The role of neglected and underutilised crops in food and nutrition security under climate change: Insights from South Africa

Tony Carr , Richard Kunz , Tafadzwanashe Mabhaudhi, Mendy Ndlovu, Pauline Scheelbeek

Neglected and underutilised crop species (NUS) are increasingly discussed as options to enhance the resilience, diversity and nutritional quality of food systems under climate change. However, their productivity and nutritional contribution remain insufficiently quantified at larger scales, making it unclear to what extent they can contribute to food and nutrition outcomes. In South Africa, we compare the nutritional yield and climate response of sorghum, taro, and bambara groundnut with widely grown crops, namely maize, potato, and soybean, used here as reference crops. The analysis combines AquaCrop-simulated crop yields with nutrient composition data. Reference crops achieve higher yields and total nutritional outputs in most regions, with NUS supplying median nutritional yields of approximately 4-35% of their reference crops, depending on crop and nutrient. However, NUS match or exceed reference crops for specific nutrients in parts of eastern South Africa, with sorghum exceeding maize in iron yield and taro exceeding potato in zinc yield. Under climate change, reference crops maintain higher absolute yields across all crop pairs. Yield differences between NUS and their reference crops remain stable for sorghum-maize but increase for taro-potato and bambara-soybean, favouring reference crops. Yield differences decrease in some locations, primarily due to declines in reference crop yields under less favourable, drier conditions, bringing them closer to NUS yields. Despite stronger gains in NUS productivity relative to reference crops in some locations, and advantages for specific nutrients, these remain limited. Without crop improvement, NUS are unlikely to substitute conventional crops at scale, but can complement them by contributing to micronutrient supply and production stability when integrated in suitable agroecological zones.