Organic management and cover crop species steer soil microbial community structure and functionality along with soil organic matter properties

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17 Citations (Scopus)

Abstract

It is well recognized that organic soil management stimulates bacterial biomass and activity and that including cover crops in the rotation increases soil organic matter (SOM). Yet, to date the relative impact of different cover crop species and organic vs. non-organic soil management on soil bacteria and fungi and on SOM quantity and quality remains to be tested. We used a long-term (10 years) full-factorial field experiment to test the combined effects of organic vs. conventional soil management with different cover crop species (oat or rye) and the legacy effects of seven soil health treatments (SHTs: treatments with compost, chitin, marigold, grass–clover, biofumigation or anaerobic soil disinfestation (ASD), and fallow as control) on microbial community biomass, structure and catabolic activity and on SOM quantity and quality (dissolved organic carbon (DOC), aromaticity and water repellency). Microbial community traits were assessed using PLFA/NLFA analyses and multi-substrate induced respiration. We found that organic soil management enhanced total microbial biomass by increasing bacterial, saprotrophic and arbuscular mycorrhizal fungal biomass; and increased total microbial catabolic activity, associated with maintaining high microbial efficiency (low qCO2). Effects of organic management were amplified by oat as cover crop, which enhanced the abundance of saprotrophic fungi resulting in a higher fungal:bacterial ratio. Total SOM concentration was similar among treatments, however the most easily accessible fraction, i.e. DOC, was higher in organic compared to conventional soils. Also, the aromaticity of the DOC was lower in organic than in conventional systems, which was associated with lower water repellency. There was a legacy effect of SHTs on fungal:bacterial ratio in that chitin and marigold showed higher fungal:bacterial ratio compared to compost, biofumigation and ASD even 6 years after the last application. We conclude that organic soil management enhances the abundance of all microbial groups and their total catabolic activity, associated with a higher concentration and lower aromaticity of dissolved organic matter. These effects can be enlarged by the growth of specific cover crops and the application of certain soil health treatments.
Original languageEnglish
Pages (from-to)7-17
JournalAgriculture, Ecosystems and Environment
Volume263
DOIs
Publication statusPublished - 1 Aug 2018

Fingerprint

cover crop
soil management
cover crops
microbial communities
soil organic matter
microbial community
community structure
dissolved organic carbon
organic soils
biofumigation
disinfestation
organic soil
soil
chitin
composts
biomass
oats
soil quality
compost
fungus

Keywords

  • Aromaticity
  • Dissolved organic matter
  • Legacy effects
  • MicroResp
  • PLFA/NLFA
  • Water repellency

Cite this

@article{a477537f1d9a401e9a90e478b8f89fb8,
title = "Organic management and cover crop species steer soil microbial community structure and functionality along with soil organic matter properties",
abstract = "It is well recognized that organic soil management stimulates bacterial biomass and activity and that including cover crops in the rotation increases soil organic matter (SOM). Yet, to date the relative impact of different cover crop species and organic vs. non-organic soil management on soil bacteria and fungi and on SOM quantity and quality remains to be tested. We used a long-term (10 years) full-factorial field experiment to test the combined effects of organic vs. conventional soil management with different cover crop species (oat or rye) and the legacy effects of seven soil health treatments (SHTs: treatments with compost, chitin, marigold, grass–clover, biofumigation or anaerobic soil disinfestation (ASD), and fallow as control) on microbial community biomass, structure and catabolic activity and on SOM quantity and quality (dissolved organic carbon (DOC), aromaticity and water repellency). Microbial community traits were assessed using PLFA/NLFA analyses and multi-substrate induced respiration. We found that organic soil management enhanced total microbial biomass by increasing bacterial, saprotrophic and arbuscular mycorrhizal fungal biomass; and increased total microbial catabolic activity, associated with maintaining high microbial efficiency (low qCO2). Effects of organic management were amplified by oat as cover crop, which enhanced the abundance of saprotrophic fungi resulting in a higher fungal:bacterial ratio. Total SOM concentration was similar among treatments, however the most easily accessible fraction, i.e. DOC, was higher in organic compared to conventional soils. Also, the aromaticity of the DOC was lower in organic than in conventional systems, which was associated with lower water repellency. There was a legacy effect of SHTs on fungal:bacterial ratio in that chitin and marigold showed higher fungal:bacterial ratio compared to compost, biofumigation and ASD even 6 years after the last application. We conclude that organic soil management enhances the abundance of all microbial groups and their total catabolic activity, associated with a higher concentration and lower aromaticity of dissolved organic matter. These effects can be enlarged by the growth of specific cover crops and the application of certain soil health treatments.",
keywords = "Aromaticity, Dissolved organic matter, Legacy effects, MicroResp, PLFA/NLFA, Water repellency",
author = "Mart{\'i}nez-Garc{\'i}a, {Laura B.} and Gerard Korthals and Lijbert Brussaard and J{\o}rgensen, {Helene Bracht} and {de Deyn}, {Gerlinde B.}",
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language = "English",
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pages = "7--17",
journal = "Agriculture, Ecosystems and Environment",
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T1 - Organic management and cover crop species steer soil microbial community structure and functionality along with soil organic matter properties

AU - Martínez-García, Laura B.

AU - Korthals, Gerard

AU - Brussaard, Lijbert

AU - Jørgensen, Helene Bracht

AU - de Deyn, Gerlinde B.

PY - 2018/8/1

Y1 - 2018/8/1

N2 - It is well recognized that organic soil management stimulates bacterial biomass and activity and that including cover crops in the rotation increases soil organic matter (SOM). Yet, to date the relative impact of different cover crop species and organic vs. non-organic soil management on soil bacteria and fungi and on SOM quantity and quality remains to be tested. We used a long-term (10 years) full-factorial field experiment to test the combined effects of organic vs. conventional soil management with different cover crop species (oat or rye) and the legacy effects of seven soil health treatments (SHTs: treatments with compost, chitin, marigold, grass–clover, biofumigation or anaerobic soil disinfestation (ASD), and fallow as control) on microbial community biomass, structure and catabolic activity and on SOM quantity and quality (dissolved organic carbon (DOC), aromaticity and water repellency). Microbial community traits were assessed using PLFA/NLFA analyses and multi-substrate induced respiration. We found that organic soil management enhanced total microbial biomass by increasing bacterial, saprotrophic and arbuscular mycorrhizal fungal biomass; and increased total microbial catabolic activity, associated with maintaining high microbial efficiency (low qCO2). Effects of organic management were amplified by oat as cover crop, which enhanced the abundance of saprotrophic fungi resulting in a higher fungal:bacterial ratio. Total SOM concentration was similar among treatments, however the most easily accessible fraction, i.e. DOC, was higher in organic compared to conventional soils. Also, the aromaticity of the DOC was lower in organic than in conventional systems, which was associated with lower water repellency. There was a legacy effect of SHTs on fungal:bacterial ratio in that chitin and marigold showed higher fungal:bacterial ratio compared to compost, biofumigation and ASD even 6 years after the last application. We conclude that organic soil management enhances the abundance of all microbial groups and their total catabolic activity, associated with a higher concentration and lower aromaticity of dissolved organic matter. These effects can be enlarged by the growth of specific cover crops and the application of certain soil health treatments.

AB - It is well recognized that organic soil management stimulates bacterial biomass and activity and that including cover crops in the rotation increases soil organic matter (SOM). Yet, to date the relative impact of different cover crop species and organic vs. non-organic soil management on soil bacteria and fungi and on SOM quantity and quality remains to be tested. We used a long-term (10 years) full-factorial field experiment to test the combined effects of organic vs. conventional soil management with different cover crop species (oat or rye) and the legacy effects of seven soil health treatments (SHTs: treatments with compost, chitin, marigold, grass–clover, biofumigation or anaerobic soil disinfestation (ASD), and fallow as control) on microbial community biomass, structure and catabolic activity and on SOM quantity and quality (dissolved organic carbon (DOC), aromaticity and water repellency). Microbial community traits were assessed using PLFA/NLFA analyses and multi-substrate induced respiration. We found that organic soil management enhanced total microbial biomass by increasing bacterial, saprotrophic and arbuscular mycorrhizal fungal biomass; and increased total microbial catabolic activity, associated with maintaining high microbial efficiency (low qCO2). Effects of organic management were amplified by oat as cover crop, which enhanced the abundance of saprotrophic fungi resulting in a higher fungal:bacterial ratio. Total SOM concentration was similar among treatments, however the most easily accessible fraction, i.e. DOC, was higher in organic compared to conventional soils. Also, the aromaticity of the DOC was lower in organic than in conventional systems, which was associated with lower water repellency. There was a legacy effect of SHTs on fungal:bacterial ratio in that chitin and marigold showed higher fungal:bacterial ratio compared to compost, biofumigation and ASD even 6 years after the last application. We conclude that organic soil management enhances the abundance of all microbial groups and their total catabolic activity, associated with a higher concentration and lower aromaticity of dissolved organic matter. These effects can be enlarged by the growth of specific cover crops and the application of certain soil health treatments.

KW - Aromaticity

KW - Dissolved organic matter

KW - Legacy effects

KW - MicroResp

KW - PLFA/NLFA

KW - Water repellency

U2 - 10.1016/j.agee.2018.04.018

DO - 10.1016/j.agee.2018.04.018

M3 - Article

VL - 263

SP - 7

EP - 17

JO - Agriculture, Ecosystems and Environment

JF - Agriculture, Ecosystems and Environment

SN - 0167-8809

ER -