Ke Yue-Jin, Hu Xue-Yu, Yi Qing, Yu Zhong
Huan Jing Ke Xue. 2014 Jan;35(1):93-9.
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 degrees C and 700 degrees C (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.
为了研究生物炭的稳定性以及生物炭添加到土壤中对土壤有机碳的影响，进行了为期130天的培养试验，采用500℃和700℃制备的稻草生物炭（RBC500和RBC700），添加比例分别为0%（对照）、3%、6%和100%（纯生物炭），以检测添加生物炭后耕地土壤中总有机碳（TOC）、易氧化碳（EOC）的变化以及CO₂释放情况。结果表明：与对照相比，土壤中TOC和EOC的含量均随生物炭添加比例的增加而增加。在相同生物炭添加比例下，RBC500对TOC和EOC增加量的贡献大于RBC700。所有处理的TOC含量在最初30天内均下降，最大降幅为15.8%，在培养后期趋于稳定。与TOC相同，所有处理的EOC含量在30天后也趋于稳定，但在培养初期的30天内，当RBC500添加量为3%和6%时，土壤中的EOC分别下降了72.4%和81.7%，而当RBC700添加量为3%和6%时，EOC分别下降了61.3%和69.8%。在培养末期，添加相同温度制备生物炭的土壤中EOC含量相似。培养初期土壤EOC含量的降低可能与生物炭不稳定组分引起的矿化作用有关。在130天的培养期内，累积CO₂释放量表现为土壤与生物炭混合物<对照<纯生物炭。土壤中添加生物炭可减少CO₂释放，最大降幅为41.05%。从长期来看，生物炭作为土壤改良剂有利于减少温室气体排放和土壤碳固定。生物炭可作为土壤碳固存载体。
