Gérard S. auteur aut IRD Marsden C. auteur aut IRD Belaud E. auteur aut IRD Biryol Charlotte auteur aut IRD Capowiez Y. auteur aut IRD Estopinan J. auteur aut IRD Ferchaud F. auteur aut IRD Forest M. auteur aut IRD Ngao J. auteur aut IRD Goury R. auteur aut IRD Masson A. S. auteur aut IRD Orrière S. auteur aut IRD Hedde M. auteur aut IRD text journalArticle eng text/pdf reformatted digital access Mediterranean agroecosystems increasingly face prolonged summer drought, extended bare-soil periods and heat extremes, all of which constrain soil biota and threaten long-term soil functioning. Management practices maintaining plant cover during summer, such as cover crops, may alleviate these constraints but generally require irrigation in dry regions. However, the ecological consequences of combining summer cover crops with irrigation remain poorly quantified for soil fauna, particularly in heterogeneous agroforestry systems. We monitored earthworm communities for six years (2019-2024) at the DIAMS experimental platform, a replicated Mediterranean alley-cropping agroforestry trial where an irrigated summer cover crop was implemented factorially. Earthworms were surveyed each winter across contrasted habitat types to assess delayed (legacy) effects of summer management. To isolate irrigation effects from spatial heterogeneity and interannual climatic variability, we applied a Difference-in-Differences framework complemented by event-study analyses. Summer crop irrigation did not affect earthworm biomass or species richness but induced habitat-specific changes in abundance. Abundance increased in irrigated agroforestry crop alleys (×3.5 in AF_C and ×2.5 in AF_C1m), while no detectable effects occurred in monoculture or tree-dominated habitats. Communities were largely dominated by Microscolex dubius, suggesting that irrigation primarily enhanced the survival or recruitment of this disturbance-tolerant species. Irrigation effects were stronger following dry autumns, indicating climate-dependent legacy responses. Overall, our results show that irrigation benefits for soil fauna are strongly context-dependent, emerging primarily in exposed crop habitats and shaped by habitat heterogeneity, seasonal legacy effects and interannual climatic variability. specialized Soil biodiversity Agroecology Soil conservation Resource-mediated pathways Community dynamics Ecological trajectories FRANCE HERAULT 074 082 076 021 408 110455 [11 p.] 2026 0167-8809 https://www.documentation.ird.fr/hor/fdi:010097125 10.1016/j.agee.2026.110455 0167-8809 [F B010097125] https://www.documentation.ird.fr/hor/fdi:010097125 https://horizon.documentation.ird.fr/exl-doc/pleins_textes/2026-06/010097125.pdf IRD - Base Horizon / Pleins textes 2026-06-10 2026-06-12 fdi:010097125 fre