horizon vs soil horizon

horizon and soil horizon both are nouns.

Word	Noun	Adjective	Verb	Adverb
horizon	Yes	No	No	No
soil horizon	Yes	No	No	No

As nouns, soil horizon is a hyponym of horizon; that is, soil horizon is a word with a more specific, narrower meaning than horizon:

horizon: a specific layer or stratum of soil or subsoil in a vertical cross section of land
soil horizon: a layer in a soil profile

Other hyponyms of horizon include geological horizon.

horizon (noun)	soil horizon (noun)
the range of interest or activity that can be anticipated	a layer in a soil profile
the line at which the sky and Earth appear to meet
a specific layer or stratum of soil or subsoil in a vertical cross section of land
the great circle on the celestial sphere whose plane passes through the sensible horizon and the center of the Earth