Accueil
Sélection de la langue
Adresse
Infodoc : Réseau des bibliothèques et centres de documentation d'AgroParisTechFrance
contact
Array
(
[TITRE] => <b>Type de document : </b>
[TITRE_CLEAN] => Type de document
[OPAC_SHOW] => 1
[TYPE] => list
[AFF] => Tiré à part
[ID] => 4
[NAME] => cp_typdoc
[DATATYPE] => integer
[VALUES] => Array
(
[0] => 7
)
)
| Titre : |
Aluminium and uptake of base cations by tree roots : a critique of the model proposed by sverdrup et al.
|
| Titre de série : | Water, air and soil pollution, Vol 75 - n°1-2 |
| Auteur(s) : |
P. Hogberg, Auteur (et co-auteur)
P. Jensen, Auteur (et co-auteur) |
| Type de document : | Tiré à part |
| Sujets : | Absorption ; Racine ; Modèle ; Acidification ; pH ; Pollution du sol ; Aluminium ; Arbre ; Calcium |
| Résumé : |
Sverdrup et al. (1992) proposed a model intended to evaluate effects of soil solution (Ca2+ + Mg2=)/A13+ ratios on the uptake of Ca2+ and Mg2+ (here called base cations = BC) by tree roots. They considered the adsorption of BC on exchange sites on root surfaces to be a major step, and the competition between A13+ and BC for exchange sites on roots to be crucial. Although this may certainly affect the rates of uptake., it will not exclude base cations from entering the rootcells through ion channels or by carriers. Above all, the model overlooks important gradients in the rhizosphere, e.g. pH-gradients and root exudates, which have profound influences on the speciation of Al. One should instead consider modifying existing models accounting for processes in a buffered soil medium and ha[...] Sverdrup et al. (1992) proposed a model intended to evaluate effects of soil solution (Ca2+ + Mg2=)/A13+ ratios on the uptake of Ca2+ and Mg2+ (here called base cations = BC) by tree roots. They considered the adsorption of BC on exchange sites on root surfaces to be a major step, and the competition between A13+ and BC for exchange sites on roots to be crucial. Although this may certainly affect the rates of uptake., it will not exclude base cations from entering the rootcells through ion channels or by carriers. Above all, the model overlooks important gradients in the rhizosphere, e.g. pH-gradients and root exudates, which have profound influences on the speciation of Al. One should instead consider modifying existing models accounting for processes in a buffered soil medium and handling gradients in the rhizosphere (e.g. Nye and Tinker, 1977). This would also require considerations on mycorrhizas and possible changes in the capacity for uptake of certain ions, which could be induced by deficiencies. |
| Date de publication : | 1994 |
| Format : | pp. 121-125 / réf. |
| Langue(s) : | Anglais |
| Lien vers la notice : | https://infodoc.agroparistech.fr/index.php?lvl=notice_display&id=149856 |
Exemplaires (1)
| Localisation | Emplacement | Pôle | Section | Cote | Support | Disponibilité |
|---|---|---|---|---|---|---|
| Kourou | Archives | AgroParisTech-Kourou | TP4756 | Papier Périodique | Empruntable Disponible |