African smallholders should adopt climate-smart agriculture to make a sustainable transition towards cleaner, circular, and more productive food systems. Farmers must play a key role in that process. However, the adoption and diffusion of climate-smart technologies have been slow. Here, a cross-sectional econometric analysis using primary data on sustainable farming practices in the cereal legume farming systems of Ethiopia, Malawi, South Africa, and Tanzania is applied to analyze the drivers and intensity of innovation adoption. Socio-economic barriers reduce adoption intensity among marginalised farmers, and proper incentives are needed to overcome them. Business links between technology-ready smallholders and small-to-medium enterprises must be created to enable the uptake and scaling-up of innovations and the development of industrial application models. Such results can support the design of evidence-based strategies for the sustainable transformation of production systems. While national climate policies already include climate-smart agriculture as an adaptation blueprint, policymakers need empirical evidence to support large-scale adoption. This research is an innovative contribution to that effort. It uses a unique household dataset where data is scarce; it considers the impact of smallholders’ conditioning factors on technology climate-smartness level; and it estimates the correlations among a wide range of practices, agro-ecologies, and geographical contexts