| 水稻秸秆生物炭对耕地土壤有机碳及其CO2释放的影响 |
| 摘要点击 4268 全文点击 1848 投稿时间：2013-04-02 修订日期：2013-05-13 |
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| 中文关键词 生物炭 土壤有机碳 矿化作用 CO2 减排 |
| 英文关键词 biochar soil organic carbon mineralization CO2 emission reduction |
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| 中文摘要 |
| 为探究生物炭自身稳定性及其输入土壤后对于土壤本体有机碳的影响，本研究模拟自然条件，分别将500℃和700℃裂解的水稻秸秆生物炭（RBC500和RBC700）以0%（空白土壤）、3%、6%和100%（纯生物炭）的比例添加至耕地土壤进行室内培养实验，观测总有机碳（TOC）与易氧化态碳（EOC）含量的变化及CO2排放特征. 结果表明，与空白土壤处理相比，土壤TOC、EOC含量均随水稻秸秆生物炭添加量的增加而升高；相同添加量条件下，RBC500对土壤TOC与EOC增加的贡献均高于RBC700. 各处理土壤TOC含量在前30 d内均降低（最大降幅为15.8%），并于培养后期趋于稳定；土壤EOC含量在培养初30 d内均降低，当生物炭添加比例为3%和6%时，RBC500使土壤的EOC含量降幅分别为72.4%和81.7%，大于RBC700的61.3%和69.8%；培养结束时，添加相同裂解温度生物炭的土壤EOC值相近. 培养前期土壤中EOC含量的下降可能与生物炭中易分解组分引起的矿化作用有关. 在130 d培养期内，CO2累计排放量大小顺序为：土壤+生物炭混合处理<纯土壤处理<纯生物炭处理，可见，生物炭的土壤处理可以减少土壤CO2的排放，最大减排率可达41.05%. 在一个长的时间尺度内，生物炭的土壤处理有利于土壤碳的固定. 生物炭施用于土壤可作为碳储存载体. |
| 英文摘要 |
| In order to investigate the stability of biochar and the effect of biochar when added into soil on soil organic carbon, a 130-day incubation experiment was conducted with rice straw biochar produced at 500℃ and 700℃ (RBC500 and RBC700) and with addition rates of 0% (control), 3%, 6% and 100% (pure biochar), to detect the change of total organic carbon (TOC), easily oxidized carbon (EOC) and status of CO2 release,following addition of biochar in arable soil. Results showed that: the content of both TOC and EOC in soil increased with biochar addition rates comparing with the control. RBC500 had greater contributions to both TOC and EOC increasing amounts than those of RBC700 under the same biochar addition rate. TOC contents of all treatments decreased during the initial 30 days with the largest decreasing amplitude of 15.8%, and tended to be stable in late incubation stages. Same to that of TOC, EOC contents of all treatments also tended to remain stable after 30 days, but in the 30 days of early incubation, EOC in the soil decreased by 72.4% and 81.7% respectively when the added amount of RBC500 was 3% and 6%, while it was reduced by 61.3% and 69.8% respectively when the added amount of RBC700 was 3% and 6%. EOC contents of soil added with biochar produced at the same temperature were similar in the end of incubation. The reduction of soil EOC content in early incubation may be related to mineralization caused by labile fractions of biochar. During the 130-day incubation, the accumulated CO2 releases showed an order of soil and biochar mixtures < the control < pure biochars. Biochar amendment in soil could reduce CO2 release, the largest reduction amplitude is 41.05%. In a long time scale, biochar as a soil amendment is favorable to the deduction of greenhouse gas release and soil carbon immobilization. Biochar could be used as a soil carbon sequestration carrier. |
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