Co-designing sustainable biochar business models with sub-Saharan African communities for inclusive socio-economic transformation.

Smallholder farmers in sub-Saharan Africa (SSA) encounter multiple livelihood challenges. Embracing circular bioeconomy principles, particularly considering agricultural and food processing residues, could enable inclusive, locally led, sustainable development pathways within rural communities. Biochar products are one such example of a bio-based material that can be generated using circular principles and deployed for sustainable community development, including among smallholder farmers. This research leverages empirical evidence from four SSA regions to explore the potential of inclusive and sustainable biochar business models, namely: (i) Northern Region, Ghana, (ii) Yamoussoukro, Côte d'Ivoire, (iii) Casamance, Senegal, and (iv) Western Region, Uganda. Co-creation workshops using the Triple-Layered Business Model Canvas framework were carried out in each region with local stakeholders to evaluate the social, ecological, and economic implications of four locally relevant biochar applications: water filtration, biogas purification, soil amendment, and cooking fuel briquettes. Data was analysed at an aggregate level for all regions and applications. The study describes this consolidated biochar business model and examines the implications for SSA communities. The resulting sustainable bio-based business model can guide value chain actors and policymakers in SSA communities towards rural sustainable development with a better understanding of the needs, opportunities, challenges, and impacts of biochar-based value chain development.

Adoption of novel climate-smart farming systems for enhanced carbon stock and carbon dioxide equivalent emission reduction in cattle corridor areas of Uganda.

Climate change remains the single major threat to the realization of increased livestock production because of its impact on the quantity and quality of feed crops and forages, water availability, animal reproduction, and biodiversity. To minimize the negative impacts of climate change on livestock, an agroforestry project was implemented in the cattle corridor areas of Uganda. Predominant agroforestry tree species and improved grass were planted. At the age of 1.5 years, the aboveground biomass, aboveground carbon stock, and carbon dioxide equivalent emissions sequestrated by each sapling species strand and grass species were determined. From the results, the aboveground biomass (F = 92.21, p = 0.020), aboveground carbon stock (F = 101.01, p = 0.035), and the carbon dioxide equivalent emissions sequestrated (F = 71.02, p = 0.0401) varied significantly among the studied species. Among the agroforestry saplings, Calliandra callothyrus (10.0 ± 0.7 ton/acre) had the highest aboveground biomass, while Markhamia lutea (4.3 ± 0.3 tons/acre) and Albizia chinense (4.1 ± 0.2 tons/acre) had the lowest aboveground biomass. Similarly, the aboveground carbon stock was the highest in Calliandra callothyrus strand (4.70 ± 0.1 tons/acre) and lowest in the Albizia chinense strand (1.94 ± 0.2 tons/acre). At a strand level, Calliandra callothyrus (17 ± 0.4 ton/acre) sequestrated the highest quantities of carbon dioxide equivalent emissions, followed by Maesopsis eminii (10 ± 0.2 ton/acre) and Grevillea robusta (9 ± 0.5 ton/acre) species strands. Markhamia lutea (7 ± 0.2 ton/acre) and Albizia Chinense (7 ± 0.1 ton/acre) strands sequestrated the lowest quantities of carbon dioxide equivalent emissions. At the age of 1.5 years, the grass species were fully grown but only stored 0.51 ± 0.0 and 0.47 ± 0.0 tons/acre of Aboveground carbon for Chloris gayana and Centrosema pubescens, respectively. The carbon dioxide equivalent emissions sequestrated by the grass: Chloris gayana (1.9 ± 0.0 ton/acre) and Centrosema pubescens (1.7 ± 0.0 ton/acre) were also less than that of the agroforestry saplings. From this study, the agroforestry species with higher wood biomass and fast growth rate are recommended for carbon dioxide emission sequestration.