Formulation and Performance Evaluation of Plantain Peel-Based Biofertiliser for Maize Production in Benue State

Declining soil fertility and high costs of synthetic fertilisers threaten agricultural productivity in Benue State, North Central Nigeria. This study formulates a biofertiliser from fermented plantain peel waste co-inoculated with nitrogen-fixing Azospirillum brasilense and phosphate-solubilising Bacillus megaterium strains isolated from farm soils in Makurdi Local Government Area. Plantain peels were composted under controlled moisture and temperature conditions for 21 days and characterised for nutrient content, pH, carbon-to-nitrogen ratio, moisture, and microbial populations. Field trials were conducted on maize over one planting season at three sites in Benue State, applying the biofertiliser at 2, 4, and 6 tonnes per hectare alongside an unfertilised control and a synthetic NPK fertiliser reference. Plant height, stem girth, leaf area index, cob weight, and grain yield were measured at harvest. Results indicated that application at 4 t/ha produced grain yields statistically comparable to the NPK reference, with a 34% increase over the unfertilised control. Soil available phosphorus and total nitrogen improved significantly in biofertiliser-treated plots. The formulation maintained viable microbial counts above 10^8 CFU/g throughout a 90-day shelf-life evaluation. The findings support plantain peel biofertiliser as a cost-effective soil amendment strategy for smallholder maize farmers in North Central Nigeria. Keywords: plantain peel, biofertiliser, Azospirillum, maize yield, Benue State