Accéder directement au contenu Accéder directement à la navigation
Article dans une revue

Pathway to persistence: plant root traits alter carbon accumulation in different soil carbon pools through microbial mediation

Abstract : Aims: Mineral-associated organic matter, mainly derived from microbial by-products, persists longer in soil compared to particulate organic matter (POM). POM is highly recalcitrant and originates largely from decomposing root and shoot litter. Theory suggests that root traits and growth dynamics should affect carbon (C) accumulation into these different pools, but the specific traits driving this accumulation are not clearly identified. Methods: Twelve herbaceous species were grown for 37 weeks in monocultures. Root elongation rate (RER) was measured throughout the experiment. At the end of the experiment, we determined morphological and chemical root traits, as well as substrate induced respiration (SIR) as a proxy for microbial activity. Carbon was measured in four different soil fractions, following particle-size and density fractionation. Results: Root biomass, RER, root diameter, hemicellulose content and SIR (characteristic of N2-fixing Fabaceae species), were all positively correlated with increased C in the coarse silt fraction. Root diameter and hemicellulose content were negatively correlated with C in the POM fraction, that was greater under non N2-fixing Poaceae species, characterized by lignin-rich roots with a high carbon:nitrogen ratio that grew slowly. The accumulation of C in different soil pools was mediated by microbial activity. Conclusions: Our results show that root traits determine C input into different soil pools, mediated primarily by microbial activity, thus determining the fate of soil organic C. We also highlight that C in different soil pools, and not only total soil organic C, should be reported in future studies to better understand its origin, fate and dynamics.
Liste complète des métadonnées

https://hal.inrae.fr/hal-02879796
Déposant : Yannick Brohard <>
Soumis le : mercredi 24 juin 2020 - 11:42:46
Dernière modification le : mercredi 8 juillet 2020 - 12:01:31

Identifiants

Citation

Lorenzo Matteo Walter Rossi, Zhun Mao, Luis Merino Martin, Catherine Roumet, Florian Fort, et al.. Pathway to persistence: plant root traits alter carbon accumulation in different soil carbon pools through microbial mediation. Plant and Soil, Springer Verlag, In press, ⟨10.1007/s11104-020-04469-5⟩. ⟨hal-02879796⟩

Partager

Métriques

Consultations de la notice

22