Influence of Biofertilizer-Fortified Organic and Inorganic Nitrogenous Fertilizers on Performance of Sesame (Sesamum indicum Linn.) and Soil Properties Under Savanna Ecoregion

Application of chemical fertilizers as supplement to the pre-existing soil nutrients has become inevitable for obtaining optimum crop performance in the tropics. However, persistent application of inorganic fertilizers affects soil physicochemical conditions and reduces crop productivity. Integration of mycorrhizal inoculum as biofertilizer and organic manure with little inorganic fertilizer input could improve crop performance and soil quality. However, there is little information on response of crops particularly Sesame (Sesamum indicum L.) to such integrated nutrient management approach. Two greenhouse experiments were carried out at Ladoke Akintola University of Technology (LAUTECH), Ogbomoso, Nigeria and Institute of Agricultural Research and Training (I.A.R&T), Moor plantation, Ibadan, Nigeria to assess response of sesame to integrated nutrient management approach. Twelve factorial combinations each of integrated green tithonia biomass and urea, with and without Glomus clarum mycorrhizal inoculum were investigated. Trials were arranged in a completely randomized design with three replications. Data were collected on growth and yield parameters and analysed using ANOVA at p < 0.05. Mycorrhizal inoculation significantly enhanced sesame growth (except number of branches) and yield with or without applied N-source(s), compared to their non-inoculated counterparts. Sesame responded best to inoculation of 75% tithonia + 25 % Urea + Glomus clarum which significantly enhanced plant height, stem circumference, number of leaves, biomass yield and seed yield. Soil physical and chemical properties significantly improved with increasing application of green Tithonia-biomass. At above 50 % of urea integration, values of growth and yield parameters were statistically similar but significantly higher than the control. Thus, green Tithonia-biomass integration at 75 % level with urea at 25 % level to meet up N-requirement of sesame + mycorrhizal inoculum is suitable for optimum growth and yield of sesame and improved soil quality under savanna ecoregion.