Why does Okonkwo seek refuge in his motherland in "Things Fall Apart"?

Okonkwo has no choice but to seek refuge in his
motherland.  In Things Fall Apart we learn that in Ibo society, when a woman marries,
she goes to her husband's family and resides with them.  Thus Okonkwo lives in his
father's village.  When he is exiled from his fatherland, he is forced to return to his
motherland and live there for seven years.  His mother's family receives him and
provides a place for he and his family to live.  But he isn't allowed to take much with
him and has to leave all of his seed yams behind.  We learn in the book that a man's
wealth relies heavily on the number of yams he has and grows, so Okonkow's masculinity
is greatly reduced in his exile through his forceable domicilary with his mother's
family and the loss of his yam stores.