Soil properties influencing Hg vertical pattern in temperate forest podzols.

Mercury content of twelve podzols from NW Spain was studied to elucidate the main soil properties involved in the Hg accumulation of these soils. The highest average Hg concentrations (Hg) were found in the Bh and Bs horizons (64 and 105 μg kg), whereas the lowest occurred in the E horizons (15 μg kg). Moderate values of Hg were obtained for the A and C horizons (38 and 52 μg kg).

Arsenic fractionation in agricultural acid soils from NW Spain using a sequential extraction procedure.

Arsenic fractionation has been studied in nine vineyard soils from a wine-producing area in Galicia (NW Spain) characterized by an unusually high As content. Total As concentrations are 7 to 10 times higher the maximum values allowed by the legislation, reaching maximum value of 200 mg kg(-1). The study of As fractionation revealed that those fractions showing strong correlations to crystalline Fe and Al hydrous oxides (r>0.

Total copper content and its distribution in acid vineyards soils developed from granitic rocks.

Total and extractable (5 extractants) Cu concentrations were determined in thirteen acid vineyards soils. Mean total copper concentration was 259 mg kg(-1) and most of the soil samples (87%) were above the upper limit allowed by the European Union for this element in soils. The largest Cu fraction was found to be that bound to soil organic matter, which accounted for 49% of the total Cu.

Uranium and thorium in weathering and pedogenetic profiles developed on granitic rocks from NW Spain.

Uranium and thorium were analyzed in seven weathering and pedogenetic soil profiles developed on granitic rocks from NW Spain. Concentrations were measured by X-ray fluorescence spectrometry (XRF) and the U- and Th-bearing minerals were studied by scanning electron microscopy (SEM) and energy dispersive X-ray spectrometry (EDS). Both elements were determined in rock, bulk soil and in different grain-size fractions (sand: 2000-50 microm, silt: 50-2 microm, and clay: <2 microm).