Nitrogen fertilizers are substances or mixes of them containing one of the basic elements for plants – nitrogen. This is the element, which could be assimilate only through roots and not like e.g. oxygen from air. Therefore proper selection of this component in fertilizers is extremely important element in crops.

The most popular nitrogen fertilizers are divided into two groups depending on the location of the nitrogen in the molecule – it could create nitrate group and nitrate compounds (saltpeters), or ammonia group in amonia fertilizers.

Main saltpeters are:
– calcium nitrate Ca(NO₃) – norwegian saltpeter,
– potassium nitrate KNO₃ – indian saltpeter,
– sodium nitrate NaNO₃ – chile saltpeter,
– ammonia nitrate NH₄NO₃ – rich in nitrogen.

Main ammonia fertilizers, except nitrate, are:
– ammonia sulfate – NH₄SO₄,
– ammonia chloride – NH₄Cl,
– ammonia carbonate – NH₄CO₃.

Very popular fertilizer is widely used carbamide (urea), which is organic amide compound with high nitrogen content. Additionaly as nitrogen fertilizers also we could be called variety of animal waste, properly crafted and granulated: fish meal, meat, horn etc.