why does the land seem to represent the father

The land represents a sense of freedom and ownership to father Logan. Owning their farm validates them as people regardless of how badly whites treat them. At one point father Logan explains the significance of a fig tree,

But that fig tree’s got roots that run deep, and it belongs in that yard as much as that oak and that walnut. It keeps on blooming, bearing good fruit year after year, knowing all the time it’ll never get as big as them other trees. Just keeps on growing and doing what it gotta do. It don’t give up. It give up, it’ll die. There’s a lesson to be learned from that little tree, Cassie girl, ‘cause we’re like it. We keep doing what we gotta, and we don’t give up. We can’t.”

The tree becomes a metaphor for their own struggle