Urea–Straw–Starch Fertilizer with Tunable Water- and Nutrient-Retaining Properties Assisted by High-Energy Electron-Beam Irradiation

[Image: see text] A novel type of water- and nutrient-retaining fertilizer (WNRF) was prepared by mixing, melting, and extruding high-energy electron-beam (HEEB)-irradiated corn straw, urea, and starch. HEEB irradiation technique effectively killed pathogenic microorganisms in straw and further improved the adsorption and binding capacity of straw to urea and water. Compared to nonirradiated HEEB samples, the optimal WNRF improved the water retention rate by 25.63%, the migrate-to-surface loss control rate by 60.2%, and the leaching loss control rate by 34.71%, respectively. Thus, it effectively facilitated the growth of pak choi with a 24% increase in the dry matter weight of the shoot. This work provides a promising approach to improve water and nutrient availability in arid and semi-arid regions and to promote the efficient utilization of straw resources.