Etude multi-site d’une nouvelle approche du travail du sol en maraîchage biologique : les planches permanentes

English. The effect of controlled traffic with permanent crop beds was compared to mouldboard ploughing inFrance for organic vegetable production. Four trials were carried out over a period of three to sevenyears at four sites with different pedo-climatic conditions. Variable results were obtained, depending onsoil type (susceptibility to compaction), tillage machinery type, vegetable type (root or not, grown fromseed or transplant) and weed development. However, our study shows that a permanent bed system isan interesting alternative that improves soil biological activity and decreases labour time using a tractor,leading to significant energy savings. However, this method has limitations depending on pedo-climaticconditions and the lack of suitable equipment. Further research is required to determine the soil tillagetechniques to be used according to pedological conditions (silty soils, for instance), to improve weedcontrol and to ensure the incorporation of fresh organic matter (crop residues and green manure).

French. La pratique des planches permanentes a été évaluée en France sur quatre parcelles cultivées enmaraîchage biologique en conditions pédo-climatiques contrastées. Après 3 à 7 ans de pratique, lesrésultats sont assez différenciés selon le type de sol (plus ou moins sensible à la compaction), lematériel utilisé, le type de légume (planté ou semé, racine ou non) et la pression des adventices. Lasuppression du labour sur cet itinéraire a permis d'augmenter l'activité biologique et de diminuer jusqu'à30% les temps de travaux.