Managing weeds in permanent cover crop-based no-till systems without glyphosate while limiting other herbicide applications

This issue deals with the results of winning projects in 2017 and 2018 from the CASDAR (Compte d'Affectation Spéciale Développement Agricole et Rural) call for projects, ‘Innovation and Partnership’ and ‘Technological Research. These projects are funded by the Ministry of Agriculture and Food.

International audience

English. Direct seeding under permanent cover is an ambitious farming system. In the political context of glyphosate potential removal, the CASDAR ENGAGED project (2018-2022) brought together a number of agricultural stakeholders working with farmers in the Normandy Region on a project that aimed to 1/ conduct a technical survey on alternatives to glyphosate use, 2/ conduct field trials of technical practices on a network of farmers' plots, and 3/ redesign cropping systems in workshops with farmers and crop advisors. While technical monitoring enabled innovative practices implemented during the crop phase and fallow period to be identified, field trials tested crop management techniques such as shredding the cover crop, increasing the sowing density of the cereal crop and reducing the use of appropriate herbicides. Through the work of students and workshops with extension agents, the workshop-based redesign enabled farmers to face situations involving greater change than those they had undertaken on their own farms. The ENGAGED project showed that the framework of restrictions, based on a drastic reduction in herbicide use, does not make it possible to achieve yields equivalent to conventional management. The cover crop then becomes the main weed responsible for major yield losses and few viable technical solutions have been identified for a single crop year.