Macro and micro-nutrient effects on the yield and nutrient concentration of maize (Zea mays L.) in South Western Nigeria

Despite various fertilizer recommendations, maize (Zea mays L.) yields in tropical forest and savanna zones are very low. These low yields could be attributed in part to the exclusion of some secondary and all micro nutrients in fertilizer recommendations for maize, a condition which often leads to nutrient imbalance. The inclusion of some secondary and micro nutrients in fertilizer recommendation for successful maize cultivation in this zone has been suggested 2, 16] but no one has proposed a balanced nutrient program for this purpose. Field trials were therefore conducted to investigate the potential for improving maize yields by fertilizing soils of different parent materials with both macro and micro nutrients in three ecological zones of maize production in south western Nigeria.The study has indicated that in addition to NPK, Mg was necessary for high yield of maize on forest soils derived from sedimentary materials while on forest and savanna soils formed from basement complex rocks, inclusion of Mg, Fe, Cu and Zn to NPK was required. This was further confirmed with ear leaf tissue and soil analyses. High nutrient concentration in earleaf does not necessarily guarantee high yield of maize. It is therefore concluded that there is a need for soil testing program in this region.