基于固态13C核磁共振波谱研究植物残体分解和转化机制的进展

植物残体在土壤中的分解和转化影响了其养分归还和有机质形成过程。由于缺乏高分辨率的分析方法,对不同气候、植被和土壤类型条件下植物残体在分解过程中化学结构组成的演变特征和机制仍不清楚。核磁共振波谱技术在解析自然有机物化学组成方面具有独特的优势,本文综述了基于固态~(13)C核磁共振波谱(solid-state ~(13)C-NMR spectroscopy)技术评价植物残体的基质质量、解析植物残体的分解速率及其官能团组成的变化特征、揭示土壤腐殖质特性等方面的主要进展。未来针对植物残体分解和有机质形成机制的研究,应该结合稳定性同位素质谱和扫描电镜分析方法,综合分析植物残体中的有机化合物组成和物理结构;从多时空尺度揭示不同类型植物残体中有机碳官能团的降解路径;结合高通量测序和基因芯片分析方法,深入研究土壤微生物群落与植物残体化学结构的协同演变机制,提出不同气候–土壤–植被类型区促进土壤有机质形成的调控措施。

Advances in Studying Mechanisms of Plant Residue Decomposition and Turnover Based on Solid-State 13C Nuclear Magnetic Resonance Spectroscopy

Decomposition and turnover of plant residues in soil play critical roles in the nutrient release and organic matter formation. Due to the deficit of high-resolution detection method, the characteristics and mechanisms of chemical structure of plant residues changing with climate, vegetation and soil conditions during their decomposition process remain unclear. Nuclear magnetic resonance (NMR) spectroscopy is a powerful tool to elucidate direct information on chemical composition of nature organic matter. The recent progresses were reviewed in evaluating the quality of plant residues, predicting the decomposition rate and the transformation of functional groups of organic carbon, and analyzing the characteristics of soil humus by using the solid-state13C NMR spectroscopy. To deepen our understanding of mechanisms of plant residue decomposition and organic matter formation, the composition and structure of biological macromolecules in plant residues should be comprehensively analyzed by using combinedδ13C mass spectrometry and scanning electron microscopy. Then the decomposition pathway of functional groups of organic carbon could be studied at different temporal and spatial scales. And the synergetic change of microbial community composition and chemical structure of plant residues could be revealed by using high-throughput sequencing and gene chip methods. These will be helpful to put forwards the best management practices to promote the soil organic matter formation under different climate, soil and plant conditions.