Legume and mineral fertilizer derived nutrient use efficiencies by maize in a Guinea Savannah of Cote d’Ivoire

This paper deals with reclamation of marginal savannah lands in central Cote d’Ivoire. It aimed at assessing legume-derived nutrient use efficiencies (NUE) by maize and quantifying the importance of these legumes as nutrient source relative to inorganic fertilizers. Experimentations included eight treatments in a RCB design (n=3): four herbaceous legume-maize successions and four continuous maize cropping with urea (U, 46% N, 50 kg ha -1 ), triple superphosphate (TSP, 45% P, 30 kg ha -1 ), urea+triple superphosphate (U+TSP) and a control. The NUE was estimated through Apparent Recovery (AR). In addition, the N- and P-fertilizer replacement indices (N-FRI and P-FRI) by legumes, which express their importance as source of N and P for maize relative to inorganic fertilizers, were estimated. The AR of N legume and P legume by maize varied from 16.6 to 29.1 % and from 29 to 62 %, respectively while those of N urea and PTSP were only 12 and 4.3 % on U and TSP plots, respectively. Values of legume N-FRIs and P-FRIs suggest that the legumes’ impact on maize yield corresponded to that of the application of 131 to 195 kg urea ha -1 and 27.5 to 96 kg TSP ha -1 , respectively. Compared to U and TSP, legume-derived nutrients were more efficiently used by maize, particularly nutrients from P. phaseoloides . Keywords: Agroecology ; Crop nutrition ; Ferralsols ; Legumes ; Marginal land reclamation ; Nutrient sources