ABSTRACT
To develop high efficiency stabilized N fertilizer, a pot experiment was conducted to examine the effects of stabilized ammonium sulfate with different nitrification inhibitors on soil avai-lable nitrogen (N) contents, nitrification inhibition rate, apparent nitrification rate, yield, some agronomic parameters and N fertilizer utilization rate of corn in black soil of Jilin Provinve. In this study, blank (CK) and (NH4)2SO4 (N) were set as controls, and nitrification inhibitor 3,4-dimethyl-pyrazolate phosphate (DMPP), 2-chloro-6-trimethyl-pyridine (CP), ammonia protectant N-GD and nitrogen fertilizer synergist HFJ and their combination applied to ammonium sulfate to form nine treatments. The results showed that compared with the treatment of N, application of DMPP and its combinations in black soil significantly affected soil available N contents and the apparent nitrification rate. The contents of ammonium increased by 1.4-2.0 times, while the contents of nitrate and the apparent nitrification rate of soil decreased by 13.6%-17.9% and 55.3%-59.8%, respectively. DMPP, DMPP+HFJ, DMPP+N-GD had the highest nitrification inhibition rate, which reached higher than 16.5%. DMPP+HFJ+N-GD and HFJ increased the chlorophyll content in maize leaves by 4.5-5.3 times. The addition of nitrification inhibitors and fertilizer synergist to ammonium sulfate did not affect plant height. Compared with the treatment of N, HFJ increased corn biomass, grain yield, economic coefficient, harvest index, agronomic utilization rate of fertilizer, N uptake utilization rate, fertilizer contribution rate and N partial productivity of corn by 1.2, 2.5, 0.7, 0.6, 2.7, 2.1, 1.3 and 2.5 times, respectively. In general, HFJ, DMPP, DMPP+HFJ, DMPP+N-GD performed best in black soil. By considering both the cost and N utilization rate, N fertilizer synergist HFJ is the first choice for stable ammonium sulfate N fertilizer biochemical inhibitor, followed by DMPP+HFJ or DMPP+N-GD.
Subject(s)
Fertilizers/analysis , Soil , Ammonium Sulfate , Nitrification , NitrogenABSTRACT
A chamber culture experiment was conducted to measure soil nitrogen transformation following application of stabilized ammonium fertilizers in black soil and cinnamon soil. There were three application levels (0.20, 0.50, 1.00 g N·kg-1 dry soil, respectively) of nitrogen fertilizer. The results showed that nitrification gradually delayed with the increased amount of ammonium application in the cinnamon soil. The treatment of 1.00 g N·kg-1 significantly inhibited nitrification. Nitrification in the cinnamon soil occurred at day 3 and day 7 with 0.20, 0.50 g N·kg-1 dry soil respectively. In the black soil, nitrification occurred at day 3 in all treatments, with nitrification potential decreasing with the increases of ammonium application amount. Nitrification maintained three weeks and two weeks under treatment of 0.20 g N·kg-1 dry soil in cinnamon soil and in black soil, and maintained four weeks and three weeks under treatment of 0.50 g N·kg-1 dry soil. The application with nitrification inhibitors 3,4-dimethylpyrazole phosphate (DMPP) of 1.0% of total nitrogen and dicyandiamide (DCD) of 4.0% of total nitrogen significantly inhibited nitrification, decreased nitrate concentration and nitrification potential. Our results suggested that nitrification would be inhibited as increased ammonium amount in cinnamon and higher than in black soil. In addition, nitrification was significantly inhibited under the ammonium addition rate of 0.20, 0.50 g N·kg-1 dry soil with nitrification inhibitor. Therefore, for the nitrification inhibitor culture experi-ment, it is recommended that the amount of ammonium addition does not exceed 1.00 g N·kg-1 dry soil, and the best concentration is 0.50 g N·kg-1 dry soil.
