This mostly depended on the fertility of the soil nearby the manor, the amount of serfs a lord had and the trade that he had set up with other manors. The reason for this is that if a manor had fertile soil, the lord had set up ample trade between manors, and therewere enough serfs to work on the land, they were pretty much self-suficient. However, if these things were lacking, then self-sufficiency was not necessarily achieved.