Total and plant available micronutrients in soil

Mikroelementi su esencijalni elementi potrebni za rast i razvoj viših biljaka i sisavaca. Mikroelementi iz skupine teških metala su Mn, Fe, Cu, Zn, Mo i Ni. U ovom radu proučavani su svi osim Mo i Ni. Biljkama su potrebni u manjim količinama od makroelemenata. Provedene su agrokemijske analize uzoraka tala istočnog dijela kontinentalne Hrvatske kojima se utvrĎivala ukupna količina Fe, Mn, Cu i Zn zlatotopkom, odnosno i raspoloţiva frakcija EDTA i DTPA otopinama. Analizama je utvrĎeno da su ukupne količine ţeljeza u prosjeku 28.446 mg kg-1, mangana je znatno manje u odnosu na ţeljezo s prosjekom od 658 mg kg-1, u tlima je utvrĎeno prosječno 62,3 mg kg-1 cinka, a najmanje su ukupne koncentracije bakra, prosječno 20,6 mg kg-1. Raspoloţive frakcije ekstrahirane s EDTA kazuju da je u tlu biljci dostupno 60,6 mg kg-1, mangan je opet na drugom mjestu s prosjekom od 34,5 mg kg-1, slijedi bakar s 4,65 mg kg-1 i cink s 1,61 mg kg-1. Iako je ţeljeza u tlu najviše, relativno je najmanji udio raspoloţive frakcije Fe u ukupnim količinama, za razliku od bakra s relativno najvećim udjelom raspoloţive frakcije. DTPA otopinom ekstrakirano je 81,2 mg kg-1 ţeljeza, 37,4 mg kg-1 mangana, 0,72 mg kg-1 cinka i 2,37 mg kg-1 bakra. Moţemo zaključiti da su EDTA i DTPA metode usporedive, mogu se koristiti na isti način, ali se interpretacija rezultata ovih dviju metoda mora temeljiti na posebnim kalibracijama svake metodeTrace elements are essential elements for the growth and development of higher plants and mammals. Trace elements from the group of heavy metals are micronutrients Mn, Fe, Cu, Zn, Mo and Ni. This paper deals with all except Mo and Ni. The plants need micronutrients in smaller amounts than macronutrients. Agrochemical analyses of soil samples from eastern Croatia were conducted with aim to determine total content of Fe, Mn, Cu and Zn by aqua regia, and plant available fraction by EDTA and DTPA extractants. It was determined that the total amount of iron was in average 28.446 mg kg-1, manganese was significantly lower with an average of 658 mg kg-1, the average content of zinc was 62,3 mg kg-1 and the lowest was total concentration of copper, on average 20,6 mg kg-1. Fractions extracted with EDTA show that Fe was in highest available fraction (60.6 mg kg-1), manganese was in second place with an average of 34,5 mg kg-1, followed by copper (4,65 mg kg-1) and zinc (1,61 mg kg-1). The iron in the soil has highest total and available concetracion, but lowest relative part of total fraction was available. Available fraction extracted by DTPA was 81,2 mg kg-1 iron, 37,4 mg kg-1 manganese, 0,72 mg kg-1 zinc and 2,37 mg kg-1 copper. EDTA and DTPA methods are comparable, can be used in the same way, but the interpretation of the results of these two methods must be based on specific calibration of each metho