Differences in soil sulfur fractions due to limitation of atmospheric deposition
2009
Balík, J. | Kulhánek, M. | Černý, J. | Száková, J. | Pavlíková, D. | Čermák, P.
The aim of this work was to estimate the changes in contents of different sulfur (S) fractions in soils under conditions of lowering inputs of S from emissions together with the influence of application of manure and mineral fertilizers. Soil samples from long-term field experiments were used for this purpose. The samples were taken from 10 sites from precise long-term field experiments with different soil-climatic conditions in the Czech Republic. The samples were analyzed using the following fractionation: (i) water soluble S (H<sub>2</sub>O extracts), (ii) sorbed S (0.032M NaH<sub>2</sub>PO<sub>4</sub> extracts) and (iii) S occluded with carbonates (1M HCl extract). Furthermore, the concentration of total S (S<sub>tot</sub>) and organic S (S<sub>org</sub>) was determined. Soil samples were taken in the years 1981 and 2007. During 26 years a decrease of S<sub>tot</sub> by about 3–8%, water soluble S by 65–68% and sorbed S by 39–44% were observed in the topsoil of the evaluated soils. Furthermore, a low increase in the content of organic S was observed. The estimated ratio of S<sub>org</sub> reached 78.7–80.9% from S<sub>tot</sub> in the year 1981 and 87.7–89.8% in 2007. Farmyard manure (40 t/ha) applied every 4 years did not have a significant influence on S fractions and S<sub>tot</sub> contents in soils; intensive S fertilizing increased S<sub>tot</sub> and mobile S forms contents in soils. Very close correlations were obtained especially between S<sub>tot</sub> and water soluble S and organic S.
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