作 者 ：罗希茜,郝晓晖,陈涛,邓婵娟,吴金水,胡荣桂*
期 刊 ：生态学报 2009年 29卷 2期 页码：740~748
关键词：长期施肥；稻田土壤；微生物功能多样性；BIOLOG；
Keywords:long-term fertilization, paddy soil, functional diversity, BIOLOG,
摘 要 ：微生物群落功能多样性对土壤管理具有重要指示作用，施肥措施对土壤微生物群落功能多样性产生重要的影响，从而影响土壤有机质的含量，引起土地碳贮量变化，进而影响到陆地生态系统的碳汇。以位于湖南省桃江县国家级稻田肥力长期定位试验点的土样为研究对象，采用BIOLOG测试板对不同施肥处理下土壤微生物功能多样性进行了研究。研究结果显示，土壤微生物的碳源利用率因长期不同的施肥处理而发生分异。Shannon和Simpson指数的结果显示所有施肥处理均有利于维持微生物群落多样性，但秸秆还田和习惯施肥使群落均匀度（McIntosh指数）降低。主成分分析表明，试验点土壤微生物群落利用的主要碳源为氨基酸类和糖类，但不同施肥处理碳源利用类型有差异。结果可以得出，不同的施肥对土壤微生物功能多样性产生了不同影响，从而影响土壤有机质中碳、氮含量。这些信息可以为深入研究施肥对全球碳氮循环以及全球气候变迁提供依据。
Abstract:Microbial community functional diversity is a sensitive indicator of soil management, such as fertilization, especially long-term fertilization. In this paper, the functional diversity of soil microbial community was detected by BIOLOG system. The Average Well Color Development (AWCD) in BIOLOG plates indicated the ability of carbon utilization of microbial community. The indices of Shannon, Simpson and McIntosh were calculated to show the richness, dominance and evenness of the functional diversity, while the principal component analysis of substrate reactions reflected the main carbon sources utilized by microbial community. The results showed that all the treatments exhibited the elevation of AWCD during the first 72 hours of incubation, but the differences among the treatments were obvious. Both applications of organic manure mixed with chemical fertilizer and chemical fertilizer caused high increase of the AWCD while applying straw-incorporation and local traditional fertilization had less affection on the AWCD, which was even lower than the treatment without fertilizer. It was implicated that long-term fertilization resulted in the variation of the carbon utilization efficiency of soil microbial communities. The microbial community diversity indices were calculated based on the AWCD data at 72h and the differences among the treatments were significant. The treatments of organic manure mixed with chemical fertilizer and chemical fertilizer remarkably improved the richness, dominance and evenness of soil microbial community in comparison with the other treatments. Both treatments of straw-incorporation and local traditional fertilization induced increase of the richness and the dominance except the evenness which decreased compared to the treatment without fertilization. The nine principal components were extracted from the principal component analysis and their cumulative contribution of variance accounted to 85.73 percent. The variance contribution rate of PC1 and PC2 were 34.21% and 13.73%, respectively. The correlation coefficients between main substrates and PC1 or PC2 indicated that the main carbon sources for soil microbes were carbohydrates and amino acids in all treatments and there were significant differences of carbon substrate utilization patterns in different treatments. Therefore, long-term fertilization had significant affections on the functional diversity of soil microbial community, which, in turn, could induce variations of carbon and nitrogen composition of soil organic matter.
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