study of prehistoric human customs, 1878, from agrio-, from Greek agrios "wild," literally "living in the fields," from agros "field" (from PIE root *agro- "field") + -logy. Related: Agriologist (n., 1875); agriological.
It is the hypothetical source of/evidence for its existence is provided by: Sanskrit ajras "plain, open country," Greek agros "field," Latin ager (genitive agri) "a field," Gothic akrs, Old English æcer "field."
word-forming element meaning "a speaking, discourse, treatise, doctrine, theory, science," from Greek -logia (often via French -logie or Medieval Latin -logia), from -log-, combining form of legein "to speak, tell;" thus, "the character or deportment of one who speaks or treats of (a certain subject);" from PIE root *leg- (1) "to collect, gather," with derivatives meaning "to speak (to 'pick out words')." Often via Medieval Latin -logia, French -logie. In philology "love of learning; love of words or discourse," apology, doxology, analogy, trilogy, etc., Greek logos "word, speech, statement, discourse" is directly concerned.
<a href="https://www.etymonline.com/word/agriology">Etymology of agriology by etymonline</a>
Harper, D. (n.d.). Etymology of agriology. Online Etymology Dictionary. Retrieved $(datetime), from https://www.etymonline.com/word/agriology