The effect of pedological conditions on the sources and sinks of silicon in the Vertic Planosols in south-western Ethiopia

Landscapes and soils through time

Auteur(s) et Affiliation(s)

CORNELIS, J.-T.

Earth and Life Inst., Univ. catholique de Louvain (UCL), Louvain-la-Neuve, Belgique

DUMON, M.

Dep. of Geology and Soil Science, Univ., Ghent, Belgique

TOLOSSA, A.R.

Dep. of Geology and Soil Science, Univ., Ghent, Belgique

Dept. of Natural Resources Management, Jimma Univ. College of Agriculture and Veterinary Medicine, Ethiopie

DELVAUX, B.

Earth and Life Inst., Univ. catholique de Louvain (UCL), Louvain-la-Neuve, Belgique

DECKERS, J.

Dep. of Earth and Environmental Sciences, K. Univ., Geo-Inst., Heverlee, Belgique

VAN RANST, E.

Dep. of Geology and Soil Science, Univ., Ghent, Belgique

SAUER, D.

Inst. of Geography, Univ. of Technology, Dresden, Allemagne

JAHN, R.

Soil Science and Soil Protection Group, Univ., Halle, Allemagne

STAHR, K.

Inst. of Soil Science and Land Evaluation, Univ. of Hohenheim, Stuttgart, Allemagne

Description :
The aim of this paper is to assess the impact of pedological conditions on the sources of dissolved Si and its dynamics in a Vertic Planosol characterized by contrasting bleached and vertic horizons. The activity of dissolved Si as H4SiO4 in the aqueous phase of the Vertic Planosols in south-western Ethiopia seems to be controlled in the bleached E horizon by the balance between the dissolution of feldspars and volcanic glass, active uptake by grasses (formation of phytoliths), neoformation of kaolinite and intense lateral leaching. In the vertic Bw horizon the sources and sinks of Si are governed by the dissolution of phytoliths, the adsorption on and desorption from Fe oxides and slow leaching. These results clearly indicate that the contrasting pedological conditions in the bleached and vertic horizons impact the sources and sinks of Si in the Vertic Planosols in south-western Ethiopia, and as such could partly control terrestrial Si fluxes.

Type de document :
Congrès

Source :
International Conference Landscapes and Soils through Time, Stuttgart, Allemagne, 2011-07-29/2011-08-01, Catena (Giessen), issn : 0341-8162, 2014, vol. 112, p. 131-138, nombre de pages : 8, Références bibliographiques : 1 p.

Date :
2014

Editeur :
Pays édition : Allemagne, Cremlingen-Destedt, Catena

Langue :
Anglais