丛枝菌根真菌侵染对紫色土水稳性团聚体特征的影响

为了研究接种丛枝菌根真菌对土壤团聚体特征的影响,采用盆栽试验,以白三叶草(Trifolium pratense)为宿主植物,在两不同供磷水平条件下,分别接种丛枝菌根真菌Glomus intraradices和Glomus mosseae,收获后分析土壤团聚体数量、分布和分形维数,并运用通径分析对不同作用因子进行统计。结果表明:与对照相比,接种丛枝菌根真菌显著提高了球囊霉素相关的土壤蛋白含量,土壤水稳性大团聚体数量也显著增加。接种处理提高了土壤的平均重量直径,几何平均直径,而且降低了土壤分形维数。通径分析表明,在影响土壤水稳性大团聚体的众多因子中,菌丝密度具有最大的作用,且以直接作用为主,球囊霉素相关土壤蛋白也表现出较大的作用系数,但以间接作用为主。同时接种的两种菌种表现出对土壤结构改良作用大小的不同,在实际运用中需要考虑到此点。

Influence of Mycorrhizal Inoculation on Water Stable Aggregates Traits in Purple Soil

To investigate the influence of Arbuscular Mycorrhizal fungi(AMF) inoculation on the traits of aggregate,a pot experiment was carried with Trifolium pratense(white clover) as host plants which inoculated with two different Arbuscular Mycorrhizal fungi,i.e.Glomus intraradices and Glomus mosseae under two phosphorus supplied levels.After harvest,soils were screened through sieves with different sizes and then measured of the amounts of different size of aggregate to obtain geometric mean diameter,mean weight diameter and fractal features of soils.And path analysis was also used to checkup the indirect or direct factors.The results showed that Mycorrhizal inoculation increased glomalin related soil protein(GRSP) concentration and the amount of water stable aggregate(WSA) significantly compared with the non-mycorrhizal treatments.Mean weight diameter(MWD) and geometric mean diameter(GMD) of mycorrhizal soil were significantly higher than non-mycorrhizal soil,while the effect of mycorrhizal inoculation was in contrast on fractal features.And all these results accounted for the important role of Arbuscular Mycorrhizal inoculation in improving quality of soil structure.The path analysis results showed hyphae density had the highest index on WSA amount and which through direct effect mainly.The GRSP also had exerted a greater influence on WSA amount but mainly in an indirect way.The different abilities of AM fungi to improve soil structure needed to be considered in the case of their applications.