Next-generation nano-biostimulants: smart nano carrier mediated delivery system for sustainable crop production

Abstract

The increased demand for sustainable agriculture production under conditions of climatic stress and soil quality deterioration accelerates the need for innovative input technologies. Nano-bio–stimulants are substances or microorganisms that enhance plant growth through physiological modulation, manage abiotic stress and are independent of direct nutrient uptake, and have emerged as promising tools. However, their practical application is often limited by rapid degradation, inadequate delivery, and poor solubility. Nanotechnology offers a transformative solution through the development of a nanocarrier-based delivery system that enhances the bioavailability, stability, and sustained release of bioactive compounds over an extended period. Importantly, this review distinguishes nanofertilizers, which are nutrient-providing systems, from bio-stimulants, which are physiological modulators and nano-carriers (delivery vehicles), which are often treated as interchangeable in previous literature. This review focuses on the design principles, fabrication strategies, and release mechanisms of smart nanocarriers for bio-stimulant delivery, while critically discussing their interactions with the plant-soil system, environmental implications, and commercialisation challenges. Establishing a clear conceptual framework enables a more mechanistic understanding of how nano-enabled systems influence plant responses and supports the development of efficient, eco-friendly, and sustainable agricultural technologies by improving resource-use efficiency, reducing agrochemical loads, and enhancing resilience.