A Review on Nano Enabled Controlled Release Fertilizers and their Nutrient Release Mechanisms

The imbalance in nutrient release from conventional fertilizers and plant nutrient uptake leads to a surplus accumulation of nutrients in the soil. A key approach to tackle this issue involves the engineering of nano-enabled fertilizers for the controlled release of nutrients to crops. In this context, it is important to understand the strategies for designing and utilizing nano-enabled fertilizers that can effectively regulate nutrient release and enhance nutrient use efficiency (NUE). This review focuses on nano-structured materials that serve as nutrient carriers: nano-clays, hydroxyapatite (HA) nanoparticles, mesoporous silica, carbon-based nanomaterials, polymeric nanoparticles, and other nanomaterials. In addition, the nutrient release mechanisms in controlled release fertilizers (CRFs)/slow-release fertilizers (SRFs) are discussed. The discussion and perspectives presented emphasizes the need for standardized and comprehensive fertilizer evaluation systems, design of multifunctional nanomaterials, and the creation of stimuli-responsive nanocarriers to improve NUE.