Organo-Mineral Interactions Are More Important for Organic Matter Retention in Subsoil Than Topsoil
2020
Poirier, Vincent | Basile-Doelsch, Isabelle | Balesdent, Jérôme | Borschneck, Daniel | Whalen, Joann, K | Angers, Denis, A | Université du Québec en Abitibi-Témiscamingue (UQAT) | Centre Européen de Recherche et d'Enseignement des Géosciences de l'Environnement (CEREGE) ; Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Collège de France (CdF (institution))-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE) | McGill University = Université McGill [Montréal, Canada] | Agriculture and Agri-Food (AAFC) | Fonds de recherche du Quebec-Nature et technologie (FRQNT)Max Bell Foundation at McGill UniversityNatural Sciences and Engineering Research Council of Canada (NSERC)Green Crop Network by NSERCNETGP298866-03Centre SEVE by FRQNT Strategic Networks program
International audience
اظهر المزيد [+] اقل [-]إنجليزي. Decomposing crop residues contribute to soil organic matter (SOM) accrual; however, the factors driving the fate of carbon (C) and nitrogen (N) in soil fractions is still largely unknown, especially the influence of soil mineralogy and autochthonous organic matter concentration. The objectives of this work were (1) to evaluate the retention of C and N from crop residue in the form of occluded and mineral-associated SOM in topsoil (0-20 cm) and subsoil (30-70 cm) previously incubated for 51 days with 13 C-15 N-labelled corn residues, and (2) to explore if specific minerals preferentially control the retention of residue-derived C and N in topsoil and subsoil. We used topsoil and subsoil having similar texture and mineralogy as proxies for soils being rich (i.e., topsoil) and poor (i.e., subsoil) in autochthonous organic matter. We performed a sequential density fractionation procedure and measured residue-derived C and N in occluded and mineral-associated SOM fractions, and used X-ray diffraction analysis of soil density fractions to investigate their mineralogy. In accordance with our hypothesis, the retention of C and N from crop residue through organo-mineral interactions was greater in subsoil than topsoil. The same minerals were involved in the retention of residue-derived organic matter in topsoil and subsoil, but the residue-derived organic matter was associated with a denser fraction in the subsoil (i.e., 2.5-2.6. g cm −3) than in the topsoil (i.e., 2.3-2.5 g cm −3). In soils and soil horizons with high clay content and reactive minerals, we find that a low SOM concentration leads to the rapid stabilization of C and N from newly added crop residues.
اظهر المزيد [+] اقل [-]الكلمات المفتاحية الخاصة بالمكنز الزراعي (أجروفوك)
المعلومات البيبليوغرافية
تم تزويد هذا السجل من قبل Institut national de la recherche agronomique