• ISSN 1008-505X
  • CN 11-3996/S
刘平静, 肖杰, 孙本华, 高明霞, 张树兰, 杨学云, 冯浩. 长期不同施肥措施下土细菌群落结构变化及其主要影响因素[J]. 植物营养与肥料学报, 2020, 26(2): 307-315. DOI: 10.11674/zwyf.19102
引用本文: 刘平静, 肖杰, 孙本华, 高明霞, 张树兰, 杨学云, 冯浩. 长期不同施肥措施下土细菌群落结构变化及其主要影响因素[J]. 植物营养与肥料学报, 2020, 26(2): 307-315. DOI: 10.11674/zwyf.19102
LIU Ping-jing, XIAO Jie, SUN Ben-hua, GAO Ming-xia, ZHANG Shu-lan, YANG Xue-yun, FENG Hao. Variation of bacterial community structure and the main influencing factors in Eum-orthic Anthrosols under different fertilization regimes[J]. Journal of Plant Nutrition and Fertilizers, 2020, 26(2): 307-315. DOI: 10.11674/zwyf.19102
Citation: LIU Ping-jing, XIAO Jie, SUN Ben-hua, GAO Ming-xia, ZHANG Shu-lan, YANG Xue-yun, FENG Hao. Variation of bacterial community structure and the main influencing factors in Eum-orthic Anthrosols under different fertilization regimes[J]. Journal of Plant Nutrition and Fertilizers, 2020, 26(2): 307-315. DOI: 10.11674/zwyf.19102

长期不同施肥措施下土细菌群落结构变化及其主要影响因素

Variation of bacterial community structure and the main influencing factors in Eum-orthic Anthrosols under different fertilization regimes

  • 摘要:
    目的 研究不同施肥处理下土壤细菌群落的特征,为建立促进土壤生态系统稳定和健康的养分管理制度提供依据。
    方法 陕西省杨凌示范区“国家黄土肥力与肥料效益监测基地”的28年长期定位试验始于1990年秋,种植制度为冬小麦–夏休闲,无灌溉。本研究选取定位试验中不施肥 (CK)、施用氮磷钾肥 (N、P2O5、K2O分别为135、108、67.5 kg/hm2,NPK) 和有机无机肥配施 (70% N来自牛粪,MNPK) 3个处理。于2018年6月小麦收获后采集0—20 cm耕层土样,测定养分含量、含水量、微生物量碳含量、微生物量氮含量及目标土壤微生物。以1%琼脂糖凝胶电泳法检测土壤中DNA,根据97%相似度对序列进行OTU聚类、α多样性分析 (包括Shannon、ACE和Chao1等指数),使用CANOCO 4.5软件对土壤细菌门水平群落结构、细菌相对丰度等与土壤理化性质进行冗余分析。
    结果 与CK相比,NPK和MNPK处理显著提高了土壤有机碳、全氮、微生物量碳、微生物量氮、硝态氮和铵态氮含量,显著降低了土壤pH值。不同处理细菌基因拷贝数为每克干土6.69 × 109~16.46 × 109,与CK相比,NPK和MNPK处理细菌数量分别提高了77%和146%。MNPK处理的土壤细菌Shannon多样性指数显著高于CK和NPK处理,而Simpson指数显著低于CK和NPK处理,NPK与CK处理间两个指数无显著差异。3个处理的细菌丰富度指数 (Chao1指数和ACE指数) 和均匀度指数均没有显著差异。在门水平上,共获得35个细菌类群,其中,放线菌门 (Actinobacteria)、变形菌门 (Proteobacteria)、酸杆菌门 (Acidobacteria) 和绿弯菌门 (Chloroflexi) 为主要优势菌门 (相对丰度 > 10%),占到全部菌门的80.1%~81.7%。与CK相比,MNPK处理显著降低了放线菌门 (F = 5.845,P < 0.05) 的相对丰度,增加了拟杆菌门 (F = 4.461,P < 0.05) 的相对丰度,3个处理间其他菌门均无显著差异。冗余分析结果显示,CK与NPK、MNPK处理的土壤细菌群落结构具有明显差异,且MNPK处理对土壤细菌群落组成的影响更大。土壤理化性质对细菌菌群影响表现为:土壤硝态氮 > 可溶性有机碳 > pH > 铵态氮 > 有机碳 > 土壤含水量,这些理化因子均是影响微生物生长的关键因子。
    结论 关中土区旱作雨养条件下,化肥平衡施用和有机无机肥配施均显著提高了土壤中细菌数量、多样性和丰富度,有机无机肥配施还改变了细菌群落结构,特别是降低了放线菌门、增加了拟杆菌门的丰度,更有利于土壤生态系统的稳定和健康。

     

    Abstract:
    Objectives The fertility change in nutrient contents and microbial structure of farmland after long-term fertilization was studied in this paper, which would provide theoretical base for reasonable fertilization practice to maintain a stable and healthy soil ecosystem.
    Methods The investigated farmland was from a 28-years’ long-term fertilization experiment in the “National Monitoring Base of Soil Fertility and Fertilizer Efficiency on Loess Soil” in Yangling Demonstration Zone, Shaanxi Province, where the cropping system was winter wheat-summer fallow and without irrigation. The soil samples were collected from three of the experiment treatments, namely, no fertilization control (CK), pure chemical fertilizer (NPK, N–P2O5–K2O=135–108–67.5 kg/hm2) and chemical fertilizer and manure combination (MNPK, 70% of N from cattle manure). After harvest of wheat, soil samples of 0–20 cm in depth were collected. The soil nutrient contents, water content, microbial biomass C and N contents were determined. The DNA of genome in soil samples were extracted and detected by 1% agarose gel electrophoresis, and sequenced afterwards. The Shannon, ACE and Chao1 indices were calculated.
    Results Compared with CK, the NPK and MNPK significantly increased soil organic carbon, total nitrogen, microbial biomass carbon, microbial biomass nitrogen, nitrate nitrogen and ammonium nitrogen, while significantly reduced soil pH. The copy number of bacterial genes were 6.69 × 109 – 16.46 × 109 per gram of dry soil for the three treatments, and those in NPK and MNPK treatments were 77% and 146% significantly higher than that in CK. The Shannon diversity index of soil bacteria of MNPK was significantly higher, while Simpson index were significantly lower than those of CK and NPK treatments, and there was no significant difference between NPK and CK. The bacterial richness index (Chao1 index and ACE index) and the uniformity index were not significantly different among the 3 treatments. A total of 35 groups of bacteria were obtained at the level of phylum, in which Actinobacteria, Proteobacteria, Acidobacteria and Chloroflexi were the main dominant ones (relative abundance > 10%), and accounted for 80.1%–81.7% of the total bacteria phyla. Compared with CK, MNPK significantly reduced the relative abundance of Actinomycetes (F = 5.845, P < 0.05) and increased that of Bacteroides (F = 4.461, P < 0.05). There was no significant difference for other phyla of bacteria among the 3 treatments. The results of redundancy analysis showed that the soil bacterial community structures were significantly different between no fertilization (CK) and fertilization (NPK and MNPK), and MNPK had a greater impact than NPK on soil bacterial community composition. The importance of soil physical and chemical properties affecting the bacterial communities was as follows: nitrate nitrogen > soluble organic carbon > pH > ammonium nitrogen > organic carbon > soil water content.
    Conclusions In the rain-fed farmland in Eum-orthic anthrosol area of Guanzhong, the bacteria population, diversity and richness are significantly improved in soils under long-term balanced chemical fertilization and combination of organic and inorganic fertilization. Combination of organic and inorganic fertilizers could increase the bacteria diversity that is more efficient in increasing the abundance of Bacteroides and decreasing that of Actinomycetes, which represents more stable and healthy in soil ecosystem.

     

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