Soil and soil water chemistry at some Polish sites with acid podzol soils

Results of monitoring studies from three sites in Poland with moderate, high and very high levels of acid anions in precipitation (Janow Forest, Izerskie Mountains and forest of Pulawy region) are compared in this paper. Field observations of precipitation, throughfall, soil and soil water chemistry at the sites are presented. The Pulawy area where is large factory which produces nitrogen fertilizers receives the highest deposition of nitrogen and sulfur compounds. Also the deposition of ammonium and sum of divalent cations (Ca2+ + Mg2+) is the highest in this region. It was found that the molar critical load ratio, Al-i/(Mg2++Ca2+), where Al-i. is monomeric, inorganic aluminum, is very high in the all soils studied (up to 2.6). Al3+, sulfate- and hydroxy-complexes are the dominating forms of aluminum in soil water. The observed aluminum concentrations can not be explained by equilibrium with a gibbsite (Al(OH)(3)) mineral phase, as assumed in many acidification models.