PEDOLOGICAL, GEOLOGICAL AND GEOCHEMICAL CHARACTERISTICS OF THE LOCATIONS INCLUDED IN THE PROJECT OF GEOCHEMICHAL MAPPING OF AGRICULTURAL SOILS AND GRAZING LAND SOILS IN CROATIA

Abstract

Pan-Europski projekt geokemijskog kartiranja poljoprivrednih tala i pašnjaka – GEMAS (GEochemical Mapping of Agricultural Soils and grazing land soils), pokrenut je 2007. godine uz sudjelovanje 35 europskih Geoloških službi, a pod vodstvom EuroGeoSurveys-Geochemistry Expert Group (EGS). U R. Hrvatskoj je u izvedbi projekta kao nositelj sudjelovao Hrvatski geološki institut - Hrvatska geološka služba (HGI-CGS), kao stalna članica EGS-a, te kao suradnik Zavod za pedologiju Agronomskog fakultet Sveučilišta u Zagrebu, uz financijsku potporu Ministarstva znanosti, obrazovanja i športa. Svrha ovog rada je prikazati pedološke, geološke i geokemijske značajke tla lokacija uključenih u GEMAS projekt. Metodologija terenskog rada definirana je usuglašenim uputama EuroGeoSurveys Geokemijske ekspertne grupe. Uzorkovanje je provedeno po unaprijed definiranoj pravilnoj kvadratnoj mreži 50x50km2 sa slobodom izbora lokacije uzorkovanja unutar kvadrata. Na teritoriju R. Hrvatske uzeto je 58 kompozitnih uzoraka od čega 29 na oraničnim površinama, a 29 na trajnim travnatim površinama. Dubina uzorkovanja za poljoprivredno tlo bila je 0-20 cm, a za travnate površine 0-10 cm. Radi utvrđivanja sistematske pripadnosti tala dodatno su uzimani uzorci iz pedoloških profila (8 lokacija) i iz sondažnih bušotina. Kemijske analize svih uzoraka s projekta napravljene su u ACME Analytical Laboratories, Vancouver (Kanada). Analizirana frakcija bila je <2 mm, a uzorci su pripremani u zlatotopci. Analitičke tehnike bile su ICP-AES i ICP-MS. Pedološka analiza uzoraka napravljena je prema standardnim metodama, odnosno odgovarajućim HRN ISO normama u laboratoriju Zavoda za pedologiju na Agronomskom fakultetu u Zagrebu, gdje su utvrđena osnovna fizikalna i kemijska svojstva tla. Podloga većine uzetih uzoraka izgrađena je od karbonatnih stijena jure, krede i paleogena, dok su tercijarne i kvartarne klastične naslage druge po zastupljenosti. Srednja koncentracija 10 potencijalno toksičnih elemenata (As, Cd, Co, Cu, Cr, Hg, Mo, Ni, Pb i Zn) veća je u tlima na travnatim površinama za razliku od poljoprivrednih tala. Poljoprivredna tla pokazuju veće koncentracije makroelemenata K, Ca, Mg i P. Na 8 reprezentativnih lokacija otvoreni su pedološki profili i analizom je utvrđeno da se na tim lokacijama javlja 6 tipova tla od kojih tri tipa pripadaju odjelu automorfnih, a tri odjelu hidromorfnih tala. Na preostalim lokacijama utvrđeno je 13 tipova tala, odnosno veći broj njihovih nižih jedinica. Od toga, 9 tipova tala pripada odjelu automorfnih tala, a četiri tipa tla odjelu hidromorfnih tala.Pan-European project of “Geochemical Mapping of Agricultural Soils and Grazing Lands“ (GEMAS) was launched in 2007., with the participation of 35 European Geological Surveys, and under the leadership of EuroGeoSurveys - Geochemistry Expert Group (EGS_GEG). The project in the Republic of Croatia was carried out by the Croatian Geological Survey (HGI-CGS) and the Department of Soil Science at the Faculty of Agriculture of the University of Zagreb with the financial support from the Ministry of science, education and sports. The purpose of this study was to present the pedological, geological and geochemical characteristics of soils from the locations included in the GEMAS project. The methodology of field work is defined by the agreed guidelines of the EuroGeoSurveys Geochemistry expert group. Sampling was conducted at a pre-defined regular square network 50x50 km2, with freedom of choosing sampling locations within the square. On the territory of the Republic of Croatia, 58 composite samples were taken, 29 of which on arable land, and 29 on permanent grassland. The depth of sampling for agricultural soil was 0-20 cm, and for the grassland soil 0-10 cm. In order to determine the systematic affiliation of soils, further samples were taken from soil profiles (8 sites) and from auger holes. Chemical analysis of samples was done in the ACME Analytical Laboratories, Vancouver (Canada). Analysed fraction was <2 mm, and samples were prepared in aqua regia. Analytical techniques were ICP-AES and ICP-MS. Soil analysis of samples was made according to the standard methods and relevant HRN ISO standards in the laboratory of the Soil Science Department at the Faculty of Agriculture in Zagreb, where the basic physical and chemical soil properties were determined. The parent material for soil of most samples is built of carbonate rocks from Jurassic, Cretaceous and Paleogene, while the Tertiary and Quaternary clastic sediments are second in abundance. The mean concentration of 10 potentially toxic trace elements (As, Cd, Co, Cu, Cr, Hg, Mo, Ni, Pb and Zn) was higher in soils on grassland, as opposed to agricultural soils. Agricultural soils showed higher concentrations of major elements K, Ca, Mg and P. In 8 representative locations soil profiles were opened, and the analysis showed that 6 soil types occur at these locations, three of which belong to the automorphic soil division, and three to the hydromorphic soil division. At the remaining sites, 13 soil types were found, including many of their lower units. Nine of these soil types belong to the automorphic division, and four to the hydromorphic division