29 research outputs found
EnquĂȘte semis direct sous couvert vĂ©gĂ©tal transition agronomique et Ă©volution des problĂšmes malherbologiques
National audienceUne Ă©quipe de lâInrae de Dijon (UMR AgroĂ©cologie) a enquĂȘtĂ© sur la pratique du semis direct sous couvert et ses effetssur lâĂ©volution de la flore adventice. Une enquĂȘte nĂ©cessaire, Ă laquelle a participĂ© TCS. En voici les rĂ©sultats
Evolution des problĂšmes malherbologiques Ă lâadoption du semis direct sous couvert
National audienceLe semis direct sous couvert regroupe un ensemble de pratiques appliquĂ©es simultanĂ©ment en vue de rĂ©pondre Ă trois principes : rĂ©duction totale du travail du sol, couverture optimale des sols et diversification de la succession culturale. Cette approche reprĂ©sente, en France, une stratĂ©gie innovante qui semble convaincre de plus en plus dâagriculteurs. En se privant du travail du sol, la gestion des adventices en semis direct sous couvert devient plus complexe, ce qui limite lâadoption gĂ©nĂ©ralisĂ©e du semis direct sous couvert. Afin dâĂ©clairer les problĂšmes malherbologiques rencontrĂ©s en semis direct sous couvert, un questionnaire en ligne Ă destination des agriculteurs a Ă©tĂ© diffusĂ©e en France. Les adventices les plus problĂ©matiques (trois Ă cinq) Ă©taient demandĂ©es pour diffĂ©rents moments : avant adoption du semis direct sous couvert, post adoption et lorsque la gestion des adventices est considĂ©rĂ©e comme maitrisĂ©e par les agriculteurs. 425 rĂ©ponses complĂštes ont Ă©tĂ© enregistrĂ©es. Avec un pourcentage de citations qui diminue dĂšs lâadoption du semis direct sous couvert, les espĂšces adventices annuelles restent problĂ©matiques pour les agriculteurs dans ce systĂšme. Les pourcentages de citations pour les espĂšces Ă cycle de vie pluriannuel augmentent Ă lâadoption du semis direct sous couvert puis Ă la maĂźtrise du systĂšme. Les chardons (cirses) deviennent le taxon le plus problĂ©matique citĂ© par les agriculteurs. Evolution of weed problems when adopting direct seeding under cover Direct seeding under cover combines systems with almost total reduction of tillage, optimal soil cover and diversification of rotation. This set of systems represents in France an innovative strategy adopted each year by more and more farmers. Without tillage, weed control becomes a challenge for farmers and weeds an obstacle for the system spread. In order to clarify the weed problems encountered after the adoption of direct seeding under cover, a farmer survey was broadcast in France. Most problematic weeds (tree to five) were asked for different times: before adopting direct seeding under cover, after the adoption and when the system is considered as a controlled system when referring to weed management. 425 French completed answers were recorded. Since direct seeding under cover is adopted, annual weed become less cited by farmers but still represent a large part of weed problems. Certain weeds with a multiannual cycle seem to cause more and more problems. According to farmers, thistles become the main weed problem in direct seeding under cover
Weed Management in the Transition to Conservation Agriculture: Farmersâ Response
National audienceRecently adopted in France, conservation agriculture still faces some challenges to its adoption, particularly weed management. To highlight the weed management practices used by farmers in conservation agriculture and the changes induced by its adoption, a large sample of 425 French farmers were invited to complete an online survey. Weed management practices used by farmers were requested for three periods: before adoption, during the first years of conservation agriculture (one to two years after adoption), and when the agricultural system is considered âmasteredâ by the farmer. The use of each farming practice was firstly studied independently for each period. Then, a multiple correspondence analysis followed by a hierarchical ascendant classification resulted in groups of farmers with different combinations of practices for each period. Finally, the groups of farmers were followed through the periods. Results showed that changes in weed management done according to farmers when adopting and mastering conservation agriculture are multiple and vary according to farmers and their previous weed management. Although some similar choices were identified, some farmersâ trajectories, especially those with a prior combination driven by either a soil disturbance strategy or a crop competitiveness strategy, are difficult to identify when adopting conservation agriculture. Upon mastering the agricultural system, farmersâ choices become more apparent
Ah, pas de géante ! L'ambroisie trifide Ambrosia trifida
National audienceLâambroisie trifi de (Ambrosia trifi da L., 1753) est une plante annuelle de la famille des astĂ©racĂ©es. Elle est originaire dunord de lâAmĂ©rique et a Ă©tĂ© introduite en France au dĂ©but du XXe siĂšcle. Ambrosia trifi da est aujourdâhui signalĂ©e enparcelles cultivĂ©es, en rĂ©gion Occitanie, et plus rĂ©cemment en rĂ©gion Auvergne-RhĂŽne-Alpes
Ătude des communautĂ©s adventices et semis direct sous couvert â mĂ©thodologies et premiers rĂ©sultats
National audienceLâestimation des changements de flore liĂ©s Ă la mise en place dâun nouveau type de systĂšme de culture pose des questions sur le type dâĂ©chantillonnage Ă rĂ©aliser. Si les relevĂ©s de type « parcours » sur une zone de la parcelle semblent les plus satisfaisants pour capter les changements de diversitĂ© spĂ©cifique, le choix du nombre et de la pĂ©riode de relevĂ©s pose encore question afin dâobtenir des jeux de donnĂ©es les plus satisfaisants possibles pour rĂ©pondre aux objectifs fixĂ©