文献类型： 外文期刊

作者： Wang, Lianfeng ¹ ; Du, Huachao ¹ ; Han, Zuoqiang ¹ ; Zhang, Xilin ² ;

作者机构： 1.Dalian Jiaotong Univ, Coll Environm & Chem Engn, Dalian 116028, Peoples R China

2.Heilongjiang Acad Agr Sci, Inst Soil & Fertilizers, Harbin 150086, Peoples R China

3.Chinese Acad Sci, Inst Soil Sci, State Key Lab Soil & Sustainable Agr, Nanjing 210008, Jiangsu, Peoples R China

关键词： N_2O emission;Nitrification;Denitrification;PH;Soil respiration

期刊名称：JOURNAL OF ENVIRONMENTAL SCIENCES （ 影响因子：5.565； 五年影响因子：5.066 ）

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收录情况： SCI

摘要： N_2O fluxes as a function of incubation time from soil with different available N contents and pH were determined. Cumulative carbon dioxide (CO_2) emissions were measured to indicate soil respiration. A 144-hr incubation experiment was conducted in a slightly acidic agricultural soil (pH_(H_2O) 5.33) after the pH was adjusted to four different values (3.65, 5.00, 6.90 and 8.55). The experiments consisted of a control without added N, and with NH_4~+-N and NO_3~--N fertilization. The results showed that soil pH contributed significantly to N_2O flux from the soils. There were higher N_2O emissions in the period 0-12 hr in the four pH treatments, especially those enhanced with N-fertilization. The cumulative N_2O-N emission reached a maximum at pH 8.55 and was stimulated by NO_3~--N fertilization (70.4 μg/kg). The minimum emissions appeared at pH 3.65 and were not stimulated by NO_3~--N or NH_4~+-N fertilization. Soil respiration increased significantly due to N-fertilization. Soil respiration increased positively with soil pH (R~2 = 0.98, P < 0.01). The lowest CO_2-C emission (30.2 mg/kg) was presented in pH 3.65 soils without N-fertilization. The highest CO_2-C emissions appeared in the pH 8.55 soils for NH_4~+-N fertilization (199 mg/kg). These findings suggested that N_2O emissions and soil respiration were significantly influenced by low pH, which strongly inhibits soil microbial nitrification and denitrification activities. The content of NO_3~--N in soil significantly and positively affected the N_2O emissions through denitrification.