Intensive use of external inputs in specialized industrial farming systems has created significant socio-ecological externalities, including water and air pollution from nutrients and pesticides, soil erosion and depletion of carbon stocks, biodiversity loss and rising production costs. Ecological intensification is a strategy for reducing reliance on inputs by intentionally designing agroecosystems to harness biological processes and ecological relationships for the sustainable functioning of the system. Incorporating perennials and diversifying systems are two avenues for achieving ecological intensification, and both are characteristics of agroforestry. This preliminary report uses examples of agroforestry in the US state of California as a proof of concept to explore the agronomic and economic feasibility and sustainability benefits of agroforestry in intensive irrigated and temperate farming systems. An exploratory study of farmers experimenting with agroforestry systems and other agricultural professionals identified eight different variants of agroforestry systems being practiced on prime agricultural land in California, ranging from simple use of winter cover crops in orchards to multi-storied cropping systems with integrated grazing. Respondents noted benefits of reduced inputs and production costs, and better nutrient cycling, soil health and pest control. Trade-offs and challenges included increases in labor requirements and management complexity. Knowledge gaps included lack of guidance in biophysical systems design, lack of clarity about economic tradeoffs, and lack of information about ecosystem services benefits. In light of interviewees’ responses, we discuss the constraints and factors needed to foster the successful expansion of agroforestry systems in California and other regions characterized by industrialized farming.