Escalating prices of inorganic fertilizers, driven by factors like surging energy costs and geopolitical tensions, have led farmers to seek sustainable alternatives to maintain yields. Notably, fertilizer production consumes substantial energy, relying on fossil fuels (as seen in N-fertilizers using the Haber-Bosch process) or fossil ore deposits (e.g., phosphate rock). Synthetic fertilizers pose considerable environmental risks, including soil degradation, reduced organic matter content, leaching, pollution, and climate change exacerbation. As the global population expands, there is heightened pressure to augment food production, potentially surpassing the continent's capacity to meet demand, especially in Africa. The Circular Economy (CE) concept, introduced by the European Commission, advocates for material recovery to combat environmental and social challenges. While postharvest residues hold potential as substitutes for raw materials in fertilizer production, the fertilizer industry has yet to fully exploit this renewable resource. Encouraging the fertilizer industry to integrate biomass valorisation in their technologies could be facilitated through direct subsidies. Agriculture currently contributes to approximately 21% of greenhouse gas emissions, intensifying the impacts of climate change. Indiscriminate burning of agricultural waste exacerbates these issues, with only a fraction being utilized for fodder, erosion control, and fertilizer. The majority is disposed of through burning, which can have dire health consequences due to the inhalation of toxic fumes. This method also contributes significantly to carbon emissions, exacerbating global warming. Implementing innovative waste management techniques that prioritize environmental and human health is crucial, yet not all waste categories are addressed, and widespread adoption faces certain challenges. Various plant biomass resources have been utilized in the production of different types of manures worldwide, primarily in the form of compost or biochar. While the conversion of plant biomass to biochar or compost holds promise for carbon sequestration and soil enhancement, concerns such as high energy requirements, emissions during production, limited scalability, environmental trade-offs, nutrient loss, long processing times, potential odour and pathogen issues, and the need for significant space and infrastructure must be addressed. This study aims to develop eco-friendly and cost-effective methods for the instantaneous conversion of residual plant biomass into organic fertilizer. Additionally, it seeks to compare its impact on the growth, development, and yield of maize plants to that of NPK 20:10:5 and rabbit manure. Consideration will be given to fertilizer yield and conversion time in comparison to biochar and compost.