Book excerpt: Forestry and agroforestry education and extension programmes for forest and farm communities have not kept up with needs in many places. However, the success of achieving international sustainability goals and implementing global commitments with respect to sustainable production, halting land degradation, ecosystem restoration and climate change mitigation is contingent on having capacity in place at local levels, or building it, across a large part of the world’s rural lands. This publication reviews the current and potential application of farmer field schools (FFS) to strengthen the capacities and skills of smallholders and family framers in sustainable forestry and agriculture production. From 2020 to 2021, FAO conducted a stocktaking study to identify opportunities, challenges and lessons learned in the application of the Farmer Field Schools (FFS) approach on forestry and agroforestry. Through the review of over 400 documents (peer-reviewed and grey literature), 36 in-depth key informant interviews and a stakeholder workshop, this stocktaking identified twenty-one majors FFS programmes in forestry and agroforestry, with over 200 000 graduates distributed across every region of the Global South. Three decades of FFS experience on forestry, particularly agroforestry, has taken place in multiple geographic, environmental, and social contexts – from arid and semi-arid savannahs to high rainfall mountain environments. This experience represents a diverse, well-tested, decentralized and, locally situated knowledge base on which to build future programmes aiming at strengthening farmers and forest dwellers’ capacity to create sustainable agricultural systems that include trees and perennial crops. This stocktaking argues that though enhanced understanding of agro-ecological dynamics and farmer-led experimentation, the FFS can enable farmers across the globe to sustain or improve productivity while reducing their dependence on externally based inputs. Forestry and agroforestry applications promise to enhance the environmental integrity and socio-economic impacts of FFS, mainly by increasing the presence of perennials in production systems, useful for stabilizing food security and strengthening on-farm ecosystem services.