Potassium Nitrate (NOP) is an alkali metal nitrate used in fertilizers as a source of nitrogen and potassium – two of the macro-nutrients for plants. NOP is most common use & typical water soluble potash fertilizer can be sed to fertigation, nutrigation, foliar nutrition. Quick release & fast acting.It is not very hygroscopic, oxidative in acidic environment, can react explosively with reducing agents but it is not explosive on its own.