13C differentiation of dissolved organic carbon pool during carbon mineralization in soil from a native deciduous forest and a coniferous plantation

International audience

Etude et gestion des processus biogéochimiques couplant les cycles du carbone et de l'azote à l'origine de la libération de composés polluants, du sol vers les compartiments eau et air de l'environnement

Mitigation of N2O emissions in agroecosystems: the role of N2O-reducers

CT3 ; EnjS4 ; Département EA; Mitigation of N2O emissions in agroecosystems: the role of N2O-reducers. 16. International Symposium on Microbial Ecology - ISME16

Legacy effects of contrasting water and N-availability patterns on plantmicrobial response to rewetting

National audience; Introduction. Shifts in the frequency and magnitude of rain events (precipitation regime) associated with climate change may affect plant morphological and physiological strategies as well as soil microbial activity.Objectives. The objective of this study was to determine i) how precipitation history shapes the response dynamics of soil bacterial and fungal communities to rewetting, as well as plant-microbial competition for N, and ii) how the N status of the system may modulate the effect of precipitation regime.Materials & methods. The legacy effects of 12 weeks of contrasting precipitation (frequent or infrequent watering, equal total water input) and N inputs was asse…

Le traçage isotopique pour étudier la production par les microorganismes du sol d'oxyde nitreux, gaz à effet de serre.

Domaine SCIENCES DE L’ALIMENT ET AGRO-ENVIRONNEMENT

Effect of integrated weed management in cropping system on soils, microbial activity and N2O fluxes

National audience

N2O emissions during and after legume crops cultivation

International audience

Loss in microbial diversity affects nitrogen cycling in soil

International audience; Microbial communities have a central role in ecosystem processes by driving the Earth's biogeochemical cycles. However, the importance of microbial diversity for ecosystem functioning is still debated. Here, we experimentally manipulated the soil microbial community using a dilution approach to analyze the functional consequences of diversity loss. A trait-centered approach was embraced using the denitrifiers as model guild due to their role in nitrogen cycling, a major ecosystem service. How various diversity metrics related to richness, eveness and phylogenetic diversity of the soil denitrifier community were affected by the removal experiment was assessed by 454 s…

La dénitrification et la production de N2O dans la rhizosphère de maïs : diversité et activité des populations bactériennes impliquées

Effects of precipitation regime and N-availability on the dynamics of plant-microbial and soil biogeochemical cycling responses to rewetting

International audience; Introduction. Shifts in the frequency and magnitude of rain events (precipitation regime) associated with climate change may affect plant morphological and physiological strategies as well as soil microbial activity. Objectives. The objective of this study was to determine i) how precipitation history shapes the response dynamics of soil bacterial and fungal communities to rewetting, as well as plant-microbial competition for N, and ii) how the N status of the system may modulate the effect of precipitation regime. Materials & methods. The legacy effects of 12 weeks of contrasting precipitation (frequent or infrequent watering, equal total water input) and N inputs w…

Defining the conditions of liming products application to promote nitrous oxide reduction in an acidic agricultural soil

With a lifetime of more than 100 years in the atmosphere, N2O is an important greenhouse gas with a global warming potential (GWP) of ~ 300 for a 100-year timescale that also takes part in the destruction of the ozone layer (Ravishankara et al., 2009). While N2O emissions are projected to increase in the coming years (Aneja et al., 2019), the promotion of the N2O reduction to N2 in soils could appear as a possible solution for mitigating soil N2O emission (Hénault et al., 2019). The N2O reduction path appears to be mainly driven by the soils’ pH with a progressive inhibition when pH is lower than 6.8. The aim of the proposed study was to test during laboratory experiments the time and the d…

Emissions de N2O pendant et après la culture de légumineuses

National audience

Utiliser les symbiotes des Légumineuses pour favoriser la réduction du gaz à effet de serre N2O dans les sols

Comparaison de l’effet de la fertilisation azotée sur la croissance et la fixation symbiotique de dix espèces de légumineuses

National audience; voir pdf

Comparative effect of inorganic N on plant growth and N2 fixation of ten legume crops

International audience; [pas de résumé]

Peaks of in situ N2O emissions are influenced by N2O producing and reducing microbial communities across arable soils

International audience; Introduction Agriculture is the main source of terrestrial N2O emissions, a potent greenhouse gas and the main cause of ozone depletion ((Hu et al., 2015). The reduction of N2O into N2 by microorganisms carrying the nitrous oxide reductase gene (nosZ) is the only known biological process eliminating this greenhouse gas. Recent studies showed that a previously unknown clade of N2O-reducers (nosZII) was related to the potential capacity of the soil to act as a N2O sink (see Hallin et al., 2017 and references therein). However little is known about how this group responds to different agricultural practices. Here, we investigated how N2O-producers and N2O-reducers were …

Effects of integrated weed management in cropping systems on soils, microbial activity and N2O fluxes

International audience; Cultivated soils have been widely highlighted as a major source of nitrous oxide (N2O) emissions. This suggests that greenhouse gas emissions should be taken in account when evaluating the impact of new cropping systems. The development of integrated weed management in cropping systems introduces new agricultural practices (combinations of crop rotation, soil management, fertilization, and mechanical and chemical weed control, etc.), which may affect the microbial processes responsible for N2O production in soils. However, the effect of those practices remains to be assessed. Thus, the main objectives of our study is to provide (i) an accurate estimation of the inten…

Effect of temperature on soil microbial structure and fractionation during C mineralisation

International audience; Microbial carbon mineralization in soils leads to the production of different gaseous or dissolved components that have environmental impacts. Our study deals with the influence of soil temperature on the production of gaseous and dissolved carbon components during carbon mineralization in forest soils in France. After an incubation of soil samples for 42 days at 4 different temperatures, we determined both size and 13C isotopic signature of dissolved organic carbon and CO2 pools. We also characterised the soil microbial community structure (PLFA profiles). While temperature clearly increases the CO2 production, a low decrease of the dissolved organic carbon pool was…