agronomist vs cultivator

agronomist

noun
  • A scientist whose speciality is agronomy. 

cultivator

noun
  • A person who cultivates. 

  • Any of several devices used to loosen or stir the soil, either to remove weeds or to provide aeration and drainage. 

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