Nitrate Nitrogen and Ammonium Nitrogen硝态氮与铵态氮
Nitrate nitrogen (NO₃⁻-N) and ammonium nitrogen (NH₄⁺-N) are the two inorganic nitrogen forms plants can take up directly. Their behaviour in soil differs markedly, and they are therefore suited to different situations.
Key points
- Ammonium nitrogen carries a positive charge and is readily held by the negatively charged soil colloid, so it moves little and leaches less; nitrate nitrogen carries a negative charge, is not retained and moves readily with water.
- Under waterlogged or poorly aerated conditions nitrate nitrogen is prone to denitrification and is lost as nitrogen gas or nitrous oxide — the latter a potent greenhouse gas.
- Ammonium nitrogen volatilises as ammonia from the surface of alkaline soils, which is why deep placement of ammonium-bearing fertilizer outperforms surface application.
- Under GB/T 15063-2020, nitrate nitrogen in compound fertilizer is tested only where the package declares its presence, and the limit is ≥1.5%.
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Category and source
- Category：Quality and labelling
- Definition basis：GB/T 15063-2020 Compound Fertilizers
Updated：Oct 16, 2026