Smart sensors, fragile trust: Governance of digital soil-testing tools in smallholder agriculture in Kenya

Digital advisory tools based on bio-physical data collection are increasingly promoted as pathways to improve soil fertility management and agricultural sustainability in smallholder systems. Advances in sensor technologies have enabled portable soil-testing devices that promise rapid, field-level diagnostics and tailored fertilizer recommendations. However, the effective use and scaling of such tools depend not only on technical performance but also on institutional arrangements, governance structures, user trust, and the inclusiveness of service delivery. This study examines how different institutional arrangements shape the development, scaling, and use of a digital soil-testing tool in smallholder agriculture, with particular attention to governance challenges related to transparency, accuracy, incentives, and trust. It aims to identify conditions under which digital soil diagnostics can contribute to improved soil fertility management beyond their technical potential. The analysis draws on a governance framework grounded in new institutional economics and applies qualitative methods, including key informant interviews, farmer interviews, and document analysis. The study focuses on Kenya, where the digital soil-testing tool has been deployed under diverse arrangements involving private service providers, public extension services, cooperatives, and development actors. Evidence is analysed across three phases: development, scaling, and farmer use. The findings show that digital soil-testing tools can reduce barriers to soil diagnostics and enable site-specific recommendations, particularly when embedded in existing service delivery systems. However, governance challenges substantially constrain their effectiveness. Limited transparency regarding tool accuracy, the absence of certification or quality assurance mechanisms, and conflicts of interest, especially where soil testing is bundled with input sales potentially undermine trust and consistent use. Software licensing structures and capacity gaps among service providers further affect further affect the long-term viability and sustainability of service delivery model. Strengthening farmers' ability to interpret and question advisory outputs emerges as critical for mitigating information asymmetry thus reducing the scope for opportunistic behaviour. The study highlights that the success of digital soil diagnostics depends on governing systems, not just deploying sensors. By foregrounding trust, institutional incentives, and accountability, the findings offer transferable insights for the design and governance of digital advisory services in smallholder agriculture. Policy options such as certification systems, public oversight, and investment in user capabilities are central to equitable and sustainable scaling of digitally enabled, bio-physically grounded advisory systems. • Digital advisory tools can reduce barriers to farm-level soil diagnostics when embedded in appropriate service systems • Public, private, and third-sector actors jointly shape digital advisory outcomes • Limited transparency and verifiability constrain assessment of digital tool performance • Information asymmetry affects farmer trust and use of digital advisory services • Certification and public oversight are key to equitable scaling of digital tools