Nitrification inhibitors are also known as nitrogenous fertilizer synergists. Nitrification inhibitors have long been used to increase crop yields so we have preliminary knowledge of nitrification inhibitor. In China, Lvda light chemical engineering institute studied the nitrification inhibitor at first and achieved great results.

The purpose of applying nitrogen fertilizer synergizer is to inhibit the propagation and activity of nitrifying bacteria in soil, so as to inhibit the transformation from ammonium nitrogen to nitrate nitrogen and the denitrification process of nitrate nitrogen, and finally it improves the utilization rate of nitrogen fertilizer.

Nitrogen fertilizer synergist should have the following characteristics:

(1)The inhibition effect of nitrification is good, without hydrolyzing fertilizers and organic fertilizers in the soil. It does not hydrolyze fertilizers and organic fertilizers in the soil.

(2)It is not easy to decompose and lose. It is stable in the soil and does not affect farming operations.

(3)It is safe for people, crops, etc.

(4)The application effect of chemical fertilizer will not be affected.

(5)It can be evenly mixed with fertilizer without deterioration.

(6)It is cheap, and consumption is small.

In foreign countries, since the 1950s, in order to improve nitrogen utilization, foreign scholars have been working on research of nitrification inhibitors. A company in the United States developed 2-chloro-6-trichloromethyl pyridine. It is the first nitrification inhibitor variety. In Japan, there was a systematic study in Triazine derivatives. They then added thiourea and amino-4-chloro-6-methyrimidine to study on compound fertilizer. Soviet Union also carried out tests on dicyandiamide and thiourea. After decades of efforts, domestic and foreign research on the application effect of nitrogen fertilizer synergist in agriculture has achieved some results, proving that nitrogen fertilizer synergist has the following effects in agriculture:

(1)Nitrogen fertilizer synergist can improve the utilization rate of nitrogen fertilizer. In Japan, fertilizer efficiency can be increased by about 20% by applying nitrogen fertilizer synergistic agent containing about 0.5-5% of nitrogen into the soil.

(2)Nitrogen fertilizer synergist can improve crop yield. The highest yield of rice could be increased by 86.2% by applying nitrogenous fertilizer with synergistic agent.

(3)Soil properties can be improved to reduce the rate of soil acidification and create favorable conditions for the growth of crops.

(4)Adding nitrogen fertilizer synergist in fertilizer can reduce the harm of bacteria to crops. It can prevent the root rot and it is good for the growth of crops.

(5) Some varieties of nitrogen fertilizer synergist also have the efficacy of sterilization and insecticide.