Community Structure Analyses Are More Sensitive to Differences in Soil Bacterial Communities than Anonymous Diversity Indices

ABSTRACT Changes in the diversity and structure of soil microbial communities may offer a key to understanding the impact of environmental factors on soil quality in agriculturally managed systems. Twenty-five years of biodynamic, bio-organic, or conventional management in the DOK long-term experiment in Switzerland significantly altered soil bacterial community structures, as assessed by terminal restriction fragment length polymorphism (T-RFLP) analysis. To evaluate these results, the relation between bacterial diversity and bacterial community structures and their discrimination potential were investigated by sequence and T-RFLP analyses of 1,904 bacterial 16S rRNA gene clones derived from the DOK soils. Standard anonymous diversity indices such as Shannon, Chao1, and ACE or rarefaction analysis did not allow detection of management-dependent influences on the soil bacterial community. Bacterial community structures determined by sequence and T-RFLP analyses of the three gene libraries substantiated changes previously observed by soil bacterial community level T-RFLP profiling. This supported the value of high-throughput monitoring tools such as T-RFLP analysis for assessment of differences in soil microbial communities. The gene library approach also allowed identification of potential management-specific indicator taxa, which were derived from nine different bacterial phyla. These results clearly demonstrate the advantages of community structure analyses over those based on anonymous diversity indices when analyzing complex soil microbial communities.

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Intercropping with Potato-Onion Enhanced the Soil Microbial Diversity of Tomato

Microorganisms ◽

10.3390/microorganisms8060834 ◽

2020 ◽

Vol 8 (6) ◽

pp. 834

Author(s):

Naihui Li ◽

Danmei Gao ◽

Xingang Zhou ◽

Shaocan Chen ◽

Chunxia Li ◽

...

Keyword(s):

Community Structure ◽

Organic Carbon ◽

Bacterial Community ◽

Soil Organic Carbon ◽

Microbial Communities ◽

Fungal Community ◽

Soil Microbial Communities ◽

Tomato Seedling ◽

Soil Microbial ◽

Potato Onion

Intercropping can achieve sustainable agricultural development by increasing plant diversity. In this study, we investigated the effects of tomato monoculture and tomato/potato-onion intercropping systems on tomato seedling growth and changes of soil microbial communities in greenhouse conditions. Results showed that the intercropping with potato-onion increased tomato seedling biomass. Compared with monoculture system, the alpha diversity of soil bacterial and fungal communities, beta diversity and abundance of bacterial community were increased in the intercropping system. Nevertheless, the beta-diversity and abundance of fungal community had no difference between the intercropping and monoculture systems. The relative abundances of some taxa (i.e., Acidobacteria-Subgroup-6, Arthrobacter, Bacillus, Pseudomonas) and several OTUs with the potential to promote plant growth were increased, while the relative abundances of some potential plant pathogens (i.e., Cladosporium) were decreased in the intercropping system. Redundancy analysis indicated that bacterial community structure was significantly influenced by soil organic carbon and pH, the fungal community structure was related to changes in soil organic carbon and available phosphorus. Overall, our results suggested that the tomato/potato-onion intercropping system altered soil microbial communities and improved the soil environment, which may be the main factor in promoting tomato growth.

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Intertillage during Natural Farming Rice Paddy Production Negatively Impacted the Microbial Abundances in Soils but Not Diversities

Applied and Environmental Soil Science ◽

10.1155/2021/6676456 ◽

2021 ◽

Vol 2021 ◽

pp. 1-11

Author(s):

Jin-Feng Lin ◽

Eva-Maria Minarsch ◽

Munehide Ishiguro ◽

Yoshitaka Uchida

Keyword(s):

Bacterial Community ◽

Soil Microbial Communities ◽

Soil Surface ◽

Rice Paddy ◽

Diversity Indices ◽

Vegetative Stage ◽

Rice Paddies ◽

Community Structures ◽

Natural Farming ◽

Soil Bacterial

In natural farming rice paddies, intertillage (tillage between rows, during rice growth period) is often performed mainly to remove weeds without the use of chemicals. Also, the intertillage disturbs soil surfaces, potentially impacting the characteristics of soil microbial communities, such as their diversity and abundance. Natural farming systems aim to maintain biodiversity, but it remains unclear whether the intertillage impacts soil microbes in rice paddies. Thus, this study aimed to understand to what extent “five times intertillage” treatment (5T) influences soil bacterial abundance and community structures compared with no tillage (NT), under a natural farming rice paddy system. Soils were sampled at rice proximity, soil surface, and 10 cm depth in a natural farming rice paddy, during the early to late vegetative phase (June to July), in Hokkaido, Japan. The 16S rRNA community structures and abundance were analyzed by next generation sequencing (NGS) and quantitative PCR, respectively. We observed that NT had significantly higher bacterial abundances at the soil surface than 5T. However, there were no clear differences between 5T and NT, regarding the bacterial community structures, including their diversity indices. Instead, the sampling timings markedly impacted the bacterial community structures for the rice proximity and soil surface, showing increasing diversity indices at the late vegetative stage, compared to the early vegetative stage, suggesting the interaction between the crop growth and bacterial communities. In this study, we did not observe the significant difference between the rice yield from NT (2.3 ± 0.7 t·ha−1) and 5T plots (2.7 ± 0.9 t·ha−1); however, the 5T might have negatively impacted soil bacterial abundances but not the community structure of the bacteria.

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Inoculation of Ensifer fredii strain LP2/20 immobilized in agar results in growth promotion and alteration of bacterial community structure of Chinese kale planted soil

Scientific Reports ◽

10.1038/s41598-020-72986-5 ◽

2020 ◽

Vol 10 (1) ◽

Author(s):

Neelawan Pongsilp ◽

Pongrawee Nimnoi

Keyword(s):

Community Structure ◽

Bacterial Community ◽

Bacterial Community Structure ◽

Soil Microbial Communities ◽

Soil Bacterial Community ◽

Field Conditions ◽

Total N ◽

Soil Inoculation ◽

Chinese Kale ◽

Soil Bacterial

Abstract In our former research, we succeeded in using agar, alginate, and perlite as immobilization materials to maintain long-term survival of the inoculant, Ensifer fredii LP2/20, in a controlled glasshouse. Therefore the information on the establishment and activity of the inoculant to promote plant growth under field conditions, the effects of the inoculant on the soil microbial communities and specific microbial taxa, and the association between the inoculant and soil elements merit further studies. Here, we found that agar was the most suitable material that supported the establishment of the inoculant under field conditions. RNA-based analysis showed that E. fredii LP2/20 immobilized in agar was still metabolically active at day 50 after being introduced into soil. Inoculation of E. fredii LP2/20 immobilized in agar conferred the highest plant dry weight (up to 89.94%) and all plant elements including total N (9.55%), P (17.94%), K (68.42%), Ca (39.77%), Mg (30.76%), Fe (29.85%), and Zn (22.44%). Inoculation of E. fredii LP2/20 immobilized in agar increased soil chemicals including soil organic matter (99.02%), total N (272.48%), P (31.75%), K (52.74%), Fe (51.06%), and Zn (63.10%). High-throughput next-generation sequencing of bacterial 16S rRNA amplicons showed that the Proteobacteria, Acidobacteria, Bacteroidetes, and Firmicutes were dominant phyla in Chinese kale field soil. Inoculation of E. fredii LP2/20 significantly affected the soil bacterial community structure by decreasing total bacterial richness and diversity. The numbers of alpha- and gamma-Proteobacteria were significantly increased while the number of delta-Proteobacteria was significantly decreased due to E. fredii LP2/20 establishment. Soil total P, K, and Ca and soil pH were the important factors that shaped the soil bacterial community composition.

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Soil Microbial Community Successional Patterns during Forest Ecosystem Restoration

Applied and Environmental Microbiology ◽

10.1128/aem.00764-11 ◽

2011 ◽

Vol 77 (17) ◽

pp. 6158-6164 ◽

Cited By ~ 126

Author(s):

Natasha C. Banning ◽

Deirdre B. Gleeson ◽

Andrew H. Grigg ◽

Carl D. Grant ◽

Gary L. Andersen ◽

...

Keyword(s):

Community Structure ◽

Microbial Community ◽

Bacterial Community ◽

Fungal Community ◽

Soil Microbial Community ◽

Ecosystem Restoration ◽

Community Structures ◽

Soil Microbial ◽

Soil Bacterial ◽

Edaphic Variables

ABSTRACTSoil microbial community characterization is increasingly being used to determine the responses of soils to stress and disturbances and to assess ecosystem sustainability. However, there is little experimental evidence to indicate that predictable patterns in microbial community structure or composition occur during secondary succession or ecosystem restoration. This study utilized a chronosequence of developing jarrah (Eucalyptus marginata) forest ecosystems, rehabilitated after bauxite mining (up to 18 years old), to examine changes in soil bacterial and fungal community structures (by automated ribosomal intergenic spacer analysis [ARISA]) and changes in specific soil bacterial phyla by 16S rRNA gene microarray analysis. This study demonstrated that mining in these ecosystems significantly altered soil bacterial and fungal community structures. The hypothesis that the soil microbial community structures would become more similar to those of the surrounding nonmined forest with rehabilitation age was broadly supported by shifts in the bacterial but not the fungal community. Microarray analysis enabled the identification of clear successional trends in the bacterial community at the phylum level and supported the finding of an increase in similarity to nonmined forest soil with rehabilitation age. Changes in soil microbial community structure were significantly related to the size of the microbial biomass as well as numerous edaphic variables (including pH and C, N, and P nutrient concentrations). These findings suggest that soil bacterial community dynamics follow a pattern in developing ecosystems that may be predictable and can be conceptualized as providing an integrated assessment of numerous edaphic variables.

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The effects of soil depth on the structure of microbial communities in agricultural soils in Iowa, USA

10.1101/2020.03.31.018416 ◽

2020 ◽

Author(s):

Jingjie Hao ◽

Yen Ning Chai ◽

Raziel A. Ordóñez ◽

Emily E. Wright ◽

Sotirios Archontoulis ◽

...

Keyword(s):

Community Structure ◽

Microbial Community ◽

Bacterial Community ◽

Microbial Communities ◽

Community Composition ◽

Microbial Community Structure ◽

Soil Depth ◽

Bacterial Community Composition ◽

Soil Microbial Communities ◽

Soil Microbial

AbstractThe determination of how microbial community structure changes within the soil profile, will be beneficial to understanding the long-term health of agricultural soil ecosystems and will provide a first step towards elucidating how deep soil microbial communities contribute to carbon sequestration. This study aimed to investigate the differences in the microbial community abundance, composition and diversity throughout from the surface layers down to deep soils in corn and soybean fields in Iowa, USA. We used 16S rRNA amplicon sequencing of soil samples to characterize the change in microbial community structure. Our results revealed decreased richness and diversity in bacterial community structure with increasing soil depth. We also observed distinct distribution patterns of bacterial community composition along soil profiles. Soil and root data at different depths enabled us to demonstrate that the soil organic matter, soil bulk density and plant water availability were all significant factors in explaining the variation in soil microbial community composition. Our findings provide valuable insights in the changes in microbial community structure to depths of 180 cm in one of the most productive agricultural regions in the world. This knowledge will be important for future management and productivity of agroecosystems in the face of increasing demand for food and climate change.

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Structural and Functional Responses of Soil Microbial Communities to Biodegradable Plastic Film Mulching in Two Agroecosystems

10.1101/650317 ◽

2019 ◽

Author(s):

Sreejata Bandopadhyay ◽

Henry Y. Sintim ◽

Jennifer M. DeBruyn

Keyword(s):

Community Structure ◽

Bacterial Community ◽

Microbial Communities ◽

Bacterial Community Structure ◽

Crop Production ◽

Soil Microbial Communities ◽

Plastic Film ◽

Plastic Mulch ◽

Soil Microbial ◽

Mulch Films

AbstractPolyethylene (PE) plastic mulch films are used globally in crop production but incur considerable disposal and environmental pollution issues. Biodegradable plastic mulch films (BDMs), an alternative to PE-based films, are designed to be tilled into the soil where they are expected to be mineralized to carbon dioxide, water and microbial biomass. However inadequate research regarding the impacts of repeated incorporation of BDMs on soil microbial communities has partly contributed to limited adoption of BDMs. In this study, we evaluated the effects of BDM incorporation on soil microbial community structure and function over two years in two geographical locations: Knoxville, TN, and in Mount Vernon, WA. Treatments included four plastic BDMs, a completely biodegradable cellulose mulch, a non-biodegradable PE mulch and a no mulch plot. Bacterial community structure determined using 16S rRNA amplicon sequencing revealed significant differences by location and season. Differences in bacterial communities by mulch treatment were not significant for any season in either location, except for Fall 2015 in WA where differences were observed between BDMs and no-mulch plots. Extracellular enzyme rate assays were used to characterize communities functionally, revealing significant differences by location and sampling season in both TN and WA but minimal differences between BDMs and PE treatments. Limited effects of BDM incorporation on soil bacterial community structure and soil enzyme activities when compared to PE suggest that BDMs have comparable influences on soil microbial communities, and therefore could be considered an alternative to PE.ImportancePlastic film mulches increase crop yields and improve fruit quality. Most plastic mulches are made of polyethylene (PE), which is poorly degradable, resulting in undesirable end-of-life outcomes. Biodegradable mulches (BDMs) may be a sustainable alternative to PE. BDMs are made of polymers which can be degraded by soil microbial enzymes, and are meant to be tilled into soil after use. However, uncertainty about impacts of tilled-in BDMs on soil health has restricted adoption of BDMs. Our previous research showed BDMs did not have a major effect on a wide range of soil quality indicators (Sintim et al. 2019); here we focus on soil microbial communities, showing that BDMs do not have detectable effects on soil microbial communities and their functions, at least over the short term. This informs growers and regulators about use of BDMs in crop production, paving a way for an agricultural practice that reduces environmental plastic pollution.

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Organic Amendments and Sampling Date Influences on Soil Bacterial Community Composition and Their PredictiveFunctional Profiles in an Olive Grove Ecosystem

Agriculture ◽

10.3390/agriculture11111178 ◽

2021 ◽

Vol 11 (11) ◽

pp. 1178

Author(s):

Laura L. de Sosa ◽

Beatriz Moreno ◽

Rafael Alcalá Alcalá Herrera ◽

Marco Panettieri ◽

Engracia Madejón ◽

...

Keyword(s):

Microbial Community ◽

Bacterial Community ◽

Agricultural Soils ◽

Soil Microbial Communities ◽

Soil Bacterial Community ◽

Olive Grove ◽

Soil Microbial Diversity ◽

Soil Microbial ◽

Soil Bacterial ◽

The Impact

A collapse of soil microbial diversity, mainly due to chemical inputs, has been reported to lead to the degradation of conventional agroecosystems. The use of compost from urban and agricultural waste management, in order to achieve a net gain in the storage of C, is an adequate management of agricultural soils, especially in rainfed conditions. However, the great variability of composts of different maturity and origins and of the soils to which they are added limits the ability to predict the impact of these amendments on the dynamics of soil microbial communities. This study was designed to gain insights on the effect of exogenous organic matter management on the soil bacterial community and its contribution to key functions relevant to agricultural soils. To achieve this, two different types of compost (alperujo or biosolids composts) at two doses were used as soil amendments twice for 3 years in a rainfed olive grove ecosystem. A metagenomic analysis was carried out to assess the abundance and composition of the soil bacterial communities and predicted functions. We only detected a minor and transitory effect on the bacterial abundance of the soil, the structure of the community and the potential functions, less related to the dose or the type of compost than to seasonal variations. Although the result suggests that the soil bacteria were highly resilient, promoting community stability and functional resilience after the addition of the two composts, more efforts are necessary to assess not only the resulting soil microbial community after organic fertilization but the intrinsic microbial community within the organic amendment that acts as an inoculum, and to what extent the changes in its dose could lead to the functionality of the soil.

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