Isotope and molecular evidence for direct input of maize leaf wax n-alkanes into crop soils

Eric Lichtfouse (1) , Brigitte Elbisser , Jérôme Balesdent (2) , André A. Mariotti (3) , Gérard Bardoux (3)

1 ASD - Agronomy for Sustainable Development
2 LEMIRE - Laboratoire d'Ecologie Microbienne de la Rhizosphère et d'Environnements Extrêmes
3 Bioemco - Biogéochimie et écologie des milieux continentaux

The contribution of plant carbon to crop soils can be followed by isotope labelling at natural abundance, such as growing a C4 plant on a soil which was previously under C3 vegetation. For this purpose, carbon isotope compositions and relative abundances of n alkanes of maize leaf waxes and maize crop soils were compared. Isotope values of soil n alkanes increased with time of maize cultivation as the result of maize carbon integration into soil organic matter. With increasing time of cultivation, the increase in isotopic difference between n-heptacosane (C27) and n nonacosane (C29) is explained, at least partly, by a direct input of maize leaf n-alkanes. The amount of maize-derived carbon within each n-alkane has been calculated by isotopic means.

Mots clés: n-alkane; soil; plant; waxes; maize; Zea mays; 13C

Domaines: Science des sols; Chimie analytique; Géochimie; Agronomie

Eric Lichtfouse, Brigitte Elbisser, Jérôme Balesdent, André A. Mariotti, Gérard Bardoux. Isotope and molecular evidence for direct input of maize leaf wax n-alkanes into crop soils. Organic Geochemistry, 1994, 22 (2), pp.349-351. ⟨10.1016/0146-6380(94)90181-3⟩. ⟨hal-00190969⟩