作　　者： (王争妍）; (雷紫烟）; (叶志雄）; (伍玉鹏）;

机构地区： 华中农业大学资源与环境学院,武汉430070

出　　处： 《农业环境科学学报》 2017年第9期1908-1915,共8页

摘　　要： 为探讨蚯蚓作用下不同C/N秸秆还田对土壤CO_2及N_2O排放的影响,利用室内培养实验,选取不同C/N的四种秸秆(油菜饼、玉米叶、水稻秸、玉米秆)为材料,以无秸秆的处理为对照,比较有、无蚯蚓(Metaphire guillelmi)作用下不同秸秆施入土壤后的CO_2及N_2O排放规律。为期60 d的培养显示,无论添加何种秸秆,土壤CO_2和N_2O的累积排放量均不同程度增加,且CO_2排放系数(EFs-C)与秸秆C/N呈显著的负相关关系(R2=0.827 3)。蚯蚓活动刺激了土壤CO_2和N_2O的产生,接种蚯蚓后的油菜饼、玉米叶、水稻秸、玉米秆和对照处理CO_2累积排放量较相应的无蚯蚓处理分别增加了0.3、0.5、0.9、1.0、1.8倍,N_2O累积排放量较相应的无蚯蚓处理分别增加了1.4、1.7、1.7、1.4、9.5倍。然而,进一步的分析显示,蚯蚓提高了低C/N油菜饼处理的N_2O排放系数(EFs-N),却降低了其他秸秆处理的EFs-N。此外,低C/N油菜饼混入土壤后在培养前期即产生了较高含量的无机氮和可溶性碳,而其余秸秆混入土壤后却导致无机氮含量低于对照处理;虽然接种蚯蚓在培养后期缓慢增加了高C/N秸秆处理的无机氮,但仍低于无秸秆的蚯蚓对照处理。研究表明,接种蚯蚓和施入秸秆均能促进土壤CO_2及N_2O的排放,但蚯蚓作用下不同秸秆施用对EFs-N的影响却可能因秸秆C/N的不同而产生差异。 A microcosm incubation experiment was performed to assess soil CO2 and N2O emissions after different residues were added to the soil, with or without earthworm（Metaphire guillelmi）inoculation. Four residues（rapeseed cake, corn leaf, rice straw, and corn stalk）with different C/N were chopped and thoroughly mixed with soil. Treatments without residue addition were set up as the control. During the 60-day incubation, residue incorporation increased the soil CO2 and N2O emission fluxes. In addition, the fraction of CO2emissions（EFs-C）showed a significant negative correlation with residue C/N（R2=0.827 3）. Earthworm inoculation also increased the soil CO2 and N2O fluxes.In the treatment with rape cake, corn leaf, rice straw, and corn stalk incorporation and control, cumulative CO2 and N2O emissions were increased 0.3, 0.5, 0.9, 1.0, 1.8 times and 1.4, 1.7, 1.7, 1.4, 9.5 times, respectively, by earthworm inoculation and by the counterpart treat-ment without earthworm inoculation. However, further analysis showed that earthworms increased the fraction of N2 O emissions（EFs-N）with rape cake incorporation, but decreased EFs-Nwith the incorporation of other residues. In addition, rape cake incorporation led to a quick in-crease inorganic N and dissolved organic carbon content at the beginning of incubation, while the incorporation of other residues led to comparatively lower inorganic N content compared to the counterpart control. Inorganic N content in high C/N residue treatments was slightly increased by earthworm inoculation, but it remained lower than the counterpart treatment without the incorporation of residues. Both earthworm inoculation and residue incorporation can stimulate CO2 and N2O emissions, but their interaction effects on EFs-Nmay vary by the different residue C/N values.

关 键 词： 蚯蚓 秸秆还田 二氧化碳 氧化亚氮