复垦基质中有机碳和丛植菌根真菌对团聚体形成的影响

The Effect of Organic Carbon and Arbuscular Mycorrhizal Fungi on Aggregate Formation in Reclaimed Soil in Mining Area

以构建的植物-微生物-复合基质矿区生态系统为考察对象,对基质中团聚体的粒径分级和有机碳含量分布进行分析测试,并探讨丛植菌根真菌、有机碳、团聚体3者之间的相关性.结果表明：各个时期矿区复合基质水稳性团聚体含量均呈现随团聚体粒径减小逐渐增加的趋势.复垦初始时,矿区土壤中主要以0.25mm的团聚体占主体.复垦前复合基质2,2-1,1-0.5,0.5-0.25,0.25-0.106mm各团聚体中有机碳的含量相似.复垦4a后,各种土壤水稳性团聚体1-0.5mm有机碳含量最多,为7.93-20.35g/kg.现场试验结果通过相关性分析可得,团聚体与有机碳相关性较小,仅为0.124 7,这可能与复合基质的组成及团聚体的形成时间较短相关.研究结果同时表明,菌根真菌（AMF）分泌物球囊霉素（GRSP）与团聚体有显著相关性,这表明AMF接种有利于团聚体的形成及有机碳的固定,有利于矿区土壤的生态修复.

A close correlation exists between soil aggregation and soil organic carbon content. Based on the plant-microorganism-composite matrix of mining area ecosystem constructed in our previous studies, the water-stable aggregate size grading of matrix particle, as well as the content and distribution of soil organic carbon were detected. Furthermore,the correlation of arbuscular mycorrhizal fungi,organic carbon and water-stable aggregates were analyzed. The results showed that water-stable aggregate content increased as the soil particle size reduced. Before reclamation, 〈0. 106 mm water-stable aggregates were the predominant particles. However,four years after reclamation, 〈0.25 mm water-stable aggregate were the dominant particles,which accounted for more than 50% of the total amount,while 〉2 mm water-stable aggregates were the least. Before reclamation, the highest organic carbon content in the composite matrix existed in %0. 106 mm water-stable aggregates,which was up to 8.58 g/kg. Four years after reclamation,the organic carbon content of soil in 1 -0.5 mm water-stable aggregates was the highest,which was between 7.96-20.39 g/kg. Correlation analysis of the field test results indicated that,water-stable aggregates and organic carbon was not well correlated in this study,with the correlation coefficient as 0. 124 7. This might be resulted from the composition of the composite matrix. Another possible explanation could be that four years after reclamation was short for the water-stable aggregates to form. On the other hand,the glomalinrelated soil protein （GRSP） secreted by Arbuscular mycorrhizal fungi（AMF） showed a significant correlation to the water-stable aggregates. This implied that AMF inoculation has positive impact on the aggregates formation and soil organic carbon sequestration,facilitating the ecological restoration of mine soil.