Precision Nutrition: Harnessing Nano-fertilizers and Smart Inputs for a Paradigm Shift in Nutrient Use Efficiency (NUE)

The transition toward sustainable intensification in global agriculture is currently hindered by the systemic inefficiency of conventional agrochemicals. Conventional fertilization often results in nutrient losses exceeding 60%, driving environmental degradation through nitrogen leaching, phosphorus runoff, and greenhouse gas emissions. This review evaluates the transformative potential of nano-fertilizers and smart inputs as a sophisticated solution to enhance Nutrient Use Efficiency (NUE) and mitigate ecological footprints. By engineering fertilizers at the molecular scale, nanotechnology enables the development of smart delivery systems that respond dynamically to the crop’s physiological needs. We analyze the mechanisms of encapsulation using biodegradable polymers, carbon nanotubes, and mesoporous silica, which facilitate the "triggered release" of nutrients in response to environmental stimuli such as rhizosphere pH, soil moisture, or specific root exudates. Unlike bulk fertilizers, these nano-enabled inputs ensure a synchronized supply of macro- and micronutrients, significantly reducing the frequency of application while maximizing biomass accumulation and biofortification. Furthermore, the review explores the dual-action role of smart inputs in enhancing abiotic stress resilience, where nano-elicitors prime the plant’s antioxidant defense systems against drought and salinity. We also integrate the role of nano-biosensors in digital farming, providing a feedback loop for real-time soil health monitoring. Despite the agronomic advantages, the manuscript critically discusses the environmental fate of nanomaterials, the potential for trophic transfer, and the current lack of harmonized global regulations. We conclude that while nano-fertilizers represent a paradigm shift in precision agronomy, a multidisciplinary approach involving material science, plant physiology, and ecotoxicology is essential to move these technologies from the laboratory to large-scale, sustainable field adoption.