Nano-Fertilizers (NFs) for Resurgence in Nutrient Use Efficiency (NUE): a Sustainable Agricultural Strategy

Agriculture systems worldwide rely on synthetic fertilizers to meet the food production demand of the burgeoning population. Over the decades, the abundant use of these synthetic chemicals has posed a significant threat to the environment and declined crop nutrient uptake efficiency (NUE). Nanocarriers can modulate nutrient release kinetics and extend their availability in the rhizosphere and phyllosphere, improving NUE and crop nutrition. Our review provides insights into the role of nano-fertilizers (NFs) in promoting sustainable agriculture, various macro- and micronutrient fertilizers and formulations and green synthesis methods. An extensive and systematic literature review was conducted, and the data under various sections has been identified using a computerized bibliographic search via the Web of Science, Scopus, Google Scholar and CAB abstracts, as well as several websites. Over the past decade, considerable research has been conducted employing the NFs for crop nutrition, development, doses and formulations, improving NUE, impacting crop stress resilience, improving economic viability and environmental sustainability and promoting safety. Use of NFs over conventional fertilizers has yielded a positive and significant impact, encompassing all crop production scenarios. NFs provided sustained nourishment to crops throughout the development phases, from germination to harvest, while minimizing the runoff and leachate losses and improving soil properties. Several advancements in the NFs production utilizing green synthesis methods involving microbes and plant materials are developed to reduce pollution, environmental hazards and global warming. Conventional fertilizers possess major constraints like dynamic chemical forms, which are more challenging for plants to absorb and do not provide sustained release of nutrients. NFs are the best alternatives to increase nutrient uptake, crop yield and soil productivity. However, the synthesis approaches involve high-energy and aggressive chemical reagents. The green synthesis of NFs remains the sustainable, eco-friendly, economically viable, reliable and energy-efficient approach which uses microbial and plant extracts. However, the future potential of NFs in promoting sustainability relies on toxicology research that reveals their limitations, offering a thorough understanding of safe crop nutrition with NFs.