organic fertiliser vs organic fertilizer

organic fertiliser and organic fertilizer both are nouns.

Word	Noun	Adjective	Verb	Adverb
organic fertiliser	Yes	No	No	No
organic fertilizer	Yes	No	No	No

As nouns, organic fertiliser and organic fertilizer are synonyms defined as:

organic fertiliser and organic fertilizer: a fertilizer that is derived from animal or vegetable matter

Other synonyms of organic fertiliser include organic.

organic fertiliser (noun)	organic fertilizer (noun)
a fertilizer that is derived from animal or vegetable matter	a fertilizer that is derived from animal or vegetable matter