The urgent need for sustainable solutions in agriculture has prompted the exploration of novel materials to mitigate issues such as excessive fertilizer use, inefficient water management, and soil contamination. Addressing these challenges, this work presents innovative interpenetrated polymeric networks (IPN) based on chitosan (CTS) crosslinked with tris(cyclic carbonate) (TrisCC), engineered as controlled-release biostimulant delivery systems (BDS). The IPN synthesis employed TrisCC, prepared by means of click thiol-ene chemistry, and varying CTS concentrations (2–6% w/v) to modulate network characteristics. A fixed crosslinker-to-CTS ratio targeted 30% amino group involvement, and product properties were thoroughly characterized, including rheology, micromorphology, swelling, biodegradability, and in vitro release of biostimulants, such as melatonin (MEL) or glycine betaine (GB).

The IPN formulated with 6% CTS (CTS₆-TrisCC₃₀) demonstrated optimal mechanical strength and a highly porous architecture, achieving a remarkable swelling index of 4300%. All systems displayed soil biodegradability, with half-life values influenced by the degree of crosslinking and polymer concentration. Sustained, aqueous release profiles for MEL and GB indicated consistent attainment of bioactive concentrations.

These results highlight the considerable promise of CTS-based IPNs as sustainable, controlled‑release platforms for agricultural biostimulants. The innovation lies in the integration of natural biopolymer networks with tunable degradation and release properties, potentially enabling precise nutrient and stress-mitigation strategies in crops. Future work will focus on validating these delivery systems under field conditions to confirm their agronomic efficacy in real‑world environments.

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