smart hydrogel and cyanobacterial biofertilizer in sustainable urban agriculture

Increasing urbanization and water scarcity highlight the urgent need for sustainable technologies in urban agriculture. this study aimed to compare two green technological solutions: an intelligent starch-alginate-based hydrogel loaded with npk fertilizer and a cyanobacterial bio-fertilizer, comprising nostoc punctiforme and cylindrospermum stagnale. the hydrogel s characteristics, including swelling kinetics and controlled nutrient release in soil, were evaluated. the efficacy of these two technologies was then compared in a pot experiment with wheat plants under well-watered and drought-stress conditions. results indicated that the synthesized hydrogel, with a swelling capacity of 6.2 g/g and a 58.5% npk release over 20 days, shows significant potential for moisture retention and gradual nutrient supply. under drought stress, the hydrogel treatment led to the highest protein accumulation in plants, indicating its role in mitigating oxidative stress. in contrast, the cyanobacterial treatment, particularly the n. punctiforme strain, produced the highest shoot biomass under both conditions, demonstrating its strong growth-promoting ability. in conclusion, this study demonstrates that the smart hydrogel is more effective in enhancing drought tolerance, while the cyanobacterial bio-fertilizer excels in stimulating plant growth. integrating these two technologies could be a promising strategy for achieving sustainable urban agriculture.