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Effect of formate and glucose organic carbon on N2O emission from two soils |
Received:February 14, 2018 |
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KeyWord:root exudates;denitrification;fungi;denitrifying fungi;N2O |
Author Name | Affiliation | E-mail | MA Shu-tan | State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China University of Chinese Academy of Sciences, Beijing 100049, China | | YAN Xiao-yuan | State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China | yanxy@issas.ac.cn |
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Abstract: |
Incubation experiments were performed to preliminarily investigate the effects of some root exudates on soil N2O emissions by adding different amounts of formate or glucose(0, 0.5, 1 μmol C·g-1) to vegetable field and paddy soils. In the absence of formate or glucose, the N2O-N emissions(2.65~2.69 μg·kg-1) from the vegetable field soil were significantly less than those of the paddy soil(6.19~11.79 μg·kg-1) (P<0.01). In the presence of glucose, N2O-N emissions(2.47~3.44 μg·kg-1) from the vegetable field soils were also significantly less than those of the paddy soil(9.55~13.34 μg·kg-1) (P<0.01). Whereas, in the presence of 1 μmol C·g-1 formate, the N2O-N emissions (54.86 g·kg-1) from vegetable field soils were significantly larger than those of the paddy soil(42.40 g·kg-1) (P<0.01). The amount of NO-3 addition didn't significantly affect soil N2O emissions. Quantitative PCR and high-throughput sequencing were used to explore the underlying microbial mechanism showing that microbial copy number of the paddy soil(including fungi, bacteria, denitrifying bacteria) was 3~8 times higher than that of the vegetable field soil. According to the results of high-throughput sequencing analysis, the relative abundance of denitrifying fungi in vegetable field(53.8%) was much higher than that of the paddy soil(6.6%). It had been reported denitrifying fungi could utilize formate as electronic donor in the process of denitrification. Our results also indicated that low-molecular-weight organic carbon with trace addition significantly stimulated soil N2O emission, and the effects depended on microbial community structure. Denitrifying fungi probably dominated N2O emission when the vegetable field soil was amended with formate. |
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