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Low soil fertility is one of the main constraints to crop production in the West African savanna. However, the response of major cereals to fertilizer applications is often far below the potential yields. Low fertilizer efficiency, inadequacy of current fertilizer recommendations, and the ignorance of nutrients other than N, P, and K may limit crop production. Nutrient limitations to maize production were identified in on-farm trials in Togo and in several long-term experiments in Nigeria and Benin. Maize ear leaf samples were analyzed for macro and micro-nutrients, and the Diagnosis and Recommendation Integrated Systems (DRIS) was applied to rank nutrients according to their degree of limitation to maize. In the on-farm trials, both yield and DRIS results indicated that, when N is supplied, P limited maize production in all fields, reducing yields by 31% on average. Sulfur was limiting in 81% of the fields and was …