Aggregate size and glucose level affect priming sources: A three-source-partitioning study
Aggregate size and glucose level affect priming sources: A three-source-partitioning study
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聚集体大小和葡萄糖水平影响启动源：三源分区研究
DOI：
10.1016/j.soilbio.2016.03.013
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发表时间：
2016-06
影响因子：
9.7
通讯作者：
Kuzyakov Yakov
中科院分区：
文献类型：
--
作者：
Tian Jing;Pausch Johanna;Yu Guirui;Blagodatskaya Evgenia;Kuzyakov Yakov
通过添加新鲜基质的引发效应（PE），可以加速团聚体中有机质（SOM）的分解。然而，知识的来源矿化和PE在骨料尺寸类是缺席的。我们应用三源同位素（14 C + δ 13 C）方法来确定聚集体大小等级如何影响三种C源（添加底物、新的和旧的SOM）对CO2流出和PE的贡献，这取决于添加引物的量。用长期种植C3植物后种植3年玉米的土壤（C4植物）区分新C（C4单键C; < 3年）和老C（C3单键C; >3年）。土壤样品分为三个团聚体大小类（>2 mm、2-0.25 mm和<0.25 mm的微团聚体）培养49 d后，随着团聚体尺寸的减小，葡萄糖矿化为CO2的比例增加，但14 C掺入微生物量减少，表明与微团聚体相比，大团聚体中的C利用效率更高。短时间PE为阳性，并伴有溶解性有机碳的快速减少。49天后，在两种葡萄糖水平下，大聚集体与微聚集体的PE更高。由低葡萄糖水平诱导的阳性PE仅在大的大聚集体（>2 mm）中观察到，但在高葡萄糖修正后在大聚集体（>0.25 mm）和微聚集体（<0.25 mm）中均观察到。这些结果表明，SOM池是更可分解的宏观与微团聚体和SOM池参与PE根据其生化可用性。在低葡萄糖水平下，在较大的大团聚体中，更多的引发CO2来源于最近的C4单键C而不是旧的C3单键C。高浓度葡萄糖处理后，新近C4单键C对初始CO2的相对贡献从大团聚体（37.8%）增加到微团聚体（100%）。因此，增加葡萄糖添加量刺激了大团聚体中旧的C3单键C的分解，而不是微团聚体。这表明微团聚体比大团聚体更能保护土壤有机质不被分解，因此，微团聚体可以被认为是一个潜在的长期固碳库。综上所述，团聚体的大小对土壤有机质的分解至关重要，它决定了PE的来源，从而决定了固碳的保护。添加引物对PE中涉及的C源的影响取决于聚集体的大小。
Decomposition of soil organic matter (SOM) protected within aggregates can be accelerated via priming effect (PE) by the addition of fresh substrates. However, the knowledge of the sources of mineralization and PE in aggregate size classes is absent. We applied the three-source-partitioning isotopic (14C + δ13C) approach to determine how aggregate size classes affect the contribution of three C sources (substrate added, recent and old SOM) to CO2efflux and PE depending on the amount of added primer. Soil from a field with 3 years of maize cropping (C4plants) after long-term C3vegetation was used to differentiate between recent C (C4single bondC; < 3 years) and old C (C3single bondC; >3 years). Soil samples were separated into three aggregate size classes (>2 mm, 2–0.25 mm macroaggregates and <0.25 mm microaggregates) and were incubated for 49 days after being amended with two levels of14C labeled glucose.The proportion of glucose mineralized to CO2increased with decreasing aggregate size, but14C incorporation into microbial biomass decreased, indicating higher C use efficiency in macroaggregates compared with microaggregates. The short-time PE was positive and was accompanied by a rapid reduction of dissolved organic C. After 49 days, the PE was higher in macro-versus microaggregates at both glucose levels. Positive PE induced by a low glucose level was observed only in large macroaggregates (>2 mm), but was observed in both macroaggregates (>0.25 mm) and microaggregates (<0.25 mm) after high glucose amendment. These results indicate that SOM pools are more decomposable in macro-versus microaggregates and that the SOM pools are involved in PE according to their biochemical availability. More primed CO2originated from recent C4single bondC than old C3single bondC in larger macroaggregates under a low glucose level. The relative contribution of recent C4single bondC to primed CO2increased from macroaggregates (37.8%) to microaggregates (100%) after high glucose amendment. Therefore, increasing glucose addition stimulated the decomposition of old C3single bondC in macroaggregates, but not in microaggregates. This indicates that microaggregates protect SOM against decomposition better than macroaggregates, and consequently, microaggregates can be considered as a potential reservoir for long-term C sequestration.Concluding, aggregate size is crucial for SOM decomposition, and it determines the source of PE and thus the protection of sequestrated C. The effects of the added primer on C sources involved in PE depend on the aggregate size.
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影响因子：
9.7
作者：
C. Creamer;Davey L. Jones;J. Baldock;M. Farrell
通讯作者：
C. Creamer;Davey L. Jones;J. Baldock;M. Farrell
DOI：
10.2136/sssaj1988.03615995005200060019x
发表时间：
1988-11
影响因子：
2.9
作者：
A. Seech;E. Beauchamp
通讯作者：
A. Seech;E. Beauchamp
影响因子：
11.6
作者：
Salome, Clemence;Nunan, Naoise;Chenu, Claire
通讯作者：
Chenu, Claire
影响因子：
4.9
作者：
Jing Tian;J. Pausch;M. Fan;Xiaolin Li;Qiyuan Tang;Y. Kuzyakov
通讯作者：
Jing Tian;J. Pausch;M. Fan;Xiaolin Li;Qiyuan Tang;Y. Kuzyakov
影响因子：
6.1
作者：
S. Rabbi;B. Wilson;B. Wilson;P. Lockwood;H. Daniel;I. Young
通讯作者：
S. Rabbi;B. Wilson;B. Wilson;P. Lockwood;H. Daniel;I. Young