Emissions of nitrous oxide, nitrogen oxides and ammonia from a maize field in the North China Plain
2011
Zhang, Yuanyuan | Liu, Junfeng | Mu, Yujing | Pei, Shuwei | Lun, Xiaoxiu | Chai, Fahe
The exchange fluxes of nitrous oxide (N₂O), nitrogen oxides (NOₓ) and ammonia (NH₃) from a maize field with three different treatments were simultaneously measured using static and dynamic chambers in the North China Plain (NCP) from June 28 to October 11, 2009. The three treatments included control plot (CK, without crop, fertilization and irrigation), fertilizer N plot (NP) and wheat straw returning plus fertilizer N plot (SN). N-fertilizer application greatly stimulated the emissions of N₂O, NOₓ and NH₃, with durations of about 10 days for N₂O and NO, and about 7 days for NH₃. Fertilizer loss rates were 1.08% (NP plot) and 1.20% (SN plot) as N₂O–N, were 1.93% (NP plot) and 0.76% (SN plot) as NO–N, and were 5.24% (NP plot) and 3.03% (SN plot) as NH₃–N. In comparison with the NP plot, the significant low fertilizer loss rates as NO–N and NH₃–N from the SN plot indicated that the wheat straw returning to the field could reduce NOₓ and NH₃ emissions. The molar ratio of NO/N₂O was greater than unity for most data during the pulse emission periods induced by fertilization, and thus, nitrification was the dominant process for N₂O and NO emissions during these periods. Considering the significant amount (>80%) of N₂O and NOₓ emissions occurred during the pulse emission periods, the emissions of NOₓ and N₂O from the investigated field were mainly ascribed to nitrification process.
显示更多 [+] 显示较少 [-]