Umanyolo we-NPK uyinto efakwa enhlabathini ukuze inikeze izakhi ezimbili noma ngaphezulu ezidingekayo ekukhuleni nasekukhiqizeni izitshalo. Izivundisi ze-NPK zithuthukisa ukuvunda kwemvelo komhlabathi noma esikhundleni samakhemikhali athathwe enhlabathini ngokuvuna, ukuklaba, ukucwilisa noma ukuguguleka. Ama-fertilizer okwenziwa ama-inorganic fertilizer akhiwe ngendlela efanele futhi izinhlanganisela zinikeza izakhamzimba ezimbili noma ezintathu eziyinhloko: I-nitrogen, i-Phosphorus ne-Potassium (N, P kanye no-K) yezitshalo ezihlukahlukene nezimo zokukhula. I-N (Nitrogen) ikhuthaza ukukhula kwamaqabunga futhi yakha amaprotheni kanye ne-chlorophyll.