agronomy vs harvesting

agronomy

noun
  • The science of utilizing plants, animals and soils for food, fuel, feed, and fiber and more. To do this effectively and sustainably, agronomy encompasses work in the areas of plant genetics, plant physiology, meteorology, animal sciences and soil science. 

harvesting

noun
  • The gathering of a mature crop; a harvest. 

  • The gathering of any resource. 

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