Testing digital behavior change interventions to increase farmer enrollment in the soil passport eco-scheme: null results from a large-scale randomized controlled trial in Flanders

Promoting sustainable agricultural practices is essential for climate change mitigation, soil conservation, and ensuring long-term food security. However, adoption of policy-supported tools remains limited in many farming contexts. This study evaluates whether digital behavior change interventions (BCIs) can increase farmers’ uptake of the Soil Passport eco-scheme, a digital tool for soil health management in Flanders. Using a large-scale preregistered randomized controlled trial (N = 14,285), three behavior change techniques (BCTs) — often called nudges — were implemented within digital messages: (i) demonstration, (ii) dynamic social norms, and (iii) loss framing. Farmers were randomly assigned to a status quo group (no intervention), a control group (information provision), or one of three treatment groups. The results show no statistically significant effects of any intervention on eco-scheme enrollment, nor any effect of information provision alone. These null findings suggest that the deployment of digital BCIs incorporating BCTs may be insufficient to drive eco-scheme adoption. The null results point to the need for complementary structural and relational policy approaches and highlight the importance of several aspects of intervention design beyond the techniques themselves, including delivery mode, messenger, operationalization, and intervention dose.