Environmental Sustainability of Soybean Production in the Democratic Republic of Congo: Cases of Production Systems in the South‐Kivu and Kasaï‐Lomami Provinces

ABSTRACT Soybean is increasingly grown in the Democratic Republic of the Congo (DRC), produced mainly in small‐scale systems and supplied locally for human consumption. Prospects of large‐scale expansion and intensification, with potential environmental drawbacks, loom and call for a sustainability analysis of soybean agri‐food systems. We assessed the environmental impacts of different soybean production systems, and evaluated options for inputs reduction and yields improvement, in the east and centre of the DRC. We mapped soybean value chains of production in small and large‐scale systems, used the Life Cycle Assessment (LCA) method for inventory and assessment ecological impacts on climate change, acidification, fossil energy use, particulate matter formation, land use, biodiversity loss, and soil quality. We additionally examined the correlations between productivity and environmental sustainability. Results showed that small‐scale systems were mostly with less than 1 hectare, largely intercropped (> 80%) and had better land‐use efficiencies. Seed and compost inputs rates oscillated significantly across small‐scale farmers' systems, still their ecological footprints were similar. In contrast, large‐scale soybean productions were monocropped, with no amendment but relied on mineral fertilizers, and mechanized operations with fossil fuels. Large‑scale production delivered about four times more soybean yield but caused severe environmental impacts of tenfold higher than small‑scale production systems, in all the impact categories assessed except for land occupation. In small‐scale production systems, productivity and environmental sustainability indicators correlated positively with each other, but negatively with farm size, pinpointing the need to maintain and support the adoption of better farming practices even as the farm size increases. Our sensitivity analysis suggested that production in small‐scale with improved quantity and quality of seeds and compost inputs could achieve an economically viable yield with still much lower ecological impacts compared to the large‐scale production. Therefore, a system optimizing both productivity and environmental preservation is to be sought after. Our study and the LCA method implementation limitations are discussed and call for further investigation with larger samples sizes and adaptation of emissions modelling to the region for comprehensive LCA.