Nitrification inhibitor is a kind of chemical substances which can inhibit the biological transformation process of ammonium nitrogen into nitrate nitrogen (NCT). Nitrification inhibitor can reduce the formation and accumulation of nitrate nitrogen in soil, thereby reducing the loss of nitrogen fertilizer in the form of nitrate nitrogen and the impact on the ecological environment. Some research results show that nitrification inhibitor can reduce nitrogen leaching loss and greenhouse gas (nitrogen oxides) emissions, and can improve fertilizer efficiency under certain conditions. However, the nitrification inhibitor has not been widely used due to factors such as the process, cost and the impact of the nitrification inhibitor on the environment. It is necessary to find some nitrification inhibitors which have good effects on inhibiting nitrification without polluting the environment.
Nitrification inhibitor can selectively inhibit the activity of nitrifying bacteria in soil, thus preventing the reaction speed of the conversion of ammonium nitrogen into nitrate nitrogen in soil. Ammonium nitrogen can be absorbed by soil colloids and it is not easy to be lost. However, under the condition of soil permeability, ammonium nitrogen can be converted into nitrate nitrogen under the action of microorganisms. This process is called nitrification. The rate of reaction depends on soil moisture and temperature. When the temperature is less than 10 ° C, the nitration reaction is slow. When the temperature is more than 20 ° C, the reaction is quickly. In addition to some crops such as rice that can directly absorb ammonium nitrogen under irrigation conditions, most crops can absorb nitrate nitrogen. However, nitrate nitrogen is easy to be lost in soil. Reasonable using of nitrification inhibitors to control nitrification reaction rate can reduce the loss of nitrogen and improve the utilization rate of nitrogen fertilizer. Nitrification inhibitor is usually applied after mixing with nitrogen fertilizer.
In addition to reducing the loss of nitrogen fertilizer and increasing the yield by increasing the utilization rate of nitrogen fertilizer, nitrification inhibitor can also reduce the content of nitrite in crops, improve crop quality and reduce the pollution of soil, groundwater and environment when the amount of fertilizer is too high.
However, in some cases, the effects of nitrification inhibitors on the yield increase of crops are not stable.
There are three main types of nitrification inhibitors: CP, DCD and DMPP. I. 2-chloro-6 -(trichloromethyl) pyridine (also known as nitropyridine), Code (CP). The products of Dow Company in the United States are: Entrench ; chemical trademark of Changzhou Runfeng is : Banlong. 2. Dicyandiamide (Code: DCD); 3. 3, 4-dimethylpyrazole phosphate (Code: DMPP), produced by BASF, Germany. In addition to the three mainstream nitrification inhibitors, there also are amidine thiourea (ASU), 2-methyl-4, 6-bis (Trichlorotoluene) triazine (MDCT), 2-sulfathiazole (ST), etc.
Example: nitrification inhibitors
Content % ≥ 99.5
Moisture % ≤ 0.30
Ash % ≤ 0.05
Melting point: 209 ° C - 209 ° C
Calcium content (ppm) ≤ 350
Properties: white crystal; Relative density: 1.40; Melting point: 202-212 ° C; It is soluble in water and ethanol, and slightly soluble in ether and benzene. It is stable and non-flammable when it is dry.
Utility: It is added to fertilizer for using as nitrification inhibitor.
The common nitrification inhibitors include:
Product name: N－Serve. It is a nitrification inhibitor of 2-chlorine-6 - (trichloromethyl) pyridine. The effective time is 6 weeks when the minimum concentration of 0.5 ~ 10ppm is applied to the soil.
Potassium azide (containing 2%-6% potassium nitrate) can be applied in anhydrous ammonia.
The nitrification inhibitor with Japanese product named AM is 2-amino-4-chloro-9-methylpyridine. In Japan, other nitrification inhibitors (such as sulfathiazole, dicyandiamide, thiourea-N-2, 5-dichlorobenzidine, 4-amino-1, 2, 3-triazole, and amidine thiourea) are also used when applying compound fertilizers.
Research about the effect
To better solve the problems such as low utilization rate of nitrogen fertilizer and short fertilizer effect period, the agricultural effect about application of several nitrification inhibitor at home and abroad is deeply researched. And a group of nitrification inhibitors are expected to be chosen out, which is suitable for climate and soil conditions in Northeast China to improve nitrogen fertilizer effect, increase crop yield, save work and fertilizer, and reduce the eluviation pollution of NO_3. This experiment adopts the network cultivate, pot experiment and field plot test to research the effect that the different dosage of single factor effect of ATC, Dwell, MPC and DCD and combined synergy, nitrification in soil urea nitrogen transformation degree of inhibition effect and to the north of the main crop production of corn, rice and other major economic traits.