Nano-fertilizers in Rice Production: Yield, Nutrient Efficiency and Environmental Perspectives

Abstract

Rice (Oryza sativa L.) is the cornerstone of food security for more than half of the global population, yet sustaining yield growth has become a pressing challenge due to declining soil fertility, inefficient fertiliser use, and increasing climatic stress. Against this backdrop, nano-fertilisers have emerged as a promising innovation designed to improve nutrient delivery, minimise losses, and enhance rice productivity. The objective of this review is to critically evaluate the effect of nano-fertilisers on rice productivity, focusing on their influence on yield attributes, nutrient-use efficiency, and grain quality. This article synthesises evidence across multiple nutrient systems, including nano-urea for nitrogen delivery, nano-phosphates for improved phosphorus utilisation, zinc oxide nanoparticles for micronutrient enrichment, and silicon nanoparticles for stress mitigation. The review also considers innovative application approaches such as foliar sprays, seedling root dipping, and seed nano-priming, which have shown potential to improve germination, seedling vigour, and tolerance to abiotic stress in direct-seeded rice systems. The findings presented here indicate that nano-fertilisers can deliver measurable agronomic benefits. Field and controlled studies have shown yield improvements ranging from modest to significant, depending on crop variety, soil condition, and application method. Beyond yield, nano-fertilisers enhance nutrient-use efficiency by synchronising nutrient release with plant demand, thereby reducing leaching and volatilisation losses. They also contribute to biofortification, with zinc nanoparticles in particular increasing the micronutrient content of edible rice grains. Importantly, these innovations may also serve as tools for climate resilience, with evidence of improved tolerance to heat, salinity, and drought stress. Despite these advantages, challenges remain in scaling nano-fertilisers responsibly. Uncertainties about long-term soil accumulation, potential impacts on beneficial microbes, and safe dosage thresholds must be addressed through rigorous multi-year trials. Economic feasibility and farmer adoption also require consideration, particularly in resource-limited contexts. In conclusion, nano-fertilisers hold strong potential to transform rice cultivation by improving productivity, reducing fertiliser inputs, and enhancing grain nutritional value while minimising environmental costs. With careful research to establish standardised application protocols and comprehensive safety assessments, nano-fertilisers could become an integral component of sustainable, climate-smart rice production systems worldwide.