Sustainability assessment of products of the tropical tree moringa in Ghana with a focus on small-scale producers

With their numerous products and uses, multifunctional crops offer an attractive means for improving smallholder farmer livelihoods. This study applies a Life Cycle Sustainability Assessment (LCSA) to Moringa oleifera (moringa), a multifunctional crop with diverse applications in nutrition, cosmetics, and water treatment. The LCSA includes an Environmental Life Cycle Assessment (ELCA), Social Life Cycle Assessment (SLCA), and Life Cycle Costing (LCC). Surveys were conducted with 58 smallholder farmers and five moringa processors in Ghana. The ReCiPe 2016 Midpoint method was used for the ELCA. The 10-year Net Present Value (NPV) and Payback Period (PBP) were calculated for farmers and processors in the LCC. The SLCA focused on the Worker stakeholder category, particularly smallholder farmer impacts, including indicators for Next Generation Farming, Inclusiveness, Access to Services, Food Security, and Livelihood. A composite sustainability score was calculated from the ELCA, SLCA, and LCC results using the Characteristic Objects Method (COMET), a multi-criteria decision analysis method resistant to rank-reversal. The study compared five supply chains: leaf-only, leaf-and-seed, leaf-and-seed with seedcake reuse, seed-only, and seed-only with seedcake reuse. Environmental hotspots were identified in leaf and seed collection. Economically, leaf-only cultivation provided the highest 10-year NPV for farmers, while seed-only with seedcake reuse yielded the highest NPV for processors. The leaf-only supply chain had the best PBP for both farmers and processors. Socially, leaf-only cultivators outperformed reference points across all indicators, making it the most socially sustainable supply chain. Our findings highlight that improving market access, organizing seed cultivators into farmer-based groups, and optimizing farm gate product collection can enhance the sustainability of moringa supply chains, offering a model for other multifunctional crops in rural development. This study is the first to integrate LCSA with COMET, a promising approach that could be adopted in other sustainability assessment case studies.