Review : Microbial Volatile Organic Compounds (mVOCs) emissions by soil

EABIOMEINRAAGROSUPReview : Microbial Volatile Organic Compounds (mVOCs) emissions by soil. SOMmi

Modelling winter oilseed rape carbon accumulation during the reproductive phase

Actes sur CDROMInternational audienceThe observed decrease in oilseed rape conversion of intercepted radiation efficiency during reproductive phase could be due to leaf falling off, pod senescence or to the specific energy cost of oil production. In reason of its interest in modelling, we tried to identify and quantify the processes really involved in this decrease, for different genotypes under contrasted nitrogen fertilisations

Profiles of volatile organic compound emissions from soils amended with organic waste products

Volatile Organic Compounds (VOCs) are reactive compounds essential to atmospheric chemistry. They are mainly emitted by living organisms, and mostly by plants. Soil microbes also contribute to emissions of VOCs. However, these emissions have not yet been characterised in terms of quality and quantity. Furthermore, long-term organic matter amendments are known to affect the microbial content of soils, and hence the quantity and quality of VOC emissions. This study investigates which and how much of these VOCs are emitted from soil amended with organic waste products (OWPs). Four OWPs were investigated: municipal solid waste compost (MSW), green waste and sludge co-compost (GWS), bio-waste compost (BIOW) and farmyard manure (FYM). These OWPs have been amended every two years since 1998 until now at a rate of ~4 tC ha−1. A soil receiving no organic inputs was used as a reference (CN). VOCs emissions were measured under laboratory conditions using a Proton Transfer Reaction-Quadrupole ion guide Time of Flight-Mass Spectrometry (PTR-QiToF-MS). A laboratory system was set up made of two Pyrex chambers, one for samples and the second empty, to be used as a blank. Our results showed that total VOC emissions were higher in BIOW than in MSW. Further findings outlined that the most emitted compounds were acetone, butanone and acetaldehyde in all treatments, suggesting a common production mechanism for these compounds, meaning they were not affected by the OWP amendment. We isolated 21 VOCs that had statistically different emissions between the treatments and could therefore be considered as good markers of soil biological functioning. Our results suggest that organic matter and pH jointly influenced total VOC emissions. In conclusion, OWPs in soil affect the type of VOC emissions and the total flux also depends on the pH of the soil and the quantity of organic matter

The importance of branching and branches characteristics on oilseed rape genotype x nitrogen interactions

actes sur CDROMInternational audienceClassical yield components analysis can be highlighted for winter oilseed rape by an architectural analysis of morphology and morphogenesis during the reproductive phase. For two conventional genotypes (Aviso and Montego) cultivated under usual agronomic practices and two nitrogen availability levels, the differences observed in grain yield mainly rely on branching and branches characteristics. The analyse of the dynamics of branching, pod setting and grain growth allows to decipher the different processes involved and to precise their dependence on genotype

Microbial volatiles organics compounds (mvocs) emitted from soils amended with organic wastes

EABIOmEAGROSUPVolatile organic compounds (VOCs) have a central role in environmental pollution. They influence the chemistry and the composition of the atmosphere. In particular, biogenic volatile organic compounds (bVOCs) contribute 90% to global VOCs emissions1. Microorganisms contribute to bVOCs emissions and their emissions could be affected by different type of organic waste in soil2. The aim of this study is focused on determining the effect of organic wastes on VOC emitted by microorganisms in soils. The technique used for mVOC detection is the Proton Transfer Reaction-Time of Flight-Mass Spectrometry*(PTR-TOF-MS). PTR-TOF-MS technique provides on-line detection of VOC with two mains advantages: rapidity and the detection limit as low as 0.1 ppt by volume3. Five sample of the same soil with 4 different organic waste contributions were analyzed: (1) Municipal solid waste, (2) Green waste and sludge, (3) bio-waste, (4) farmyard manure and a control sample without organic waste. We also compared dry and humid conditions for each sample. Results show that VOC emissions are higher in humid samples than dry ones. Different VOCs such as acetone, Methyl Ethyl Ketone, acetaldehyde, toluene, ethanol and monoterpenes contribute between 60% and 80% of total emissions. Furthermore, other compounds emitted in smaller quantities are analyzed in order to identify a VOC profile belonging to each type of organic waste in soil. Finally, perspectives concerning the study of the correlation between mVOC emissions profiles with microorganism diversity and activity in soil will be discussed. Also analysis of soils genetic content and manipulation of genetic diversity of soils will be performed. 1 Roger Atkinson, ‘Atmospheric Chemistry of VOCs and NOx’, Atmospheric Environment, 34.12–14 (2000), 2063–2101 . 2 Mallard P. et al., ‘Impacts environnementaux de la gestion biologique des déchets : bilan des connaissances’ (2005). 3 Christos Soukoulis and others, ‘PTR-ToF-MS, A Novel, Rapid, High Sensitivity and Non-Invasive Tool to Monitor Volatile Compound Release During Fruit Post-Harvest Storage: The Case Study of Apple Ripening’, Food and Bioprocess Technology, 6.10 (2012), 2831–43 . *Financed by ANAeE France <http://www.anaee.com/

Emissions de composés organiques volatils par des sols amendés par des PRO: évolution saisonnière et lien avec la diversité microbienne

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