This text tackles the various problems concerning with the variety of agrarian contracts, the income evolution and the specific mechanisms which ruled the commercialization of agrarian surplus from the 16th to the 19th century. The author points out that manorial managing ability, of the time of increasing their pressure over tenant farmers, varied considerably among regions in accordance to the different property relationships. He also insists on the fact that the process or surplus commercialization was considerably conditioned by agrarian structure, by other technical and organizational factors, and by the own "manorial constitution" of society.