Crop resilience enhancement through chitosan-based hydrogels as a sustainable solution for water-limited environments.

Frequent droughts significantly affect agricultural productivity and highlight the need for effective solutions to improve water availability for crops. This study investigates the potential of chitosan-based hydrogels, biodegradable biopolymers known for their water-retaining properties, to improve soil moisture and promote plant growth during drought periods. Chitosan hydrogels were synthesized using Pluronic F127 and compared with chitosan and chitosan in combination with sodium alginate (CS/Alg-Na). Comprehensive chemical characterizations were performed by Fourier transform infrared spectroscopy (FTIR), nuclear magnetic resonance (NMR) and field emission scanning electron microscopy (FESEM). The CS/Pl-F127 hydrogels showed high porosity and a water absorption capacity of 81.5 %, while the CS/Alg-Na exhibited a denser network with a capacity of 93.35 % and improved mechanical strength. Plants in the CS/Pl-F127 hydrogel had a shoot elongation rate of 5.9 mm/day on Day 9, which continued until Day 40. In contrast, shoot elongation in the CS/Alg-Na hydrogel peaked at 7.1 mm/day on Day 20 and maintained growth under drought conditions until Day 33. These results show that all chitosan-based hydrogels improve water use efficiency. CS/Alg-Na provides the best support for plant growth under drought conditions, followed by CS/Pl-F127 and pure chitosan.