应用红外光谱研究微生物对黑土添加麦秸后腐殖质结构特征变化的影响。 结果表明: (1)土壤水溶性物质(WSS)的结构和官能团数量受微生物影响较大。 细菌有利于提高WSS中脂肪族烷烃类物质含量, 其他处理结果相反。 (2)放线菌在减少土壤富里酸(FA)羟基含量的能力最强, 而真菌对FA的“净生成”能力最强, 其有利于提高土壤FA中羧基和碳水化合物的含量。 除混合菌外, 其他处理均有利于土壤FA中多糖的降解, 且速率大于脂类分解。 (3)除混合菌外, 其他处理均有利于降低土壤胡敏酸(HA)中脂肪族烷烃类物质的数量。 真菌可有效提高土壤HA的羧基含量, 而细菌作用相反。 微生物可消耗和利用HA中的多糖类物质, 促使植物残体类腐殖质向土壤成熟腐殖质转化。

The effects of different microbial communities on the structural characteristics of humus from the black soil amended with wheat straw were studied by FTIR Spectroscopy. The results indicated that (1) The structure and amount of functional groups in the water soluble substances (WSS) was tremendously influenced by the tested microorganisms, of which the amino and aryl ether was degraded rapidly in the inoculation process, and in the meantime, the content of hydroxyl groups was significantly reduced. The bacteria was helpful to increasing the amount of aliphatic hydrocarbons, while the other inoculated treatments were contrary. At the end of culture, the phenols and polysaccharides were gradually consumed, but the content of carboxyl groups had an increasing trend. (2) In the aspect of reducing hydroxyl groups of fulvic acid (FA), the role of actinomycetes was the biggest. The fungi had the biggest effect in improving the net generation of FA content. In addition, the fungi was conducive to improve the contents of carboxyl groups and carbohydrates of FA fraction. Except the mixed strains, the other treatments were all beneficial to the degradation of polysaccharide in the FA fraction, whose rate was greater than the decomposition of lipids. (3) The bacteria, actinomycetes and fungi were all helpful to reducing the amount of aliphatic hydrocarbons of HA fraction except the mixed strains. The content of carboxyl was effectively increased by fungi, but the effect of bacteria was contrary. The tested microorganisms could consume and utilize the polysaccharides of HA fraction, which could transform the humic-like fractions from plant residues into the real humus of soil.