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Precise field experiments were established at 3 sites with oilseed rape under different soil-climatic conditions in the Czech Republic (Humpolec, Hněvčeves and Uhříněves) in the years [2008][2009][2010]. In this experiment, four fertilizing treatments with increasing S rate were evaluated. The contents of bioavailable (S W ), adsorbed (S ads ), occluded (S ocl ), and hydroiodic acid (HI) reducible (S HI ) sulfur were measured. The contents of the fractions within the studied sites in the samples collected before fertilizers application were comparable. The S W , S ads a S ocl contents did not exceed 10 mg S/kg. The S HI contents differed depending on site and year. Fertilizing using S as CaSO 4 positively influenced the contents of S W , S ads , and S HI in soil. Sulfur fertilizing had also the positive tendencies to increase the winter rape yields but the differences between studied treatments were not statistically significant.

The first metre of bed sediments of the Rhône River functions as a filter for fluxes of heavy metals and epigean organisms between surface and interstitial environments. To study the efficacy of this bank filtration, three sampling stations were established at increasing distances from pumping wells, resulting in a gradient of hydraulic characteristics. Station A, a permanent downwelling area with very high hydraulic gradients, low hydraulic conductivity, low oxygen content, and rather high metal concentrations contained a fauna exclusively composed of epigean organisms. At station B, intermediate hydraulic gradients, high hydraulic conductivity near the surface, and variable direction of water exchanges resulted in well-oxygenated pore water and a diversified fauna with hypogean and epigean species. Finally, at station C, low hydraulic gradient, low hydraulic conductivity, low water exchange, and high sediment metal concentrations resulted in low pore-water oxygen concentrations and low interstitial fauna density and diversity. At this site, low oxygen content and low biodiversity were related to the clogging of shallow sediments and low filtration efficiency. Thus, bank filtration efficiency, a property that depends mainly on natural or human-induced hydraulic gradients and sediment granulometry, determines pore-water chemistry, metal distribution, and faunal composition in the shallow interstitial environments of the Rhône River.

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Soil samples (from Czech and German long-term field experiments) were used to estimate different soil phosphorus (P) fractions. More than 200 topsoil (0-30 cm) samples from different fertilizing treatments were taken. These were analyzed for P in soil solution (P CaCl 2 ) [0.01M CaCl 2 extract], exchangeable sorbed P (P ex ) [anion exchange (aE) membranes] and bioavailable P [Doppel-lactat and Mehlich 3 (P Dl and P M3 )]. other fractions analyzed were total inorganic (P in ), total (P M-tot ) and organic (P org ) P [fractionation after Marks], P sorbed on Fe and al (P Feal ) [fractionation after Schwertmann] and residual P (P ar ) [aqua regia extract]. Comparison of medians appeared to be better for evaluating extraction abilities. Phosphorus fractions were in the following order: (P ar = 100%); P CaCl 2 (0.2%) < P ex (9%) < P Dl (10%) < P M3 (16%) < P in (24%) < P org (37%) < P Feal (55%) < P M-tot (59%). low amounts of P in , P org and P M-tot did not verify the applicability of the Marks' fractionation for the set of studied soils. Close correlations at P ≤ 0.001 were found for all methods for estimating the fractions of bioavailable phosphates (P CaCl 2 , P ex , P Dl and P M3 ). Statistically significant relations were observed between P in with P ar , P M-tot and P Feal .

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