Why were slaves the high demand in the southern colonies

Most of the southern people back then owned land so they would grow their own crops but they would have the slaves work for them to get the crops as well as taking care of them, They would also just use them for anything else they wanted done but didn't want to do it. They would also have companies but the workers would have to be slaves and then they wouldn't have to take care of them or have anything to do but have them work.

Because there was land and there was warm temperature a the slaves could not go to the north