College of Life Sciences, Northwest A & F University, Yangling, Shaanxi, 712100, PR China; College of Agronomy, State Key Laboratory of Crop Stress Biology in Arid Areas/Northwest A & F University, Yangling, Shaanxi, 712100, PR China.
College of Agronomy, State Key Laboratory of Crop Stress Biology in Arid Areas/Northwest A & F University, Yangling, Shaanxi, 712100, PR China.
Environ Res. 2020 May;184:109261. doi: 10.1016/j.envres.2020.109261. Epub 2020 Feb 17.
To unravel the linkages between ecological ratios (C:N:P) and the microbial community in rhizosphere soil in response to fertilizer management, soil samples were collected from a proso millet (Panicum miliaceum L.) field under different fertilizer management systems, including nitrogen fertilizer (NF), phosphorus fertilizer (PF), combined N and P (NP) fertilizer, and organic fertilizer (OF); no fertilizer (CK) was used as a control. Furthermore, 16S rRNA and ITS gene sequencing were applied to represent the bacterial and fungal diversity in the soil. Moreover, the elemental properties, including the carbon (C), nitrogen (N), and phosphorus (P) contents, in the microbial biomass and rhizosphere soil were evaluated. The results showed that the C, N, and P contents and microbial biomass (MBC, MBN and MBP, respectively) in the rhizosphere soil were augmented following fertilizer management. Increases in the alpha diversity indices (Shannon and Chao 1) of soil bacteria and fungi were observed in response to the fertilizers, and the responses were more closely related to the soil C:N and N:P ratios than to the C:P ratio. Additionally, with high relative abundances (>1%) across all soil samples, the composition of soil microbial phyla levels revealed different trends following fertilizer management. The abundances of Actinobacteria and Gemmatimonadetes increased, while the abundances of Acidobacteria and Nitrospirae decreased (P < 0.05) following fertilizer management. Among the fungal taxa, the abundances of Ascomycota and Mortierellomycota responded positively to fertilizer. These results were largely influenced by changes in the C:N and N:P ratios in both the soil and microbial biomass. Overall, significantly increased C:N and decreased N:P ratios in the soil reflected the N deficiency that would limit increased microbial biomass and diversity. Together, all of these results indicated that interactions between ecological ratios (C:N:P) and microbial community composition play vital roles in resource imbalance in dynamic environments. Thus, N status should be an important factor for sustainable agricultural management. Moreover, the synergistic effects were better with the combination of C, N, and P or with organic fertilizer than with C, N and P separately.
为了揭示生态比（C:N:P）与根际土壤微生物群落之间的联系，针对不同施肥管理系统下的谷子（Panicum miliaceum L.）田，我们采集了土壤样本，这些系统包括氮肥（NF）、磷肥（PF）、氮磷复合肥（NP）和有机肥（OF）；不施肥（CK）作为对照。此外，我们还应用了 16S rRNA 和 ITS 基因测序来表示土壤中细菌和真菌的多样性。此外，还评估了微生物生物量和根际土壤中的元素特性，包括碳（C）、氮（N）和磷（P）含量。结果表明，施肥后，根际土壤中的 C、N 和 P 含量以及微生物生物量（MBC、MBN 和 MBP）均增加。土壤细菌和真菌的 alpha 多样性指数（Shannon 和 Chao 1）也因施肥而增加，其响应与土壤 C:N 和 N:P 比密切相关，而与 C:P 比无关。此外，在所有土壤样本中，相对丰度（>1%）较高的土壤微生物门水平组成在施肥后呈现出不同的趋势。与施肥管理相关的是，放线菌门和芽单胞菌门的丰度增加，而酸杆菌门和硝化螺旋菌门的丰度减少（P < 0.05）。在真菌类群中，子囊菌门和无梗囊霉门的丰度对肥料有积极响应。这些结果主要受土壤和微生物生物量中 C:N 和 N:P 比变化的影响。总的来说，土壤中 C:N 比显著增加，N:P 比降低，反映了氮素缺乏，这将限制微生物生物量和多样性的增加。综上所述，生态比（C:N:P）与微生物群落组成之间的相互作用在动态环境中的资源失衡中起着至关重要的作用。因此，氮素状况应该是可持续农业管理的一个重要因素。此外，C、N 和 P 或有机肥的协同作用优于 C、N 和 P 单独的协同作用。
