Titelangaben
Franken, Gudrun ; Pijpers, Marc ; Matzner, Egbert:
Aluminium chemistry of the soil solution in an acid forest soil as influenced by percolation rate and soil structure.
In: European Journal of Soil Science.
Bd. 46
(1995)
Heft 4
.
- S. 613-619.
ISSN 1351-0754
DOI: https://doi.org/10.1111/j.1365-2389.1995.tb01357.x
Abstract
The predicted activity of A1 in the soil solutions of acid forest soils often differs from that observedin the field. We have investigated the influence of soil structure and flow rate of the soil solution onthe aluminum release to explain this divergence. Disturbed and undisturbed samples of soil werecollected from the A and B horizons of a dystric cambisol at Waldstein (Fichtelgebirge, Germany).The samples were irrigated with solutions mixed according to field data on throughfall or soilsolution composition with pH 3.5 with flow rates of 4 mm d-I, 12 mm d-l and 36 mm d-I. Thepercolates were analysed for major ions. Resulting relations between pH and pAl were comparedwith batch experiments. In neither the A horizon nor in the B horizon did soil structure influencethe relation between pH and pAl. The apparent equilibrium between pH and pAl was described asthe pK,,, value with pK,,, = pAl- a pH (where a is an empirical constant). It was found that thepK,,, values for the column percolates were in the range of variation of those found in batchexperiments.Flow rate had no influence on pK,,, at 4 and 12 mm d-'. At 36 mm d-' a significant increase ofpK,, was observed. This relative undersaturation of Al was more pronounced in the A horizonthan in the B horizon. When flow is fast Al release into the percolating soil solution might belimited by diffusion.