What are the ways to choose the varieties of nitrogen fertilizer?

There are many kinds of nitrogen fertilizer, which can be divided into ammonium nitrogen fertilizer, nitrate nitrogen fertilizer and amide nitrogen fertilizer according to the form of compounds. Ammonium nitrogen fertilizer includes ammonium bicarbonate, ammonium sulfate, ammonium chloride, ammonia, liquid ammonia, etc.; nitrate nitrogen fertilizer includes ammonium nitrate, sodium nitrate, calcium nitrate, etc.; amide nitrogen fertilizer includes urea, calcium cyanide (lime nitrogen) and so on. In order to improve the application effect of nitrogen fertilizer, it is very important to select nitrogen fertilizer varieties scientifically.

Generally speaking, crops with high carbohydrate content, such as potatoes, are suitable to apply ammonium nitrogen fertilizer. The application of ammonium nitrogen and nitrate nitrogen to cereal crops such as wheat and corn is also effective, but in rainy areas, it is still appropriate to apply ammonium nitrogen fertilizer in order to prevent nitrogen leaching. Urea and ammonium chloride should be used in paddy field, but ammonium sulfate and nitrate nitrogen fertilizer should not be selected. Because sulfate is easy to be reduced to hydrogen sulfide in paddy field, which makes rice root blacken or even rot, nitrate is easy to leach with water and denitrification in paddy field, resulting in nitrogen loss. Ammonium chloride is suitable for hemp crops, because chloride ion can increase the toughness and tension of the fiber. The effect of combined application of nitrate nitrogen and ammonium nitrogen is good, nitrate nitrogen can improve the flammability of tobacco, while ammonium nitrogen can promote the formation of aromatic volatile oil in tobacco leaves and increase the aroma of tobacco. the combined application of the two forms of nitrogen fertilizer can improve its quality.

The application of ammonium sulfate in sulfur-deficient soil helps to improve the sulfur nutrition of crops. On the other hand, ammonium chloride should not be applied to the chlorine-sensitive crops such as potato, sweet potato, sugar beet, citrus and tea, otherwise it will obviously affect its yield and quality.