scholarly journals Effects of Cover Cropping on Microbial Communities Associated with Heterodera schachtii and Nematode Virulence

Soil Systems ◽  
2019 ◽  
Vol 3 (4) ◽  
pp. 67
Author(s):  
Rasha Haj Nuaima ◽  
Holger Heuer ◽  
Andreas Westphal
Keyword(s):  
Microbial Communities ◽  
Cover Crops ◽  
Sandy Loam ◽  
Soil Microbial Communities ◽  
Brassica Species ◽  
Microbial Colonization ◽  
Heterodera Schachtii ◽  
Parasitic Nematodes ◽  
Cover Cropping ◽  
Nematode Virulence

Nematode-resistant cover crops can suppress populations of plant-parasitic nematodes. Samples of a loamy and a sandy loam soil were collected from two sugar beet fields in Lower Saxonia, northern Germany (“Jeinsen” and “Gross Munzel”) to measure the effects of cover cropping on the population genetic structure and infectivity of Heterodera schachtii as well as the composition of soil microbial communities. These fields allowed for a comparison of cover cropping with Brassica species resistant to Heterodera schachtii to fallow. In a series of radish bioassays with H. schachtii populations from Jeinsen and Gross Munzel, ratios of second-stage juveniles in roots per eggs in soil were higher in soil from under Brassica cropping than from under fallow. In denaturing gradient gelelectrophoresis, profiles of the parasitism gene vap1 differed between Brassica and fallow treatments in both populations. At Gross Munzel, microbes of soils and within nematode cysts differed between Brassica and fallow areas. Specifically, the frequency and occurrence of isolates of Pochonia chlamydosporia and Exophiala salmonis were lower within the cysts from Brassica than from fallow treatments. Overall, cover cropping with resistant Brassica species affected the bacteria and fungi infecting the cysts and subsequently, the infectivity of the H. schachtii population. Cover crop effects on nematode virulence (vap1 gene) and microbial colonization of the cysts could affect long-term nematode population dynamics.

scholarly journals Cover crop-driven shifts in soil microbial communities could modulate tomato early crop growth via plant-soil feedbacks

2021 ◽  
Author(s):  
Micaela Tosi ◽  
John Drummelsmith ◽  
Dasiel Obregón ◽  
Inderjot Chahal ◽  
Laura L. Van Eerd ◽  
...  
Keyword(s):  
Microbial Communities ◽  
Cover Crops ◽  
Cover Crop ◽  
Crop Residues ◽  
Management Strategies ◽  
Soil Microbial Communities ◽  
Crop Productivity ◽  
Residue Management ◽  
Soil Microbial ◽  
Plant Soil

Abstract Sustainable agricultural practices such as crop diversification, cover crops and residue retention are increasingly applied to counteract detrimental effects of agriculture on natural resources. Since part of their effects occur via changes soil microbial communities, it is critical to understand how these respond to different practices. Our study analyzed five cover crop (cc) treatments (oat, rye, radish, rye-radish mixture and no-cc control) and two crop residue management strategies (retention/R+ or removal/R-) in an 8-year diverse horticultural crop rotation trial from ON, Canada. Cc effects were small but stronger than those of residue management. Radish-based cover crops tended to be the most beneficial for both microbial abundance and richness, yet detrimental for fungal evenness. Cc species, in particular radish, also shaped fungal and, to a lesser extent, prokaryotic community composition. Crop residues modulated cc effects on bacterial abundance and fungal evenness (i.e., more sensitive in R- than R+), as well as microbial taxa. Several microbial structure features, some affected by cc, were correlated with early tomato growth in the following spring (e.g., composition, taxa within Actinobacteria, Firmicutes and Ascomycota). Our study suggests that, whereas mid-term cc effects were small, they need to be better understood as they could be influencing crop productivity via plant-soil feedbacks.

Functional response of soil microbial communities to tillage, cover crops and nitrogen fertilization

2016 ◽  
Vol 108 ◽  
pp. 147-155 ◽  
Author(s):  
Elodie Nivelle ◽  
Julien Verzeaux ◽  
Hazzar Habbib ◽  
Yakov Kuzyakov ◽  
Guillaume Decocq ◽  
...  
Keyword(s):  
Microbial Communities ◽  
Functional Response ◽  
Cover Crops ◽  
Nitrogen Fertilization ◽  
Soil Microbial Communities ◽  
Soil Microbial

scholarly journals Site and Bioenergy Cropping System Similarly Affect Distinct Live and Total Soil Microbial Communities

2021 ◽  
Vol 12 ◽  
Author(s):  
Sarah I. Leichty ◽  
Christopher P. Kasanke ◽  
Sheryl L. Bell ◽  
Kirsten S. Hofmockel
Keyword(s):  
Microbial Communities ◽  
Soil Texture ◽  
Sandy Loam ◽  
Soil Microbial Communities ◽  
Cropping System ◽  
Fungal Communities ◽  
Fungal Community Composition ◽  
Soil Microbial ◽  
Total Community ◽  
Rna And Dna

Bioenergy crops are a promising energy alternative to fossil fuels. During bioenergy feedstock production, crop inputs shape the composition of soil microbial communities, which in turn influences nutrient cycling and plant productivity. In addition to cropping inputs, site characteristics (e.g., soil texture, climate) influence bacterial and fungal communities. We explored the response of soil microorganisms to bioenergy cropping system (switchgrass vs. maize) and site (sandy loam vs. silty loam) within two long-term experimental research stations. The live and total microbial community membership was investigated using 16S and ITS amplicon sequencing of soil RNA and DNA. For both nucleic acid types, we expected fungi and prokaryotes to be differentially impacted by crop and site due their dissimilar life strategies. We also expected live communities to be more strongly affected by site and crop than the total communities due to a sensitivity to recent stimuli. Instead, we found that prokaryotic and fungal community composition was primarily driven by site with a secondary crop effect, highlighting the importance of soil texture and fertility in shaping both communities. Specific highly abundant prokaryotic and fungal taxa within live communities were indicative of site and cropping systems, providing insight into treatment-specific, agriculturally relevant microbial taxa that were obscured within total community profiles. Within live prokaryote communities, predatory Myxobacteria spp. were largely indicative of silty and switchgrass communities. Within live fungal communities, Glomeromycota spp. were solely indicative of switchgrass soils, while a few very abundant Mortierellomycota spp. were indicative of silty soils. Site and cropping system had distinct effects on the live and total communities reflecting selection forces of plant inputs and environmental conditions over time. Comparisons between RNA and DNA communities uncovered live members obscured within the total community as well as members of the relic DNA pool. The associations between live communities and relic DNA are a product of the intimate relationship between the ephemeral responses of the live community and the accumulation of DNA within necromass that contributes to soil organic matter, and in turn shapes soil microbial dynamics.

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.

Changes in composition and activity of soil microbial communities in peach and kiwifruit Mediterranean orchards under an innovative management system

Soil Research ◽  
2010 ◽  
Vol 48 (3) ◽  
pp. 266 ◽  
Author(s):  
Adriano Sofo ◽  
Giuseppe Celano ◽  
Patrizia Ricciuti ◽  
Maddalena Curci ◽  
Bartolomeo Dichio ◽  
...  
Keyword(s):  
Microbial Communities ◽  
Cover Crops ◽  
Denaturing Gradient Gel Electrophoresis ◽  
Diversity Index ◽  
Soil Depth ◽  
Soil Microbial Communities ◽  
Soil Management ◽  
Organic Input ◽  
Soil Microbial ◽  
Peach Orchard

The aim of this work was to evaluate the effects of 2 soil management systems, so called ‘innovative’ (INN) and ‘conventional’ (CON), on genetic and metabolic diversity of soil microbial communities of peach and kiwifruit orchards. INN system included minimum tillage, organic matter inputs from compost and cover crops, winter pruning, and adequate irrigation and fertilisation. CON system was characterised by conventional tillage, zero organic input, empirical pruning, strong chemical fertilisation, and excessive irrigation. After 4 years of treatments, soil samples were collected in different orchard sites. In peach and kiwifruit INN orchards, average fruit yields were significantly higher than in CON. INN orchards had a significantly higher total number of bacteria. The patterns of denaturing gradient gel electrophoresis of bacterial 16S rDNA/RNA from peach orchard showed differences between soils under drip emitters and along the inter-rows, whereas those from kiwifruit orchard clearly distinguished between INN and CON for both bacteria (16S rRNA) and fungi (18S rDNA/RNA). Shannon’s substrate diversity index, evaluated by Biolog® metabolic assay, was affected by soil treatment in peach orchard and by soil depth in kiwifruit orchard. Principal component analysis of Biolog® values clearly discriminated INN and CON soils of both orchards. The results revealed qualitative and quantitative changes of soil microbial communities in response to an innovative and sustainable soil management.

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