Abstract

Biofertilizers are an agroecological alternative to improve plants’ development by increasing nutrient availability and acquisition. A technical evaluation trial was carried out to estimate the effect of a new Rhizobium-based biofertilizer (Fertiriz) on the development of cowpea bean (Vigna unguiculata (L.) Walp). The study included two assays in cowpea according to complete randomized designs with three replications. The first experiment was in chambers under semi-controlled conditions and comprised nine treatments: an absolute control (without any fertilizer), 50 and 100% mineral fertilizer (NPK), three lots of the bioproduct, and their combination with 50% NPK. The second assay was in an open field experiment and just involved the three lots and an absolute control; no mineral fertilizer was used. The first Rhizobium inoculation was before planting (10.8ml.kg-1 of seeds); two re-inoculations were carried out at 21 and 45 days after sowing. Treatments confirmed the best results with the total recommended chemical fertilizer without statistical differences when 50% of mineral fertilizer was combined with the new biofertilizer inoculations. The general development (stem height and thickness), the number of pods per plant and grains yield were significantly higher in both experiments of cowpea when the new biofertilizer was used, compared to the non-inoculated control. The evaluation of nodulation showed a good number of nodules on roots, and most of them were active. Results validate technically the effectiveness of the new biofertilizer Fertiriz and demonstrated that it can save 50% of mineral fertilizer without affect the development or yield in cowpea.

Keywords:Biofertilizer; Biological nitrogen fixation; Plant growth-promoting rhizobacteria; Sustainable agriculture