不同施肥处理稻田甲烷和氧化亚氮排放特征

    Methane and nitrous oxide emission from paddy field under different fertilization treatments

    • 摘要: 采用静态箱-气相色谱法对长期不同施肥处理(NPKS、CK、NPK和NKM)的稻田CH4和N2O排放进行了观测。结果表明,稻田CH4和N2O排放季节变化规律明显不同,二者排放通量季节变化呈显著负相关(p<0.01)。与单施化肥和CK相比,施用有机肥显著促进CH4排放,排放量最高的NPKS处理早晚稻田排放量分别是:526.68 kg/hm2和1072.92 kg/hm2。对于N2O排放,早稻田各处理间差异不显著,NPK处理排放量最大,为1.48 kg/hm2;晚稻田各处理差异极显著(p<0.01),NPKS处理排放量最大,为1.40 kg/hm2。晚稻田CH4排放通量和10 cm土层温度及土壤pH值相关极显著(p<0.01),并与二者存在显著的指数关系。没发现N2O排放通量与温度及pH值间存在显著相关。稻田CH4和N2O排放受多种因素影响,但对全球变暖的贡献率CH4远大于N2O。NPKS处理的增温潜势最大,NPK处理的最小。

       

      Abstract: The effects of various long-term fertilization treatments(NPKS, CK, NPK and NKM) on CH4 and N2O emission from rice fields were observed by using the static chamber-GC theory with manual method. The seasonal variations of CH4 and N2O emission is disparate, a negative correlation of CH4 flux with N2O flux was perceivable. The mixture of organic fertilizer with nitrogenous fertilizer would lead large CH4 flux, while there was only a few CH4 emission from the treatment with only chemical fertilizer and CK. The NPKS treatment has the largest CH4 emission: 526.68 kg/hm2 in early rice and 1072.92 kg/hm2 in late rice. The effects of different fertilizers on N2O emission from early and late rice were dissimilar. The maximum of the N2O emission occurs in the NPK from early rice(no significance of difference), but it is NPKS from late rice(p<0.01). NPK treatment has the largest N2O emission from early rice: 1.48 kg/hm2, the NPKS also has the largest N2O emission from late rice: 1.40 kg/hm2. Correlation analysis demonstrated that CH4 flux was significantly correlated with soil temperature in 10 cm depth and soil pH value during late rice period(p<0.01), the exponential relationship between CH4 emission and them was also detected. There are many factors which affect CH4 and N2O emission from rice fields, the fertilization is one of the most important factors. The GWP of CH4 from rice fields is much larger than N2O, the NPKS treatment has the largest GWP among all the treatments, but the NPK has the least.

       

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