Zinc Oxide Nanoparticles as Novel Nanofertilizers: A Comprehensive Agricultural Perspective

Nano-biotechnology has emerged as a transformative platform for developing next-generation fertilizers capable of delivering nutrients to plants in a controlled, targeted, and highly efficient manner. Nanoparticle-engineered fertilizers provide several advantages over conventional formulations, including improved nutrient bioavailability, sustained and slow-release behaviour, enhanced uptake efficiency, and reduced nutrient losses to the environment. Zinc oxide nanoparticles (ZnO NPs) and their derivatives have gained significant attention as promising nano fertilizers due to their large surface area, controlled nutrient-release capabilities, and demonstrated physiological benefits to crops. The application of Zn ONPs as nanofertilizers can strengthen plant tolerance to abiotic stresses—such as drought, salinity, and heavy metal toxicity—thereby promoting crop resilience and yield stability. The evolving research landscape indicates that ZnO nanofertilizers can serve as highly effective alternatives to conventional zinc salts when formulated and applied with appropriate consideration for dose optimization, safety, and environmental stewardship. This review critically synthesizes recent advances in ZnO nano fertilizer research, encompassing their synthesis routes, physicochemical characteristics, mechanisms of uptake and translocation in plants, and agronomic efficacy across diverse cropping systems. Additionally, it examines their interactions within soil–plant systems, potential toxicity and environmental risks, and future directions for developing safe, sustainable, and nano-enabled agricultural practices.