A. Gottlein et H. Stanjek, MICROSCALE VARIATION OF SOLID-PHASE PROPERTIES AND SOIL SOLUTION CHEMISTRY IN A FOREST PODZOL AND ITS RELATION TO SOIL HORIZONS, European journal of soil science, 47(4), 1996, pp. 627-636
In order to evaluate micro-scale heterogeneities 55 micro suction cups
were placed in an array at 15 mm intervals in a profile face of a cam
bic podzol. The chemistry of soil solution (mineral anions, pH. UV abs
orption as a measure for DOC) was compared with solid-phase properties
from soil samples (2 cm3 volume), which had surrounded the suction cu
ps. Sequential extraction techniques (water, HN4Cl, hydroxylamin-hydro
chloride, citrate-bicarbonate, oxalate, dithionite-citrate-bicarbonate
) and base titrations were applied to characterize the solid phase. Al
though the average soil solution concentrations between horizons often
differed significantly, the spatial distributions of pH and SO42- did
not correlate with soil horizon borders. Even if concentration isolin
es and soil horizon borders were parallel, marked concentration gradie
nts could be observed within individual soil horizons. The less intens
e the interaction between solute ion and soil matrix, the greater was
the variation in solution concentration within a soil horizon. For the
soil solid phase only a weak correlation of slow buffer reactions to
soil horizons was found. The distribution of extractable Fe and Al was
typical for a podzol profile, however, with very steep gradients with
in single soil horizons. Except for pH, which was related mainly to ci
trate-bicarbonate extractable aluminium, no solid-phase characteristic
showed a clear correlation with soil solution chemistry.