Many Rhizobium, arbuscular mycorrhizal fungi and Trichoderma based inoculants on one hand, and foliar fertilizers on the other hand are commercially produced, mostly in developed countries, and available in sub-Saharan African markets. However, studies on cowpea (Vigna unguiculata) responses to these microbial and chemical products in the Sahel savanna agroecological zone do somewhat not exist. RACA6 (Bradyrhizobium sp.), Rhizatech (Arbuscular mycorrhizal fungi) and Eco-T (Trichoderma harzianum) were the microbial inoculants used either in single or combined application with two foliar fertilizers (Agroleaf high P and Agrolyser). The response of cowpea to rhizobial inoculant was not significant for shoot dry weight. T. harzianum slightly increased while Rhizatech and RACA6 decreased the shoot dry weight. P uptake was significantly improved by the biological and foliar fertilizers application. Direct application of P increased grain yield more than biofertilization. This study was aimed at getting an insight of microbiological fertilizer in cowpea production. Further attention could be given to how rapid and effective soil microbes could be selected.
Keywords: Arbuscular mycorrhizal fungi, Trichoderma harzianum, cowpea, Sahel savanna, foliage feeding, fertilizers.