Biofertilizer based on echinochloa pyramidalis (lam.), panicum maximum l., tithonia diversifolia (hemsel.) a. gray and cow dung, an alternative to the use of chemical fertilizers in urban and peri-urban agriculture in Brazzaville, Republic of Congo

Rural agricultural production that feeds urban areas is supplemented by products from urban and peri-urban agriculture, which, to compensate for low yields, resort to practices that are not very environmentally friendly. The market belts of Brazzaville are no exception to these practices. Chemical fertilizers are used to raise production levels. The present study was undertaken to contribute to the mitigation of the excessive use of chemical fertilizers in these vegetable markets, through biofertilizers that could optimize crop yields. Two completely randomized blocks with six treatments each of E. pyramidalis, P. maximum, T. diversifolia and cow dung were set up. Each treatment had 30 plants in the first set-up and 81 plants in the second. The first set-up was first cultivated with Amaranthus hybridus L.. Mineral fertilizer NPK 15-15-15 and NPK 20-10-10 was used as control. Growth parameters of crown Height and Diameter were measured every seven days until harvest. The dry biomass was estimated with 35 plants per treatment and per replication for the second experimental design. Results obtained show case low overall mortality rates of about 1.1% for the first set-up and 2.05% for the second set-up. The variance analysis at the 5% threshold, during harvest, revealed a treatment impact on height (P<0.001), crown diameter (P<0.001) for both experimental designs, and total dry biomass (P<0.001). The combinations E. pyramidalis + T. diversifolia, E. pyramidalis + P. maximum + T. diversifolia + Cow dung and P. maximum + T. diversifolia were the best.