Molecular dynamics of organic matter in a cultivated soil
Molecular dynamics of organic matter in a cultivated soil
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DOI：
10.1016/s0146-6380(01)00166-8
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发表时间：
2002-01-01
影响因子：
3
通讯作者：
Balesdent, J
中科院分区：
文献类型：
--
作者：
Gleixner, G;Poirier, N;Balesdent, J
土壤有机碳的动态包括在全球碳（C）循环情景中，使用不同的，但通常是任意定义的，动力库。为了改进全球碳模型，需要更好的土壤有机质（SOM）的化学结构和动力学库之间的关系。为了评估SOM的分子停留时间和植物输入的关系，热解-GC/MS-C-IRMS进行玉米植株和两个样品从同一土壤中经历了植被变化，从C3植物小麦的C4植物玉米。这种植被的变化增加了自然的C-13丰富的材料的土壤。玉米的热解产物主要是多糖和木质素，在土壤中未检测到。然而，多糖衍生产物也是土壤中的主要热解产物，也检测到含氮或非特异性热解产物。停留时间（基于C-13天然标记）显示了一个连续的值，这是独立的化学结构，只有两个热解产物呈现出相对较长的停留时间（约10分钟）。100年）。研究结果表明，慢碳池中有机质的稳定化主要是由于碳水化合物和含氮物质中碳的再循环以及物理和化学保护。(C)2002爱思唯尔科技有限公司版权所有。
The dynamics of soil organic carbon are included in global carbon (C) cycle scenarios using different, but generally arbitrary defined, kinetic pools. To improve global C models, better relationships between the chemical structure of soil organic matter (SOM) and its kinetic pools are needed. To assess the molecular residence time of SOM and the relation with plant inputs, pyrolysis-GC/MS-C-IRMS was performed on maize plants and on two samples from the same soil that had undergone a vegetation change from the C3 plant wheat to the C4 plant maize. This vegetation change has added naturally C-13-enriched material to the soil. Most pyrolysis products from the maize were derived from polysaccharides and lignins, and were not detected in soils. However, polysaccharide-derived products were also major pyrolysis products in soils, N-containing or unspecific pyrolysis products were also detected. The residence times (based on C-13 natural labelling) revealed a continuum of values, that was independent of chemical structure, with only two pyrolysis products presenting a relatively long residence time (ca. 100 years). An unexpected long life-time for N-containing (similar to49 years) and polysaccharide-derived (similar to54 years) pyrolysis products was found. Our results suggest that mainly recycling of carbon in carbohydrates and N-containing materials in addition to physical and chemical protection is responsible for SOM stabilization in the slow carbon pool. (C) 2002 Elsevier Science Ltd. All rights reserved.