Africa does not lack resources to propel sustainable food and nutrition security for all. The problem has been systematic attempts at replacing supposedly inferior knowledge systems with those thought to be superior. That had been the main cause of lack of sustainability and resilience of development efforts, especially in developing countries. No knowledge system can claim superiority over another. Effective integration of knowledge systems is what will result in the achievement of the SDGs, especially SDG2. The Plug-In Principle describes a methodology for the effective integration of indigenous and “modern” knowledge systems to ensure sustainable outcomes of development interventions. The two-way plug-in, in the right order, ensures increased productivity, resilience and sustainability of agricultural and other systems.