Index >> Nitrification and Denitrification >> Controlled Release Fertilizers and Nitrification Inhibitors

The prohibitive cost of these materials, at present, prevents their immediate utility on the farm.
Some of the chemicals which are known to act as nitrification inhibitors are produced in U.S.A. and Japan, and are expensive. These chemicals are substituted pyridines, pyrimidines, acetanilides, anilines and isothiocyanates. The two major compounds which have been commercially produced by the Dow Chemical Co., U.S.A. and the Toyo Koatsu Co., of Japan are 2-chloro-6-(trichloromethyl)-pyridine, commonly known as N­serve and 2-amino-4-chloro-6-methyl pyridine commonly known as AM. At level of 1.0 ppm, N-serve inhibits the growth of Nitrosomonas europea and N. agiUs. Oxidation of ammonium by fresh cell suspensions of Nitrosomonas was completely suppressed at 1.p ppm of the chemical.
In experiments done at the Indian Agricultural Research Institute, it was seen that N-serve and AM effectively retarded the nitrification of ammonium sulphate and reduced the losses of nitrogen from soil under water-logged conditions. Increase in yields of rice due to application of ammonium sul­phate in the presence of N-serve has also been observed . The beneficial effect of N-serve has also b!!en recorded in experiments carried out by independent workers with graJses, tomato and spinach.

Table 36 Influence of nitrification inhibitor treatment and variety on grain yield and nitrogen uptake by rice (from Prasad, 1974)