| 论文题目: |
Priming effect of stable C pool in soil and its temperature sensitivity |
| 论文题目英文: |
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| 论文编号: |
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| 第一作者: |
You, Mengyang |
| 第一作者英文: |
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| 刊物名称: |
Geoderma |
| 卷期页码: |
401, , |
| 发表年度: |
2021 |
| 联系作者: |
李禄军 |
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| 影响因子: |
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| 参与作者: |
M. Y. You, P. He, S. S. Dai, M. Burger and L. J. Li |
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| 摘要: |
It is important to understand the effects of exogenous carbon (C) additions on the mineralization of native soil C in agricultural soils under changing global temperatures. The slowly mineralizable C pools represent the major component of soil carbon. Once the labile fraction of soil C is depleted through mineralization, additions of exogenous labile C may enhance decomposition of slowly mineralizable soil C through the so-called priming effect (PE). The effect of exogenous C on mineralization of slowly mineralizable C in soils that have undergone extended substrate depletion is not well understood. The aim of this study was to assess the effects of exogenous C addition on the PE and its temperature sensitivity (Q(10)) in two substrate depleted soils. The Mollisols with two levels of C 6.8% and 2.9% were pre-incubated at 15 and 25 degrees C for 864 days, followed by 42-day incubations with and without C-13-enriched corn (Zea mays) leaf addition at 15 and 25 degrees C. Soil organic carbon (SOC) decreased by 7%-9% in low and 1%-3% in high C soil after the long-term pre-incubation, respectively. In the 42-day incubation following the long-term pre-incubation, the incubation at the higher temperature (25 degrees C) significantly increased cumulative CO2 production compared to that at the lower temperature (15 degrees C) for both high and low C soils with or without exogenous C addition. Furthermore, corn leaves addition stimulated CO2 production derived from resistant OC in both soils, resulting in a positive PE. Higher incubation temperature resulted in a greater PE in both soils independent of pre-incubation temperature. The temperature sensitivity (Q(10)) of the PE in the low C soil pre-incubated at 25 degrees C was greater than that pre-incubated at 15 degrees C, but in the high C soil, the Q(10) of PE was lower after pre-incubation at 25 degrees C. The results confirmed that exogenous C addition and a higher temperature accelerate native SOC mineralization and suggested that the temperature sensitivity of the PE depended on the soil C content and the long-term temperature regime a soil is subjected to. |
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