scientific agriculture vs agronomy

scientific agriculture and agronomy both are nouns.

Word	Noun	Adjective	Verb	Adverb
scientific agriculture	Yes	No	No	No
agronomy	Yes	No	No	No

As nouns, scientific agriculture and agronomy are synonyms defined as:

scientific agriculture and agronomy: the application of soil and plant sciences to land management and crop production

scientific agriculture (noun)	agronomy (noun)
the application of soil and plant sciences to land management and crop production	the application of soil and plant sciences to land management and crop production