Smart fertilizers: What should we mean and where should we go?

The current agricultural system faces several challenges, the most important being ability to feed increasing world population and mitigate climate change. In this context, improvement of fertilizers’ agronomic efficiency while reducing their cost environmental impact is one biggest tasks. Available literature shows that many efforts have been made develop innovative fertilizers defined as ‘smart fertilizers’, for which, different interpretations definitions used. This paper aims define, classify, describe new frontier so-called smart with a particular focus on field-scale studies herbaceous species. Most analysed papers associate ‘smart’ concept controlled and/or slow release nutrients, using both terms synonymous. Some others broadened concept, including nutrients reduce impact. Based our critical analysis available literature, we conclude fertilizer can be considered when applied soil, it allows control over rate, timing, duration release. Our definition is: ‘Smart any single or composed (sub)nanomaterial, multi-component, bioformulation containing more that, through physical, chemical, biological processes, adapt timing nutrient plant demand, enhancing yields at sustainable costs compared conventional fertilizers’. Highlights - A Nanofertilizers are powder liquid formulations which involve synthesis, design use materials nanoscale level. Composite mixed coated exploit synergy among materials. Bioformulations active dormant microorganisms capable trigger physiological growth responses in plants. Limited information crops open field conditions.