IMPACT OF FERTILIZATION ON IRON, MANGANESE AND ZINC STATUS IN OATS GROWN ON VERTISOLS OF SERBIA

Oats (Avena sativa L. cultivar Slavuj) was grown in pot experiment under glasshouse conditions. Soil substrate was arable lands (total 10) of vertisol type (in Serbian smonica) collected from Central Serbia and Kosovo. Two kg of air-dried soil was weighed for each plastic pot and homogenized with 1.06 kg of fertilizer NPK 15:15:15 (equivalent of 800 kg ha(-1) of the fertilizer or 120 N : 120 P2O5 : 120 K2O ha(-1)). Than four additional fertilization treatments (in sulphate form; three replicates) with iron (Fe), manganese (Mn) and zinc (Zn) sulphate form) were created as follows: a) the control; b) Fe (8 mg Fe pot(-1)); c) Mn (8 mg Mn pot(-1)) and Zn (8 mg Zn pot(-1)). Differences in chemical properties among ten vertisols were mainly in wide ranges from 4.64 to 6.97 (PH in 1n KCl), from 2.69% to 3.99% (humus contents), from 0.6 to 28.0 P2O5 mg 100 g(-1), from 19.0 to 46.0 K2O mg 100 g(-1) (AL-method) from 0.04 to 0.23 mg Fe kg(-1), from 3.1 to 9.7 mg Mn kg(-1), and from 0.6 to 1.9 mg Zn kg(-1). (0.005 M DTPA extraction). In general, soil properties considerably higher influenced on Fe, Mn and Zn status in top of oats (harvesting 45 days after emergence). For example, the ranges among soils were from 1.7 to 78.9 mg Fe kg(-1), from 37.6 to 165.8 mg Mn kg(-1) and from 18.4 to 24.8 mg Zn kg(-1). As affected by Fe fertilization oats Fe was increased for 8% compared to the control, while due to Zn fertilization oats Zn was increased for 35%. Possible application of fertilization of vertisols with micronutrients could be indicated by previous soil testing.