Effects of nitrogen and soil moisture on nitrous oxide emission from an alfisol in Wuhan, China

Soil moisture and nitrogen fertilizer are the key factors affecting nitrous oxide (N2O) emission from agricultural croplands. The aim of this study was to ascertain the relationship between N2O emission with soil moistures (35%, 60%, 85% and 110% WFPS) and N fertilizer rates (0, 0.2, 0.4 g N kg(-1)) in alfisol. A laboratory experiment was employed and emissions of N2O were measured regularly over a 61-days incubation period. N2O emissions were significant affected by soil moisture and the largest N2O emissions were occurred at 85% WFPS with a total 6.4, 10.4 mg kg(-1) from N-1, N-2, respectively, represented 3.1% and 2.6% of N applied. N2O emisssions from dry soils (35% and 60% WFPS) were relatively low in this study. Nitrogen application significantly affected the N2O emission and soil moisture is the main factor in producing N2O emissions under a certain nitrogen fertilizer rate. The results demonstrate that it is very important to manage the nitrogen fertilizer rate and soil water when vegetables are planted in the alfisol.