INFLUENCE OF NITROGEN FERTILIZATION ON SUGAR BEET ROOT YIELD AND QUALITY

During 2006 and 2007 we studied influence of growing nitrogen quantities in fertilization of sugar beet on root yield and quality. The experiment was set up in 5 different variants of fertilization: G(0) - 54 kg N ha(-1) (fertilization based on the soil analysis to obtain 70-80 t ha(-1) root yield); G(1) - 81 kg N ha(-1); G(2) - 108 kg N ha(-1); G(3) - 135 kg N ha(-1); 162 kg N ha(-1) (increase by 27 kg ha(-1) for each further variant), In the terms of climate investigation years were significantly different. First year was level with multiyear average, and the second one was dry and hot. In the year that climatically do not vary from multiyear average, average root yield and sugar yield were increasing significantly by the variant G,, with stagnation and decrease afterwards. Sugar content started decreasing significantly even front the variant G(1). In dry and warm season root and sugar yield started decreasing from the variant G(0), and Sugar content after variant G(2). Hybrids similarly reacted to nitrogen fertilization increase.