Nano/Micro‐Engineered Hydrogel Carriers for Sustainable Agriculture: Bridging Structural Form to Field Performance

ABSTRACT Hydrogels are 3D polymeric networks that can absorb and retain significant amounts of water and exhibit physical properties such as swelling and contraction in response to changes in the external environment. Owing to these unique physicochemical properties, hydrogels have attracted interest as effective solutions to key challenges in modern agriculture, such as soil moisture imbalance, inefficient fertilizer and pesticide utilization, and nutrient loss. This review provides a comprehensive overview of the structural fundamentals and intrinsic properties of hydrogels, along with various nano/micro‐scale fabrication strategies for producing various hydrogel forms, such as beads, capsules, films, and blocks. In particular, we highlight recent advances in nano/micro‐engineered hydrogels for controlled nutrient release, microbial protection, and the mitigation of environmental pollutants. Finally, we discuss the current state of hydrogel commercialization and identify the remaining technical challenges, underscoring their potential as pivotal materials for sustainable agriculture.