Nitrogen fertilizers are inorganic and organic substances containing nitrogen, which are introduced into the soil to increase yields. To mineral nitrogen fertilizers include amide, ammonium and nitrate. Nitrogen fertilizers are obtained mainly from synthetic ammonia. Due to the high mobility of nitrogen compounds, its low content in the soil often limits the development of cultivated plants, so the introduction of nitrogen fertilizers has a great positive effect.

Of all types of fertilizers, nitrogen is most susceptible to action from soil microorganisms. In the first week after applying up to 70% of the mass of fertilizer consumed by bacteria and fungi (immobilized), only after their death, the nitrogen that enters into their composition can be used by plants. Large losses of nitrogen fertilizers are due to the removal of readily soluble nitrates and ammonium salts from the soil profile, as well as during denitrification (gaseous losses) and due to nitrification (formation of nitrates and their removal). As a result, the utilization rate of fertilizers by plants rarely reaches 50%, their use can cause eutrophication of nearby water bodies. The N2O formed during denitrification is a strong greenhouse gas.