| CH4 is a typical greenhouse gas and rice fields are one of the main sources of CH4 emission. Straw incorporation is a common agricultural measure may increase CH4 emission in rice fields. Biochar, which is produced from pyrolysis of straw, has been proposed as a promising means for carbon sequestration in paddy fields while disposing rice straw. However, the mechanism and effect of biochar on CH4 emission from paddy soils is still controversial. Therefore, this paper investigated the effect of biochar on CH4 emission in paddy soil and reveal how biochar affect soil CH4 emissions by statistical analysis. The main conclusions are as follows:(1) Without straw application, low temperature biochar (BC300) is unstable, it cloud decrease soil Eh, promote the abundance of methanogens and increase soil CH4 emission. However, high temperature biochar (BC500 and BC700 ) had no significant effect on soil Eh and soil CH4 emission for its stability. Therefore,application of 1% low temperature biochar could significantly increase 161.9 ± 22.3%of soil CH4 emission, while high temperature biochar had no significant effect on soil CH4 emission.(2) With straw application, biochar cloud adsorb soil DOC contens, decrease the abundance of methanogens and decrease soil CH4 emission. Moreover, the decrease induced by high temperature biochar was stronger than that of low temperature biochar. Therefore, application of 1% biochar cloud significantly decrease soil CH4 emission. Moreover,low temperature biochar and high temperature biochar cloud decrease 23.5 ± 21.2% and 50.8 ± 9.7% of soil CH4 emission,respective. |
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