DCD is the first reported compound with nitrification inhibition. In the 1970s and 1980s, the United States began to promote and apply it as a commodity in agriculture. DCD has remarkable nitrification inhibition effect. In the condition of T < 15 ℃, the inhibition rate can reach more than 80%. The inhibition lasted for six months. Nitrogen content in DCD is high (66.7%). When applied to the soil, it can play an role of slow-release nitrogen fertilizer. It can be completely degraded into CO2, NH3 and H2O in the soil without pollution to the environment. DCD has low volatility. It is suitable to be combined with solid nitrogen fertilizer. It is more easily soluble in water, so in addition to the function of mixing with fertilizer as a cooperative inhibitor, it can also be combined with liquid organic manure such as cow manure or livestock manure to inhibit nitrification to to reduce the leaching loss of nitrate nitrogen.
When the application amount of nitrification inhibitor
DMPP 0.5~1.5KG`hm-2, the nitrification inhibition under field conditions can last for 4-10 weeks. When it is uniformly distributed in the soil, 0.39 μgDMPP`g-1 soil can have the remarkable nitrification inhibition effect. Compared with DCD, the degradation rate of DMP in soil is slow. At the end of a growing season, DCD can be fully mineralized, while DMPP remains at 16% of the initial application amount. Due to the adsorption of soil colloid and organic matter, the mobility in the soil is very limited and it is not easy to separate from NH4+ in the soil profile and generate the problem of leaching loss problem. 3, 4-dmpp has low biological toxicity, and will not cause any toxicity to crops when applied at 8 times the recommended dose. And the residue in agricultural products is low. But according to research of Irigoyen, under the condition of 10 ℃ and 20 ℃, compared with DCD, the nitrification inhibition intensity and effective inhibition time of DMPP showed no advantage.