EFFECT OF NITROGEN FERTILIZATION AND CULTIVAR ON MINERAL COMPOSITION OF WHEAT GRAIN

Environmental hazards of intensive agriculture have renewed an interest in the low-input nitrogen (N) fertilization practices for wheat (Triticum aestivumL.). A two-year study was conducted to determine the influence of N fertilization, namely the low-N (67 kg N ha-1) and high-N (194 kg N ha-1) rates on grain yield and mineral composition of three bread wheat cultivars widely grown in Croatia. More favorable weather conditions significantly increased grain yields and concentrations of most minerals except P. When compared to the high-N rate, the use of the low-N rate brought about significant losses in grain yields (20%) and reduction in the concentration of N (23%), Ca (14%), Zn (8%) and Mg (6%), but had no effect on the concentrations of P and K. Cultivars significantly differed for mineral element concentrations and this variation tended to be similar to or lower than the variation caused by growing conditions or N fertilization.