Biochar carbon stability in four contrasting soils

作者：Yunying Fang, Balwant Singh, Bhupinder Pal Singh, B. P. Singh, B. P. Singh, Evelyn S. Krull · 发表于：European Journal of Soil Science · 年份：2013 · DOI：10.1111/ejss.12094 · 被引用次数：271 · 研究领域：Soil Carbon and Nitrogen Dynamics、Clay minerals and soil interactions、Soil and Unsaturated Flow

Summary There is a limited understanding of the effects of soil properties on biochar carbon ( C ) stability. This knowledge is essential to evaluate the capacity of biochar for long‐term soil C sequestration fully. In this study two biochars, produced by slow pyrolysis at 450 or 550°C from a δ 13 C ‐depleted (−36.4‰) Eucalyptus saligna Sm. woody material, were incubated in four soils ( I nceptisol, E ntisol, O xisol and V ertisol) of contrasting chemical and mineralogical properties. The total biochar‐ C mineralized over 12 months was 0.30–1.14 and 0.97–2.71% from the soil‐biochar mixtures incubated at 20 and 40°C, respectively. The total biochar‐ C mineralized (mg CO 2 ‐C per unit of native soil organic C (SOC) basis) from soils incubated with the 450°C biochar was approximately twice the corresponding amount mineralized from the 550°C biochar systems. The influence of soil properties on biochar‐ C mineralization was greater for the 450°C biochar than the 550°C biochar. The smallest proportion of C mineralized from the 450°C biochar occurred in the Inceptisol incubated at 20°C and in the O xisol at 40°C. However, when expressed on a per unit of native SOC basis, the C mineralization of the 450 and 550°C biochars was least in the O xisol and greatest in the I nceptisol at both incubation temperatures. Mean residence times ( MRTs ) of the biochars estimated using the two‐pool exponential model varied between 44 and 610 years. The estimated MRT of the biochars may vary under f...