Improving agricultural productivity among smallholder farmers is a goal of much tropical agricultural research. Smallholder farmers are often faced with poor soil fertility. Researchers have developed agroforestry technologies including improved fallows and biomass transfer to address these problems. These technologies have been promoted for nearly thirty years through the public extension system, international and national research institutions. However, levels of adoption of agroforestry practices are low and impacts on smallholder farmers’ livelihood negligible. This study examines particularly the role of extension technologies and practices on trialling and adoption of agroforestry in four districts of eastern Zambia. A survey was completed of 388 smallholder farmers. Data analysis shows that trialling of agroforestry technologies is generally low, 44.9 percent of farmers trialled improved fallow technology and 21.4 percent trialled biomass transfers. Logistic regression analysis is completed to establish the roles of main sources of information, the work of extension officers and researchers, farmer training in how to practice agroforestry, and farmer visits to extension. Despite low trialling rates, retention among farmers who had trialled these agroforestry practices was high (over 70%). Understanding the factors influencing trialling of agroforestry technologies is crucial to ensuring that many farmers take up agroforestry technologies.