landfill vs leaf litter

landfill

noun
  • A site at which refuse is buried under layers of earth. 

  • The material so disposed of. 

verb
  • To dispose of (garbage) by burying it at a landfill site. 

leaf litter

noun
  • Dead plant material, such as fallen leaves, bark, and twigs, that has fallen to the ground and may be used by animals as habitat or for nest-building, eventually decomposing and releasing nutrients into the soil. 

How often have the words landfill and leaf litter occurred in a corpus of books? (source: Google Ngram Viewer )