土壤学报2011，Vol.48Issue(1)：112-124,13.
南方典型水稻土长期试验下有机碳积累机制研究Ⅳ.颗粒有机质热裂解-气相-质谱法分子结构初步表征
SOC ENHANCEMENT IN MAJOR TYPES OF PADDY SOILS UNDER LONG-TERM AGRO-ECOSYSTEM EXPERIMENTS FROM SOUTH CHINA Ⅳ· MOLECULAR CHARACTERIZATION OF PARTICULATE ORGANIC CARBON BY TMAH THERMOCHEMOLYSIS-GC /MS
摘要
Abstract
Tetramethyla mmonium hydroxide ( TMAH ) thermochemolysis-gas chromatography/mass spectrometry (GC/MS) was employed to investigate the supramolecular structure of particulate organic carbon ( POC ) sampled from a Tai Lake paddy soil under a long-term field experiment with different fertilization systems.The chromatograms revealed peaks related to compounds derived from lignin and aliphatic compounds. The dominant lignin-derived compounds were mainly derivatives of guaiacyl (G) and p-hydroxyphenyl (P) structures,suggesting the contribution of a non-woody (grass) lignin type (mainly crop residues from rice and rape). The most abundant aliphatic compounds were C8-C30 fatty acid methyl esters (FAMEs) dominated by even-numbered carbon species, in which short chain FAMEs of microbial origin were prevalent. Soil fertilizations induced differences of the distribution of each thermochemolysis compound both in bulk soil and water-stable aggregations,and thereby the relative contribution of each compound to the stability of POC. Generally, the lignin compounds and aliphatic compounds of microbial origin contributed to the accumulation and stabilization of POC under the treatment of chemical fertilizer plus pig manure. Nevertheless, the enhanced POC under chemical fertilizer plus crop straw was attributed preferentially to aliphatic compounds of higher plant origin, followed by those of microbe origin. The higher POC content in water-stable aggregates under organic-inorganic fertilization treatments was supposed to be predominantly due to the decomposition of higher plants. The C stabilization by molecular recalcitrance is supposed to contribute to the C sequestration and stabilization in paddy soils under good managements, the relative distribution of which can indicate the different source of newly-accumulated soil organic C.关键词
水稻土/长期试验/固碳机理/化学组分/热化学分解/气相质谱/施肥Key words
Paddy soil/ Long-term experiment/ Carbon sequestration mechanism/ Chemical component/Thermochemolysis/ GC/MS/ Fertilization management分类
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周萍,潘根兴,Alessandro Piccolo,Riccardo Spaccini..南方典型水稻土长期试验下有机碳积累机制研究Ⅳ.颗粒有机质热裂解-气相-质谱法分子结构初步表征[J].土壤学报,2011,48(1):112-124,13.基金项目
国家自然科学基金重点项目(40830528,40231016)和江苏省普通高校研究生科研创新计划项目(CX07B-188z)资助 （40830528,40231016）
