engleski

Trace metal contents in agricultural topsoils and subsoils of the Island of Rab, Croatia

The Island of Rab, located in the northern part of the Adriatic Sea, is part of the Kvarner island group. The complex pedological structure of the island is caused by a great variability of its karst underground. In relation to this, geochemical characteristics and soil types largely determine the yield quality. Owing to intensive agricultural production in such environments, due to geological and climatic conditions and anthropogenic influence, trace metals can readily be transferred to soil solution, and leached to groundwater, vegetation and ultimately humans. Other sources of trace metals, including natural weathering processes, can also contribute to the presence of trace metals in soil. This can pose a threat to water sources, which are located in the central flysch zone, a large potential water source for agriculture and drinking water. To assess the current situation of soils a multi-element geochemical survey was conducted. Following a 500 m and 1 km square grid, 42 topsoil and 31 subsoil samples were collected. Soil properties and 16 soil element contents were determined in order to (i) characterize agricultural soils, (ii) analyze the relationship between trace metal contents and soil properties, and (iii) identify lithogenic and anthropogenic sources contributing to trace metal content in soils, by using univariate and multivariate statistics, and by producing interpolation maps. The trace metal contents do not exceed the threshold values established by Croatian government regulation, with the exception of copper. A high chromium, nickel and cadmium concentration in spots seems to be of lithogenic origin.

trace metals; agricultural soils; lithogenic and anthropogenic sources; multivariate statistics; interpolation maps

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