Effects Of Microcapsule Of Nitrification Inhibitors Named 2- Chloro- 6(Trichloromethyl) Pyridine On Soil Nitrogen Transformation And Maize

The Northeast of China is the largest production base of maize in our country. Although urea is the major nitrogen fertilizer variety widely used in the agricultural production, but its utilization rate is relatively low, which cannot be ignored. After the application of urea into the soil, it is hydrolyzed by urease in the soil and then produces ammonium nitrogen; further, ammonium nitrogen is transformed into nitrate nitrogen under the action of nitrifying bacteria and denitrifying bacteria in the soil in a short period. However, nitrate nitrogen is not easily adsorbed by soil colloid because it easily flows away with water under the conditions of large rainfall and irrigation; moreover, ammonia volatilization under the action of denitrifying bacteria,the losses of nitrogen fertilizer not only cause a large amount of waste, but also pose a great threat to the environment. Since the 20 th century, the nitrification inhibitor, which has been widely used to regulate nitrogen transformation in many countries, which is a effective method to reduce the loss of nitrogen, to realize efficient utilization of nitrogen fertilizer. In this paper, we studied the effect and the underlying mechanisms of the nitrification inhibitor 2-chloro-6(trichloromethyl) pyridine microcapsule on nitrification inhibition and maize yield in the black soil through the laboratory and field tests. We compared the inhibition effect of nitrification inhibitors under different concentrations on nitrogen nitrification, and discussed the mechanisms underlying its inhibition on microbial and the influence of nitrification inhibitors on ammonia volatilization, which is aimed to find out the optimal concentrations of nitrification inhibitors in the black soil, further providing the theory support for the production practice. The main results were as follows:1.The effect of the nitrification inhibitor 2-chloro-6(trichloromethyl) pyridine microcapsule on nitrogen transformationCompared with the treatment fertilized uniquely with urea, 2-chloro-6(trichloromethyl) pyridine microcapsule effectively delayed the oxidation process of ammonium nitrogen by inhibiting the growth of ammonia oxidizing bacteria in the soil. Improving soil ammonium nitrogen content and pH simultaneously, 2-chloro-6(trichloromethyl) pyridine microcapsule reduced the nitrate nitrogen and nitrite nitrogen content from45.2%-47.4%. Throughout the experiment processes, the ammonium nitrogen content in the soil were positively correlated with pH, and were negatively correlated with the ammonia oxidizing bacteria and nitrate content. The difference in inhibition effect was not significant under different concentrations of nitrification inhibitors;2. The effect of the nitrification inhibitor 2-chloro-6(trichloromethyl) pyridine microcapsule on ammonia volatilizationCompared with the treatment fertilized uniquely with urea, 2-chloro-6(trichloromethyl) pyridine microcapsule significantly increases the amount of ammonia volatilization, which lasted 28 days, and the increases in the amount of ammonia volatilization in the three treatments(NIM1, NIM2 and NIM3) were up to 2.83, 2.81, 2.83-fold of the control, respectively. However, the difference in the ammonia volatilization levels was not significant under different concentrations of nitrification inhibitors.3. The effect of the nitrification inhibitor 2-chloro-6(trichloromethyl) pyridine microcapsule on plant height and diameter coarseNitrification inhibitors 2- chloro- 6(trichloromethyl) pyridine microcapsules have effects on plant height、diameter coarse of corn Especially on sixth of July and nineteenth of June.The sixth of July,Compared with the treatment fertilized uniquely with urea, using single basal fertilization way the plant height add up to 9.3cm,the diameter coarse add up to 0.07 cm,using 1/2 basal1/2 fertilizer manner way he plant height add up to 7.9cm,the diameter coarse add up to 0.06 cm.The nineteenth of June,Compared with the treatment fertilized uniquely with urea,using single basal fertilization way the plant height add up to 11.2cm,the diameter coarse add up to 0.19 cm,using 1/2 basal1/2 fertilizer manner way he plant height add up to 13.8cm,the diameter coarse add up to 0.10 cm.4. The effect of the nitrification inhibitor 2-chloro-6(trichloromethyl) pyridine microcapsule on maize yieldCompared with the treatment fertilized uniquely with urea, 2-chloro-6(trichloromethyl) pyridine microcapsule promoted the reproductive growth of the maize shoot, using 1/2 basal1/2 fertilizer manner way and 1% nitrification inhibitors the increase rates of maize yield were up to 7.84%,and0.5% nitrification inhibitors the increase rates of maize yield were up to 6.0%.using single basal fertilization way and 1% nitrification inhibitors the increase rates of maize yield were up to 7.35%,and 0.5% nitrification inhibitors the increase rates of maize yield were up to 5.68% moreover, but it was not significant between the two treatments. The optimal strategy was listed below, the nitrification inhibitor dosage was 0.5%, and a combination of 1/2 basal1/2 fertilizer manner way was used as the main fertilization manner.