TOTAL AND PLANT AVAILABLE TOXIC TRACE ELEMENTS (Cd, Cr, Co AND Pb) AT FARMS OF EASTERN CROATIA

Sažetak

UDK  631.453(497.5)

It is well known that soil properties, metal speciation and plant species, especially soil- plant interactions, determine the availability of metals in soils. Therefore, various one- step extraction methods such as EDTA and DTPA have been used to represent the available fraction. In present study we observed the total (aqua regia) and available fraction (EDTA and DTPA) of toxic trace elements (Co, Cd, Cr and Pb) from soil on two farms (Berak and Vinogradci) in eastern Croatia that have different soil properties. The study included 106 soil samples from soil depth 0-30 cm that were collected during 2013- 2014. Samples were analyzed for standard soil properties (pH, organic matter, AL-P, AL- K) as well as for total and available fractions of toxic trace elements. Analyses of main soil properties show vide variety of soils. Soil pH (in H2O) was in range 4.4-8.6 (avg: 6.5), thus sampling sites included range from very acid to alkaline soils. Farm in Berak (average pH was 7.2) had more alkaline soils while farm in Vinogradci was acidic (average pH was 5.9). Organic matter varied from 1.1-2.8% (avg: 1.9), average phosphorous was 17.4 mg/100g and potassium 20.9 mg/100g. Total concentration of trace elements extracted by aqua regia show satisfactory results as not one sample had elevated levels of toxic trace elements (Co, Cd, Cr and Pb). In that regard all sites satisfy Croatian regulation on pollutants in agricultural fields. However, EDTA and DTPA extractions show higher availability of Cr, Co and Pb for both extractions (EDTA and DTPA) at farm in Vinogradci where soils are more acidic compared to farm Berak. Only available Cd was shown to be higher in Berak than in Vinogradci.