Earthworms do not increase greenhouse gas emissions (CO2 and N2O) in an ecotron experiment simulating a realistic three-crop rotation system

Earthworms are known to stimulate soil greenhouse gas (GHG) emissions, but the majority of previous studies have used simplified model systems or lacked continuous high-frequency measurements. To address this, we conducted a two-year study using large lysimeters (5 m2 area and 1.5 m soil depth) in an ecotron facility, continuously measuring ecosystem-level CO2, N2O, and H2O fluxes. We investigated the impact of endogeic and anecic earthworms on GHG emissions and ecosystem water use efficiency (WUE) in a simulated agricultural setting. Although we observed transient stimulations of carbon fluxes in the presence of earthworms, cumulative fluxes over the study indicated no significant increase in CO2 emissions. Endogeic earthworms reduced N2O emissions during the wheat culture (-44.6%), but this effect was not sustained throughout the experiment. No consistent effects on ecosystem evapotranspiration or WUE were found. Our study suggests that earthworms do not significantly contribute to GH..., The CO2 concentration was measured at the inlet and outlet of each dome (every 12 min) using a multiplexer system coupled with two LI-7000 CO2/H2O analysers (LI-COR Biosciences, Lincoln, NE, USA). The Reichstein et al. (2005) C flux partitioning algorithm was used to estimate the daytime ecosystem respiration based on an exponential regression model (Lloyd et al., 1994). This allowed for the estimation of ecosystem respiration over 24 h (Reco = Reco_night + Reco_day) and gross primary production (GPP = NEE_day – Reco_day).
Ecosystem-level N2O fluxes were measured continuously as an open system using a TILDAS Compact Single analyser (N2O Aerodyne Research, Inc., USA). The analyzer was coupled to a multiplexer system allowing N2O fluxes measurement every 72 min for each Macrocosm. Evapotranspiration (ET) was computed as the lysimeter weight difference between two consecutive days. Four shear beam load cells per lysimeter (CMI-C3, Precia-Molen, Privas CEDEx France), with an accuracy of ±2..., , # Earthworms greenhouse gas emissions in an ecotron experiment datasets

[https://doi.org/10.5061/dryad.mgqnk9955](https://doi.org/10.5061/dryad.mgqnk9955)

The experimental setup involved applying an earthworm treatment with three levels (i) anecic earthworms, (ii) endogeic earthworms, and (iii) a control with very low earthworm biomass (as the total elimination of earthworm is unfeasible) in large lysimeters. The experiment simulated a three plant species crop rotation consisting of a succession of Triticum aestivum (winter wheat) - Sinapsis alba (winter white mustard) - Zeamays (maize). The experiment was conducted in the European Ecotron of Montpellier (Montferrier-sur-Lez, France, www.ecotron.cnrs.fr). It utilized the Macrocosms experimental platform consisting in twelve identical and independent units, each consisting of an 30 m³ aboveground compartment enclosed by a highly transparent material to light and UV radiation (250 μm thick Teflon-FEP film, DuPont, USA). Additionally, it...