Nitrification inhibitor is commonly known as nitrogen fertilizer synergist. It is the raw material of stable fertilizer. Thus, nitrification inhibitors are a class of substances that can improve the stability of ammonium and urea and increase the efficiency of nitrogen fertilizer in this way.

Common nitrification inhibitors are listed as follows: nitrogen-pyridine, code is CP and trade name is n-serve. Americans tend to add nitrification inhibitor in this way. In autumn, they add nitrogen containing fertilizer or nitrification inhibitor. In spring, they aslo add nitrogen containing fertilizer or nitrification inhibitor. The crops are rice, sorghum and wheat. The appropriate amount of nitrogen-pyridine is about 1% of the effective composition of nitrogen fertilizer. When its concentration in soil is 1-100ppm, it has obvious inhibitory effect on soil nitrification. It is valid for 30 days. In the 1980s, experiments by the Chinese academy of agricultural sciences showed that it can increase yield or save fertilizer on rice, corn, wheat, sorghum, cotton, rubber and rape. However, domestic and foreign experiments show that it has an inhibitory effect on the growth and development of leguminous crops. For example, the continuous application of the residues has residual toxin to the later soybean and has a tendency to reduce soybean yield.

Dicyandiamide, the code is DCD. Under the influence of dicyandiamide, the ammonium in the fertilizer can be stabilized for 6-8 weeks, depending on the total amount of nitrogen applied, the proportion of dicyandiamide added as well as soil temperature and humidity. Dicyandiamide fertilisers can be used in most crops. Nitrogen containing fertilizer includes ammonium sulfate, ammonium nitrate sulfate, urea and ammonium nitrate urea, etc. The appropriate addition proportion is that Dicyandiamide nitrogen accounted for 5%-10% of the total nitrogen. Within one month after application, it has obvious inhibitory effect on soil microorganisms. It will become normal after two and a half months. The application amount is 10% of the amount of nitrogen fertilizer (in terms of active ingredients). Dicyandiamide is both synergistic and slow acting nitrogen fertilizer.

3,4 -- dimethylpyrazole phosphate, code is name DMPP, and trade name is "ENTEK". The effect of saving nitrogen and increasing yield has been preliminarily obtained through the application test on crops such as potato, summer maize, banana.

In recent years, this kind of stable fertilizer has developed rapidly, and there are many items in the market. Farmers often ask about the application principles of this kind of fertilizer, which are summarized as follows:

The first step is to understand and choose. The nitrification inhibitor production enterprises should indicate truthfully on the product packing bag and cannot substitute the real with the virtual such as indicating the type of nitrification inhibitors, the amount added, and nitrogen fertilizer dosage range. Different kinds have appropriate addition amount. Some proportion is 0.25%, and others are 0.7%-1%, etc.

The effect of nitrification inhibitors varies with the application conditions. For example, it shows increased yield in the grain crops of irrigated land, shows uncertain fertilizer effect in vegetable crops and shows reduced yield in leguminous crops. Paddy fields are better than dry fields and so on according to soil conditions.

At present, there are many kinds of products in the market. Which kind to choose for farmers depends on two aspects. First, the results of field tests and the quality of products should be taken into consideration. Second, pay attention to whether it is safe for people, animals and seedlings. Have fewer side effects to beneficial microorganisms such as soil rhizobium.