WordNet records no synonym and no antonym for nitrification. It is the only member of each of its synsets, which is common for technical, taxonomic and single-sense vocabulary — there is no other English word that means the same thing. The broader and narrower terms below are the useful relations in that case.
Counts are distinct word forms across every sense. A synonym that appears under three senses is counted once here and shown three times below, under each sense it belongs to.
the chemical process in which a nitro group is added to an organic compound (or substituted for another group in an organic compound)
the oxidation of ammonium compounds in dead organic material into nitrates and nitrites by soil bacteria (making nitrogen available to plants)
Synonyms, antonyms and the broader and narrower relations for nitrification come from Princeton University’s WordNet. Full sources and licences.