Tracking short-term effects of nitrogen-15 addition on nitrous oxide fluxes using fourier-transform infrared spectroscopy.

摘要: Synthetic fertilizer N additions to soils have significantly increased atmospheric NO concentrations, and advanced methods are needed track the amount of applied that is transformed in field. We developed a method for continuous measurement isotopologues (NNO, NNO, NNO) following 0.4 0.8 g m N-labeled substrate as KNO or urea [CO(NH)] using Fourier-transform infrared (FTIR) spectroscopy. evaluated this two 4-wk experimental trials on coastal floodplain site near Nowra, New South Wales, Australia, which managed silage production. deployed an automated five-chamber system connected portable FTIR spectrometer with multipass cell measure isotopologue fluxes. Emissions all were evident immediately addition. All responded positively rainfall events, but only 7 10 d Cumulative N-NO fluxes (sum three isotopologues) per chamber 14 addition ranged from 1.5 10.3 mg m. Approximately 1% (range 0.7-1.9%) total was emitted NO. Repeatability (1σ) measurements better than 0.5 nmol mol 1-min average concentration measurements, minimum detectable each <0.1 ng s. The results indicate spectroscopic technique can effectively trace transfer atmosphere after addition, allowing powerful quantification emissions under field conditions.