土壤有机磷形态与矿化速率分析方法研究进展

Advance in Approaches of Determining Form and Mineralization Rate of Soil Organic

大多数土壤的有机磷(Po)占全磷30%~65%,矿化后可被植物直接利用,成为生态系统生物有效磷重要来源。准确测定Po形态组成及矿化速率是科学利用土壤Po库的基础。本文目的是对目前常见土壤Po形态组成和矿化速率测定技术的优缺点、适用范围进行总结分析,为研究人员选择合适测定技术提供依据。搜集并分析近20年来中国知网和Web of Science数据库中92篇关于Po形态组成与矿化速率方法研究论文。介绍了3种常用Po形态测定技术(连续分级法、酶水解法和核磁共振法)和近年来兴起的3种Po矿化速率测定技术(同位素稀释技术、连续观测-差减法和模型法)的基本原理,分析了几种技术适用范围、主要优缺点和互补性。尽管目前仍无针对土壤Po形态组成和矿化速率“最佳”测定方法,但是,研究人员可根据待测土壤理化性质和实验目的选择“合适”的测定技术。提出未来应在酶水解技术标准化、^(13)C和^(31)P核磁共振技术联用、发展包含植物因素Po矿化速率测定技术、联用形态和矿化速率测定技术等方面开展深入研究。

As an important component of total soil phosphorus(P),mineralized organic P(Po)is a major source of replenishing bioavailable P pool in many terrestrial ecosystems.There are many forms of Po with different bioavailability in soil.These forms of Po also differ in their ability of resisting the hydrolysis catalyzed by phosphatases.It is therefore necessary to accurately determine the forms and mineralization rates of soil Po to understand the biogeochemical cycling of Po and to use the legacy Po in soil.The aims were to clarify the advantages,disadvantages,scopes of application of several most commonly used approaches of determining the forms and mineralization rate of soil Po.The selected 92 papers in the databases of CNKI and the Web of Science in recent 20 years with a topic of the forms and mineralization rate of soil Po were discussed.Three approaches of determining the forms of soil Po were reviewed,including sequential fractionation procedure,enzyme addition assays and ^(31)P nuclear magnetic resonance spectroscopy.There is no a‘best’approach of determining the forms and mineralization rate of soil Po.However,scientists can select a‘proper’one according to the physical-chemical properties of targeted soils and experimental goals.It is recommended to carry out more researches on the following fields:developing a standard procedure of enzyme addition assays,jointly utilizing ^(13)C and ^(31)P nuclear magnetic resonance spectroscopy to identify more unsolved Po forms,modifying methods of determining mineralization rate of soil Po to reflect the effects of plants,and combinedly utilizing approaches of determining the forms and mineralization rate to understand the mechanisms of transformation and mineralization of soil Po.