Nitrous oxide emission and nitrogen use efficiency in response to nitrophosphate, N-(n-butyl) thiophosphoric triamide and dicyandiamide of a wheat cultivated soil under sub-humid monsoon conditions

Abstract. A field experiment was designed to study the effects of nitrogen (N) source and urease inhibitor N-(n-butyl) thiophosphoric triamide (NBPT) or nitrification inhibitor dicyandiamide (DCD) on nitrous oxide (N 2 O) emission and N use efficiency (NUE) in a sandy loam soil. Six treatments including no N fertilizer (control), N fertilizer urea alone (U), urea plus NBPT (NBPT), urea plus DCD (DCD), urea plus NBPT and DCD (NBPT plus DCD) and nitrate-based fertilizer nitrophosphate (NP) were designed and implemented separately during the wheat growth period. Seasonal cumulative N 2 O emissions with urea alone amounted to 0.49 ± 0.12 kg N 2 O-N ha −1 and were significantly ( P 2 O-N ha −1 by application of DCD, NBPT and NBPT plus DCD, respectively. Cumulative N 2 O emissions from NP were 0.28 ± 0.01 kg N 2 O-N ha −1 . A single N 2 O flux peak was identified following basal fertilization, and DCD and/or NBPT inhibition effects mainly occurred during the peak emission period. The NP application significantly ( P 2 O emissions. The application of NP instead of urea would be an optimum agricultural strategy for reducing N 2 O emissions and increasing crop yield and NUE for wheat cultivation in soils of the North China Plain.