What kinds of nitrogen fertilizers are there?

What kinds of nitrogen fertilizers are there? What are the characteristics? Also ask the netizens who know to help introduce the types of nitrogen fertilizers such as ammonium bicarbonate, urea, ammonium chloride and ammonium nitrate. The characteristics of the farming network are listed below for netizens' reference. 1, the characteristics of ammonium bicarbonate: general ammonium bicarbonate nitrogen content is about 17%, is chemically unstable white crystal, easy to absorb moisture and decompose, easy to volatilize, has a strong pungent, eye-smoking ammonia smell, the greater the humidity, the higher the temperature, the faster the decomposition, easy to dissolve in water, showing an alkaline reaction (pH8.2-8.4). Ammonium bicarbonate is an unstable compound, which decomposes completely at atmospheric pressure and temperature up to 70 ℃. When the temperature is 20 ℃, the loss rates of 1 day, 5 days and 10 days are 9%, 48% and 74%, respectively. It is easy to absorb moisture, dissolve and agglomerate in a humid environment (caking itself is a sign of slow decomposition). In the process of storage and application, corresponding measures should be taken to prevent its volatilization loss. Suitable for all kinds of soil and crops, it is suitable to be used as base fertilizer, and attention should be paid to deep covering soil when topdressing. 2. The characteristics of urea: the nitrogen content of general urea is about 46%. Common urea is white crystal and has strong hygroscopicity. At present, most of the urea produced are translucent particles and have been treated with anti-moisture absorption. When the temperature is 10-20 ℃, the hygroscopicity is weak, and with the increase of air temperature and humidity, the hygroscopicity increases. Urea is a neutral fertilizer, and long-term application has no side effects on the soil. After being applied to the soil, it is easy to be hydrolyzed into ammonium carbonate by the action of urease secreted by soil microorganisms and absorbed by crops. The hydrolysis rate of urea is not only related to soil acidity, humidity and temperature, but also affected by soil type, ripening degree and fertilization depth. In general, the time for urea to hydrolyze into ammonium carbonate is about 10 days at 10 ℃, 4-5 days at 20 ℃, and 2 days at 30 ℃. Therefore, the fertilizer effect of urea is relatively slow, and topdressing should be made in advance. Urea is suitable for all kinds of soil and crops, and can be used as base fertilizer, topdressing and foliar spraying (spraying concentration is 1-2%). 3. The characteristics of ammonium chloride: the nitrogen content of ammonium chloride is generally about 24-25%, which is white crystal, easy to dissolve in water, small hygroscopicity, no caking, good physical shape and easy to store. Ammonium chloride is acidic and is also a physiologically acidic fertilizer. Ammonium chloride should not be applied to acid soil, saline-alkali soil and chlorine-avoiding crops (fruit trees, tobacco, etc.). Chloride ion has a certain inhibitory effect on nitrifying bacteria, and the nitrification leaching effect of nitrogen applied to soil is weaker than that of other nitrogen fertilizers. Therefore, ammonium chloride is a better nitrogen fertilizer in paddy field. The application of ammonium chloride should be combined with watering to try to leaching chloride into the subsoil so as to reduce its adverse effects on crops. Ammonium chloride is not suitable to be used as seed fertilizer. 4. The characteristics of ammonium nitrate: the general nitrogen content of ammonium nitrate is about 33-35%. There are two kinds of ammonium nitrate: crystalline and granular, the former has strong hygroscopicity, while the latter has slightly worse hygroscopicity because of the anti-moisture agent on the surface. Ammonium nitrate is soluble in water and pH is neutral. Ammonium nitrate contains both ammonium nitrogen (NH4+-N) with less mobility in soil and nitrate nitrogen (NO3--N) with higher mobility, both of which can be well absorbed and utilized by crops. Therefore, ammonium nitrate is a good nitrogen fertilizer which does not leave any substance in the soil, and it is a physiological neutral fertilizer. Ammonium nitrate should be used as topdressing fertilizer for crops in dry fields, and it is more economical to apply it in small amounts. It is not suitable to be applied in paddy field or as base fertilizer or seed fertilizer. Click to get more nitrogen, phosphorus, potassium application techniques click to get more chemical fertilizer application techniques