土壤磷形态组分分级及31P-NMR 技术应用研究进展

农田生态系统中土壤磷形态转化，影响土壤磷对作物的有效供应。土壤磷分为无机磷和有机磷两大部分。化学连续提取法 (chemical sequential fractionation，CSF) 研究土壤磷形态分级，采用不同的化学提取剂，分级提取土壤中组成或分解能力接近的有机无机含磷化合物，是目前表征土壤磷素形态的重要方法。但该方法虽历经改进，仍难以确切反映土壤磷的实际组成，提取的不同磷形态间存在重叠，有机磷和无机磷组分分级存在一定的误差；不同分级磷组分对作物的有效性，需谨慎评估。核磁共振波谱技术 (nuclear magnetic resonance，NMR) 根据核磁共振波谱图上共振峰的位置、强度和精细结构来研究土壤中含磷化合物的分子结构。液相31P-NMR 可以同吋检测出土壤中多种磷组分，如正磷酸盐、磷酸单酯、磷酸二酯、膦酸脂、焦磷酸盐和多聚磷酸盐，识别土壤提取物磷形态，可将有机磷与无机磷分开。本文综述了应用31P-NMR 技术研究土壤磷形态组分的一些进展，总结了样品制备过程、NMR 测试参数及在土壤磷形态转化研究中的应用。二维31P-NMR 技术发展为鉴定分析土壤中更多种类的含磷化合物提供了契机。

Research advance in soil phosphorus fractionations and their characterization by chemical sequential methods and 31P-NMR techniques

Transformation of soil phosphorus (P) is an important part in P cycle in ecological system,which influences soil P availability for crops.Soil total P includes organic and inorganic P.Chemical sequential fractionation (CSF) methods with different chemical extraction solvents are often used to determine different forms of P in soils.Despite the extensive use of these CSF procedures,there are obvious shortcomings,e.g.less accurately distinguishing inorganic and organic forms of P.Nuclear magnetic resonance (NMR) can be used to identify exactly molecular forms of P in soils.Some reports of 31P-NMR technique to study soil P forms and transformation were reviewed in this paper,and advances in the preparation process of soil samples and 31P-NMR analysis parameters were summarized.Two-dimensional 31p-NMR spectroscopy will be developed to improve P fractionation in quantification in soils.