Extension models in sustainable agriculture adoption in South Asia and sub-Saharan Africa

Using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) methodology, we rigorously analysed the characteristics, strengths, and limitations of various extension models, including Fee-for-Service, Farmer Field Schools, Training and Visit, and Farmer-to-Farmer approaches. This review identifies persistent barriers to the widespread adoption of sustainable agricultural practices, such as limited access to resources, inadequate training, and the lack of tailored solutions for diverse farming contexts, which stem from the inherent limitations of conventional agricultural extension models. We also discuss a hybrid approach that integrates conventional and emerging participatory, demand-driven models, customised for smallholder farmers’ unique needs and constraints. This integrative strategy is suggested to enhance the dissemination and adoption of sustainable agricultural practices, thereby contributing to sustainable development and food security in South Asia and sub-Saharan Africa. We emphasise the need to leverage the complementary strengths of diverse extension models to address existing challenges and drive effective policy interventions.