MAIZE NUTRIENT ASSESSMENT IN BENIN REPUBLIC: CASE OF UPPER OUÉMÉ CATCHMENT.

□ Nutrient deficiency in maize (Zea maysL.) was assessed through critical value methods (CVM) and the Diagnosis and Recommendation Integrated System (DRIS) to compare mean yield, foliar nutrient status, and variance of nutrients in low-and high-yielding groups. A two year (2001 and 2002) field experiment was set in Benin. Based on DRIS, the most limiting nutrients in 2001 were phosphorus (P) followed by sulfur (S), potassium (K), and zinc (Zn), whereas in 2002, it was manganese (Mn), followed by Zn and magnesium (Mg). However, based on the CVM, nitrogen (N) and S were deficient in both years. Calcium (Ca) was deficient in 2002 and adequate in 2001. Leaf P and K concentrations were adequate in 2002 both in high and low yielding populations based on DRIS and CVM. Standard nutrient levels and DRIS norms established for maize can be used to evaluate crop nutritional status and correct nutritional imbalances. [ABSTRACT FROM AUTHOR]