How did technology hurt the tenant farmers?

The tenant farmers are being replaced by machines..... new tractors, the "machine man". Because of this, many of the tenant farmers are no longer needed.

"..... the machine man, driving a dead tractor on the land he does not know and love, understands only chemistry; and he is contemptuous of the land and of himself. When the corrugated iron doors are shut, he goes home, and his home is not the land."