分根装置中接种AMF对1～2mm土壤水稳性团聚体的影响

Influence of arbuscular mycorrhizal fungi inoculation on 1-2mm soil water stable aggregates in split root system

采用分根装置研究了丛枝菌根真菌侵染白三叶草（Trifolium repens）后对中性紫色土1-2 mm土壤水稳性团聚体（WSA1-2mm）含量的影响,并运用通径分析对其主要影响因子进行了量化比较。结果表明,接种Glomus intrara-dices、G.mosseae和G.etunicatum的菌根室土壤有机质、球囊霉素相关土壤蛋白（GRSP）含量均有增加的趋势;接种3种菌种都显著增加了菌根室土壤WSA1-2mm含量。通径分析结果表明,菌丝密度对WSA1-2mm含量有较大的直接效应（直接通径系数0.678）,而GRSP对WSA1-2mm的影响系数较小,既有直接效应又有间接效应,但以直接效应为主。菌丝和GRSP对1-2mm土壤水稳性团聚体作用大小的差异可能源于二者作用机制的不同。

A split root device experiment was used to investigate the influence of arbuscular mycorrhizal（AM） fungi inoculation on 1-2 mm soil water stability aggregates（WSA1-2mm） in the neutral purple soil while white clover（Trifolium repens） as the host plants.The results show that compared with the non-mycorrhial treatment,the contents of organic matter and glomalin related soil protein（GRSP） of mycorrhizal soil are slightly increased under the inoculation with Glomus intraradices,G.mosseae and G.etunicatum,while the WSA1-2mm contents of mycorrhizal soil are significantly increased.The results of path analysis indicate that the hyphae density has a high direct effect on WSA1-2mm（direct path coefficient is 0.678）,GRSP has both direct and indirect effect,but through direct effect mainly.The different mechanism of these factors may account for the difference.