Assessment on Nitrous Oxide (N2O) Emissions different Nitrogen Application Rates during the Red Pepper Cultivation in Flat Upland

Generally, nitrogen (N) fertilization higher than the recommended dose is applied during vegetable cultivation for increasing in productivity. However, excessive N application rate beyond plant requirement could cause adverse environmental impact such as nitrate leaching and nitrous oxide emission. In this experiment, the impacts of N fertilization was studied on nitrous oxide (N₂O) emission to standardize the optimum fertilization level for minimizing of N₂O emission as well as most of the crop productivity. Herein, we assessed the N₂O emission in the flat upland soil which was cultivated with different N application rates on red pepper for 3 years (2010∼2012). N₂O emission was measured in chemical N fertilizer amounts 0 (N 0), 95 (N 0.5), 190 (N 1.0), 380 (N 2.0) kg ha-1 by using the abnormal shape chamber closed repeating three times. In average for 3 years, the total N₂O emissions of each treatment in field of soybean were 2.110 (N 0), 3.165 (N 0.5), 5.039 (N1.0), and 7.228 (N 2.0) kg N₂O ha -1 yr -1 , respectively. And then the primary regression between nitrogen fertilizer amount and the total N2O emission was showed as y = 0.0138x + 2.0942 (r 2 =0.9885), and an average of the emission factor was EF1 0.0148(0.0118∼0.0191) N₂O-N kg N -1 kg -1 from 2010 to 2012. The result was a little higher than the emission default of the IPCC 1996 Guideline (EF1 0.0125) when the results are converted into N₂O emission factor.