Why pro-environmental farming technologies diffuse unevenly across smallholder contexts: Evidence from a cross-country policy analysis

CONTEXT Pro-environmental agricultural technologies often diffuse slowly among smallholder farmers, yet some are widely adopted in certain regional contexts while stalling in others. Such regional differences in adoption are poorly understood, since existing adoption studies focus primarily on farmer-level socioeconomic factors. Here, we focus on institutional and policy factors. OBJECTIVE We examine the mechanisms through which institutional support evolves and shapes diffusion outcomes for two emission- and water-saving technologies, namely alternate wetting and drying (AWD) and laser land leveling (LLL), across smallholder rice systems in Bangladesh, India, and Vietnam. In all three countries, both technologies have been promoted for decades, yet regional adoption experiences vary. METHODS We review national and state-level policies that facilitate technology-specific interventions and interview experts in all three study countries to examine the historical evolution of institutional support and technology diffusion. Using qualitative content analysis, we extract key factors and mechanisms explaining regional technology adoption patterns. RESULTS AND CONCLUSIONS We show that institutional support is critical, yet often remains limited. Moreover, technology diffusion is frequently constrained by counterproductive policy measures such as subsidized irrigation and misaligned water regulations, potentially exacerbating other socioeconomic adoption barriers and discouraging the uptake of water-saving technologies. Where technologies are embedded in explicit policy priorities—such as AWD in Vietnam's Mekong Delta and LLL in northwestern India—specific and longer-term institutional support follows, helping to overcome adoption barriers and driving widespread, sustained diffusion. Where such policy action is absent, diffusion stalls. SIGNIFICANCE Institutional support is widely recommended for accelerating the diffusion of pro-environmental technologies, yet it is costly and rarely emerges spontaneously in smallholder contexts. Here, we advance the knowledge on how such institutional support evolves, what sustains it, and how it shapes diffusion outcomes. One important factor is higher-order policy prioritization of conservation goals and technology-specific institutional commitment for widespread diffusion.