Microbial crop residue decomposition dynamics in organic and conventionally managed soils

Arcand, Melissa M.; Helgason, Bobbi L.; Lemke, R.

doi:10.1016/j.apsoil.2016.07.001

Cited by 75 publications

(36 citation statements)

References 70 publications

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“…Consequently, while it is widely recognized that microorganisms perform a crucial role in many key ecosystem functions involved in soil fertility and environmental and water quality (6), the importance of microbial diversity is still debated (7,8). However, this question is critical when the impact of climatic changes (9) and land management (10)(11)(12) on microbial diversity in soil ecosystems is considered.…”

Section: Importancementioning

confidence: 99%

High Microbial Diversity Promotes Soil Ecosystem Functioning

Maron

Sarr

Kaisermann

et al. 2018

Appl Environ Microbiol

323

158

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In soil, the link between microbial diversity and carbon transformations is challenged by the concept of functional redundancy. Here, we hypothesized that functional redundancy may decrease with increasing carbon source recalcitrance and that coupling of diversity with C cycling may change accordingly. We manipulated microbial diversity to examine how diversity decrease affects the decomposition of easily degradable (i.e., allochthonous plant residues) versus recalcitrant (i.e., autochthonous organic matter) C sources. We found that a decrease in microbial diversity (i) affected the decomposition of both autochthonous and allochthonous carbon sources, thereby reducing global CO emission by up to 40%, and (ii) shaped the source of CO emission toward preferential decomposition of most degradable C sources. Our results also revealed that the significance of the diversity effect increases with nutrient availability. Altogether, these findings show that C cycling in soil may be more vulnerable to microbial diversity changes than expected from previous studies, particularly in ecosystems exposed to nutrient inputs. Thus, concern about the preservation of microbial diversity may be highly relevant in the current global-change context assumed to impact soil biodiversity and the pulse inputs of plant residues and rhizodeposits into the soil. With hundreds of thousands of taxa per gram of soil, microbial diversity dominates soil biodiversity. While numerous studies have established that microbial communities respond rapidly to environmental changes, the relationship between microbial diversity and soil functioning remains controversial. Using a well-controlled laboratory approach, we provide empirical evidence that microbial diversity may be of high significance for organic matter decomposition, a major process on which rely many of the ecosystem services provided by the soil ecosystem. These new findings should be taken into account in future studies aimed at understanding and predicting the functional consequences of changes in microbial diversity on soil ecosystem services and carbon storage in soil.

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Section: Importancementioning

confidence: 99%

High Microbial Diversity Promotes Soil Ecosystem Functioning

Maron

Sarr

Kaisermann

et al. 2018

Appl Environ Microbiol

323

158

View full text Add to dashboard Cite

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“…Arcand et al [23] observed changes in the microbial community in the soils where organic residues were supplied. The authors pointed to the dominance of fungi and heterotrophic bacteria, which actively degraded complex compounds such as cellulose, lignin and chitin.…”

Section: The Count Of Microorganismsmentioning

confidence: 99%

The Influence of Tillage and Cover Cropping on Soil Microbial Parameters and Spring Wheat Physiology

et al. 2020

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The soil tillage system and the distribution of stubble catch crops increase the content of organic carbon, thus increasing the biochemical activity of soil. The aim of the study was to assess the impact of leguminous cover crops and different tillage soil systems before spring wheat sowing on the count of soil microorganisms, biochemical activity, microbiological diversity and the physiological state of the plants in correlation with yield. The study compared and analysed the following systems: (1) conventional tillage (CT) to a depth of 22 cm, followed by spring wheat sowing using four simplified cultivation technologies called conservation tillage. The following simplified tillage systems were evaluated: (2) skimming before sowing the cover crop and spring wheat sowing after ploughing tillage (CT), (3) skimming before sowing of the cover crop (sowing wheat with no-till technology (NT)), (4) direct sowing of ground cover plants (NT) and spring wheat sowing after ploughing cultivation (CT) and (5) direct sowing of cover crop (NT) and sowing wheat directly into cover crop (NT). The results showed that applying the cover crop and soil tillage method before sowing wheat improved all tested parameters. The highest values of the analysed parameters were observed in the treatment with soil skimming before sowing of the cover plant, and then with sowing the wheat directly into the mulch. The activity of dehydrogenase was 90% higher, while the activity of phosphatase was 32% higher, in comparison to the control group. Both the activity of catalase and the biological index of fertility were 200% higher, in comparison to the control group. Metagenomic analysis showed that soil bacterial communities collected during treatment 'zero' and after different cultivations differed in the structure and percentage of individual taxa at the phylum level.

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“…Organically managed soils can harbor microbial communities that are distinct in structure and function compared to conventionally managed soils due to differences in edaphic factors stemming from legacies of pest management, nutrient inputs, and other agronomic practices such as tillage ( García-Ruiz et al, 2008 ; Joergensen et al, 2010 ; Kong et al, 2011 ; Chaudhry et al, 2012 ; Li et al, 2012 ; Dai et al, 2014 ; Hartmann et al, 2014 ; Arcand et al, 2016 ). Soil C stocks have been shown to decline with conversion to organic management ( Bell et al, 2012 ), but have also remained on par with conventional soils ( Malhi et al, 2009 ) and even increased due to higher microbial CUE relative to conventionally managed soils ( Syswerda et al, 2011 ; Kallenbach et al, 2015 ).…”

Section: Introductionmentioning

confidence: 99%

Resource Legacies of Organic and Conventional Management Differentiate Soil Microbial Carbon Use

2017

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Long-term contrasts in agricultural management can shift soil resource availability with potential consequences to microbial carbon (C) use efficiency (CUE) and the fate of C in soils. Isothermal calorimetry was combined with 13C-labeled glucose stable isotope probing (SIP) of 16S rRNA genes to test the hypothesis that organically managed soils would support microbial communities with greater thermodynamic efficiency compared to conventional soils due to a legacy of lower resource availability and a resultant shift toward communities supportive of more oligotrophic taxa. Resource availability was greater in conventionally managed soils, with 3.5 times higher available phosphorus, 5% more nitrate, and 36% more dissolved organic C. The two management systems harbored distinct glucose-utilizing populations of Proteobacteria and Actinobacteria, with a higher Proteobacteria:Actinobacteria ratio (2.4 vs. 0.7) in conventional soils. Organically managed soils also harbored notable activity of Firmicutes. Thermodynamic efficiency indices were similar between soils, indicating that glucose was metabolized at similar energetic cost. However, differentially abundant glucose utilizers in organically managed soils were positively correlated with soil organic matter (SOM) priming and negatively correlated to soil nutrient and carbon availability, respiration, and heat production. These correlation patterns were strongly reversed in the conventionally managed soils indicating clear differentiation of microbial functioning related to soil resource availability. Fresh C addition caused proportionally more priming of SOM decomposition (57 vs. 51%) in organically managed soils likely due to mineralization of organic nutrients to satisfy microbial demands during glucose utilization in these more resource deprived soils. The additional heat released from SOM oxidation may explain the similar community level thermodynamic efficiencies between management systems. Restoring fertility to soils with a legacy of nutrient limitation requires a balanced supply of both nutrients and energy to protect stable SOM from microbial degradation. These results highlight the need to consider managing C for the energy it provides to ıcritical biological processes that underpin soil health.

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Microbial crop residue decomposition dynamics in organic and conventionally managed soils

Cited by 75 publications

References 70 publications

High Microbial Diversity Promotes Soil Ecosystem Functioning

High Microbial Diversity Promotes Soil Ecosystem Functioning

The Influence of Tillage and Cover Cropping on Soil Microbial Parameters and Spring Wheat Physiology

Resource Legacies of Organic and Conventional Management Differentiate Soil Microbial Carbon Use

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