Gestion territoriale des adventices : effets des propriétés du paysage sur les communautés adventices et sur leur régulation par les carabidae

Landscape-scale management is known to affect pest and biodiversity levels in agroecosystems. Here, we focus on the lanscape drivers of arable weeds, first by reviewing evidence of direct landscape effects on weed species richness and abundance and then by analyzing current knowledge on landscape effects on carabids, which are well-known weed seed predators that contribute to the biological regulation of weeds. Our analysis shows that (i) heterogeneous landscapes usually harbor higher species richness and more diversified communities than simple ones, (ii) total weed and carabid abundances appear seldomly affected by the landscape context of arable fields and (iii) weed seed predation in fi…

The influence of oilseed rape and grasslands on the abundance of weed seed-eating carabids at different spatial scales

National audience

Identification of weed community traits response to conservation agriculture

International audience; Conservation agriculture is designed to deliver more sustainable cropping systems by preserving agricultural soils with tillage abandonment. However, knowledge on the impacts of Conservation agriculture adoption on weed infestation level and potential shifts in the composition of weed communities appears low and contradictory. We used a trait-based approach to investigate whether there are shifts in values of a set of traits within weed communities following the adoption of Direct Drilling with cover-crop (DD) which is one of the Conservation Agriculture practices. Weed surveys were conducted across a range of times since conversion to DD in 52 winter wheat fields lo…

Régulations biologiques des adventices: la prédation par les carabidés en semis direct sous couvert

Traits de réponse de la flore adventice à la mise en place du semis direct sous couvert

Conservation Agriculture is designed to deliver more sustainable cropping systems by preserving agricultural soils with tillage abandonment. However, knowledge on the impacts of Conservation Agriculture adoption on weed infestation level and potential shifts in the composition of weed communities appears low and contradictory. We used a trait-based approach to investigate whether there are shifts in values of a set of traits within weed communities following the adoption of Direct Drilling with cover-crop (DD) which is one of the Conservation Agriculture practices. Weed surveys were conducted across a range of times since conversion to DD in 52 winter wheat fields located in north-eastern F…

The spatial and temporal distribution of carabid and weed seed predation in winter wheat: a comparison between conventional and conservation agriculture systems

Carabids can be key players in weed seed predation within arable crops under temperate climate. Field management options, because they affect carabid communities, may represent potential levers to increase weed seed predation levels within fields. Among these options, Conservation Agriculture is often presented as a promising management option for carabids but its effect on weed seed predation levels is less clear. In this study, carabids and weed seed predation were monitored using a grid sampling from April till September 2011 in two adjacent winter-wheat fields in North-eastern France, one conducted as no-till with cover crop for 5 years (conservation agriculture) and the other as conven…

Influence du colza et des prairies à différentes échelles spatiales sur l’abondance des carabes prédateurs de graines d’adventices

National audience; Les coléoptères carabidae sont très représentés dans les cultures annuelles où ils peuvent contribuer au contrôle biologique de bioagresseurs. Ainsi, les carabes omnivores et granivores consomment des quantités importantes de graines de plantes adventices. Des études récentes suggèrent que la réponse des communautés de carabes à l’organisation du paysage est en partie dépendante de leur guilde trophique. Néanmoins, dans le cas de carabes consommateurs de graines d’adventices, on connait peu les types d’occupation du sol qui les favorisent au sein d’un paysage et l’échelle spatiale à laquelle ces insectes répondent. Ici, nous avons analysé les variations de l’abondance de …

Ragweed seed predation by invertebrates in cultivated area

National audience

First results of weed evolution in no tillage systems in winter wheat in France

International audience; The adoption of no-tillage is presently a strong trend in Europe. If this cropping system is to be widely adopted in the 1980s in the North and South America, in Australia, no tillage is used by few farmers in France where agriculture and tillage are considered synonymous by farmers and agronomists. Weed infestation is generally described as to increase when the selection pressure due to soil tillage is reduced. The European strengthened regulations on herbicide used and the ban of transgenic crop in France does not facilitate the development of non-tillage. This communication presents the first results on the evolution of weed communities on farmer’s fields in East …

Effet de l'adoption du semis direct sous couvert sur la composition des communautés adventices

National audience

Peut-on identifier des traits de réponses des adventices au semis direct ?

International audience