Biochar Carbon Stability in a Clayey Soil As a Function of Feedstock and Pyrolysis Temperature
Biochar Carbon Stability in a Clayey Soil As a Function of Feedstock and Pyrolysis Temperature
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DOI：
10.1021/es302545b
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发表时间：
2012-11-06
影响因子：
11.4
通讯作者：
Smernik, Ronald J.
中科院分区：
文献类型：
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作者：
Singh, Bhupinder Pal;Cowie, Annette L.;Smernik, Ronald J.
生物炭碳(C)的稳定性是决定其在土壤中长期固碳价值的主要因素。长期(5年)的实验室实验是在受控条件下进行的，这些生物炭由5种C3生物质原料(桉树木材和树叶、造纸厂污泥、家禽粪便、牛粪)在400℃和/或550℃下制成，这些生物炭在含有主要来自C4植物来源的有机碳的变性土中培养，并定期测量总CO2-C和相关的增量C-13。生物炭的0.5%到8.9%之间。C的矿化时间超过5年。有机质生物炭中碳的矿化速度快于植物性生物炭，400℃生物炭中的C矿化速度快于550℃生物炭中的C。碳在生物炭中的平均停留时间(MRT)估计在90到1600年之间。这些都是保守的估计，因为它们代表了相对不稳定和中等稳定的生物炭C组分的MRT。此外，在水分较低、温度较低或养分供应受限的田间条件下，生物炭C-MRT可能会较高。生物炭碳的稳定性与非芳香族碳的初始比例和生物炭中芳香碳的缩合程度之间存在很强的相关性，支持利用这些性质来预测土壤中生物炭碳的稳定性。
The stability of biochar carbon (C) is the major determinant of its value for long-term C sequestration in soil. A long-term (5 year) laboratory experiment was conducted under controlled conditions using 11 biochars made from five C3 biomass feedstocks (Eucalyptus saligna wood and leaves, papermill sludge, poultry litter, cow manure) at 400 and/or 550 degrees C. The biochars were incubated in a vertisol containing organic C from a predominantly C4-vegetation source, and total CO2-C and associated delta C-13 were periodically measured. Between 0.5% and 8.9% of the biochar. C was mineralized over 5 years. The C in manure-based biochars mineralized faster than that in plant-based biochars, and C in 400 degrees C biochars mineralized faster than that in corresponding 550 degrees C biochars. The estimated mean residence time (MRT) of C in biochars varied between 90 and 1600 years. These are conservative estimates because they represent MRT of relatively labile and intermediate-stability biochar C components. Furthermore, biochar C MRT is likely to be higher under field conditions of lower moisture, lower temperatures or nutrient availability constraints. Strong relationships of biochar C stability with the initial proportion of nonaromatic C and degree of aromatic C condensation in biochar support the use of these properties to predict biochar C stability in soil.