The southern colonies (and the colonies in the Caribbeans) required slave labor and indentured servants to maintain plantations that grew valuable crops such as sugar canes and tobacco. Harvesting these crops were often labor intensive that many free workers were unwilling to do without high wages that plantation owners did not wish to pay. These crops could only be grown in the south (or the Caribbean) due to the soil and climate.
The lands used in agriculture
"Feudus" is a term from latin and describes the relationship between the nobil and a vassal. Tha vassal worked the nobil land in exchange for products, money or other obligations