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Camuy-Vélez LA, Banerjee S, Sedivec K. Grazing intensity alters network complexity and predator-prey relationships in the soil microbiome. Appl Environ Microbiol 2024:e0042524. [PMID: 39235241 DOI: 10.1128/aem.00425-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2024] [Accepted: 08/13/2024] [Indexed: 09/06/2024] Open
Abstract
Grasslands are recognized as important reservoirs of soil biodiversity. Livestock grazing is implemented as a grassland management strategy to improve soil quality and enhance plant diversity. Soil microbial communities play a pivotal role in grassland ecosystems, so it is important to examine whether grazing practices affect the soil microbiome. Previous studies on grazing have primarily focused on bacteria and fungi, overlooking an important group-protists. Protists are vital in soil microbiomes as they drive nutrient availability and trophic interactions. Determining the impact of grazing on protists and their relationships with bacterial and fungal communities is important for understanding soil microbiome dynamics in grazed ecosystems. In this study, we investigated soil bacterial, fungal, and protist communities under four grazing levels: no grazing, moderate-use grazing, full-use grazing, and heavy-use grazing. Our results showed that heavy grazing led to a greater diversity of protists with specific groups, such as Discoba and Conosa, increasing in abundance. We also found strong associations between protist and bacterial/fungal members, indicating their intricate relationships within the soil microbiome. For example, the abundance of predatory protists increased under grazing while arbuscular mycorrhizal fungi decreased. Notably, arbuscular mycorrhizae were negatively associated with predatory groups. Furthermore, we observed that microbial network complexity increased with grazing intensity, with fungal members playing an important role in the network. Overall, our study reports the impact of temporal grazing intensity on soil microbial dynamics and highlights the importance of considering protist ecology when evaluating the effects of grazing on belowground communities in grassland ecosystems. IMPORTANCE The significance of this study lies in its exploration of the effects of temporal grazing intensity on the dynamics of the soil microbiome, specifically focusing on the often-neglected role of protists. Our findings provide insights into the complex relationships between protists, bacteria, and fungi, emphasizing their impact on trophic interactions in the soil. Gaining a better understanding of these dynamics is essential for developing effective strategies for grassland management and conservation, underscoring the importance of incorporating protist ecology into microbiome studies in grasslands.
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Affiliation(s)
- Lennel A Camuy-Vélez
- Microbiological Sciences, North Dakota State University, Fargo, North Dakota, USA
| | - Samiran Banerjee
- Microbiological Sciences, North Dakota State University, Fargo, North Dakota, USA
| | - Kevin Sedivec
- School of Natural Resource Science, North Dakota State University, Fargo, North Dakota, USA
- Central Grasslands Research Extension Center, North Dakota State University, Streeter, North Dakota, USA
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2
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Yang C, Zhang H, Zhao X, Liu P, Wang L, Wang W. A functional metagenomics study of soil carbon and nitrogen degradation networks and limiting factors on the Tibetan plateau. Front Microbiol 2023; 14:1170806. [PMID: 37228377 PMCID: PMC10203874 DOI: 10.3389/fmicb.2023.1170806] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2023] [Accepted: 04/10/2023] [Indexed: 05/27/2023] Open
Abstract
Introduction The Three-River Source Nature Reserve is located in the core area of the Qinghai-Tibetan Plateau, with the alpine swamp, meadow and steppe as the main ecosystem types. However, the microbial communities in these alpine ecosystems, and their carbon and nitrogen degrading metabolic networks and limiting factors remain unclear. Methods We sequenced the diversity of bacteria and fungi in alpine swamps, meadows, steppes, and their degraded and artificially restored ecosystems and analyzed soil environmental conditions. Results The results indicated that moisture content had a greater influence on soil microbial community structure compared to degradation and restoration. Proteobacteria dominated in high moisture alpine swamps and alpine meadows, while Actinobacteria dominated in low moisture alpine steppes and artificial grasslands. A metabolic network analysis of carbon and nitrogen degradation and transformation using metagenomic sequencing revealed that plateau microorganisms lacked comprehensive and efficient enzyme systems to degrade organic carbon, nitrogen, and other biological macromolecules, so that the short-term degradation of alpine vegetation had no effect on the basic composition of soil microbial community. Correlation analysis found that nitrogen fixation was strong in meadows with high moisture content, and their key nitrogen-fixing enzymes were significantly related to Sphingomonas. Denitrification metabolism was enhanced in water-deficient habitats, and the key enzyme, nitrous oxide reductase, was significantly related to Phycicoccus and accelerated the loss of nitrogen. Furthermore, Bacillus contained a large number of amylases (GH13 and GH15) and proteases (S8, S11, S26, and M24) which may promote the efficient degradation of organic carbon and nitrogen in artificially restored grasslands. Discussion This study illustrated the irrecoverability of meadow degradation and offered fundamental information for altering microbial communities to restore alpine ecosystems.
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Affiliation(s)
- Chong Yang
- School of Geographical Sciences, Qinghai Normal University, Xining, China
- School of Life Sciences, Qinghai Normal University, Xining, China
| | - Hong Zhang
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, China
| | - Xinquan Zhao
- Northwest Plateau Institute of Biology, Chinese Academy of Sciences, Xining, China
| | - Pan Liu
- School of Geographical Sciences, Qinghai Normal University, Xining, China
| | - Lushan Wang
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, China
| | - Wenying Wang
- School of Life Sciences, Qinghai Normal University, Xining, China
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Abulaizi M, Chen M, Yang Z, Hu Y, Zhu X, Jia H. Response of soil bacterial community to alpine wetland degradation in arid Central Asia. FRONTIERS IN PLANT SCIENCE 2023; 13:990597. [PMID: 36684714 PMCID: PMC9848402 DOI: 10.3389/fpls.2022.990597] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/10/2022] [Accepted: 11/25/2022] [Indexed: 06/17/2023]
Abstract
A large number of studies have reported the importance of bacterial communities in ecosystems and their responses to soil degradation, but the response mechanism in arid alpine wetlands is still unclear. Here, the non-degraded (ND), slightly degraded (SD), and heavily degraded (HD) regions of Bayinbuluk alpine wetland were used to analyzed the diversity, structure and function of bacterial communities in three degraded wetlands using 16S rRNA. The results showed that with the increase of degradation degree, the content of soil moisture (SM) and available nitrogen (AN) decreased significantly, plant species richness and total vegetation coverage decreased significantly, Cyperaceae (Cy) coverage decreased significantly, and Gramineae (Gr) coverage increased significantly. Degradation did not significantly affect the diversity of the bacterial community, but changed the relative abundance of the community structure. Degradation significantly increased the relative abundance of Actinobacteria (ND: 3.95%; SD: 7.27%; HD: 23.97%) and Gemmatimonadetes (ND: 0.39%; SD: 2.17%; HD: 10.78%), while significantly reducing the relative abundance of Chloroflexi (ND: 13.92%; SD: 8.68%; HD: 3.55%) and Nitrospirae (ND: 6.18%; SD: 0.45%; HD: 2.32%). Degradation significantly reduced some of the potential functions in the bacterial community associated with the carbon (C), nitrogen (N) and sulfur (S) cycles, such as hydrocarbon degradation (ND: 25.00%; SD: 1.74%; HD: 6.59%), such as aerobic ammonia oxidation (ND: 5.96%; SD: 22.82%; HD: 4.55%), and dark sulfide oxidation (ND: 32.68%; SD: 0.37%; HD: 0.28%). Distance-based redundancy analysis (db-RDA) results showed that the bacteria community was significantly related to the TC (total carbon) and Gr (P < 0.05). The results of linear discriminant analysis effect size (LEfSe) analysis indicate significant enrichments of Alphaproteobacteria and Sphingomonas in the HD area. The vegetation communities and soil nutrients changed significantly with increasing soil degradation levels, and Sphingomonas could be used as potential biomarker of degraded alpine wetlands.
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Affiliation(s)
- Maidinuer Abulaizi
- College of Resources and Environment, Xinjiang Agricultural University, Urumqi, China
| | - Mo Chen
- College of Grassland Science, Xinjiang Agricultural University, Urumqi, China
| | - Zailei Yang
- College of Resources and Environment, Xinjiang Agricultural University, Urumqi, China
| | - Yang Hu
- College of Resources and Environment, Xinjiang Agricultural University, Urumqi, China
| | - Xinping Zhu
- College of Resources and Environment, Xinjiang Agricultural University, Urumqi, China
- Xinjiang Key Laboratory of Soil and Plant Ecological Processes, Urumqi, China
| | - Hongtao Jia
- College of Resources and Environment, Xinjiang Agricultural University, Urumqi, China
- Xinjiang Key Laboratory of Soil and Plant Ecological Processes, Urumqi, China
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4
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Ruscoe HL, Taketani RG, Clark IM, Lund G, Hughes D, Dodd IC, Hirsch PR, Mauchline TH. Land Management Legacy Affects Abundance and Function of the acdS Gene in Wheat Root Associated Pseudomonads. Front Microbiol 2021; 12:611339. [PMID: 34777264 PMCID: PMC8578595 DOI: 10.3389/fmicb.2021.611339] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2020] [Accepted: 09/20/2021] [Indexed: 11/19/2022] Open
Abstract
Land management practices can vastly influence belowground plant traits due to chemical, physical, and biological alteration of soil properties. Beneficial Pseudomonas spp. are agriculturally relevant bacteria with a plethora of plant growth promoting (PGP) qualities, including the potential to alter plant physiology by modulating plant produced ethylene via the action of the bacterial enzyme 1-aminocyclopropane-1-carboxylate (ACC) deaminase (acdS). This study evaluated the impact of land management legacy on the selection and function of wheat root associated culturable pseudomonad isolates. Three distinct previous land uses prior to wheat culture (grassland, arable, and bare fallow) were tested and culturable pseudomonad abundance, phylogeny (gyrB and acdS genes), function (ACC deaminase activity), and the co-selection of acdS with other PGP genes examined. The pseudomonad community could to some extent be discriminated based on previous land use. The isolates from rhizosphere and root compartments of wheat had a higher acdS gene frequency than the bulk soil, particularly in plants grown in soil from the bare fallow treatment which is known to have degraded soil properties such as low nutrient availability. Additionally, other genes of interest to agriculture encoding anti-fungal metabolites, siderophores, and genes involved in nitrogen metabolism were highly positively associated with the presence of the acdS gene in the long-term arable treatment in the genomes of these isolates. In contrast, genes involved in antibiotic resistance and type VI secretion systems along with nitrogen cycling genes were highly positively correlated with the acdS gene in bare fallow isolated pseudomonad. This highlights that the three land managements prior to wheat culture present different selection pressures that can shape culturable pseudomonad community structure and function either directly or indirectly via the influence of wheat roots.
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Affiliation(s)
- Heather L Ruscoe
- Sustainable Agriculture Sciences, Rothamsted Research, Harpenden, United Kingdom
| | - Rodrigo G Taketani
- Sustainable Agriculture Sciences, Rothamsted Research, Harpenden, United Kingdom
| | - Ian M Clark
- Sustainable Agriculture Sciences, Rothamsted Research, Harpenden, United Kingdom
| | - George Lund
- Sustainable Agriculture Sciences, Rothamsted Research, Harpenden, United Kingdom
| | - David Hughes
- Sustainable Agriculture Sciences, Rothamsted Research, Harpenden, United Kingdom
| | - Ian C Dodd
- The Lancaster Environment Centre, Lancaster University, Lancaster, United Kingdom
| | - Penny R Hirsch
- Sustainable Agriculture Sciences, Rothamsted Research, Harpenden, United Kingdom
| | - Tim H Mauchline
- Sustainable Agriculture Sciences, Rothamsted Research, Harpenden, United Kingdom
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5
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George PBL, Fidler DB, Van Nostrand JD, Atkinson JA, Mooney SJ, Creer S, Griffiths RI, McDonald JE, Robinson DA, Jones DL. Shifts in Soil Structure, Biological, and Functional Diversity Under Long-Term Carbon Deprivation. Front Microbiol 2021; 12:735022. [PMID: 34594317 PMCID: PMC8477002 DOI: 10.3389/fmicb.2021.735022] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2021] [Accepted: 08/09/2021] [Indexed: 01/16/2023] Open
Abstract
Soil organic matter is composed of a variety of carbon (C) forms. However, not all forms are equally accessible to soil microorganisms. Deprivation of C inputs will cause changes in the physical and microbial community structures of soils; yet the trajectories of such changes are not clear. We assessed microbial communities using phospholipid fatty acid profiling, metabarcoding, CO2 emissions, and functional gene microarrays in a decade-long C deprivation field experiment. We also assessed changes in a range of soil physicochemical properties, including using X-ray Computed Tomography imaging to assess differences in soil structure. Two sets of soils were deprived of C inputs by removing plant inputs for 10 years and 1 year, respectively. We found a reduction in diversity measures, after 10 years of C deprivation, which was unexpected based on previous research. Fungi appeared to be most impacted, likely due to competition for scarce resources after exhausting the available plant material. This suggestion was supported by evidence of bioindicator taxa in non-vegetated soils that may directly compete with or consume fungi. There was also a reduction in copies of most functional genes after 10 years of C deprivation, though gene copies increased for phytase and some genes involved in decomposing recalcitrant C and methanogenesis. Additionally, soils under C deprivation displayed expected reductions in pH, organic C, nitrogen, and biomass as well as reduced mean pore size, especially in larger pores. However, pore connectivity increased after 10 years of C deprivation contrary to expectations. Our results highlight concurrent collapse of soil structure and biodiversity following long-term C deprivation. Overall, this study shows the negative trajectory of continuous C deprivation and loss of organic matter on a wide range of soil quality indicators and microorganisms.
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Affiliation(s)
- Paul B L George
- School of Natural Sciences, Bangor University, Bangor, United Kingdom.,UK Centre for Ecology & Hydrology, Bangor, United Kingdom.,Département de Médecine Moléculaire, Université Laval, Quebec City, QC, Canada
| | - David B Fidler
- School of Natural Sciences, Bangor University, Bangor, United Kingdom
| | - Joy D Van Nostrand
- Institute for Environmental Genomics, The University of Oklahoma, Norman, OK, United States
| | - Jonathan A Atkinson
- School of Biosciences, University of Nottingham, Sutton Bonington Campus, Sutton Bonington, United Kingdom
| | - Sacha J Mooney
- School of Biosciences, University of Nottingham, Sutton Bonington Campus, Sutton Bonington, United Kingdom
| | - Simon Creer
- School of Natural Sciences, Bangor University, Bangor, United Kingdom
| | | | - James E McDonald
- School of Natural Sciences, Bangor University, Bangor, United Kingdom
| | | | - Davey L Jones
- School of Natural Sciences, Bangor University, Bangor, United Kingdom.,SoilsWest, UWA School of Agriculture and Environment, The University of Western Australia, Perth, WA, Australia
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6
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Clark IM, Hughes DJ, Fu Q, Abadie M, Hirsch PR. Metagenomic approaches reveal differences in genetic diversity and relative abundance of nitrifying bacteria and archaea in contrasting soils. Sci Rep 2021; 11:15905. [PMID: 34354121 PMCID: PMC8342464 DOI: 10.1038/s41598-021-95100-9] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2021] [Accepted: 07/12/2021] [Indexed: 11/09/2022] Open
Abstract
The abundance and phylogenetic diversity of functional genes involved in nitrification were assessed in Rothamsted field plots under contrasting management regimes-permanent bare fallow, grassland, and arable (wheat) cultivation maintained for more than 50 years. Metagenome and metatranscriptome analysis indicated nitrite oxidizing bacteria (NOB) were more abundant than ammonia oxidizing archaea (AOA) and bacteria (AOB) in all soils. The most abundant AOA and AOB in the metagenomes were, respectively, Nitrososphaera and Ca. Nitrososcosmicus (family Nitrososphaeraceae) and Nitrosospira and Nitrosomonas (family Nitrosomonadaceae). The most abundant NOB were Nitrospira including the comammox species Nitrospira inopinata, Ca. N. nitrificans and Ca. N. nitrosa. Anammox bacteria were also detected. Nitrospira and the AOA Nitrososphaeraceae showed most transcriptional activity in arable soil. Similar numbers of sequences were assigned to the amoA genes of AOA and AOB, highest in the arable soil metagenome and metatranscriptome; AOB amoA reads included those from comammox Nitrospira clades A and B, in addition to Nitrosomonadaceae. Nitrification potential assessed in soil from the experimental sites (microcosms amended or not with DCD at concentrations inhibitory to AOB but not AOA), was highest in arable samples and lower in all assays containing DCD, indicating AOB were responsible for oxidizing ammonium fertilizer added to these soils.
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Affiliation(s)
- Ian M Clark
- Sustainable Agriculture Sciences Department, Rothamsted Research, Harpenden, AL5 2JQ, Hertfordshire, UK
| | - David J Hughes
- Computational and Analytical Sciences, Rothamsted Research, Harpenden, AL5 2JQ, Hertfordshire, UK
| | - Qingling Fu
- Sustainable Agriculture Sciences Department, Rothamsted Research, Harpenden, AL5 2JQ, Hertfordshire, UK
- College of Resources and Environment, Huazhong Agricultural University, Wuhan, 430070, Hubei Province, People's Republic of China
| | - Maïder Abadie
- Sustainable Agriculture Sciences Department, Rothamsted Research, Harpenden, AL5 2JQ, Hertfordshire, UK
| | - Penny R Hirsch
- Sustainable Agriculture Sciences Department, Rothamsted Research, Harpenden, AL5 2JQ, Hertfordshire, UK.
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7
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Neal AL, Hughes D, Clark IM, Jansson JK, Hirsch PR. Microbiome Aggregated Traits and Assembly Are More Sensitive to Soil Management than Diversity. mSystems 2021; 6:e0105620. [PMID: 34042469 PMCID: PMC8269249 DOI: 10.1128/msystems.01056-20] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2020] [Accepted: 01/29/2021] [Indexed: 11/20/2022] Open
Abstract
How soil is managed, particularly for agriculture, exerts stresses upon soil microbiomes, resulting in altered community structures and functional states. Understanding how soil microbiomes respond to combined stresses is important for predicting system performance under different land use scenarios, aids in identification of the most environmentally benign managements, and provides insight into how system function can be recovered in degraded soils. We use a long-established field experiment to study the effects of combined chronic (press) disturbance of the magnitude of organic carbon inputs with acute (pulse) effects of physical disturbance by tillage and chemical disturbance due to inorganic fertilization and pesticide application. We show that because of the variety of ways it can be assessed, biodiversity-here based on microbial small subunit rRNA gene phylotypes-does not provide a consistent view of community change. In contrast, aggregated traits associated with soil microbiomes indicate general loss of function, measured as a reduction of average genome lengths, associated with chronic reduction of organic inputs in arable or bare fallow soils and altered growth strategies associated with rRNA operon copy number in prokaryotes, as well as a switch to pathogenicity in fungal communities. In addition, pulse disturbance by soil tillage is associated with an increased influence of stochastic processes upon prokaryote community assembly, but fungicide used in arable soils results in niche assembly of fungal communities compared to untilled grassland. Overall, bacteria, archaea, and fungi do not share a common response to land management change, and estimates of biodiversity do not capture important facets of community adaptation to stresses adequately. IMPORTANCE Changes in soil microbiome diversity and function brought about by land management are predicted to influence a range of environmental services provided by soil, including provision of food and clean water. However, opportunities to compare the long-term effects of combinations of stresses imposed by different management approaches are limited. We exploit a globally unique 50-year field experiment, demonstrating that soil management practices alter microbiome diversity, community traits, and assembly. Grassland soil microbiomes are dominated by fewer-but phylogenetically more diverse-prokaryote phylotypes which sustain larger genomes than microbiomes in arable or bare fallow soil maintained free of plants. Dominant fungi in grassland soils are less phylogenetically diverse than those in arable or fallow soils. Soil tillage increases stochastic processes in microbiome assembly: this, combined with reduced plant biomass, presents opportunities for organisms with a capacity for pathogenesis to become established in stressed soils.
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Affiliation(s)
- Andrew L. Neal
- Department of Sustainable Agriculture Science, Rothamsted Research, North Wyke, Devon, United Kingdom
| | - David Hughes
- Department of Computational and Analytical Sciences, Rothamsted Research, Harpenden, Hertfordshire, United Kingdom
| | - Ian M. Clark
- Department of Sustainable Agriculture Science, Rothamsted Research, Harpenden, Hertfordshire, United Kingdom
| | - Janet K. Jansson
- Biological Sciences Division, Pacific Northwest National Laboratory, Richland, Washington, USA
| | - Penny R. Hirsch
- Department of Sustainable Agriculture Science, Rothamsted Research, Harpenden, Hertfordshire, United Kingdom
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8
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Li Q, Song A, Yang H, Müller WEG. Impact of Rocky Desertification Control on Soil Bacterial Community in Karst Graben Basin, Southwestern China. Front Microbiol 2021; 12:636405. [PMID: 33790877 PMCID: PMC8006366 DOI: 10.3389/fmicb.2021.636405] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Accepted: 02/15/2021] [Indexed: 11/13/2022] Open
Abstract
Microorganisms play critical roles in belowground ecosystems, and karst rocky desertification (KRD) control affects edaphic properties and vegetation coverage. However, the relationship between KRD control and soil bacterial communities remains unclear. 16S rRNA gene next-generation sequencing was used to investigate soil bacterial community structure, composition, diversity, and co-occurrence network from five ecological types in KRD control area. Moreover, soil physical-chemical properties and soil stoichiometry characteristics of carbon, nitrogen and phosphorus were analyzed. Soil N and P co-limitation decreased in the contribution of the promotion of KRD control on edaphic properties. Though soil bacterial communities appeared strongly associated with soil pH, soil calcium, soil phosphorus and plant richness, the key factor to determine their compositions was the latter via changed edaphic properties. The co-occurrence network analysis indicated that soil bacterial network complexity in natural ecosystem was higher than that in additional management ecosystem. Candidatus Udaeobacter, Chthoniobacterales, and Pedosphaeraceae were recognized as the key taxa maintaining karst soil ecosystems in KRD control area. Our results indicate that natural recovery is the suitable way for restoration and rehabilitation of degraded ecosystems, and thus contribute to the ongoing endeavor to appraise the interactions among soil-plant ecological networks.
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Affiliation(s)
- Qiang Li
- Key Laboratory of Karst Dynamics, MNR and GZAR, Institute of Karst Geology, Chinese Academy of Geological Sciences, Guilin, China.,International Research Center on Karst Under the Auspices of UNESCO, Guilin, China
| | - Ang Song
- Key Laboratory of Karst Dynamics, MNR and GZAR, Institute of Karst Geology, Chinese Academy of Geological Sciences, Guilin, China.,International Research Center on Karst Under the Auspices of UNESCO, Guilin, China
| | - Hui Yang
- Key Laboratory of Karst Dynamics, MNR and GZAR, Institute of Karst Geology, Chinese Academy of Geological Sciences, Guilin, China.,International Research Center on Karst Under the Auspices of UNESCO, Guilin, China
| | - Werner E G Müller
- ERC Advanced Investigator Grant Research Group, Institute for Physiological Chemistry, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
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Kavamura VN, Mendes R, Bargaz A, Mauchline TH. Defining the wheat microbiome: Towards microbiome-facilitated crop production. Comput Struct Biotechnol J 2021; 19:1200-1213. [PMID: 33680361 PMCID: PMC7902804 DOI: 10.1016/j.csbj.2021.01.045] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2020] [Revised: 01/29/2021] [Accepted: 01/30/2021] [Indexed: 12/17/2022] Open
Abstract
Wheat is one of the world's most important crops, but its production relies heavily on agrochemical inputs which can be harmful to the environment when used excessively. It is well known that a multitude of microbes interact with eukaryotic organisms, including plants, and the sum of microbes and their functions associated with a given host is termed the microbiome. Plant-microbe interactions can be beneficial, neutral or harmful to the host plant. Over the last decade, with the development of next generation DNA sequencing technology, our understanding of the plant microbiome structure has dramatically increased. Considering that defining the wheat microbiome is key to leverage crop production in a sustainable way, here we describe how different factors drive microbiome assembly in wheat, including crop management, edaphic-environmental conditions and host selection. In addition, we highlight the benefits to take a multidisciplinary approach to define and explore the wheat core microbiome to generate solutions based on microbial (synthetic) communities or single inoculants. Advances in plant microbiome research will facilitate the development of microbial strategies to guarantee a sustainable intensification of crop production.
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Affiliation(s)
- Vanessa N. Kavamura
- Sustainable Agriculture Sciences, Rothamsted Research, Harpenden, Hertfordshire, UK
| | - Rodrigo Mendes
- Laboratory of Environmental Microbiology, Embrapa Environment, Jaguariúna, SP, Brazil
| | - Adnane Bargaz
- Agrobiosciences, Mohammed VI Polytechnic University, Benguerir, Morocco
| | - Tim H. Mauchline
- Sustainable Agriculture Sciences, Rothamsted Research, Harpenden, Hertfordshire, UK
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10
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Edaphic factors and plants influence denitrification in soils from a long-term arable experiment. Sci Rep 2020; 10:16053. [PMID: 32994429 PMCID: PMC7524710 DOI: 10.1038/s41598-020-72679-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2019] [Accepted: 09/02/2020] [Indexed: 11/09/2022] Open
Abstract
Factors influencing production of greenhouse gases nitrous oxide (N2O) and nitrogen (N2) in arable soils include high nitrate, moisture and plants; we investigate how differences in the soil microbiome due to antecedent soil treatment additionally influence denitrification. Microbial communities, denitrification gene abundance and gas production in soils from tilled arable plots with contrasting fertilizer inputs (no N, mineral N, FYM) and regenerated woodland in the long-term Broadbalk field experiment were investigated. Soil was transferred to pots, kept bare or planted with wheat and after 6 weeks, transferred to sealed chambers with or without K15NO3 fertilizer for 4 days; N2O and N2 were measured daily. Concentrations of N2O were higher when fertilizer was added, lower in the presence of plants, whilst N2 increased over time and with plants. Prior soil treatment but not exposure to N-fertiliser or plants during the experiment influenced denitrification gene (nirK, nirS, nosZI, nosZII) relative abundance. Under our experimental conditions, denitrification generated mostly N2; N2O was around 2% of total gaseous N2 + N2O. Prior long-term soil management influenced the soil microbiome and abundance of denitrification genes. The production of N2O was driven by nitrate availability and N2 generation increased in the presence of plants.
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11
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Deckmyn G, Flores O, Mayer M, Domene X, Schnepf A, Kuka K, Van Looy K, Rasse DP, Briones MJ, Barot S, Berg M, Vanguelova E, Ostonen I, Vereecken H, Suz LM, Frey B, Frossard A, Tiunov A, Frouz J, Grebenc T, Öpik M, Javaux M, Uvarov A, Vindušková O, Henning Krogh P, Franklin O, Jiménez J, Curiel Yuste J. KEYLINK: towards a more integrative soil representation for inclusion in ecosystem scale models. I. review and model concept. PeerJ 2020; 8:e9750. [PMID: 32974092 PMCID: PMC7486829 DOI: 10.7717/peerj.9750] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2020] [Accepted: 07/27/2020] [Indexed: 11/20/2022] Open
Abstract
The relatively poor simulation of the below-ground processes is a severe drawback for many ecosystem models, especially when predicting responses to climate change and management. For a meaningful estimation of ecosystem production and the cycling of water, energy, nutrients and carbon, the integration of soil processes and the exchanges at the surface is crucial. It is increasingly recognized that soil biota play an important role in soil organic carbon and nutrient cycling, shaping soil structure and hydrological properties through their activity, and in water and nutrient uptake by plants through mycorrhizal processes. In this article, we review the main soil biological actors (microbiota, fauna and roots) and their effects on soil functioning. We review to what extent they have been included in soil models and propose which of them could be included in ecosystem models. We show that the model representation of the soil food web, the impact of soil ecosystem engineers on soil structure and the related effects on hydrology and soil organic matter (SOM) stabilization are key issues in improving ecosystem-scale soil representation in models. Finally, we describe a new core model concept (KEYLINK) that integrates insights from SOM models, structural models and food web models to simulate the living soil at an ecosystem scale.
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Affiliation(s)
- Gaby Deckmyn
- Department of Biology, Plants and Ecosystems (PLECO), Universiteit Antwerpen, Antwerpen, Belgium
| | - Omar Flores
- Department of Biology, Plants and Ecosystems (PLECO), Universiteit Antwerpen, Antwerpen, Belgium
- Biogeography and Global Change, National Museum of Natural Sciences-Spanish National Research Council (MNCN-CSIC), Madrid, Spain
| | - Mathias Mayer
- Institute of Forest Ecology, Department of Forest and Soil Sciences, University of Natural Resources and Life Sciences (BOKU), Vienna, Austria
- Biogeochemistry Group, Forest Soils and Biogeochemistry, Swiss Federal Research Institute WSL, Birmensdorf, Switzerland
| | - Xavier Domene
- CREAF, Cerdanyola del Vallès, Spain
- Universitat Autònoma de Barcelona, Cerdanyola del Vallès, Spain
| | - Andrea Schnepf
- Agrosphere Institute, IBG, Forschungszentrum Jülich GmbH, Jülich, Germany
| | - Katrin Kuka
- Institute for Crop and Soil Science, Julius Kühn-Institut (JKI), Braunschwei, Germany
| | - Kris Van Looy
- OVAM, Flemish Institute for Materials and Soils, Mechelen, Belgium
| | - Daniel P. Rasse
- Department of Biogeochemistry and Soil Quality, Norwegian Institute of Bioeconomy Research (NIBIO), Aas, Norway
| | - Maria J.I. Briones
- Departamento de Ecología y Biología Animal, Universidad de Vigo, Vigo, Spain
| | - Sébastien Barot
- Institute of Ecology and Environmental Sciences, IRD, UPEC, CNRS, INRA, Sorbonne Université, Paris, France
| | - Matty Berg
- Department of Ecological Science, Vrije Universiteit Amsterdam, Amsterdam, Netherlands
- Groningen Institute for Evolutionary Life Sciences, University of Groningen, Groningen, Netherlands
| | | | - Ivika Ostonen
- Institute of Ecology and Earth Sciences, University of Tartu, Tartu, Estonia
| | - Harry Vereecken
- Agrosphere Institute, IBG, Forschungszentrum Jülich GmbH, Jülich, Germany
| | - Laura M. Suz
- Comparative Plant and Fungal Biology, Royal Botanic Gardens, Kew, London, UK
| | - Beat Frey
- Forest Soils and Biogeochemistry, Swiss Federal Research Institute WSL, Birmensdorf, Switzerland
| | - Aline Frossard
- Forest Soils and Biogeochemistry, Swiss Federal Research Institute WSL, Birmensdorf, Switzerland
| | - Alexei Tiunov
- A.N. Severtsov Institute of Ecology and Evolution RAS, Moscow, Russia
| | - Jan Frouz
- Institute for Environmental Studies, Charles University, Prague, Czech Republic
| | - Tine Grebenc
- Slovenian Forestry Institute, Ljubljana, Slovenia
| | - Maarja Öpik
- Institute of Ecology and Earth Sciences, University of Tartu, Tartu, Estonia
| | - Mathieu Javaux
- Agrosphere Institute, IBG, Forschungszentrum Jülich GmbH, Jülich, Germany
- Earth and Life Institute, UCLouvain, Louvain-la-Neuve, Belgium
| | - Alexei Uvarov
- A.N. Severtsov Institute of Ecology and Evolution RAS, Moscow, Russia
| | - Olga Vindušková
- Department of Biology, Plants and Ecosystems (PLECO), Universiteit Antwerpen, Antwerpen, Belgium
| | | | - Oskar Franklin
- Department of Forest Ecology and Management, Swedish University of Agricultural Sciences, Umeå, Sweden
- International Institute for Applied Systems Analysis IIASA, Laxenburg, Austria
| | - Juan Jiménez
- Department of Biodiversity Conservation and Ecosystem Restoration, ARAID/IPE-CSIC, Jaca, Spain
| | - Jorge Curiel Yuste
- BC3-Basque Centre for Climate Change, Scientific Campus of the University of the Basque Country, Bilbao, Bizkaia, Spain
- IKERBASQUE, Basque Foundation for Science, Bilbao, Spain
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12
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Du Y, Ke X, Dai L, Cao G, Zhou H, Guo X. Moderate grazing increased alpine meadow soils bacterial abundance and diversity index on the Tibetan Plateau. Ecol Evol 2020; 10:8681-8687. [PMID: 32884650 PMCID: PMC7452759 DOI: 10.1002/ece3.6563] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Revised: 05/28/2020] [Accepted: 06/08/2020] [Indexed: 01/10/2023] Open
Abstract
The response of grassland soil bacterial community characteristics to different grazing intensities is central ecological topics. However, the underlying mechanisms between bacterial abundance, diversity index, and grazing intensity remain unclear. We measured alpine meadow soil bacterial gene richness and diversity index under four grazing intensities using 16S rDNA sequence analysis on the Tibetan Plateau. The results suggest that extreme grazing significantly decreased alpine meadow both bacterial gene abundance and diversity index (p < .05). The lowest operational taxonomic unit numbers were 3,012 ± 447 copies under heavy grazing in the growing season. It was significantly lower than heavy grazing with approximately 3,958 ± 119 copies (p < .05). The Shannon index for medium and high grazing grassland bacterial diversity was slightly higher than for light grazing in the growing season. Furthermore, the lowest index was approximately 9.20 ± 0.50 for extreme grazing of grassland in the growing season. The average bacterial gene abundance and diversity index in the dormancy period were slightly higher than that in the growing season. Soil bulk density, pH, ammonium, and nitrate nitrogen were the main positive factors driving grazed grassland bacterial communities. Our study provides insight into the response of alpine meadows to grazing intensity, demonstrating that moderate grazing increases bacterial community diversity in grazed grasslands.
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Affiliation(s)
- Yangong Du
- Qinghai Provincial Key Laboratory of Restoration Ecology for Cold RegionNorthwest Institute of Plateau BiologyChinese Academy of SciencesXiningChina
| | - Xun Ke
- Qinghai Provincial Key Laboratory of Restoration Ecology for Cold RegionNorthwest Institute of Plateau BiologyChinese Academy of SciencesXiningChina
| | - Licong Dai
- Qinghai Provincial Key Laboratory of Restoration Ecology for Cold RegionNorthwest Institute of Plateau BiologyChinese Academy of SciencesXiningChina
- University of Chinese Academy of ScienceBeijingChina
| | - Guangmin Cao
- Qinghai Provincial Key Laboratory of Restoration Ecology for Cold RegionNorthwest Institute of Plateau BiologyChinese Academy of SciencesXiningChina
| | - Huakun Zhou
- Qinghai Provincial Key Laboratory of Restoration Ecology for Cold RegionNorthwest Institute of Plateau BiologyChinese Academy of SciencesXiningChina
| | - Xiaowei Guo
- Qinghai Provincial Key Laboratory of Restoration Ecology for Cold RegionNorthwest Institute of Plateau BiologyChinese Academy of SciencesXiningChina
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13
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Köberl M, Wagner P, Müller H, Matzer R, Unterfrauner H, Cernava T, Berg G. Unraveling the Complexity of Soil Microbiomes in a Large-Scale Study Subjected to Different Agricultural Management in Styria. Front Microbiol 2020; 11:1052. [PMID: 32523580 PMCID: PMC7261914 DOI: 10.3389/fmicb.2020.01052] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2020] [Accepted: 04/28/2020] [Indexed: 12/31/2022] Open
Abstract
Healthy soil microbiomes are crucial for achieving high productivity in combination with crop quality, but our understanding of microbial diversity is still limited. In a large-scale study including 116 composite samples from vineyards, orchards and other crops from all over Styria (south-east Austria), agricultural management as well as distinct soil parameters were identified as drivers of the indigenous microbial communities in agricultural soils. The analysis of the soil microbiota based on microbial profiling of prokaryotic 16S rRNA gene fragments and fungal ITS regions revealed high bacterial and fungal diversity within Styrian agricultural soils; 206,596 prokaryotic and 53,710 fungal OTUs. Vineyards revealed a significantly higher diversity and distinct composition of soil fungi over orchards and other agricultural soils, whereas the prokaryotic diversity was unaffected. Soil pH was identified as one of the most important edaphic modulators of microbial community structure in both, vineyard and orchard soils. In general, the acid-base balance, disorders in the soil sorption complex, content and quality of organic substance as well as individual nutrients were identified as important drivers of the microbial community structure of Styrian vineyard and orchard soils. However, responses to distinct parameters differed in orchards and vineyards, and prokaryotic and fungal community responded differently to the same abiotic factor. In comparison to orchards, the microbiome of vineyard soils maintained a higher stability when herbicides were applied. Orchard soils exhibited drastic shifts within community composition; herbicides seem to have a substantial impact on the bacterial order Chthoniobacterales as well as potential plant growth promoters and antagonists of phytopathogens (Flavobacterium, Monographella), with a decreased abundance in herbicide-treated soils. Moreover, soils of herbicide-treated orchards revealed a significantly higher presence of potential apple pathogenic fungi (Nectria, Thelonectria). These findings provide the basis to adapt soil management practices in the future in order to maintain a healthy microbiome in agricultural soils.
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Affiliation(s)
- Martina Köberl
- Institute of Environmental Biotechnology, Graz University of Technology, Graz, Austria
| | - Philipp Wagner
- Institute of Environmental Biotechnology, Graz University of Technology, Graz, Austria
| | - Henry Müller
- Institute of Environmental Biotechnology, Graz University of Technology, Graz, Austria
| | - Robert Matzer
- ARGE obst.wein, Association of Weinbauverband Steiermark and Verband Steirischer Erwerbsobstbauern, Graz, Austria
| | | | - Tomislav Cernava
- Institute of Environmental Biotechnology, Graz University of Technology, Graz, Austria
| | - Gabriele Berg
- Institute of Environmental Biotechnology, Graz University of Technology, Graz, Austria
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14
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Jensen JL, Schjønning P, Watts CW, Christensen BT, Munkholm LJ. Short-term changes in soil pore size distribution: Impact of land use. SOIL & TILLAGE RESEARCH 2020; 199:104597. [PMID: 32362696 PMCID: PMC7074003 DOI: 10.1016/j.still.2020.104597] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/15/2019] [Revised: 01/31/2020] [Accepted: 02/04/2020] [Indexed: 06/11/2023]
Abstract
Changes in land use affect the pore size distribution (PSD) of the soil, and hence important soil functions such as gas exchange, water availability and plant growth. The objective of this study was to investigate potentially damaging and restorative soil management practices on soil pore structure. We quantified the rate of change in PSD six years after changes in land use taking advantage of the Highfield land-use change experiment at Rothamsted Research. This experiment includes short-term soil degradation and restoration scenarios established simultaneously within long-term contrasting treatments that had reached steady-state equilibrium. The land-use change scenarios comprised conversion to grassland of previously arable or bare fallow soil, and conversion of grassland to arable and bare fallow soils. In the laboratory, we exposed intact soil cores (100 cm3) to matric potentials ranging from -10 hPa to -1.5 MPa. Based on equivalent soil mass, the plant available water capacity decreased after conversion from grassland, whereas no change was observed after conversion to grassland. Structural void ratio decreased after termination of grassland and introduction of grassland in bare fallow soil, while no change was seen when changing arable to grassland. Consequently, it was faster to degrade than to restore a complex soil structure. The study illustrates that introducing grassland in degraded soil may result in short-term increase in soil density.
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Key Words
- A, Arable
- AG, Arable converted to grass
- BF, Bare fallow
- BFG, Bare fallow converted to grass
- Dex, Double-exponential model
- G, Grass
- GA, Grass converted to arable
- GBF, Grass converted to bare fallow
- Land-use change
- PAWCeq, Plant available water capacity based on identical soil quantities
- PSD, Pore size distribution
- Pore size distribution
- Soil degradation and recovery
- V2, Structural void ratio
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Affiliation(s)
- Johannes L. Jensen
- Department of Agroecology, Aarhus University, Blichers Allé 20, 8830 Tjele, Denmark
| | - Per Schjønning
- Department of Agroecology, Aarhus University, Blichers Allé 20, 8830 Tjele, Denmark
| | - Christopher W. Watts
- Department of Sustainable Agriculture Sciences, Rothamsted Research, Harpenden, Hertfordshire AL5 2JQ, United Kingdom
| | - Bent T. Christensen
- Department of Agroecology, Aarhus University, Blichers Allé 20, 8830 Tjele, Denmark
| | - Lars J. Munkholm
- Department of Agroecology, Aarhus University, Blichers Allé 20, 8830 Tjele, Denmark
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15
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Jensen JL, Schjønning P, Watts CW, Christensen BT, Obour PB, Munkholm LJ. Soil degradation and recovery - Changes in organic matter fractions and structural stability. GEODERMA 2020; 364:114181. [PMID: 32255839 PMCID: PMC7043339 DOI: 10.1016/j.geoderma.2020.114181] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/10/2019] [Revised: 01/08/2020] [Accepted: 01/12/2020] [Indexed: 05/26/2023]
Abstract
The combination of concurrent soil degradation and restoration scenarios in a long-term experiment with contrasting treatments under steady-state conditions, similar soil texture and climate make the Highfield land-use change experiment at Rothamsted Research unique. We used soil from this experiment to quantify rates of change in organic matter (OM) fractions and soil structural stability (SSS) six years after the management changed. Soil degradation included the conversion of grassland to arable and bare fallow management, while soil restoration comprised introduction of grassland in arable and bare fallow soil. Soils were tested for clay dispersibility measured on two macro-aggregate sizes (DispClay 1-2 mm and DispClay 8-16 mm) and clay-SOM disintegration (DI, the ratio between clay particles retrieved without and with SOM removal). The SSS tests were related to soil organic carbon (SOC), permanganate oxidizable C (POXC) and hot water-extractable C (HWC). The decrease in SOC after termination of grassland was greater than the increase in SOC when introducing grassland. In contrast, it was faster to restore degraded soil than to degrade grassland soil with respect to SSS at macro-aggregate scale. The effect of management changes was more pronounced for 8-16 mm than 1-2 mm aggregates indicating a larger sensitivity towards tillage-induced breakdown of binding agents in larger aggregates. At microscale, SSS depended on SOC content regardless of management. Soil management affected macroscale structural stability beyond what is revealed from measuring changes in OM fractions, underlining the need to include both bonding and binding mechanisms in the interpretation of changes in SSS induced by management.
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Key Words
- A, Arable
- AG, Arable converted to grass
- BF, Bare fallow
- CEC, Cation exchange capacity
- DI, Clay-SOM disintegration
- DispClay 1–2 mm, Clay dispersibility of 1–2 mm aggregates
- DispClay 8–16 mm, Clay dispersibility of 8–16 mm aggregates
- E, Young’s modulus
- Esp, Mass-specific rupture energy
- G, Grass
- GA, Grass converted to arable
- GBF, Grass converted to bare fallow
- HWC, Hot water-extractable carbon
- POXC, Permanganate oxidizable carbon
- Rate of change
- SSA, Specific surface area
- SSS, Soil structural stability
- Soil degradation
- Soil management
- Soil organic carbon
- Soil restoration
- Soil structural stability
- Y, Tensile strength
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Affiliation(s)
- Johannes L. Jensen
- Department of Agroecology, Aarhus University, Blichers Allé 20, 8830 Tjele, Denmark
| | - Per Schjønning
- Department of Agroecology, Aarhus University, Blichers Allé 20, 8830 Tjele, Denmark
| | - Christopher W. Watts
- Department of Sustainable Agricultural Sciences, Rothamsted Research, Harpenden, Hertfordshire AL5 2JQ, United Kingdom
| | - Bent T. Christensen
- Department of Agroecology, Aarhus University, Blichers Allé 20, 8830 Tjele, Denmark
| | - Peter B. Obour
- Department of Agroecology, Aarhus University, Blichers Allé 20, 8830 Tjele, Denmark
- Department of Natural Resources and Environmental Sciences, University of Illinois at Urbana Champaign, 1102 S. Goodwin Ave., MC-047, Urbana, IL 61801, USA
| | - Lars J. Munkholm
- Department of Agroecology, Aarhus University, Blichers Allé 20, 8830 Tjele, Denmark
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16
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Redmile-Gordon M, Gregory A, White R, Watts C. Soil organic carbon, extracellular polymeric substances (EPS), and soil structural stability as affected by previous and current land-use. GEODERMA 2020; 363:114143. [PMID: 32255838 PMCID: PMC7043399 DOI: 10.1016/j.geoderma.2019.114143] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/26/2019] [Revised: 12/12/2019] [Accepted: 12/14/2019] [Indexed: 06/11/2023]
Abstract
While soil microbial ecology, soil organic carbon (SOC) and soil physical quality are widely understood to be interrelated - the underlying drivers of emergent properties, from land management to biochemistry, are hotly debated. Biological binding agents, microbial exudates, or 'extracellular polymeric substances' (EPS) in soil are now receiving increased attention due to several of the existing methodological challenges having been overcome. We applied a recently developed approach to quantify soil EPS, as extracellular protein and extracellular polysaccharide, on the well-characterised soils of the Highfield Experiment, Rothamsted Research, UK. Our aim was to investigate the links between agricultural land use, SOC, transient binding agents known as EPS, and their impacts on soil physical quality (given by mean weight diameter of water stable aggregates; MWD). We compared the legacy effects from long-term previous land-uses (unfertilised grassland, fertilised arable, and fallow) which were established > 50 years prior to investigation, crossed with the same current land-uses established for a duration of only 2.5 years prior to sampling. Continuously fallow and grassland soils represented the poorest and greatest states of structural integrity, respectively. Total SOC and N were found to be affected by both previous and current land-uses, while extractable EPS and MWD were driven primarily by the current land-use. Land-use change between these two extremes (fallow → grass; grass → fallow) resulted in smaller SOC differences (64% increase or 37% loss) compared to MWD (125% increase or 78% loss). SOC concentration correlated well to MWD (adjusted R 2 = 0.72) but the greater SOC content from previous grassland was not found to contribute directly to the current stability (p < 0.05). Our work thus supports the view that certain distinct components of SOC, rather than the total pool, have disproportionately important effects on a soil's structural stability. EPS-protein was more closely related to aggregate stability than EPS-polysaccharide (p values of 0.002 and 0.027, respectively), and ranking soils with the 5 greatest concentrations of EPS-protein to their corresponding orders of stability (MWD) resulted in a perfect match. We confirmed that both EPS-protein and EPS-polysaccharide were transient fractions: supporting the founding models for aggregate formation. We suggest that management of transient binding agents such as EPS -as opposed to simply increasing the total SOC content- may be a more feasible strategy to improve soil structural integrity and help achieve environmental objectives.
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Affiliation(s)
- M. Redmile-Gordon
- Environmental Horticulture Department, Royal Horticultural Society, Wisley, GU23 6QB, United Kingdom
| | - A.S. Gregory
- Sustainable Agriculture Sciences Department, Rothamsted Research, Harpenden, Hertfordshire, AL5 2JQ, United Kingdom
| | - R.P. White
- Computational and Analytical Sciences Department, Rothamsted Research, Harpenden, Hertfordshire, AL5 2JQ, United Kingdom
| | - C.W. Watts
- Sustainable Agriculture Sciences Department, Rothamsted Research, Harpenden, Hertfordshire, AL5 2JQ, United Kingdom
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17
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Fu Q, Abadie M, Blaud A, Carswell A, Misselbrook TH, Clark IM, Hirsch PR. Effects of urease and nitrification inhibitors on soil N, nitrifier abundance and activity in a sandy loam soil. BIOLOGY AND FERTILITY OF SOILS 2019; 56:185-194. [PMID: 32038053 PMCID: PMC6981326 DOI: 10.1007/s00374-019-01411-5] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/12/2019] [Revised: 10/11/2019] [Accepted: 10/22/2019] [Indexed: 05/21/2023]
Abstract
Inhibitors of urease and ammonia monooxygenase can limit the rate of conversion of urea to ammonia and ammonia to nitrate, respectively, potentially improving N fertilizer use efficiency and reducing gaseous losses. Winter wheat grown on a sandy soil in the UK was treated with urea fertilizer with the urease inhibitor N-(n-butyl) thiophosphoric triamide (NBPT), the nitrification inhibitor dicyandiamide (DCD) or a combination of both. The effects on soil microbial community diversity, the abundance of genes involved in nitrification and crop yields and net N recovery were compared. The only significant effect on N-cycle genes was a transient reduction in bacterial ammonia monooxygenase abundance following DCD application. However, overall crop yields and net N recovery were significantly lower in the urea treatments compared with an equivalent application of ammonium nitrate fertilizer, and significantly less for urea with DCD than the other urea treatments.
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Affiliation(s)
- Qingling Fu
- Sustainable Agriculture Sciences Department, Rothamsted Research, Harpenden, AL5 2JQ Hertfordshire UK
- College of Resources and Environment, Huazhong Agricultural University, Wuhan, 430070 Hubei Province People’s Republic of China
| | - Maïder Abadie
- Sustainable Agriculture Sciences Department, Rothamsted Research, Harpenden, AL5 2JQ Hertfordshire UK
| | - Aimeric Blaud
- Sustainable Agriculture Sciences Department, Rothamsted Research, Harpenden, AL5 2JQ Hertfordshire UK
- Present Address: School of Applied Sciences, Edinburgh Napier University, Sighthill Campus, Edinburgh, EH11 4BN UK
| | - Alison Carswell
- Sustainable Agriculture Sciences Department, Rothamsted Research, North Wyke, Okehampton, EX20 2SB Devon UK
| | - Tom H. Misselbrook
- Sustainable Agriculture Sciences Department, Rothamsted Research, North Wyke, Okehampton, EX20 2SB Devon UK
| | - Ian M. Clark
- Sustainable Agriculture Sciences Department, Rothamsted Research, Harpenden, AL5 2JQ Hertfordshire UK
| | - Penny R. Hirsch
- Sustainable Agriculture Sciences Department, Rothamsted Research, Harpenden, AL5 2JQ Hertfordshire UK
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18
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Kavamura VN, Robinson RJ, Hayat R, Clark IM, Hughes D, Rossmann M, Hirsch PR, Mendes R, Mauchline TH. Land Management and Microbial Seed Load Effect on Rhizosphere and Endosphere Bacterial Community Assembly in Wheat. Front Microbiol 2019; 10:2625. [PMID: 31803160 PMCID: PMC6873152 DOI: 10.3389/fmicb.2019.02625] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2019] [Accepted: 10/29/2019] [Indexed: 11/13/2022] Open
Abstract
Microbial community ecology studies have traditionally utilized culture-based methodologies, though the advent of next-generation amplicon sequencing has facilitated superior resolution analyses of complex microbial communities. Here, we used culture-dependent and -independent approaches to explore the influence of land use as well as microbial seed load on bacterial community structure of the wheat rhizosphere and root endosphere. It was found that niche was an important factor in shaping the microbiome when using both methodological approaches, and that land use was also a discriminatory factor for the culture-independent-based method. Although culture-independent methods provide a higher resolution of analysis, it was found that in the rhizosphere, particular operational taxonomic units (OTUs) in the culture-dependent fraction were absent from the culture-independent fraction, indicating that deeper sequence analysis is required for this approach to be exhaustive. We also found that the microbial seed load defined the endosphere, but not rhizosphere, community structure for plants grown in soil which was not wheat adapted. Together, these findings increase our understanding of the importance of land management and microbial seed load in shaping the root microbiome of wheat and this knowledge will facilitate the exploitation of plant-microbe interactions for the development of novel microbial inoculants.
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Affiliation(s)
| | | | - Rifat Hayat
- Department of Soil Science and Soil and Water Conservation, Pir Mehr Ali Shah Arid Agriculture University, Rawalpindi, Pakistan
| | - Ian M. Clark
- Sustainable Agriculture Sciences, Rothamsted Research, Harpenden, United Kingdom
| | - David Hughes
- Computational and Analytical Sciences, Rothamsted Research, Harpenden, United Kingdom
| | - Maike Rossmann
- Laboratory of Environmental Microbiology, Embrapa Meio Ambiente, Jaguariúna, Brazil
| | - Penny R. Hirsch
- Sustainable Agriculture Sciences, Rothamsted Research, Harpenden, United Kingdom
| | - Rodrigo Mendes
- Laboratory of Environmental Microbiology, Embrapa Meio Ambiente, Jaguariúna, Brazil
| | - Tim H. Mauchline
- Sustainable Agriculture Sciences, Rothamsted Research, Harpenden, United Kingdom
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19
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El-Ramady H, Alshaal T, Elsakhawy T, Omara AED, Abdalla N, Brevik EC. Soils and Humans. WORLD SOILS BOOK SERIES 2019. [DOI: 10.1007/978-3-319-95516-2_12] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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20
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Zhou H, Zhang D, Jiang Z, Sun P, Xiao H, Yuxin W, Chen J. Changes in the soil microbial communities of alpine steppe at Qinghai-Tibetan Plateau under different degradation levels. THE SCIENCE OF THE TOTAL ENVIRONMENT 2018; 651:2281-2291. [PMID: 30326458 DOI: 10.1016/j.scitotenv.2018.09.336] [Citation(s) in RCA: 70] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/02/2018] [Revised: 08/14/2018] [Accepted: 09/26/2018] [Indexed: 01/10/2023]
Abstract
The alpine steppe at Qinghai-Tibetan Plateau is an important area for conserving water source and grassland productivity; however, knowledge about the microbial community structure and function and the risk to human health due to alpine plant-soil ecosystems is limited. Thus, we used prediction methods, such as Tax4Fun, and performed a metagenome pre-study using 16S rRNA sequencing reads for a small scale survey of the microbial communities at degraded alpine steppes (i.e., non-degraded (ND), lightly degraded (LD), moderately degraded (MD), heavily degraded (HD), and extremely degraded (ED) steppes) by Illumina high-throughput sequencing technology. Although there were no significant differences in the microbial alpha diversity among the different degraded alpine steppes and the dominant phyla at the different degraded alpine steppes, including Actinobacteria, Proteobacterial, Acidobacteria and Chloroflexi, were similar, the beta-diversity significantly differed, indicating that alpine steppe degradation might result in variation in microbial community compositions. The linear discriminate analysis (LDA) effect size (LEfSe) analysis found twenty-one biomarkers, most of which belonged to Actinobacteria, suggesting that microbes with a special function (such as the decomposition soil organic matter) might survive in alpine steppes. In addition, the functional profiles of the bacterial populations revealed an association with many human diseases, including infectious diseases. In addition, the microbial communities were mainly correlated with the populations of Gramineae and soil total phosphorous. These results suggested that alpine steppe degradation could result in variations in the microbial community composition, structure and function at Qinghai-Tibetan Plateau. Further studies investigating the degraded alpine steppe environment are needed to isolate these potential pathogenic microbes and help protect livestock using these alpine steppes.
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Affiliation(s)
- Heng Zhou
- College of Grassland Science, Gansu Agricultural University, Lanzhou, Gansu, People's Republic of China; Key Laboratory of Grassland Ecosystem, Gansu Agricultural University, Lanzhou, Gansu, People's Republic of China; Ministry of Education/Sino, U.S. Center for Grazing Land Ecosystem Sustainability, Lanzhou, Gansu, People's Republic of China.
| | - Degang Zhang
- College of Grassland Science, Gansu Agricultural University, Lanzhou, Gansu, People's Republic of China; Key Laboratory of Grassland Ecosystem, Gansu Agricultural University, Lanzhou, Gansu, People's Republic of China; Ministry of Education/Sino, U.S. Center for Grazing Land Ecosystem Sustainability, Lanzhou, Gansu, People's Republic of China.
| | - Zhehao Jiang
- College of Grassland Science, Gansu Agricultural University, Lanzhou, Gansu, People's Republic of China; Key Laboratory of Grassland Ecosystem, Gansu Agricultural University, Lanzhou, Gansu, People's Republic of China; Ministry of Education/Sino, U.S. Center for Grazing Land Ecosystem Sustainability, Lanzhou, Gansu, People's Republic of China
| | - Peng Sun
- College of Grassland Science, Gansu Agricultural University, Lanzhou, Gansu, People's Republic of China; Key Laboratory of Grassland Ecosystem, Gansu Agricultural University, Lanzhou, Gansu, People's Republic of China; Ministry of Education/Sino, U.S. Center for Grazing Land Ecosystem Sustainability, Lanzhou, Gansu, People's Republic of China
| | - Hailong Xiao
- College of Grassland Science, Gansu Agricultural University, Lanzhou, Gansu, People's Republic of China; Key Laboratory of Grassland Ecosystem, Gansu Agricultural University, Lanzhou, Gansu, People's Republic of China; Ministry of Education/Sino, U.S. Center for Grazing Land Ecosystem Sustainability, Lanzhou, Gansu, People's Republic of China
| | - Wu Yuxin
- College of Grassland Science, Gansu Agricultural University, Lanzhou, Gansu, People's Republic of China; Key Laboratory of Grassland Ecosystem, Gansu Agricultural University, Lanzhou, Gansu, People's Republic of China; Ministry of Education/Sino, U.S. Center for Grazing Land Ecosystem Sustainability, Lanzhou, Gansu, People's Republic of China
| | - Jiangang Chen
- College of Grassland Science, Gansu Agricultural University, Lanzhou, Gansu, People's Republic of China; Key Laboratory of Grassland Ecosystem, Gansu Agricultural University, Lanzhou, Gansu, People's Republic of China; Ministry of Education/Sino, U.S. Center for Grazing Land Ecosystem Sustainability, Lanzhou, Gansu, People's Republic of China
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21
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Todman LC, Fraser FC, Corstanje R, Harris JA, Pawlett M, Ritz K, Whitmore AP. Evidence for functional state transitions in intensively-managed soil ecosystems. Sci Rep 2018; 8:11522. [PMID: 30068982 PMCID: PMC6070522 DOI: 10.1038/s41598-018-29925-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2017] [Accepted: 07/17/2018] [Indexed: 11/16/2022] Open
Abstract
Soils are fundamental to terrestrial ecosystem functioning and food security, thus their resilience to disturbances is critical. Furthermore, they provide effective models of complex natural systems to explore resilience concepts over experimentally-tractable short timescales. We studied soils derived from experimental plots with different land-use histories of long-term grass, arable and fallow to determine whether regimes of extreme drying and re-wetting would tip the systems into alternative stable states, contingent on their historical management. Prior to disturbance, grass and arable soils produced similar respiration responses when processing an introduced complex carbon substrate. A distinct respiration response from fallow soil here indicated a different prior functional state. Initial dry:wet disturbances reduced the respiration in all soils, suggesting that the microbial community was perturbed such that its function was impaired. After 12 drying and rewetting cycles, despite the extreme disturbance regime, soil from the grass plots, and those that had recently been grass, adapted and returned to their prior functional state. Arable soils were less resilient and shifted towards a functional state more similar to that of the fallow soil. Hence repeated stresses can apparently induce persistent shifts in functional states in soils, which are influenced by management history.
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Affiliation(s)
- L C Todman
- Rothamsted Research, Harpenden, AL5 2JQ, UK.
| | - F C Fraser
- Cranfield University, Cranfield, Bedford, MK43 0AL, UK
| | - R Corstanje
- Cranfield University, Cranfield, Bedford, MK43 0AL, UK
| | - J A Harris
- Cranfield University, Cranfield, Bedford, MK43 0AL, UK
| | - M Pawlett
- Cranfield University, Cranfield, Bedford, MK43 0AL, UK
| | - K Ritz
- Cranfield University, Cranfield, Bedford, MK43 0AL, UK
- The University of Nottingham, Sutton Bonington Campus, Leicestershire, LE12 5RD, UK
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22
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Kavamura VN, Hayat R, Clark IM, Rossmann M, Mendes R, Hirsch PR, Mauchline TH. Inorganic Nitrogen Application Affects Both Taxonomical and Predicted Functional Structure of Wheat Rhizosphere Bacterial Communities. Front Microbiol 2018; 9:1074. [PMID: 29896167 PMCID: PMC5986887 DOI: 10.3389/fmicb.2018.01074] [Citation(s) in RCA: 64] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2018] [Accepted: 05/04/2018] [Indexed: 01/21/2023] Open
Abstract
The effects of fertilizer regime on bulk soil microbial communities have been well studied, but this is not the case for the rhizosphere microbiome. The aim of this work was to assess the impact of fertilization regime on wheat rhizosphere microbiome assembly and 16S rRNA gene-predicted functions with soil from the long term Broadbalk experiment at Rothamsted Research. Soil from four N fertilization regimes (organic N, zero N, medium inorganic N and high inorganic N) was sown with seeds of Triticum aestivum cv. Cadenza. 16S rRNA gene amplicon sequencing was performed with the Illumina platform on bulk soil and rhizosphere samples of 4-week-old and flowering plants (10 weeks). Phylogenetic and 16S rRNA gene-predicted functional analyses were performed. Fertilization regime affected the structure and composition of wheat rhizosphere bacterial communities. Acidobacteria and Planctomycetes were significantly depleted in treatments receiving inorganic N, whereas the addition of high levels of inorganic N enriched members of the phylum Bacteroidetes, especially after 10 weeks. Bacterial richness and diversity decreased with inorganic nitrogen inputs and was highest after organic treatment (FYM). In general, high levels of inorganic nitrogen fertilizers negatively affect bacterial richness and diversity, leading to a less stable bacterial community structure over time, whereas, more stable bacterial communities are provided by organic amendments. 16S rRNA gene-predicted functional structure was more affected by growth stage than by fertilizer treatment, although, some functions related to energy metabolism and metabolism of terpenoids and polyketides were enriched in samples not receiving any inorganic N, whereas inorganic N addition enriched predicted functions related to metabolism of other amino acids and carbohydrates. Understanding the impact of different fertilizers on the structure and dynamics of the rhizosphere microbiome is an important step toward developing strategies for production of crops in a sustainable way.
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Affiliation(s)
- Vanessa N. Kavamura
- Sustainable Agriculture Sciences, Rothamsted Research, Harpenden, United Kingdom
| | - Rifat Hayat
- Sustainable Agriculture Sciences, Rothamsted Research, Harpenden, United Kingdom
- PMAS Arid Agriculture University, Rawalpindi, Pakistan
| | - Ian M. Clark
- Sustainable Agriculture Sciences, Rothamsted Research, Harpenden, United Kingdom
| | - Maike Rossmann
- Laboratory of Environmental Microbiology, Embrapa Meio Ambiente, Jaguariúna, Brazil
| | - Rodrigo Mendes
- Laboratory of Environmental Microbiology, Embrapa Meio Ambiente, Jaguariúna, Brazil
| | - Penny R. Hirsch
- Sustainable Agriculture Sciences, Rothamsted Research, Harpenden, United Kingdom
| | - Tim H. Mauchline
- Sustainable Agriculture Sciences, Rothamsted Research, Harpenden, United Kingdom
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23
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Pham VTH, Murugaraj P, Mathes F, Tan BK, Truong VK, Murphy DV, Mainwaring DE. Copolymers enhance selective bacterial community colonization for potential root zone applications. Sci Rep 2017; 7:15902. [PMID: 29162884 PMCID: PMC5698314 DOI: 10.1038/s41598-017-16253-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2017] [Accepted: 11/08/2017] [Indexed: 12/31/2022] Open
Abstract
Managing the impact of anthropogenic and climate induced stress on plant growth remains a challenge. Here we show that polymeric hydrogels, which maintain their hydrous state, can be designed to exploit functional interactions with soil microorganisms. This microbial enhancement may mitigate biotic and abiotic stresses limiting productivity. The presence of mannan chains within synthetic polyacrylic acid (PAA) enhanced the dynamics and selectivity of bacterial ingress in model microbial systems and soil microcosms. Pseudomonas fluorescens exhibiting high mannan binding adhesins showed higher ingress and localised microcolonies throughout the polymeric network. In contrast, ingress of Bacillus subtilis, lacking adhesins, was unaltered by mannan showing motility comparable to bulk liquids. Incubation within microcosms of an agricultural soil yielded hydrogel populations significantly increased from the corresponding soil. Bacterial diversity was markedly higher in mannan containing hydrogels compared to both control polymer and soil, indicating enhanced selectivity towards microbial families that contain plant beneficial species. Here we propose functional polymers applied to the potential root zone which can positively influence rhizobacteria colonization and potentially plant growth as a new approach to stress tolerance.
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Affiliation(s)
- Vy T H Pham
- School of Science, Faculty of Science, Engineering and Technology, Swinburne University of Technology, Hawthorn, VIC 3122, Australia
| | - Pandiyan Murugaraj
- School of Science, Faculty of Science, Engineering and Technology, Swinburne University of Technology, Hawthorn, VIC 3122, Australia
| | - Falko Mathes
- SoilsWest, UWA School of Agriculture and Environment, Faculty of Science, The University of Western Australia, Crawley, WA6009, Australia
| | - Boon K Tan
- School of Science, Faculty of Science, Engineering and Technology, Swinburne University of Technology, Hawthorn, VIC 3122, Australia
| | - Vi Khanh Truong
- School of Science, Faculty of Science, Engineering and Technology, Swinburne University of Technology, Hawthorn, VIC 3122, Australia
| | - Daniel V Murphy
- SoilsWest, UWA School of Agriculture and Environment, Faculty of Science, The University of Western Australia, Crawley, WA6009, Australia
| | - David E Mainwaring
- School of Science, Faculty of Science, Engineering and Technology, Swinburne University of Technology, Hawthorn, VIC 3122, Australia.
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24
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Gosling P, van der Gast C, Bending GD. Converting highly productive arable cropland in Europe to grassland: -a poor candidate for carbon sequestration. Sci Rep 2017; 7:10493. [PMID: 28874831 PMCID: PMC5585225 DOI: 10.1038/s41598-017-11083-6] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2017] [Accepted: 08/14/2017] [Indexed: 12/02/2022] Open
Abstract
Sequestration of atmospheric CO2 as organic carbon by agricultural soils (SOC) is promoted as a climate change mitigation option. IPCC provides guidelines for determining carbon stocks and sequestration potential, incentivising policy changes towards management of farmland for carbon sequestration. However, the basis of the assumption that agricultural soils can sequester significant atmospheric CO2 has been questioned. We sought to determine the potential for conversion of arable cropland to grassland to sequester carbon in the short to medium term and potential limiting factors. There were no differences in SOC stocks in the top 30 cm between grassland up to 17 years old and arable cropland at 14 sites across the UK. However, SOC showed different distribution patterns, being concentrated in the top 10 cm under grassland. Soil microbial communities were significantly different between arable and grassland, with higher biomass and lesser dominance by bacteria in grassland soils. A land use conversion experiment showed these changes occurred within one year of land use change. Failure of grassland soils to accumulate SOC was attributed to reduced available soil nitrogen, resulting in low productivity. The implications of these results for carbon sequestration in soils as a climate change mitigation strategy are discussed.
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Affiliation(s)
- Paul Gosling
- AHDB, Stoneleigh Park, Kenilworth, Warwickshire, CV8 2TL, UK.
| | | | - Gary D Bending
- School of Life Sciences, University of Warwick, Coventry, CV4 7AL, UK
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25
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Gao W, Muñoz‐Romero V, Ren T, Ashton RW, Morin M, Clark IM, Powlson DS, Whalley WR. Effect of microbial activity on penetrometer resistance and elastic modulus of soil at different temperatures. EUROPEAN JOURNAL OF SOIL SCIENCE 2017; 68:412-419. [PMID: 28804253 PMCID: PMC5530443 DOI: 10.1111/ejss.12440] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/05/2016] [Revised: 03/20/2017] [Accepted: 04/04/2017] [Indexed: 05/29/2023]
Abstract
We explore the effect of microbial activity stimulated by root exudates on the penetrometer resistance of soil and its elastic modulus. This is important because it is a measure of the mechanical strength of soil and it correlates closely with the rate of elongation of roots. A sandy soil was incubated with a synthetic root exudate at different temperatures, for different lengths of time and with selective suppression of either fungi or bacteria. The shape of the temperature response of penetrometer resistance in soil incubated with synthetic exudate was typical of a poikilothermic temperature response. Both penetrometer resistance and small strain shear modulus had maximum values between 25 and 30°C. At temperatures of 20°C and less, there was little effect of incubation with synthetic root exudate on the small strain shear modulus, although penetrometer resistance did increase with temperature over this range (4-20°C). This suggests that in this temperature range the increase in penetrometer resistance was related to a greater resistance to plastic deformation. At higher temperatures (> 25°C) penetrometer resistance decreased. Analysis of the DNA sequence data showed that at 25°C the number of Streptomyces (Gram-positive bacteria) increased, but selective suppression of either fungi or bacteria suggested that fungi have the greater role with respect to penetrometer resistance. HIGHLIGHTS Effect of microbial activity stimulated by synthetic root exudates on the mechanical properties.We compared penetrometer measurements and estimates of elastic modulus with microbial community.Penetrometer resistance of soil showed a poikilothermic temperature response.Penetrometer resistance might be affected more by fungi than bacteria.
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Affiliation(s)
- W. Gao
- Department of Soil and Water SciencesChina Agricultural UniversityNo. 2 Yuanmingyuan West RoadBeijing100193China
| | - V. Muñoz‐Romero
- Eco‐efficient Cropping Systems group, Departamento de AgronomíaUniversity of CordobaEdificio C4 ‘Celestino Mutis’ Ctra. Madrid‐Cadiz km 39614071CordobaSpain
| | - T. Ren
- Department of Soil and Water SciencesChina Agricultural UniversityNo. 2 Yuanmingyuan West RoadBeijing100193China
| | - R. W. Ashton
- Sustainable Agriculture Sciences Department, Rothamsted ResearchWest CommonHarpendenAL5 2JQUK
| | - M. Morin
- Sustainable Agriculture Sciences Department, Rothamsted ResearchWest CommonHarpendenAL5 2JQUK
| | - I. M. Clark
- Sustainable Agriculture Sciences Department, Rothamsted ResearchWest CommonHarpendenAL5 2JQUK
| | - D. S. Powlson
- Sustainable Agriculture Sciences Department, Rothamsted ResearchWest CommonHarpendenAL5 2JQUK
| | - W. R. Whalley
- Sustainable Agriculture Sciences Department, Rothamsted ResearchWest CommonHarpendenAL5 2JQUK
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26
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Neal AL, Blackwell M, Akkari E, Guyomar C, Clark I, Hirsch PR. Phylogenetic distribution, biogeography and the effects of land management upon bacterial non-specific Acid phosphatase Gene diversity and abundance. PLANT AND SOIL 2017; 427:175-189. [PMID: 30996484 PMCID: PMC6438641 DOI: 10.1007/s11104-017-3301-2] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/12/2016] [Accepted: 05/25/2017] [Indexed: 05/26/2023]
Abstract
BACKGROUND AND AIMS Bacterial Non-Specific Acid Phosphatase (NSAP) enzymes are capable of dephosphorylating diverse organic phosphoesters but are rarely studied: their distribution in natural and managed environments is poorly understood. The aim of this study was to generate new insight into the environmental distribution of NSAPs and establish their potential global relevance to cycling of organic phosphorus. METHODS We employed bioinformatic tools to determine NSAP diversity and subcellular localization in microbial genomes; used the corresponding NSAP gene sequences to census metagenomes from diverse ecosystems; studied the effect of long-term land management upon NSAP diversity and abundance. RESULTS Periplasmic class B NSAPs are poorly represented in marine and terrestrial environments, reflecting their association with enteric and pathogenic bacteria. Periplasmic class A and outer membrane-associated class C NSAPs are cosmopolitan. NSAPs are more abundant in marine than terrestrial ecosystems and class C more abundant than class A genes, except in an acidic peat where class A genes dominate. A clear effect of land management upon gene abundance was identified. CONCLUSIONS NSAP genes are cosmopolitan. Class C genes are more widely distributed: their association with the outer-membrane of cells gives them a clear role in the cycling of organic phosphorus, particularly in soils.
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Affiliation(s)
- Andrew L. Neal
- Department of Sustainable Agricultural Sciences, Rothamsted Research, Harpenden, Hertfordshire, AL5 2JQ UK
| | - Martin Blackwell
- Department of Sustainable Agricultural Sciences, Rothamsted Research, North Wyke, Okehampton, Devon EX20 2SB UK
| | - Elsy Akkari
- Department of Sustainable Agricultural Sciences, Rothamsted Research, Harpenden, Hertfordshire, AL5 2JQ UK
| | - Cervin Guyomar
- Department of Sustainable Agricultural Sciences, Rothamsted Research, Harpenden, Hertfordshire, AL5 2JQ UK
- Inria/IRISA GenScale, Campus de Beaulieu, cedex, 35042 Rennes, France
| | - Ian Clark
- Department of Sustainable Agricultural Sciences, Rothamsted Research, Harpenden, Hertfordshire, AL5 2JQ UK
| | - Penny R. Hirsch
- Department of Sustainable Agricultural Sciences, Rothamsted Research, Harpenden, Hertfordshire, AL5 2JQ UK
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