Cellulose-Based Superabsorbent Hydrogel with Recyclable Moisture Regulation for Agriculture in Arid Regions

Water scarcity in arid and desert regions critically threatens agricultural sustainability. We report a cellulose-based superabsorbent hydrogel achieving an ultrahigh water absorption ratio exceeding 20,000 wt %, the highest among all reported cellulose hydrogel systems. It retains ∼82% of its swelling capacity after five wet-dry cycles, demonstrating outstanding recyclability. In desert sand at 40 °C, just 3 wt % hydrogel sustained over 10% residual moisture for 48 h without irrigation. Swelling followed a quasi-second-order model with dual-phase diffusion, enabling rapid hydration and controlled water release. Hydrogel-amended sand markedly enhanced Triticum aestivum seedling drought resilience, extending wilting time by 5-7 days. Biodegradable and recyclable, this hydrogel simultaneously boosts soil moisture retention, respiration rate, microbial activity, and crop stress tolerance, offering a powerful, sustainable strategy for agriculture and ecological restoration in water-limited regions.