Effect of Biochar, NPK, and Poultry Manure on Yield Productivity of Maize under Rainfed Conditions

The demand for maize continues to outstrip supply due to challenges such as low soil fertility, inappropriate agronomic practices, and infestations of pests and diseases. Hence, there is a need to explore sustainable solutions like Gliricidia sepium biochar and poultry manure as alternatives to improve maize yields while simultaneously enhancing soil chemical and physical properties. The study employed a 2 x 6 factorial experiment arranged in a Randomized Complete Block Design with twelve treatments and replicated three times. The treatments included; (i) two maize varieties (Obatanpa and Omankwa), and (ii) six fertiliser rates [10 t ha-1 Poultry manure (PM), 300 kg ha-1 NPK, 2.5 t ha-1 Gliricidia sepium biochar (GB), 150 kg ha-1 NPK + 1.25 t ha-1 GB, 1.25 t ha-1 GB + 5 t ha-1 PM and No fertiliser (Control)]. The results showed that Omankwa and Obatanpa planted on 10 t ha-1 PM tasseled (3 and 6 days) and silked (2 and 6 days) respectively earlier than the same varieties planted on the control during 2021. Obatanpa planted on 10 t ha-1 PM and 1.25 t ha-1 GB + 5 t ha-1 PM produced significantly higher plant height and wider stem diameter respectively at 12 weeks after planting across 2021 and 2022 than the control and Omankwa planted on same amendments. Obatanpa produced a significantly wider cob diameter than Omankwa in 2022. Obatanpa grown on 10 t ha-1 PM produced a significantly greater cob diameter than the control. Omankwa had a significantly higher total grain yield than Obatanpa in 2021. Omankwa and Obatanpa maize varieties planted on 1.25 t ha-1 GB + 5 t ha-1 PM were superior in grain yield which was 10.4% and 25.8% respectively higher than the same varieties planted on the control plot. For higher vegetative growth and total grain yield Obatanpa and Omankwa maize varieties planted on 10 t ha-1 PM and 1.25 t ha-1 GB + 5 t ha-1 PM are recommended to farmers.