Advancing controlled environment urban agriculture: integrating LED spectral engineering and intelligent nutrient delivery systems for optimized growth across diverse crop species

Urban controlled-environment agriculture (CEA) has emerged as a technologically advanced approach to food production that seeks to address land scarcity, climate instability, and the growing demand for fresh produce in cities. This review examined the role of smart technologies and automation, sustainability and economic performance, and the major challenges and future directions shaping urban CEA. The evidence shows that sensor-based monitoring, IoT-enabled control systems, predictive models, and automation have improved precision in environmental regulation, nutrient delivery, and light management, thereby strengthening productivity and operational consistency. Urban CEA also demonstrates important advantages in land-use efficiency, water conservation, and nutrient-use control, particularly in hydroponic and vertically stacked systems. However, these gains are moderated by high energy demand, infrastructure costs, operational complexity, and dependence on a limited range of high-value crops. The literature further reveals important research gaps in multi-crop optimization, cultivar development for indoor systems, and integrated assessments of technical, economic, and environmental performance. Policy support, regulatory alignment, and context-specific scale-up strategies remain critical to long-term viability. Urban CEA therefore holds significant promise, but its future depends on whether innovation can move beyond technical efficiency toward economically resilient, environmentally credible, and socially relevant production systems.