The iFAROS project aimed to show that nitrogen (N) fertilizers can be used with greater efficiency and with less impact on the environment and facilitate access to knowledge and technology use for European farmers. Soil, plant, fertilizer and other data were collected in the field, mainly by Agroscope and University of Hohenheim. Agroplanning and Disy developed a software platform to process input data and to create application maps for site-specific fertilization, which were transferred to the tractor terminal to spread the fertilizer accordingly. The workflow was applied and validated by means of field trials in Germany (2 fields in 2021) and in Switzerland (9 fields in 2019-2021) by comparing site-specific management to a standard and a control with no fertilizer. The results of the implemented workflow showed a reduction of applied N with no difference in yields and protein content was observed in the majority of the case studies. A trend of 10% higher N use efficiency and 30% lower N surplus was observed. However, there are still important gaps, such as the prevision of soil N supply from mineralization. Currently, it is not possible to model the ongoing processes and to apply the appropriate amount of N just covering plants need. The topic will be further developed in the next years in follow-up projects such as “Smart-N” in the digital application region Thurgau-Schaffhausen, supported by the FOAG, together with the Swiss Future Farm, Agroscope and Agridea.