Nano-fertilizers and smart inputs: Enhancing nutrient use efficiency in agronomy

Abstract

Nutrient use efficiency (NUE) in agriculture is critical for sustainable food production, but conventional fertilizers often achieve only ~30-40% nitrogen (N) and 10-20% phosphorus (P) use efficiency, leading to environmental pollution. Emerging nano-fertilizers and "smart" input systems offer targeted delivery and controlled release of nutrients to improve uptake and crop yield. Nano-fertilizers include nutrient-coated nanoparticles (e.g. hydroxyapatite-urea, nano-DAP, nano-NPK) that release nutrients slowly, synchronizing with plant demand. Smart inputs encompass precision irrigation and sensing networks, drone-based application and advanced fertilizer coatings that respond to soil or plant cues. These innovations have shown yield gains of 20-80% in various crops (e.g. wheat, maize, potato, tomato) at lower fertilizer rates. We review global developments with a focus on India in nano-fertilizer research, application trials and policy support (e.g. India's nano-urea and nano-DAP initiatives). Case studies span multiple cropping systems (cereals, pulses, vegetables, oilseeds). Tables summarize nano-fertilizer types, NUE comparisons and field trial results. Diagrams illustrate nano-delivery mechanisms and IoT-based precision farming. In conclusion, nano-and smart inputs show promise to boost NUE and yield while reducing losses, but challenges remain in cost, regulation and long-term safety. A coordinated research and policy effort is needed to realize these benefits in sustainable agriculture.