This text is the continuation of the article “#1 Reconciling sustainable agriculture and agro-ecology: can bees replace pesticides?“.
Here we analyse a scientific publication, according to which the biodiversity of the flora of cereal plots would make it possible to limit the harmfulness of weeds, in the absence of chemical weeding. The hypothesis is appealing, but it appears that the classical rules of reasoned weeding, as formulated by technical institutes, explain the results obtained just as well, without involving the notion of weed communities invoked by the authors, but whose stability over time has not been demonstrated. Moreover, even if one wishes to highlight the ecosystem service suggested by the authors, the occasional use of well-chosen selective weed killers would be useful… but penalized by the current indicators of the Ecophyto plan, which favour unreasonable weeding! This example once again confirms the need to better study the apparent contradictions between agro-ecology and reasoned agriculture, and to adapt public agricultural policy indicators accordingly.