Bottinelli Nicolas auteur aut IRD Jouquet Pascal auteur aut IRD Tran T. M. auteur aut IRD Aroui Boukbida Hanane auteur aut IRD Rumpel C. auteur aut IRD text journalArticle eng text/pdf born digital access Earthworm cast ageing controls soil ecosystem services such as carbon storage and nutrient availability. To test the hypothesis that biogeochemical changes during casts ageing can be traced by infrared spectroscopy, we collected topsoil aggregates and earthworm casts produced by the anecic earthworm Amynthas khami belonging to five distinct degradation stages in woodland in northern Vietnam. We analysed mid-infrared (MIR) spectra of both sample types using two approaches: (1) calculation of the proportion of aliphatic compounds and the humification index of organic matter (OM) using specific wavenumbers and (2) linear discriminant analysis (LDA) of the most important peaks and shoulders of the entire spectrum. Our results showed that aliphatic compound contribution to OM was similar and the humification index of OM lower (2-fold) in casts as compared to topsoil aggregates independent of their degradation stage. In contrast, LDA showed a continuous shift from fresh casts to aged casts and topsoil aggregates in agreement with biogeochemical changes of cast properties. We thus conclude that MIR analysis of bulk samples and LDA taking into account the absorbance intensity of most important wavenumbers is a promising tool to capture biogeochemical alterations of organic and mineral earthworm cast properties during ageing. specialized Bioturbation Aggregation Macrofauna FTIR spectroscopy VIET NAM 074 068 383 114811 [4 ] 2021 0016-7061 https://www.documentation.ird.fr/hor/fdi:010080418 0016-7061 [F B010080418] https://www.documentation.ird.fr/hor/fdi:010080418 https://www.documentation.ird.fr/intranet/publi/2020/12/010080418.pdf Accès réservé (Intranet de l'IRD) IRD - Base Horizon / Pleins textes 2021-01-14 2022-11-08 fdi:010080418 fre