A Review on the Mechanism and Application Research of CO2 Fertilization

Greenhouse CO 2 fertilization has attracted increasing attention as an effective strategy for enhancing crop productivity and resource-use efficiency while supporting sustainable agricultural development. Although numerous studies and reviews have investigated crop responses to elevated CO 2 concentrations or individual greenhouse fertilization technologies, a comprehensive engineering-oriented synthesis integrating CO 2 sources, transport and diffusion mechanisms, intelligent control systems, and carbon capture, utilization and storage (CCUS) applications remains limited. This review systematically examines the mechanisms and applications of CO 2 fertilization in protected agriculture. Natural and anthropogenic CO 2 sources, generation technologies, transport and diffusion processes, and greenhouse fertilization strategies are comprehensively analysed. Particular emphasis is placed on engineering aspects of greenhouse CO 2 management, including CO 2 generation and purification technologies, computational fluid dynamics (CFD)-based optimization, Internet of Things (IoT)-enabled monitoring, intelligent control systems, and CCUS integration. Recent advances in improving CO 2 distribution efficiency, environmental regulation, and intelligent greenhouse operation are critically investigated. Despite substantial progress, several challenges remain, including precise CO 2 regulation, spatial distribution heterogeneity, gas purification and utilization efficiency, economic feasibility, and large-scale system integration. Future research directions involving advanced CFD modeling, artificial intelligence-assisted control, digital greenhouse management, lifecycle assessment, and carbon-neutral agricultural systems are discussed. By integrating previously fragmented research areas into a unified framework, this review provides an engineering perspective for developing efficient, intelligent, and sustainable CO 2 management strategies in controlled-environment agriculture.