Enhancing Sustainability in Agricultural Supply Chains Through a Blockchain-IoT Framework for Environmental Footprint Tracking: A Tunisian Citrus Case Study

Environmental demands on modern agriculture are increasing, particularly with respect to energy efficiency, greenhouse gas reduction, and water scarcity. Consequently, transparent and trustworthy identification of the environmental footprint across agri-food supply chains has become essential. Although blockchain and Internet of Things (IoT) technologies offer promising solutions, their combined application for sustainability monitoring, especially in citrus production, remains insufficiently explored. This study proposes an integrated digital platform for monitoring and disseminating key environmental footprint indicators across the citrus supply chain, including water consumption, energy usage, and CO2 emissions. The system adopts a modular architecture that combines IoT-based environmental sensing, blockchain-secured data management using cryptographic hashing and digital signatures to ensure data integrity and immutability, and a web-based dashboard for real-time visualization and decision support. Throughout the product lifecycle, all stakeholders, from farmers to consumers, can contribute to and access tamper-proof sustainability records. Environmental performance was monitored during production, storage, and transportation phases on a medium-sized citrus farm in Tunisia using IoT sensors. The results demonstrate that environmental footprint metrics are reliably captured and securely recorded, while QR-code-based access enables consumers to retrieve verified environmental information. This allows purchasing decisions to consider not only product quality and origin but also environmental impact. By combining reliable sensing, cryptographically secured blockchain records, and transparent user interfaces, the proposed platform empowers consumers, supports national and international sustainability objectives, and promotes eco-responsible agricultural practices within digital and sustainable food systems.