The influence of nitrogen fertilization on the content of trace elements in grain of some winter wheat cultivars

Abstrakt

Three cultivars of winter wheat (Begra, Nike and Rosa) were studied at the follow-ing nitrogen application rates: 50, 100 and 150 kg N/ha. Fertilization was applied. Nitrogen was used in a form of ammonium sulphate at three equal rates before sowing, during spring vegetation start and at shooting. Phosphorus and potassium fertilization was applied before the sowing at the rates of 34.9 kg P/ha and 99.6 kg K/ha. Grain achieved from the experiment set by means of randomized blocks and performed on the fields of the Agricultural Experimental Farm, Felin in the years 1997-1999 was the material for study. Wheat grain samples were taken at the stage of full maturity. Grain, after drying, was ground and digested in muffle furnace at 450°C. The ash was dissolved in HCl (1:1) and diluted with 0.1 mol HCl/dm³. The content of Mn, Cu, Pb, Co, Fe, Ni, Cd and Zn was determined in solutions applying AAS technique. Significant differences between years were found in wheat grains referring to particular elements content, except Cd. Grain accu-mulated Mn, Pb, Ni and Zn the most in the first year, and Cu, Co and Fe in the second. It was found out that the increase of nitrogen fertilization rate invoked successive increase of Fe and Co content in winter wheat grain. Grain with the lowest fertilization rate of 50 kg N/ha contained the highest levels of Cu and Pb. The greatest concentrations of Mn, Ni and Zn were observed in wheat grain fertilized with 150 kg N/ha. Rosa cv. was distinguished among others with better ability to concentrate Pb, Co, Fe, Ni, Zn in grain, and Begra cv. Mn.