This text inaugurates a series of 3 articles, which serve as case studies to show the need to better reconcile the scientific approaches of agro-ecology (systemic and observational approach, in which the ecosystem of the plot is studied without modifying it) and integrated farming (reductionist approach, based on intervention experiments, in which only one production factor is varied at a time). In fact, although agroecology can highlight ecosystem services that may have gone unnoticed in conventional agronomy, it is still necessary to validate these observations through more reductionist experiments to convince farmers to rely on these ecosystem services. Just as Mr Jourdain unknowingly wrote prose, farmers are by nature rather reductionist, since they have to make decisions every day about every intervention they make on their crops. In order to become practical, agro-ecology will therefore have to take into account the achievements of sustainable agriculture and show that the ecosystem services it highlights make it possible to significantly reduce the harmfulness of diseases and pests. The publication studied in this first article is hardly encouraging from this point of view, since the results presented are contradicted by all comparable reductionist experiments. The work studied in the next articles (in February and March) opens up more interesting avenues, and we will see the steps (sometimes decisive) that remain to be taken to make them into examples that can be transposed on a large scale.