scholarly journals Arable agriculture changes soil microbial communities in the South African Grassland Biome

2018 ◽  
Vol 114 (5/6) ◽  
Author(s):  
Gilbert Kamgan Nkuekam ◽  
Don A. Cowan ◽  
Angel Valverde
Keyword(s):  
Microbial Communities ◽  
Agricultural Soils ◽  
Soil Microbial Communities ◽  
Fungal Communities ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
Soil Microbial Diversity ◽  
Soil Microbial ◽  
The Impact ◽  
Natural Grassland

Many studies, mostly in temperate regions of the northern hemisphere, have demonstrated that agricultural practices affect the composition and diversity of soil microbial communities. However, very little is known about the impact of agriculture on the microbial communities in other regions of the world, most particularly on the African continent. In this study, we used MiSeq amplicon sequencing of bacterial 16S rRNA genes and fungal ITS regions to characterise microbial communities in agricultural and natural grassland soils located in the Mpumalanga Province of South Africa. Nine soil chemical parameters were also measured to evaluate the effects of edaphic factors on microbial community diversity. Bacterial and fungal communities were significantly richer and more diverse in natural grassland than in agricultural soils. Microbial taxonomic composition was also significantly different between the two habitat types. The phylum Acidobacteria was significantly more abundant in natural grassland than in agricultural soils, while Actinobacteria and the family Nectriaceae showed the opposite pattern. Soil pH and phosphorus significantly influenced bacterial communities, whereas phosphorus and calcium influenced fungal communities. These findings may be interpreted as a negative impact of land-use change on soil microbial diversity and composition.

scholarly journals Soil Microbial Activity and Diversity in Response to Soil Chemical Factors in Agricultural Soils

2019 ◽  
Vol 24 (1) ◽  
pp. 43
Author(s):  
Lily Ishak ◽  
Philip Hugh Brown
Keyword(s):  
Microbial Communities ◽  
Agricultural Soils ◽  
Soil Health ◽  
Soil Microbial Communities ◽  
Soil Microbial Activity ◽  
Soil Microbial Diversity ◽  
Soil Microbial ◽  
Microbial Responses ◽  
Chemical Factors ◽  
Microbial Groups

The role of microbial communities in maintaining soil health is mostly influenced by chemical condition of soil. Microbial communities vary in response to soil chemical factors. The contradictive results from previous findings emphasise that it is difficult to define a pattern of the influence of soil chemical factors on soil microbial diversity and activity. The aim of the study was to assess soil microbial responses to soil chemical factors in agricultural soils. Composite soil (Dermosol order) samples taken from 16 commercial crop sites in Bundaberg, Queensland, Australia, were chemically and biologically analysed. It was found that bacterial and fungal activity and diversity were significantly affected by soil EC, SOM and NO3-N content, but were not influenced by soil pH, CEC, and Ca:Mg ratio. The diversity of bacterial and fungal communities displayed a positive linear relationship with soil EC, whereas the activity and diversity of these two microbial groups and SOM displayed a significant quadratic relationship. The finding suggested that microbial community was predominantly influenced by SOM content.

scholarly journals Erosion reduces soil microbial diversity, network complexity and multifunctionality

2021 ◽  
Author(s):  
Liping Qiu ◽  
Qian Zhang ◽  
Hansong Zhu ◽  
Peter B. Reich ◽  
Samiran Banerjee ◽  
...  
Keyword(s):  
Soil Erosion ◽  
Microbial Diversity ◽  
Microbial Communities ◽  
Negative Impact ◽  
Microbial Community Composition ◽  
Soil Microbial Communities ◽  
Soil Microbial Diversity ◽  
Soil Microbial ◽  
Relative Abundances ◽  
The Impact

AbstractWhile soil erosion drives land degradation, the impact of erosion on soil microbial communities and multiple soil functions remains unclear. This hinders our ability to assess the true impact of erosion on soil ecosystem services and our ability to restore eroded environments. Here we examined the effect of erosion on microbial communities at two sites with contrasting soil texture and climates. Eroded plots had lower microbial network complexity, fewer microbial taxa, and fewer associations among microbial taxa, relative to non-eroded plots. Soil erosion also shifted microbial community composition, with decreased relative abundances of dominant phyla such as Proteobacteria, Bacteroidetes, and Gemmatimonadetes. In contrast, erosion led to an increase in the relative abundances of some bacterial families involved in N cycling, such as Acetobacteraceae and Beijerinckiaceae. Changes in microbiota characteristics were strongly related with erosion-induced changes in soil multifunctionality. Together, these results demonstrate that soil erosion has a significant negative impact on soil microbial diversity and functionality.

scholarly journals Diversity and composition of the Panax ginseng rhizosphere microbiome in various cultivation modesand ages

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Ai-Zi Tong ◽  
Wei Liu ◽  
Qiang Liu ◽  
Guang-Qing Xia ◽  
Jun-Yi Zhu
Keyword(s):  
Microbial Community ◽  
Microbial Diversity ◽  
Panax Ginseng ◽  
Soil Microbial Communities ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
Continuous Cropping ◽  
Soil Microbial Diversity ◽  
Soil Microbial ◽  
Soil Borne Pathogens

Abstract Background Continuous cropping of ginseng (Panax ginseng Meyer) cultivated in farmland for an extended period gives rise to soil-borne disease. The change in soil microbial composition is a major cause of soil-borne diseases and an obstacle to continuous cropping. The impact of cultivation modes and ages on the diversity and composition of the P. ginseng rhizosphere microbial community and technology suitable for cropping P. ginseng in farmland are still being explored. Methods Amplicon sequencing of bacterial 16S rRNA genes and fungal ITS regions were analyzed for microbial community composition and diversity. Results The obtained sequencing data were reasonable for estimating soil microbial diversity. We observed significant variations in richness, diversity, and relative abundances of microbial taxa between farmland, deforestation field, and different cultivation years. The bacterial communities of LCK (forest soil where P. ginseng was not grown) had a much higher richness and diversity than those in NCK (farmland soil where P. ginseng was not grown). The increase in cultivation years of P. ginseng in farmland and deforestation field significantly changed the diversity of soil microbial communities. In addition, the accumulation of P. ginseng soil-borne pathogens (Monographella cucumerina, Ilyonectria mors-panacis, I. robusta, Fusarium solani, and Nectria ramulariae) varied with the cropping age of P. ginseng. Conclusion Soil microbial diversity and function were significantly poorer in farmland than in the deforestation field and were affected by P. ginseng planting years. The abundance of common soil-borne pathogens of P. ginseng increased with the cultivation age and led to an imbalance in the microbial community.

Effect of Phenylurea Herbicides on Soil Microbial Communities Estimated by Analysis of 16S rRNA Gene Fingerprints and Community-Level Physiological Profiles

1999 ◽  
Vol 65 (3) ◽  
pp. 982-988 ◽  
Author(s):  
Saïd el Fantroussi ◽  
Laurent Verschuere ◽  
Willy Verstraete ◽  
Eva M. Top
Keyword(s):  
16S Rrna ◽  
Microbial Communities ◽  
16S Rdna ◽  
Soil Microbial Communities ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
Rrna Gene ◽  
Metabolic Potential ◽  
Soil Microbial ◽  
Enrichment Cultures

ABSTRACT The effect of three phenyl urea herbicides (diuron, linuron, and chlorotoluron) on soil microbial communities was studied by using soil samples with a 10-year history of treatment. Denaturing gradient gel electrophoresis (DGGE) was used for the analysis of 16S rRNA genes (16S rDNA). The degree of similarity between the 16S rDNA profiles of the communities was quantified by numerically analysing the DGGE band patterns. Similarity dendrograms showed that the microbial community structures of the herbicide-treated and nontreated soils were significantly different. Moreover, the bacterial diversity seemed to decrease in soils treated with urea herbicides, and sequence determination of several DGGE fragments showed that the most affected species in the soils treated with diuron and linuron belonged to an uncultivated bacterial group. As well as the 16S rDNA fingerprints, the substrate utilization patterns of the microbial communities were compared. Principal-component analysis performed on BIOLOG data showed that the functional abilities of the soil microbial communities were altered by the application of the herbicides. In addition, enrichment cultures of the different soils in medium with the urea herbicides as the sole carbon and nitrogen source showed that there was no difference between treated and nontreated soil in the rate of transformation of diuron and chlorotoluron but that there was a strong difference in the case of linuron. In the enrichment cultures with linuron-treated soil, linuron disappeared completely after 1 week whereas no significant transformation was observed in cultures inoculated with nontreated soil even after 4 weeks. In conclusion, this study showed that both the structure and metabolic potential of soil microbial communities were clearly affected by a long-term application of urea herbicides.

Monitoring the impact of hydrocarbon contamination and nutrient addition on microbial density, activity, and diversity in soil

2010 ◽  
Vol 56 (2) ◽  
pp. 145-155 ◽  
Author(s):  
Mira Taok ◽  
Joana Mundo ◽  
Claude Olivier Sarde ◽  
Olivier Schoefs ◽  
Nelly Cochet
Keyword(s):  
Microbial Activity ◽  
Soil Microbial Communities ◽  
Nutrient Addition ◽  
Hydrocarbon Contamination ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
Nitrogen And Phosphorus ◽  
Soil Microbial ◽  
Microbial Density ◽  
The Impact

The development of optimal in situ bioremediation strategies requires a better knowledge of their impact on the soil microbial communities. We have evaluated the impact of hexadecane contamination and different nutrient amendments on soil microbial density and activity. Microbial density was measured via total DNA quantification, and microbial activity via respiration and RNA variation. The RNA/DNA ratio was also determined, as it is a potential indicator of microbial activity. PCR-amplified 16S rRNA genes were cloned and sequenced to analyze the diversity of bacterial communities. Nutrient addition significantly increased respiration and DNA and RNA concentrations in contaminated soil, indicating a limitation of degradation and growth by the availability of nitrogen and phosphorus in unamended microcosms. Hexadecane treatment slightly affected the diversity of the bacterial community, while it was dramatically reduced by nutrient treatments, particularly the addition of nitrogen and phosphorus. Microbial community composition was also altered with the enrichment of populations related to Nocardia in bioremediated soils, while uncultured Proteobacteria were mostly detected in uncontaminated soil.

scholarly journals Elevated Carbon Dioxide Alters the Structure of Soil Microbial Communities

2012 ◽  
Vol 78 (8) ◽  
pp. 2991-2995 ◽  
Author(s):  
Ye Deng ◽  
Zhili He ◽  
Meiying Xu ◽  
Yujia Qin ◽  
Joy D. Van Nostrand ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Microbial Communities ◽  
Microbial Community Composition ◽  
Soil Microbial Communities ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
Soil Microbial ◽  
Composition And Structure ◽  
Pyrosequencing Analysis ◽  
Soil Microbial Community Composition

ABSTRACTPyrosequencing analysis of 16S rRNA genes was used to examine impacts of elevated CO2(eCO2) on soil microbial communities from 12 replicates each from ambient CO2(aCO2) and eCO2settings. The results suggest that the soil microbial community composition and structure significantly altered under conditions of eCO2, which was closely associated with soil and plant properties.

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

Agriculture ◽  
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.

scholarly journals Response of the Soil Microbial Community to Changes in Precipitation in a Semiarid Ecosystem

2012 ◽  
Vol 78 (24) ◽  
pp. 8587-8594 ◽  
Author(s):  
Melissa A. Cregger ◽  
Christopher W. Schadt ◽  
Nate G. McDowell ◽  
William T. Pockman ◽  
Aimée T. Classen
Keyword(s):  
Climate Change ◽  
Microbial Community ◽  
Microbial Communities ◽  
Monsoon Season ◽  
Climatic Variability ◽  
Soil Microbial Communities ◽  
Community Response ◽  
Fungal Communities ◽  
Soil Microbial ◽  
The Impact

ABSTRACTMicrobial communities regulate many belowground carbon cycling processes; thus, the impact of climate change on the structure and function of soil microbial communities could, in turn, impact the release or storage of carbon in soils. Here we used a large-scale precipitation manipulation (+18%, −50%, or ambient) in a piñon-juniper woodland (Pinus edulis-Juniperus monosperma) to investigate how changes in precipitation amounts altered soil microbial communities as well as what role seasonal variation in rainfall and plant composition played in the microbial community response. Seasonal variability in precipitation had a larger role in determining the composition of soil microbial communities in 2008 than the direct effect of the experimental precipitation treatments. Bacterial and fungal communities in the dry, relatively moisture-limited premonsoon season were compositionally distinct from communities in the monsoon season, when soil moisture levels and periodicity varied more widely across treatments. Fungal abundance in the drought plots during the dry premonsoon season was particularly low and was 4.7 times greater upon soil wet-up in the monsoon season, suggesting that soil fungi were water limited in the driest plots, which may result in a decrease in fungal degradation of carbon substrates. Additionally, we found that both bacterial and fungal communities beneath piñon pine and juniper were distinct, suggesting that microbial functions beneath these trees are different. We conclude that predicting the response of microbial communities to climate change is highly dependent on seasonal dynamics, background climatic variability, and the composition of the associated aboveground community.

scholarly journals Effects of Monoculture, Crop Rotation, and Soil Moisture Content on Selected Soil Physicochemical and Microbial Parameters in Wheat Fields

2012 ◽  
Vol 2012 ◽  
pp. 1-13 ◽  
Author(s):  
A. Marais ◽  
M. Hardy ◽  
M. Booyse ◽  
A. Botha
Keyword(s):  
Soil Moisture ◽  
Microbial Communities ◽  
Crop Rotation ◽  
Management Practices ◽  
Agricultural Soils ◽  
Soil Microbial Communities ◽  
Soil Microbial Activity ◽  
Most Probable Number ◽  
Probable Number ◽  
Soil Microbial

Different plants are known to have different soil microbial communities associated with them. Agricultural management practices such as fertiliser and pesticide addition, crop rotation, and grazing animals can lead to different microbial communities in the associated agricultural soils. Soil dilution plates, most-probable-number (MPN), community level physiological profiling (CLPP), and buried slide technique as well as some measured soil physicochemical parameters were used to determine changes during the growing season in the ecosystem profile in wheat fields subjected to wheat monoculture or wheat in annual rotation with medic/clover pasture. Statistical analyses showed that soil moisture had an over-riding effect on seasonal fluctuations in soil physicochemical and microbial populations. While within season soil microbial activity could be differentiated between wheat fields under rotational and monoculture management, these differences were not significant.

Sign in / Sign up

Export Citation Format

Share Document