中国生态农业学报Issue(9)：1029-1037,9.DOI:10.13930/j.cnki.cjea.140067
施肥方式对冬小麦季紫色土N2O排放特征的影响
Effects of fertilizer application regimes on soil N2O emissions in the croplands of purple soil in the Sichuan Basin during wheat season
摘要
Abstract
Nitrous oxide (N2O) was undoubtedly a key element with respect to global warming and climate change. As about 60%of global anthropogenic N2O emissions have originated from agricultural soils, it has been a huge challenge to maintain high crop yields while reducing N2O emissions under the continued application of nitrogen fertilizers. Limited available field data have explored the effects of fertilizer application regimes on soil N2O emissions in the Sichuan Basin, one of the most intensive agricultural regions in China. Thus the objective of this research was to compare the effects of different N fertilizer application regimes on soil N2O emissions so as to find the best N fertilizer management practice which not only decreased N2O emission, but also maintained high crop yields. Static chamber-gas chromatographic techniques were used to measure soil N2O emissions from purple soil croplands with long-term N fertilization in treatments of pure synthetic N fertilizer (N), pig manure (OM), synthetic NPK fertilizer (NPK), pig manure combined with synthetic NPK fertilizer (OMNPK) and returned crop residues combined with synthetic NPK fertilizer (CRNPK). No fertilizer was applied under the control experiment (NF). The in situ field measurements were conducted during wheat season from November 2012 to May 2013. The results showed that cumulative N2O fluxes in different fertilization regimes were significantly different (P < 0.05) even when the same rates of total N were applied [130 kg(N)·hm-2]. Cumulative N2O fluxes in treatments of N, OM, NPK, OMNPK and CRNPK were 0.38 kg(N)·hm-2, 0.36 kg(N)·hm-2, 0.29 kg(N)·hm-2, 0.33 kg(N)·hm-2 and 0.19 kg(N)·hm-2, respectively. N2O emission factors in the respective treatments were 0.25%, 0.23%, 0.18%, 0.21% and 0.10%. Cumulative N2O flux in treatment of NF was 0.06 kg(N)·hm-2. Nitrogen fertilizer application significantly enhanced N2O emission. Inorganic N (ammonium and nitrate) content was the main controlling factor of soil N2O emission. Also rainfall significantly enhanced soil N2O emission. Wheat grain yields in treatments of N, OM, NPK, OMNPK and CRNPK were 1.34 t·hm-2, 3.71 t·hm-2, 2.80 t·hm-2, 3.13 t·hm-2 and 3.40 t·hm-2, respectively. Wheat grain yield in CRNPK treatment was not significantly different from that of OM treatment, which had the maximal yield that was much higher than yields of all the other treatments (P<0.05). Furthermore, we assessed the global warm potential (GWP) of soil N2O emission on the basis of crop grain yield under the different treatments. The results showed that the yield-based GWPs of treatments of N, OM, NPK, OMNPK and CRNPK were 132.57 kg(CO2 eq)·t-1, 45.70 kg(CO2 eq)·t-1, 49.07 kg(CO2 eq)·t-1, 48.92 kg(CO2 eq)·t-1 and 26.41 kg(CO2 eq)·t-1, respectively. The yield-based GWP of soil N2O emissions in CRNPK treatment was the lowest of all the treatments. In contrast with conventional fertilization regime (NPK), the yield-based GWP decreased by 46%. This implied that returned crop residues combined with synthetic NPK fertilizer not only increased grain yield, but also decreased soil N2O emission due to the application of N fertilizer. For wheat season, the fertilizer application regime of returned crop residues with reduced synthetic fertilizer was therefore recommended as the best fertilization measure in purple soil croplands.关键词
N2O排放/施肥方式/冬小麦季/单位产量GWP紫色土/四川盆地Key words
N2O emission/Fertilization regime/Winter wheat season/Yield-scaled GWP/Purple soil/Sichuan Basin分类
资源环境引用本文复制引用
柳文丽,李锡鹏,沈茜,朱波..施肥方式对冬小麦季紫色土N2O排放特征的影响[J].中国生态农业学报,2014,(9):1029-1037,9.基金项目
国家自然科学基金重点项目(41330744)资助 （41330744）
