<p>Polyvinyl alcohol (PVA)/ Humic acid (HA)/Citric acid (CA) (PHC) hydrogel-based urea (U)-incorporated fertiliser, designated as PVA/HA/CA/U (PHCU-hydrogel), was prepared through a simple liquid-state crosslinking method to prolong the slow release of urea. A corresponding fertiliser PVA/CA/U (PCU-hydrogel) was also synthesised without HA. The hydrogel formation and the incorporation of urea in the hydrogel matrix were confirmed by FTIR, EDX, and FESEM. The PHCU-hydrogel’s performance in water retention, swelling rate, and biodegradation was significant (<i>p</i> &lt; 0.05). Almost all the urea from both hydrogels was released into the water within 30 days. The release rate of urea in soil was 75.97% for PHCU-hydrogel and 85.84% for hydrogels without HA, over a period of 30 days. The effects of PHCU-hydrogel, which contains humic acid, on the growth of maize seedlings were also assayed by a pot experiment. The results indicated that PHCU-hydrogel demonstrated positive outcomes for all assessments compared with PCU-hydrogel, urea, or blank, with a p-value &lt; 0.05. Thus, PHCU-hydrogel can be produced using a simple method, and the controlled release of nutrients contributes significantly to enhancing both the growth and quality of maize crops.</p> Graphical abstract <p></p>