Smallholder farmers represent a critical yet underutilized component of global carbon sequestration efforts, facing systemic barriers including high transaction costs, verification complexities, and limited market access. This research develops a comprehensive blockchain-based framework designed to address these challenges through decentralized ledger technology, smart contracts, and Internet of Things integration. The proposed system incorporates multi-tiered verification protocols, tokenized carbon credits, and automated payment mechanisms to reduce intermediary dependencies while maintaining methodological rigor. Through comparative economic analysis and stakeholder assessment across three geographic regions, findings demonstrate potential transaction cost reductions of 62-68%, verification cost decreases of 76-85%, and farmer revenue increases of 200-350% compared to traditional carbon credit systems. The framework integrates satellite imagery, IoT sensors, and machine learning algorithms achieving 89% measurement accuracy at $0.85 per hectare annually. Results indicate that blockchain implementation can democratize carbon market participation while enhancing transparency, reducing fraud, and accelerating climate finance flows to agricultural communities. This research contributes novel insights bridging technological innovation with inclusive climate action strategies.