Eco-friendly alginate-urea-fluroxypyr hydrogel for sustainable agriculture: A comprehensive approach to integrated fertilizer delivery and weed control

Excessive and improper use of fertilizers and pesticides poses significant challenges to agriculture. As a promising solution for efficient and healthy agriculture, traditional controlled release systems are often limited by issues, such as a single active ingredient, uncontrollable and limited release behavior, environmental concerns. To address these limitations, a novel controlled release system was designed and constructed for synchronized fertilizer delivery and weed control. Both fertilizer and herbicide were simultaneously loaded onto sodium alginate with urea serving as a cross-linking agent to bridge sodium alginate and fluroxypyr ingeniously. The prepared alginate-urea-fluroxypyr (SUF) hydrogel was characterized to investigate its microstructure, chemical structure, controlled release behavior, biodegradability, and potential agricultural applications. The results demonstrated that the release behavior of SUF hydrogel could be regulated by adjusting the amount of urea. The release of fluroxypyr followed the Fickian diffusion in solution. SUF hydrogel exhibited effective herbicidal activity with a controlled release duration of up to 8 weeks. By combined with physical and chemical loading mechanisms, SUF hydrogel enabled the sustained and controlled release of fluroxypyr, nitrogen, phosphorus and potassium. The significantly improved utilization of pesticide, coupled with the excellent degradability, enhanced the soil fertility and minimized negative environmental impacts. Furthermore, SUF hydrogel promoted plant growth and improved nutrient availability of crops, demonstrating its dual functionality as a fertilizer and weed control agrochemical. This work presents a promising solution for advancing efficient, healthy, and sustainable agriculture practices.