Xanthan gum/ZrMOF biodegradable gel fertilizer: Sustainable water retention and crop growth.

To address the problems of ecological pollution and food safety caused by the excessive use of chemical fertilizers in modern agriculture, it has become a hot topic of current research to develop novel low-cost, biodegradable, and efficient gel slow-release fertilizers. Herein, using xanthan gum and ZrMOF as raw materials, urea as a nutrient, acrylic acid and itaconic acid as co-monomers, a novel ZrMOF gel slow-release fertilizer (ZrMOF@CpM) was prepared by free radical copolymerization. After being characterized, its swelling and water retention properties and slow-release behavior were investigated. It was demonstrated that ZrMOF@CpM with a high surface area and mesoporous structure provided rich water and fertilizer channels for slow-release fertilizer. Therefore, beside good water absorption (260.7 g/g) and water retention, its nutrient (N) slow-release performance (45 d, 49.1 %) was in accordance with the Committee for European Normalization (CEN) standards. The slow-release gel fertilizer also showed good degradation performance (35 d, 56.9 %). Additionally, maize pot trials showed that the synthesized slow-release fertilizer materials significantly promoted plant root and leaf growth. Overall, we provide a new strategy for the construction of high-efficiency, high-water retention and biodegradable agricultural gel slow-release fertilizers.