This paper presents human-centered design recommendations for agricultural software grounded in the practices of smallholder farmers in Central Borneo. Using a mixed-methods approach, which are survey (n = 286), interviews (n = 20), and co-design sessions (n = 20). From this study, we identified patterns of device use, connectivity, and information behavior, alongside themes of digital access, trust, and peer validation. Co-design activities further contextualized these findings, producing functional and non-functional requirements for agricultural applications. The resulting recommendations emphasize mobile-first, low-complexity interfaces, offline and data-efficient features, peer-driven knowledge exchange, localized content, and mechanisms for building trust. While exploratory and limited to one region, the study demonstrates how participatory methods can address socio-technical constraints and generate actionable requirements. It contributes to human-centered computing by showing how inclusive design processes inform the development of trustworthy and context-aware agricultural platforms for low-resource environments.