churl vs son of the soil

churl

noun
  • A rough, surly, ill-bred person; a boor. 

  • A free peasant (as opposed to a serf) of the lowest rank, below an earl and a thane; a freeman; also (more generally), a person without royal or noble status; a commoner. 

  • A bondman or serf. 

  • A freedman, ranked below a thane but above a thrall. 

son of the soil

noun
  • A man raised in an environment of agricultural labour. 

How often have the words churl and son of the soil occurred in a corpus of books? (source: Google Ngram Viewer )