Investigation into the use of macro- and micro-nutrients to increase maize yield was conducted in both the glasshouse and in the field. The glasshouse studies involved ten soil series commonly cultivated to maize in South Western Nigeria, while the field studies were conducted on one soil at Ibadan. Dry matter yield increased above the control with a single application of N, P, K, Ca, Mg, Fe, Cu, Zn and Mn, suggesting that most of the soils in the South Western Nigeria require additions of each of these elements for increased maize production. The size of the response to each element varied from series to series. Soils which were high in organic matter (over 3%) required the lowest N dressings for optimum dry matter yield of maize. In the field studies, a fertilizer combination which included N, P, K, Mg and the micro nutrients Fe, Cu and Zn gave a higher relative yield than the single application of N, P, K, and a combination of NP, NK, Pk or NPK. In the South West Zone of Nigeria, there is no soil testing programme and fertilizers applied by farmers and researchers have not increased yields as expected. Average maize yield on farmers' field is less than 1000 kgha−1 while on research stations it is 2500 kgha−1. When compared with 7000 kgha−1 in U.S.A., these yields are still very low. Different recommendations for the major plant nutrients have been made by many workers in the South West zone based on fertilizer trials [1, 5, 8, 13, 16]. None of the recommendations have included the micronutrients and secondary nutrients and the objective of this project was to supply relevant information on this important aspect.