Friday, 12 August 2016

Soil suppressiveness and its relations with the microbial community in a Brazilian subtropical agroecosystem under different management systems

Published Date

May 2016, Vol.96:191–197, doi:10.1016/j.soilbio.2016.02.010

Title

Soil suppressiveness and its relations with the microbial community in a Brazilian subtropical agroecosystem under different management systems

Author

Samanta B. Campos^a

Bruno B. Lisboa^b

Flavio A.O. Camargo^c

Cimelio Bayer^c

Alexander Sczyrba^d

Paul Dirksen^d

Andreas Albersmeier^e

Jörn Kalinowski^e

Anelise Beneduzi^b

Pedro B. Costa^f

Luciane Maria P. Passaglia^f

Luciano K. Vargas^b,^,

Volker F. Wendisch^a,^,

aGenetics of Prokaryotes, Faculty of Biology & Center for Biotechnology, Bielefeld University, Universitätsstr. 25, 33615, Bielefeld, Germany
bState Foundation for Research in Agriculture (Fundação Estadual de Pesquisa Agropecuária – FEPAGRO), Rua Gonçalves Dias, 570, CEP 90130-060, Porto Alegre, RS, Brazil
cFederal University of Rio Grande do Sul, Faculty of Agronomy, Department of Soil Science, Av. Bento Gonçalves 7712, CEP 91540-000, Porto Alegre, RS, Brazil
dComputational Metagenomics, Center for Biotechnology (CeBiTec), Bielefeld University, Sequenz 1, 33615, Bielefeld, Germany
eTechnology Platform Genomics, Center for Biotechnology (CeBiTec), Bielefeld University, Sequenz 1, 33615, Bielefeld, Germany
fFederal University of Rio Grande do Sul, Institute of Biosciences, Department of Genetics, Av. Bento Gonçalves, 9500, Caixa Postal 15.053, CEP 91501-970, Porto Alegre, RS, Brazil

Received 22 August 2015. Revised 29 September 2015. Accepted 20 February 2016. Available online 3 March 2016.

Highlights

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We evaluated how crop and tillage systems affect soil suppressiveness.
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We related soil suppressiveness with microbial and biochemical indicators of soil quality.
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No-tillage and high-input crop systems increase soil suppressiveness.
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Increasing microbial biomass and activity increases soil suppressiveness.
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Specific bacterial genera are related to soil suppressiveness.

Abstract

The ability of soils to detain the onset of a disease in a susceptible host is called soil suppressiveness. Soil suppressiveness can often be attributed to the activity of soil microorganisms. Considering that soil management can drastically affect microbial soil communities, the objective of this work was to evaluate the impact of different crop systems and tillage practices on the suppression of wheat head blight, caused by the soil-borne fungus Fusarium graminearum, assessing the relationships between soil suppressiveness and microbial activity and diversity. Samples were taken from a long-term (30 years) experimental set-up in a Paleudult soil under conventional tillage or no-tillage management and three cropping systems: oat (Avena strigosa)/maize (Zea mays); vetch (Vicia sativa)/maize; and black oat + vetch/maize + cowpea (Vigna sinensis). The soil-borne fungus F. graminearum, the causal agent of wheat head blight, was used as model pathogen and wheat (Triticum aestivum) as model host plant. No-tillage soil samples showed the highest level of F. graminearum suppression by significantly reducing plant disease intensity. Of the cropping systems tested, the vetch + black oat/maize + cowpea system showed the highest suppressiveness and the oat/maize system showed the lowest. Microbial biomass, respiratory activity and the activity of the chitin degrading enzyme β-glucosaminidase followed the same trend, being associated to soil organic matter. Chitinophagaceae, Acidobacteriaceae, Xanthomonadaceae and Burkholderiaceae were associated to soil suppressiveness.