. Application of 0.25 g and 0.5 g OMF increased exchange acidity by 17 and 33% respectively. Application of OG and OMF increased soil major nutrients beyond the critical level recommended for optimum crop production in south-western Nigeria.