The French agronomist Mathieu de Dombasle (1777-1843) became famous thanks to his research into a type of swing plough and new practices. Actually he has invented nothing but used the principles of the 18th century new agriculture. Nevertheless he is credited for a large spreading of his adeas and of his plough. He is really an innovator for the several means of diffusion he used. The aim of this article is the study of the inception of this innovation for tillage during the first mid 19th century : "Dombasle's plough" (without front of axle unit), from its conception until its recognition by his peers in 1820-1821. Hereafter we stress Mathieu de Dombasle method, between empiricism and theory, analyzing how the farmers have changed their practices when they used this new plough mithout wheels. From the beginning of the 19th century, theorising and putting these theories into practice in field are the two main tasks for the agronomist, implemented by Mathieu de Dombasle though this was only the genesis of such a process. Not only was he a ploughs designer but he also elaborated new farmer's practices he largely spread. This is the setting up of an innovating agronomy.

L'agronome lorrain Mathieu de Dombasle (1777-1843) est considéré comme un inventeur d'instruments aratoires perfectionnés, comme la charrue sans avant-train, et de pratiques nouvelles. En fait, il n'a rien inventé au sens propre mais il a réinvesti l'héritage de l'agriculture nouvelle du XVIIIème siècle et s'est distingué par la manière dont il a diffusé ses idées et ses machines agricoles. Dans le présent article, nous nous proposons d'analyser la genèse d'une innovation de première importance en matière de travail du sol dans la première moitié du XIXème siècle : la conception de la charrue "Dombasle" jusqu'à la reconnaissance de Mathieu de Dombasle par ses pairs en 1820-1821. La démarche "dombaslienne", oscillant entre empirisme et théorie est expliquée, tandis que l'on met plus particulièrement l'accent sur les modifications des pratiques des agriculteurs qui utilisent le nouvel instrument aratoire.