Abstract
Declining soil fertility remains a major constraint to sustainable crop production in sub-Saharan Africa. Conventional reliance on inorganic fertilisers has raised concerns about soil health and environmental sustainability. Biochar, a carbon-rich product derived from biomass pyrolysis, has emerged as a promising soil amendment for enhancing soil properties and crop productivity. This study was conducted at the Federal College of Agriculture, Akure, Nigeria, to assess and compare the effects of maize cob biochar and inorganic fertiliser, applied individually and in combination, on soil properties and the performance of maize. The experiment was carried out from April to July 2024 at the Energy Development Unit (EDU) farm, beside REC Road, Federal College of Agriculture, Akure. Maize was sown at a spacing of 75 cm × 40 cm using two seeds per hole. Biochar was applied by broadcasting at 1.5 and 3.0 tonnes per hectare three weeks before planting, while NPK 15-15-15 fertiliser was applied in rings at 100 and 200 kg per hectare four weeks after planting. Treatments included the following: control (no amendment), biochar alone, fertiliser alone, and a combined application of 1.5 t/ha biochar with 100 kg/ha fertiliser, arranged in a randomised complete block design with three replicates. Growth parameters such as plant height, leaf area index, internode length, and stem girth were monitored alongside yield indices including cob weight, grain weight per cob, and number of seeds per cob. Post-harvest soil analysis covered pH, organic carbon, nitrogen, phosphorus, potassium, sodium, calcium, and magnesium content. Results indicated that all treatments significantly enhanced maize growth and yield compared to the control. Biochar alone produced the highest values for plant height (231.69 cm), leaf area index (507.95 cm²), stem girth (3.06 cm), and internode length (16.65 cm). Biochar also improved soil pH and organic matter, while NPK fertiliser enhanced immediate nutrient availability. The combined application yielded the most balanced improvement in both growth and soil fertility. The study concludes that integrating maize cob biochar with inorganic fertiliser offers a sustainable and effective strategy for improving maize productivity and long-term soil health.
Keywords: biochar, maize growth, soil fertility, NPK fertiliser, integrated nutrient management, sustainable agriculture