Copper accumulation and availability in Serbian smonitza soil

Copper is one of the most essential trace element for plants and animals. The character of parent material has the greatest impact on the copper content in the soils. The artificially introduction in the soil of Cu is in various ways: by precipitation from the atmosphere (particularly in the vicinity smelting ferrous metal), using a variety of waste sludge, as well as beneficial to the agricultural materials (fungicides-"Bordeaux mixture", a spreader, solid and liquid manures). Thus leads to the contamination of soil, when the total content of Cu exceeds the limit value of 100 mg/kg. When the Cu of natural origin in the plot, it is for the most part is bonded in the crystal lattices of the minerals and in attached form on oxides of Mn, Fe, and Al. The characteristics of Cu is to be stronger than the other trace elements (Mn, Zn) associated in a complex with an organic substance, leading to the occurrence of the lack of available Cu to the plants in the soil very rich in organic matter (peat soil). Available forms for plants in the soil has at least a copper (Cu in solution and adsorbed on the colloid exchangeable). In the case of the artificial introduction of Cu in the plot, due to the tight attachment with an inorganic or organic materials, lags far behind the most part in the upper soil horizon and its contents were significantly reduces the depth. The aim of this work is detailed examination of the state of copper in Serbia Smonitzas and giving score to this type of soil in relation to plants supply with this element. The investigations were conducted on Vertisols (Smonitza) type of soil taken from the Ap horizon at ten different localities in Serbia: (1) Milutovac, (2) Priština, (3) Trnava, (4) Rekovac, (5) Vranje (Neradovac), (6) Zaječar, (7) Bela Crkva, (8) Blace, (9) Salaš and (10) Kragujevac. The sub-samples were air-dried, crushed in a porcelain mortar with a pestle to 1 mm particle size, were determined the chemical and physical soil properties by common analyzing methods, in use in our country in preparation for a greenhouse experiment designed to determine plant availability of Cu in soil. The pseudo-total content of copper was determined by atomic adsorption spectrophotometry after digestion of soil samples with conc. HNO3 and then treated with H2O2. The content of the available copper was determined by AAS spectrophotometry, after the extraction from soil with different extraction techniques: 0,1N HCl, 0.005M DTPA and 1N NaOAc. In addition a vegetation experiment in pots was performed in Vertisol soils taken from 10 above mentioned locations. The plants were followed 45 days in controlled laboratory conditions. Water was added to obtain optimal humidity. After 45 days the plants were dug up, rinsed with destiled water, and dried at room temperature in a dryer at t=70ºC. The dried plants were ground into a powder and content of Cu in oats was determined by AAS method, after digestion with tri-acid mixture HNO3, HClO4 and H2SO4. According to recorded content of the total Cu in the analyzed Smonitzas one can speak of its natural, geochemical origin, as found from the mean value of 36.9 mg/kg for the meadows and 29.8 mg/kg for the arable land, as well as the value of the total of the Cu individual samples, with some variations, are within normal values for unpolluted soil. The content available copper, based on three different extraction techniques, showed that the test smonitzas accomplished by the limit values, according to Ankerman, 1977, high and very high levels. That says it all about the high provision to a very affordable Cu tested Smonitza and in this regard there will not be problems in growing plants in these lands. Based on the results of state of the trace elements Cu in Serbia Smonitzas the following conclusion can be made that in the test Smonitzas total Cu content ranged from 17 to 74 mg/kg.