This film is much deeper than it appears to be. On the surface, it looks like a struggling poor family in a rural setting. Look again. On one level it is a family with their own set of relational problems. Like Tolstoy said, "All happy families are alike; each unhappy family is unhappy in its own way."
But this particular unhappy family is set against the socio-economic background of an impersonal agri-business. The agri-business, not only complicates their unhappiness, but also, slowly murders it's victims.
It is not a huge, impossible leap of imagination to cast this story onto the laborers of Amazon or Uber - workers that slave for hours without bathroom breaks for ultra-rich, off-screen masters. The parallel is painfully present in this film.
Never mind the intentional long shots of endless sugar cane fields that destroyed a once present beauty. Never mind the dark lighting of the family that remained. An important trivia here: the English translation of the title is wrong (imho). Sombra also means shadow. This family lives in a shadow. The title should be "Land and Shadow". But the shadow of what? That's what makes this film socially significant.