Smart nutrient delivery: the promise of nano-fertilizers for sustainable crop production

Abstract The growing dependence on synthetic fertilizers to satisfy global food demands has resulted in environmental concerns and decreased nutrient use efficiency (NUE) in agricultural systems. In this review, recent developments in nano-fertilizers (NFs) are systematically examined as a sustainable alternative, with emphasis on their synthesis methods, mechanisms of action, and relevance to the agri-food sector. Literature from major scientific databases was compiled and critically assessed to evaluate the effectiveness of NFs in enhancing nutrient delivery, crop productivity, and environmental sustainability. Due to their nanoscale size and unique physicochemical characteristics, NFs facilitate precise and controlled nutrient release, improving nutrient availability to plant roots and foliage while reducing losses typically associated with conventional fertilizers. Special focus is placed on green synthesis strategies that utilize plant- and microbe-based approaches, offering eco-friendly and energy-efficient production methods. Both macro-and micronutrient-based NFs have demonstrated enhanced nutrient uptake, prolonged nitrogen release, increased crop yields, and improved tolerance to abiotic stresses. Furthermore, their contributions to soil health and biofortification are also highlighted. Despite these advantages, several challenges remain, including issues related to large-scale production, potential environmental risks, regulatory constraints, and practical field application. Overcoming these limitations will require coordinated research efforts, comprehensive safety evaluations, and well-defined regulatory frameworks. Overall, this review underscores the potential of nano-fertilizers to advance modern agriculture by achieving a balance between productivity and environmental sustainability.