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Communication Dans Un Congrès Année : 2019

A possible trade-off between soil nitrogen availability and root carbon inputs to soil

Un possible compromis entre la disponibilité de l'azote dans le sol et les entrées de carbone des racines vers le sol

Résumé

The potential of agricultural soils to store carbon (C) has been claimed to require a large amount of nitrogen (N) and therefore a high soil N availability. This assumption is based on the observation that stable soil organic compounds are characterized by a narrow range in C:N ratios. However, N-fertilizer additions have also been shown to increase respiratory C losses from soils. Furthermore, most of the organic C naturally stored in soils originate from plant C inputs, which occur both by aerial litter deposition and by root turnover and rhizodeposition. Root C inputs have been shown to contribute 2-3 times more to soil C sequestration than shoot-derived C inputs. However, root C inputs may be limited or even decrease when soil N availability increases beyond a certain level. A trade-off may therefore exist between the amount of soil available N and the potential of soil C sequestration associated to the inputs of root C. The existence of such trade-off and its possible consequences for the optimization of soil C sequestration will be discussed according to evidences from scientific literature and to a modelling approach describing how root C inputs to soil can evolve with soil N availability.
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Dates et versions

hal-02947441 , version 1 (24-09-2020)

Identifiants

  • HAL Id : hal-02947441 , version 1
  • PRODINRA : 487027

Citer

Frédéric Rees, Claire Chenu, Bruno Andrieu. A possible trade-off between soil nitrogen availability and root carbon inputs to soil. International conference "Food security and climate change: 4 per 1000 initiative new tangible global challenges for the soil", INRA ; Université de Poitiers, Jun 2019, Poitiers, France. ⟨hal-02947441⟩
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