[Effects of N application and maize growth on N2O emission from soil]

With pot experiment and using static chamber-GC technique, this paper studied the effects of N application (150 and 300 mg x kg(-1) soil) and maize growth on N2O emission from soil. In maize-planted soil, the N2O emission rate increased with increasing N application rate, its peak appeared at seedling stage, and there was no significant correlation between N2O emission and air temperature. Contrarily, in bare soil, the peak of N2O emission rate occurred at the anaphase of the experiment, and there was a significant exponential correlation between N2O emission and air temperature. The total amount of N2O emission increased remarkably with increasing N application rate in both planted and bare soils. In comparing with bare soil, maize-planting reduced N2O emission by 92% and 87%, respectively at high and low N application rates, which suggested that maize-planting not only affected the seasonal variation and magnitude of N2O emission from soil, but also altered the relationship between air temperature and soil N2O emission.