Microbial community structure and functional metabolic diversity are associated with organic carbon availability in an agricultural soil
Microbial community structure and functional metabolic diversity are associated with organic carbon availability in an agricultural soil
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DOI：
10.1016/s2095-3119(15)61229-1
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发表时间：
2015-01-01
影响因子：
4.8
通讯作者：
Zhao Bing-qiang
中科院分区：
文献类型：
--
作者：
Li Juan;Li Yan-ting;Zhao Bing-qiang
探索土壤微生物群落结构和活性的土壤环境特征，可以提高我们对土壤地球化学过程和土壤质量的认识。通过在北京昌平县连续15年的施肥试验，研究了不同有机无机肥料投入后土壤环境特征尤其是有机碳有效性对土壤细菌群落结构和功能代谢多样性的影响。试验采用1991年建立的小麦-玉米轮作体系，包括4个不同施肥处理。这些治疗包括：对照（CK）、常用无机肥施用量（NPK）、无机肥常规施用量（NPKM）和无机肥常规施用量（NPKS）。利用16 S rRNA基因的变性梯度凝胶电泳（DGGE）分析了土壤微生物群落结构，并利用Biolog Eco平板分析了不同施肥处理土壤微生物群落功能代谢多样性。结果表明，长期施肥处理土壤细菌群落结构较对照显著增加。与单施无机肥（NPK）相比，长期配施无机肥（NPKM）和有机肥（NPKS）显著促进了土壤微生物群落结构的变化，其中NPKM处理是提高土壤微生物群落丰富度（S）和结构多样性（H）的最重要驱动因素。土壤微生物群落对碳源的综合利用（平均井色发展指数AWCD）、微生物基质利用多样性指数H'和均匀性指数E表明，长期施用无机有机肥（NPKM、NPKS）能显著提高土壤微生物的代谢活性和功能多样性，而NPKS和NPK处理间差异不显著。基于碳源利用谱的主成分分析（PCA）也显示长期施肥条件下土壤微生物群落的显著分离，NPKM处理与其他三个处理显著分离，主要是因为微生物对碳水化合物、羧酸、聚合物、酚类化合物和氨基酸的利用率较高。NPKS处理土壤微生物群落结构与其它3个处理不同，NPKS处理土壤微生物群落结构与其它3个处理不同，NPKS处理土壤微生物群落结构与其它3个处理不同。土壤有机碳有效性，尤其是土壤微生物生物量碳（Cmic）和Cmic/SOC比值是长期施肥条件下土壤微生物群落结构和功能代谢多样性增加的关键因素。研究结果表明，长期施用无机肥和猪粪可显著改善土壤细菌群落结构，提高土壤有机碳有效性，改善土壤微生物代谢活性，为我国土壤资源的可持续管理提供参考。
Exploration of soil environmental characteristics governing soil microbial community structure and activity may improve our understanding of biogeochemical processes and soil quality. The impact of soil environmental characteristics especially organic carbon availability after 15-yr different organic and inorganic fertilizer inputs on soil bacterial community structure and functional metabolic diversity of soil microbial communities were evaluated in a 15-yr fertilizer experiment in Changping County, Beijing, China. The experiment was a wheat-maize rotation system which was established in 1991 including four different fertilizer treatments. These treatments included: a non-amended control (CK), a commonly used application rate of inorganic fertilizer treatment (NPK); a commonly used application rate of inorganic fertilizer with swine manure incorporated treatment (NPKM), and a commonly used application rate of inorganic fertilizer with maize straw incorporated treatment (NPKS). Denaturing gradient gel electrophoresis (DGGE) of the 16S rRNA gene was used to determine the bacterial community structure and single carbon source utilization profiles were determined to characterize the microbial community functional metabolic diversity of different fertilizer treatments using Biolog Eco plates. The results indicated that long-term fertilized treatments significantly increased soil bacterial community structure compared to CK. The use of inorganic fertilizer with organic amendments incorporated for long term (NPKM, NPKS) significantly promoted soil bacterial structure than the application of inorganic fertilizer only (NPK), and NPKM treatment was the most important driver for increases in the soil microbial community richness (S) and structural diversity (H). Overall utilization of carbon sources by soil microbial communities (average well color development, AWCD) and microbial substrate utilization diversity and evenness indices (H' and E) indicated that long-term inorganic fertilizer with organic amendments incorporated (NPKM, NPKS) could significantly stimulate soil microbial metabolic activity and functional diversity relative to CK, while no differences of them were found between NPKS and NPK treatments. Principal component analysis (PCA) based on carbon source utilization profiles also showed significant separation of soil microbial community under long-term fertilization regimes and NPKM treatment was significantly separated from the other three treatments primarily according to the higher microbial utilization of carbohydrates, carboxylic acids, polymers, phenolic compounds, and amino acid, while higher utilization of amines/amides differed soil microbial community in NPKS treatment from those in the other three treatments. Redundancy analysis (RDA) indicated that soil organic carbon (SOC) availability, especially soil microbial biomass carbon (Cmic) and Cmic/SOC ratio are the key factors of soil environmental characteristics contributing to the increase of both soil microbial community structure and functional metabolic diversity in the long-term fertilization trial. Our results showed that long-term inorganic fertilizer and swine manure application could significantly improve soil bacterial community structure and soil microbial metabolic activity through the increases in SOC availability, which could provide insights into the sustainable management of China's soil resource.