ABSTRACT Sustainable agriculture requires innovative materials capable of improving soil quality, enhancing plant performance, and reducing reliance on synthetic inputs. Bioactive hydrogels have emerged as multifunctional platforms that integrate water management, nutrient regulation, and biochemical signaling within the soil–plant continuum. Their porous, tunable polymeric networks interact dynamically with soil physicochemical properties, influencing water retention, hydraulic conductivity, aggregation, and the mobility of nutrients and ions. At the biological level, hydrogels can protect beneficial microorganisms, stimulate microbial activity, and release metabolites that contribute to soil health. Biocompatibility with plant cells is equally critical, as hydrogel composition, mechanical behavior, and degradation products can modulate cellular metabolism, stress resilience, and nutrient uptake. These interactions translate into a broad range of applications, including seed coatings, moisture buffers, carriers for fertilizers and biostimulants, and platforms for controlled release of bioactive compounds. Functionalized hydrogels—incorporating amino acids, nanoparticles, or biochemical cues—can activate signaling pathways, enhance physiological responses, and improve plant growth under abiotic stress. However, dose–response relationships highlight the need for optimized formulations that balance bioactivity with ecological safety. This review consolidates advances in the physicochemical interactions of hydrogels with soil, their biological impacts on soil health, plant cell compatibility, agricultural applications, plant physiological responses, functionalization mechanisms, biostimulant effects, and the limitations and future challenges governing their implementation in sustainable agriculture.
Ortíz‐Hernández et al. (2026) studied this question.