Design and Development of Differentiated Controlled-Release Coatings for Enhanced Nitrogen Use Efficiency in Fertilizers

Title: Design and Development of Differentiated Controlled-Release Coatings for Enhanced Nitrogen Use Efficiency in Fertilizers\n\nAbstract:\nThe Haber-Bosch process, which synthesizes the majority of ammonia used in fertilizer production, plays a crucial role in global food security. However, the increased use of nitrogen fertilizers has not resulted in proportional crop yield increases, leading to wastage of resources and environmental issues. Furthermore, the energy-intensive synthesis of nitrogen fertilizers contributes significantly to global CO2 emissions. To address these challenges, efficiency-enhancing fertilizers have been developed to optimize nutrient release and reduce nitrogen losses. Meta-analysis data shows that these fertilizers significantly increase grain yields and nitrogen use efficiency compared to conventional fertilizers. However, their performance varies depending on soil texture, climate, and agricultural systems. Therefore, there is a need to improve the capability of these fertilizers to reduce nitrogen losses across diverse agricultural settings.\n\nIn this study, a novel controlled-release coating system was designed to enhance the nitrogen use efficiency of existing fertilizer technologies. The system utilized porous materials to capture substances with different molecular sizes, allowing for differentiated release related to crop growth dynamics. Sodium alginate, a biodegradable coating material, was used as the substrate, and natural polyphenol tannins and FeIII were employed as the organic ligand and inorganic cross-linking agent, respectively. The release profiles of model substances, DMPP (an inhibitor) and humic acid (a biostimulant), were evaluated, demonstrating different release patterns correlated with their molecular sizes.\n\nIn addition, the system was found to enhance the inhibition efficiency of DMPP, reducing N2O emissions and prolonging its activity cycle in soil. The slow release of DMPP in the post period allowed for continuous replenishment and stabilization of its concentration in the soil within the effective range.\n\nWhile the differentiated release system showed significant advantages over conventional formulations in the laboratory, further research is required to validate its performance under relevant agricultural conditions. Challenges such as the complexity of soils and the dynamic nature of the soil and crops microbiome need to be addressed. Additionally, cost management, scalability, and support from policies and regulations are crucial for the wider adoption of this technology.\n\nIn conclusion, the development of differentiated controlled-release coatings offers a promising approach to improve the nitrogen use efficiency of existing fertilizer technologies. By incorporating multiple operating mechanisms, these coatings have the potential to enhance crop yields, reduce nitrogen losses, and promote sustainable agriculture. Further research and collaboration are required to advance this technology and ensure its successful implementation in the field.