Traceability in agricultural supply chains remains a significant challenge, particularly in environments dominated by manual record-keeping and limited process visibility. This study presents the design and validation of a web-based prototype utilizing blockchain technology to improve traceability and operational efficiency in plant-level supply chain management. Employing the Design Thinking methodology, the solution was developed based on insights from key users, such as plant managers and auditors. The prototype integrates four core functionalities: batch registration and monitoring, generation of immutable records, role-based access control, and a user interface tailored for individuals with low technical expertise. Usability was evaluated using the System Usability Scale (SUS), achieving an average score of 90 out of 100, which indicates excellent user experience. Although the validation was limited to the prototype stage and did not involve deployment in operational environments, the results demonstrate strong potential to reduce human error, increase trust among stakeholders, and facilitate audits through reliable digital records. Furthermore, the solution offers a scalable and replicable model for small and medium-sized agricultural enterprises aiming to digitize their supply chains through emerging technologies.