PODZOLIZATION – AN ADDITIONAL PARADIGM

P. BUURMAN, A.G. JONGMANS

Laboratory of Soil Science and Geology, Wageningen University, P.O. Box 37, 6700 AA Wageningen, The Nederlands.

Abstract

Present models of podsolization emphasize the mobilization and precipitation of dissolved organic matter, together with Al(-silicates) and Fe. Such models cannot explain the dominance of pellet-like organic matter in most zonal podzols, and the discrepancy between the chemistry of percolating organic matter (DOC) and the organic matter accumulated in podzol-B horizons.

The present paper offers an explanation in which dynamics of the rooting system of the vegetation, and the decay of its litter is combined with leaching by organic acids. Such a model can explain the dominance of root-derived organic matter podzol-B horizons. It is suggested that organic matter derived from roots is dominant in zonal podzols while illuvial organic matter may dominate in (nutrient-poor of hydromorphic) intrazonal podzols.