Adrien Berquer

Understanding the mechanisms of weed assemblies in the crop fields of the ‘Zone Atelier Plaine & Val de Sèvre’ LTSER including a context of an implementation of agroecological practices

I compare different theoretical approaches in order to explain the composition and variations of weed assemblies in the agroecosystems of the ‘Zone Atelier Plaine & Val de Sèvre LTSER’. The main possible levers to understand and act on these communities are the practices managed by farmers to promote crop growth while reducing the impact of competitors on them, especially weeds. Although the current political debate is based on the limitation or ban of some molecules (neonicotinoids, glyphosate), it nevertheless questions the sustainability of the intensive agriculture currently practiced. Indeed, in addition to these molecules, other levers can be used such as changes in practices based on resources (fertilizers, irrigation, varietal selection), or by promoting the heterogeneity of landscape elements (hedges, meadows) outside the crop fields and sources of biodiversity. The aim of my thesis is therefore to understand how weeds vary in quantity and diversity along landscape gradients and intensity of practices. By extension, it will contribute to our knowledge on the benefits for the whole ecosystem of the implementation of agroecological practices.

Supervisors: Sabrina Gaba (INRAE Agripop), Olivier Martin (INRAE BioSP)
Doctoral school  : Euclide (La Rochelle Université)