Environmental Geochemistry and Health, Vol. 12, page 289
Geochemical background values for trace elements in arable soils developed from sedimentary rocks of glacial origin
K. Czarnowska and B. Gworek Department of Soil Science, Agricultural University of Warsaw, Poland Abstract The total content of trace elements was examined in some arable soils developed from boulder loam and silt formations of the Middle Poland and Baltic glaciations (62 profiles). Mean element concentrations calculated on the basis of chemical and statistical analyses were as follows: Mn = 322; Zn = 36; Cr = 30; Ni = 12.7; Pb = 10,3; Cu = 8.8; Co = 4.7; and Cd = 0.27 in mg kg -1 of soil dry weight. The authors propose to accept these figures as the geochemical background values for soils derived from sedimentary rocks of glacial origin.
Introduction
Long term investigations were performed on arable soils encountered in the least industrialises areas of Poland and situated far from main roads, i.e. containing almost natural concentrations of trace elements. This study concentrated on the brown, lessivds and psuedogley soils, as well as black earths encountered in Central and Northern Poland. In this paper, the total contents of Mn, Zn, Cr, Cu, Ni, Co, Pb and Cd are presented, with the correlation between these contents and the content of particles less than 0.02 mm in diameter. Materials and Methods
The analyses were made on 293 soil samples taken from all the characteristic genetic horizons in 62 soil profiles. In all samples the granulometric composition was determined by the Bouyoucose-Casagrande method modified by Prdszynski. The total content of trace elements was determined by the Pejwe and Rinkis method using concentrated HC1, H2SO4 and HNO3 after ashing of the organic substances at 450~ In the soil solutions thus obtained the content of Mn, Zn, Cu and Cr was determined directly by the ASA technique, while the content of Ni, Pb, Co and Cd was determined by the ASA technique after extraction into an organic phase using a APDC chelating agent and AIBK solvent. Results and Discussion
The results of the analyses were presented synthetically, taking into account only the parent rock or clays of the Baltic glaciations and the clays and silts of the Middle Poland glaciation, and using the characteristic genetic horizons (Table 1). Earlier studies conducted in the same
area show that the soils under study did not exhibit any essential differences in their chemical composition (Gworek, 1985). Such-being the case, the parent rock was shown to significantly influence the differentiation in trace element content between the soil profiles. The distribution of trace elements is mostly conditioned by the soil-forming processes. Statistical calculations of the results have shown a positive relationship between the contents of trace elements in question (except for cadmium) and the quantities of particles less than 0.02 mm in diameter. In addition, statistical calculations have also been carried out in order to establish the correlation between the contents of Mn, Zn, Cr, Ni, Co, Cd and Pb, and the quantities of particles less than 0.02 mm in diameter in the individual genetic horizons for soils derived from the three above-mentioned parent rock types. The results obtained do not show any differences between these parent rock types (Table t). Comparison of the results of analyses respective to the soil types show certain regularities which have already been reported in earlier papers (Czarnowska, 1972 and 1974; Gworek, 1985). The highest concentrations of Zn, Cr, Cu, Ni and Co were found, respectively, in B horizons in brown soils, in Bt textural horizons in lessiv6 soils, in A1 accumulation horizons in black earths. Manganese, lead and cadmium are the only elements that tend to accumulate in accumulation horizons regardless of the soil type. This could testify to the fact that manganese is subject to biological accumulation while the elevated contents of lead and cadmium in top soils could be explained by the environmental contamination and plant cycling. The amounts of trace elements reported in this paper as similar to those observed by Andersson (1977), and Tjell and Hovmand (1972) in the soils of Denmark and Sweden, developed also from the sedimentary rocks of glacial
290
Geochemical background values for trace elements
1 Trace element contents in mg kgq of soil dry weight in arable soils and coefficients of correlation (r) between these contents and amounts of particles
Geochemical background values for trace elements in arable soils developed from sedimentary rocks of glacial origin
K. Czarnowska and B. Gworek Department of Soil Science, Agricultural University of Warsaw, Poland Abstract The total content of trace elements was examined in some arable soils developed from boulder loam and silt formations of the Middle Poland and Baltic glaciations (62 profiles). Mean element concentrations calculated on the basis of chemical and statistical analyses were as follows: Mn = 322; Zn = 36; Cr = 30; Ni = 12.7; Pb = 10,3; Cu = 8.8; Co = 4.7; and Cd = 0.27 in mg kg -1 of soil dry weight. The authors propose to accept these figures as the geochemical background values for soils derived from sedimentary rocks of glacial origin.
Introduction
Long term investigations were performed on arable soils encountered in the least industrialises areas of Poland and situated far from main roads, i.e. containing almost natural concentrations of trace elements. This study concentrated on the brown, lessivds and psuedogley soils, as well as black earths encountered in Central and Northern Poland. In this paper, the total contents of Mn, Zn, Cr, Cu, Ni, Co, Pb and Cd are presented, with the correlation between these contents and the content of particles less than 0.02 mm in diameter. Materials and Methods
The analyses were made on 293 soil samples taken from all the characteristic genetic horizons in 62 soil profiles. In all samples the granulometric composition was determined by the Bouyoucose-Casagrande method modified by Prdszynski. The total content of trace elements was determined by the Pejwe and Rinkis method using concentrated HC1, H2SO4 and HNO3 after ashing of the organic substances at 450~ In the soil solutions thus obtained the content of Mn, Zn, Cu and Cr was determined directly by the ASA technique, while the content of Ni, Pb, Co and Cd was determined by the ASA technique after extraction into an organic phase using a APDC chelating agent and AIBK solvent. Results and Discussion
The results of the analyses were presented synthetically, taking into account only the parent rock or clays of the Baltic glaciations and the clays and silts of the Middle Poland glaciation, and using the characteristic genetic horizons (Table 1). Earlier studies conducted in the same
area show that the soils under study did not exhibit any essential differences in their chemical composition (Gworek, 1985). Such-being the case, the parent rock was shown to significantly influence the differentiation in trace element content between the soil profiles. The distribution of trace elements is mostly conditioned by the soil-forming processes. Statistical calculations of the results have shown a positive relationship between the contents of trace elements in question (except for cadmium) and the quantities of particles less than 0.02 mm in diameter. In addition, statistical calculations have also been carried out in order to establish the correlation between the contents of Mn, Zn, Cr, Ni, Co, Cd and Pb, and the quantities of particles less than 0.02 mm in diameter in the individual genetic horizons for soils derived from the three above-mentioned parent rock types. The results obtained do not show any differences between these parent rock types (Table t). Comparison of the results of analyses respective to the soil types show certain regularities which have already been reported in earlier papers (Czarnowska, 1972 and 1974; Gworek, 1985). The highest concentrations of Zn, Cr, Cu, Ni and Co were found, respectively, in B horizons in brown soils, in Bt textural horizons in lessiv6 soils, in A1 accumulation horizons in black earths. Manganese, lead and cadmium are the only elements that tend to accumulate in accumulation horizons regardless of the soil type. This could testify to the fact that manganese is subject to biological accumulation while the elevated contents of lead and cadmium in top soils could be explained by the environmental contamination and plant cycling. The amounts of trace elements reported in this paper as similar to those observed by Andersson (1977), and Tjell and Hovmand (1972) in the soils of Denmark and Sweden, developed also from the sedimentary rocks of glacial
290
Geochemical background values for trace elements
1 Trace element contents in mg kgq of soil dry weight in arable soils and coefficients of correlation (r) between these contents and amounts of particles
