scholarly journals Understanding Arbuscular Mycorrhizal Colonization in Walnut Plantations: The Contribution of Cover Crops and Soil Microbial Communities

Agriculture ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 1
Author(s):  
Babacar Thioye ◽  
Marc Legras ◽  
Lisa Castel ◽  
François Hirissou ◽  
Naouel Chaftar ◽  
...  
Keyword(s):  
Microbial Communities ◽  
Organic Farming ◽  
Faba Bean ◽  
Cover Crops ◽  
Mycorrhizal Fungi ◽  
Soil Microbial Communities ◽  
Arbuscular Mycorrhizal ◽  
Mycorrhizal Colonization ◽  
Symbiotic Association ◽  
Soil Microbial

Soil microorganisms play a central role in biological soil functioning. One of the beneficial microbiota that has a symbiotic association with most of the plants is arbuscular mycorrhizal fungi (AMF). Nevertheless, little is known about the impact of cover crops—widely used in conservation agriculture or organic farming—on native mycorrhizal fungi. This study was conducted in Southern France, in 20-year-old walnut orchards, where faba bean (Vicia faba Roth) was intercropped. To find whether the native AM fungal community associated with walnut trees was influenced by cover crops and soil microbial communities, analyses of soil physicochemical and microbiological indicators were carried out with roots and soil samples collected from four modalities (walnut in conventional farming with and without cover crops, and walnut in organic farming with and without cover crops). Our results showed that the presence of cover crops mainly influenced the soil microbial abundance and activities in conventional plots. In contrast, cover crops stimulated AM fungal colonization of walnut roots in organic plots, reaching 35% and 54% for arbuscule abundance and mycorrhizal intensity, respectively. In conventional plots, ergosterol and mineral nitrogen contents were mainly correlated with mycorrhizal colonization, while only acid phosphatase activity in soil was positively correlated with mycorrhizal colonization in organic plots. The use of the faba bean showed the great role played by cover crops in the enhancement of walnut trees’ mycorrhizal colonization. Identification of the functional traits of AM fungi sensitive to walnut trees is required to inform decisions in specific agricultural practices.

scholarly journals Novel Approach to Study the Diversity of Soil Microbial Communities in Qatar

2020 ◽  
Author(s):  
Jane Oja ◽  
Sakeenah Adenan ◽  
Abdel-Fattah Talaat ◽  
Juha Alatalo
Keyword(s):  
Microbial Communities ◽  
High Throughput ◽  
Mycorrhizal Fungi ◽  
High Throughput Sequencing ◽  
Soil Microbial Communities ◽  
Arbuscular Mycorrhizal ◽  
Soil Microbial ◽  
Fungal Abundance ◽  
Novel Approach ◽  
Soil Climate

A broad diversity of microorganisms can be found in soil, where they are essential for nutrient cycling and energy transfer. Recent high-throughput sequencing methods have greatly advanced our knowledge about how soil, climate and vegetation variables structure the composition of microbial communities in many world regions. However, we are lacking information from several regions in the world, e.g. Middle-East. We have collected soil from 19 different habitat types for studying the diversity and composition of soil microbial communities (both fungi and bacteria) in Qatar and determining which edaphic parameters exert the strongest influences on these communities. Preliminary results indicate that in overall bacteria are more abundant in soil than fungi and few sites have notably higher abundance of these microbes. In addition, we have detected some soil patameters, which tend to have reduced the overall fungal abundance and enhanced the presence of arbuscular mycorrhizal fungi and N-fixing bacteria. More detailed information on the diversity and composition of soil microbial communities is expected from the high-throughput sequenced data.

scholarly journals Contrasting effects of ammonium and nitrate additions on the biomass of soil microbial communities and enzyme activities in subtropical China

2017 ◽  
Vol 14 (20) ◽  
pp. 4815-4827 ◽  
Author(s):  
Chuang Zhang ◽  
Xin-Yu Zhang ◽  
Hong-Tao Zou ◽  
Liang Kou ◽  
Yang Yang ◽  
...  
Keyword(s):  
Microbial Communities ◽  
Soil Ph ◽  
Enzyme Activities ◽  
Mycorrhizal Fungi ◽  
Soil Microbial Communities ◽  
Arbuscular Mycorrhizal ◽  
Inhibitory Effects ◽  
Total N ◽  
Soil Microbial ◽  
The Individual

Abstract. The nitrate to ammonium ratios in nitrogen (N) compounds in wet atmospheric deposits have increased over the recent past, which is a cause for some concern as the individual effects of nitrate and ammonium deposition on the biomass of different soil microbial communities and enzyme activities are still poorly defined. We established a field experiment and applied ammonium (NH4Cl) and nitrate (NaNO3) at monthly intervals over a period of 4 years. We collected soil samples from the ammonium and nitrate treatments and control plots in three different seasons, namely spring, summer, and fall, to evaluate the how the biomass of different soil microbial communities and enzyme activities responded to the ammonium (NH4Cl) and nitrate (NaNO3) applications. Our results showed that the total contents of phospholipid fatty acids (PLFAs) decreased by 24 and 11 % in the ammonium and nitrate treatments, respectively. The inhibitory effects of ammonium on Gram-positive bacteria (G+) and bacteria, fungi, actinomycetes, and arbuscular mycorrhizal fungi (AMF) PLFA contents ranged from 14 to 40 % across the three seasons. We also observed that the absolute activities of C, N, and P hydrolyses and oxidases were inhibited by ammonium and nitrate, but that nitrate had stronger inhibitory effects on the activities of acid phosphatase (AP) than ammonium. The activities of N-acquisition specific enzymes (enzyme activities normalized by total PLFA contents) were about 21 and 43 % lower in the ammonium and nitrate treatments than in the control, respectively. However, the activities of P-acquisition specific enzymes were about 19 % higher in the ammonium treatment than in the control. Using redundancy analysis (RDA), we found that the measured C, N, and P hydrolysis and polyphenol oxidase (PPO) activities were positively correlated with the soil pH and ammonium contents, but were negatively correlated with the nitrate contents. The PLFA biomarker contents were positively correlated with soil pH, soil organic carbon (SOC), and total N contents, but were negatively correlated with the ammonium contents. The soil enzyme activities varied seasonally, and were highest in March and lowest in October. In contrast, the contents of the microbial PLFA biomarkers were higher in October than in March and June. Ammonium may inhibit the contents of PLFA biomarkers more strongly than nitrate because of acidification. This study has provided useful information about the effects of ammonium and nitrate on soil microbial communities and enzyme activities.

scholarly journals Soil microbial communities of Japanese apricot (Prunus mume) orchard under organic and conventional management

2019 ◽  
Vol 62 (1) ◽  
Author(s):  
Hyeon Ji Cho ◽  
Young Han Lee ◽  
Si-Lim Choi ◽  
Dong Cheol Seo ◽  
Sung Ran Min ◽  
...  
Keyword(s):  
Organic Farming ◽  
Mycorrhizal Fungi ◽  
Soil Microbial Communities ◽  
Arbuscular Mycorrhizal ◽  
Conventional Farming ◽  
Japanese Apricot ◽  
Soil Microbial ◽  
Farming Practice ◽  
Orchard Soil ◽  
Total Bacteria

AbstractOrganic farming has positive effects on soil microbial population, process, and activity. To examine effects of two different management methods (organic farming vs. conventional farming) on the cultivation of Japanese apricot, contents of fatty acid methyl ester (FAME), total glomalin, and soil chemical properties were analyzed and compared. The organic farming practice resulted in significantly higher contents of organic matter, total FAME, total bacteria, Gram-negative bacteria, arbuscular mycorrhizal fungi, and total glomalin than the conventional farming practice. Soil organic matter showed positive correlation with contents of soil microbial biomass, total bacteria, total glomalin, Gram-positive bacteria, Gram-negative bacteria, actinomycetes, and arbuscular mycorrhizal fungi. In 2018, the organic farming practice resulted in lower ratios of cy17:0 and 16:1ω7c than the conventional farming practice, indicating that microbial stress was reduced by the input of organic fertilizer into soil. Based on principal component analyses (PCA) of soil microbial communities, ratios of cy17:0 to 16:1ω7c in orchid soil can be used as microbial indicators to distinguish organically farmed orchard soil from conventionally farmed orchard soil.

Arbuscular mycorrhizal fungi and soil microbial communities under contrasting fertilization of three medicinal plants

2012 ◽  
Vol 59 ◽  
pp. 106-115 ◽  
Author(s):  
Szymon Zubek ◽  
Anna M. Stefanowicz ◽  
Janusz Błaszkowski ◽  
Maria Niklińska ◽  
Katarzyna Seidler-Łożykowska
Keyword(s):  
Medicinal Plants ◽  
Arbuscular Mycorrhizal Fungi ◽  
Microbial Communities ◽  
Mycorrhizal Fungi ◽  
Soil Microbial Communities ◽  
Arbuscular Mycorrhizal ◽  
Soil Microbial

scholarly journals Functional shifts of soil microbial communities associated with Alliaria petiolata invasion

2020 ◽  
Author(s):  
Katherine Duchesneau ◽  
Anneke Golemiec ◽  
Robert I. Colautti ◽  
Pedro M. Antunes
Keyword(s):  
Microbial Communities ◽  
Invasive Plants ◽  
Mycorrhizal Fungi ◽  
Soil Microbial Communities ◽  
Arbuscular Mycorrhizal ◽  
Alliaria Petiolata ◽  
Native Plant ◽  
Soil Microbial Diversity ◽  
Soil Microbial ◽  
Enemy Hypothesis

AbstractSoil feedback is thought to be an important contributor to the success of invasive plants. Despite evidence that invasive plants change soil microbial diversity, the functional roles of microbes impacted by invasion are still unclear. This knowledge is a critical component of our understanding of ecological mechanisms of plant invasion. Mounting evidence suggests Alliaria petiolata can suppress arbuscular mycorrhizal fungi (AMF) to disrupt native plant communities in controlled laboratory and greenhouse experiments, though it is less clear if allelochemicals persist under natural field conditions. Alternatively, invasive plants may accumulate pathogens that are more harmful to competitors as predicted by the Enemy of my Enemy Hypothesis (EEH). We examined changes in functional groups of soil bacteria and fungi associated with ten naturally occurring populations of A. petiolata using amplicon sequences (16S and ITS rRNA). To relate soil microbial communities to impacts on co-occurring plants, we measured root infections and AMF colonization. We found no changes in the diversity and abundance of AMF in plants co-occurring with A. petiolata, suggesting that mycorrhizal suppression in the field may not be as critical to the invasion of A. petiolata as implied by more controlled experiments. Instead, we found changes in pathogen community composition and marginal evidence of increase in root lesions of plants growing with A. petiolata, lending support to the EEH. In addition to these impacts on plant health, changes in ectomycorrhiza, and other nutrient cycling microbes may be important forces underlying the invasion of A. petiolata and its impact on ecosystem function.

Soil microbiota effects on rye growth: implications for integration of a rye cover crop into temperate cropping systems

2006 ◽  
Vol 21 (4) ◽  
pp. 245-252 ◽  
Author(s):  
Jason L. De Bruin ◽  
Nicholas R. Jordan ◽  
Paul M. Porter ◽  
Sheri C. Huerd
Keyword(s):  
Cover Crops ◽  
Mycorrhizal Fungi ◽  
Cropping Systems ◽  
Arbuscular Mycorrhizal ◽  
Microbial Populations ◽  
Shoot Biomass ◽  
Soil Microbiota ◽  
Soil Microbial ◽  
Growing Seasons ◽  
Final Harvest

AbstractIntegration of rye (Secale cereale L.) cover crops into the corn (Zea mays L.) soybean [(Glycine max (L.) Merr.] rotation of the upper Midwest USA can provide many agronomic and agroecological benefits. Integration is made difficult by short growing seasons, but may be facilitated by management of key agroecological interactions such as those between rye and soil microbiota. Rye growth was measured and colonization by arbuscular-mycorrhizal fungi (AMF) was determined in greenhouse experiments using soils from seven different management systems from a long-term cropping-systems experiment in southwest Minnesota. Microbial effects on rye growth were not evident before vernalization, but at final harvest (4 weeks after vernalization) soil microbial populations reduced rye shoot and root growth, relative to a pasteurized control inoculum. At final harvest, shoot biomass in 2-year rotations was 17% greater than 4-year rotations, indicating that microbial populations selected for by 4-year rotations may be more deleterious or pathogenic than those selected for by 2-year rotations. Growth of three rye cultivars was examined in all inocula; cultivars differed in their mean response to soil microbiota and their ability to host AMF. These findings suggest that management factors affect interactions between rye and soil microbiota resulting in altered rye growth.

Metabolic and genetic patterns of soil microbial communities in response to different amendments under organic farming system

Geoderma ◽  
2017 ◽  
Vol 296 ◽  
pp. 79-85 ◽  
Author(s):  
Stefano Dumontet ◽  
Ivana Cavoski ◽  
Patrizia Ricciuti ◽  
Donato Mondelli ◽  
Mohammed Jarrar ◽  
...  
Keyword(s):  
Microbial Communities ◽  
Organic Farming ◽  
Soil Microbial Communities ◽  
Farming System ◽  
Soil Microbial ◽  
Genetic Patterns ◽  
Organic Farming System
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