wAbstract
@Soil parameters change continuously over time and the duration
of pedogenesis may significantly affect a soil's sorption capacity
for nutrients and contaminants. In former studies, we showed that
progressing pedogenic development had increased the retention
capacities for Cu and Cd in young alluvial soils at the Danube
River (Austria). The present study was conducted to evaluate the
impact of pedogenesis on phosphorus (P) retention in these soils,
which represent a weathering sequence covering an age gradient
from 20 yr to 500 yr. We performed batch sorption experiments
followed by three subsequent desorption steps. Phosphorus retention
differed strongly among the studied soils and ranged from 11 to
40 when 1000 mg phosphate - P kg-1 was added. The
subsequent desorption experiments with 0.01 m KCl solution revealed
a high mobility (up to 89) of this recently added P. Correlation
analyses showed that P retention in the studied samples was positively
correlated to dithionite-extractable Al, Mn and Fe, oxalate-extractable
Mn and clay content. The present study revealed that P sorption
was not influenced by soil development. The composition of the
soil parent material, as affected by differences in sedimentation
conditions across the studied floodplain, had a stronger impact
on P sorption than the changes induced by 500 yr of pedogenesis
under the continental climate of Central Europe.
Keywords: Chronosequence; Fluvisol; Pedogenesis; Phosphorus adsorption;
Phosphorus desorptionx
1. Introduction
2. Materials and methods
@2.1. Study area and sampling
@2.2. Soil and suspended sediment characterisation
@2.3. Phosphate sorption and desorption
@2.4. Mathematical description of sorption isotherms
3. Results and discussion
@3.1. Sediment and soil characteristics
@3.2. Phosphorus sorption
@3.3. Phosphorus desorption
@3.4. Phosphorus sorption-desorption behaviour in relation to
soil properties and weathering
4. Conclusions
Acknowledgements
References