The importance of using soil series-based geochemical background values when calculating the enrichment factor in agricultural areas.

The enrichment factor (EF) is one of the most commonly used indices for determining the source of air, water and soil pollution. However, concerns have been raised about the accuracy of the EF results because the formula leaves the choice of background value to the researcher's discretion. The EF was used in this study to assess the validity of such concerns and to determine heavy metal enrichment in five soil profiles with different parent materials (alluvial, colluvial, and quartzite). Moreover, the upper continental crust (UCC) and specific local background values (sub-horizons) were used as the geochemical backgrounds. When UCC values were applied, the soils were moderately enriched in Cr (2.59), Zn (3.54), Pb (4.50) and Ni (4.69), and significantly enriched in Cu (5.09), Cd (6.54) and As (6.64). Using the sub-horizons of the soil profiles as a background value, it was found that the soils had "moderate enrichment" by As (2.59) and "minimally enrichment" by Cu (0.86), Ni (1.01), Cd (1.11), Zn (1.23), Cr (1.30), and Pb (1.50). As a result, the UCC reported an inaccurate conclusion indicating that soils were 3.84 times more heavily polluted than they were. In addition, the statistical analyses performed in this study (Pearson correlation analysis and principal component analysis) revealed that the percentage of clay in the soil horizons and the cation exchange capacity had strong positive relationships (r ≥ 0.670, p < 0.05) with certain heavy metals (Al, Zn, Cr, Ni, Pb and Cd). These findings indicated that sampling from the "lowest horizons" or "parent materials" of the soil series would yield the most accurate results in determining the geochemical background values in agricultural areas.

Stripping traditionally productive Calcisols for tandir oven manufacturing in Diyarbakir, a semi-arid region in SE Turkey.

There is a close connection between human history and different purposes for which land is used, and various purposes can lead to the loss of productive agricultural lands. The increasing population in recent decades has particularly increased the pressure on agricultural lands. Despite the large number of land/soil misuse studies conducted during this period, land/soil loss is a continuing process. We thus seek to highlight the land/soil loss caused by the use of soil materials for the construction of tandir ovens in Diyarbakir region. The use of traditional tandir ovens is particularly widespread in eastern and northeastern rural Anatolia of Turkey, for baking bread. Because the soil material used in the production of this oven does not have any production standards, tandir oven producers extract their material from the nearest available lands that are mostly productive. Consequently, this study was conducted by collecting samples from soil materials used in the production of tandir ovens to determine their agricultural productivity. Satellite imagery from different dates was also used to detect the effects of inappropriate soil extraction. A number of interviews were conducted to obtain information on the type of soils extracted for production. Laboratory analyses of samples collected from the extracted areas revealed that soils' utilized for oven production physical and chemical properties, as well as their land characteristics (flatness, depth, and stoniness), were appropriate for crop production. Consequently, these results point to accelerated future soil degradation which will threat regions food production.