INFLUENCE OF SOIL TYPE AND NITROGEN FERTILIZATION SUGAR BEET YIELD AND QUALITY

smeđem tlu (T-2), obavljeno je istraživanje utjecaja gnojidbe dušikom na elemente prinosa šećerne repe. Dušik je dodavan u jesen, predsjetvenono na osnovi zaliha Nmin u tlu te u prihrani. Dobiveni rezultati istraživanja pokazali su da je značajno veći prinos korijena i šećera ostvaren na kvalitetnijem tlu T-2 u drugoj godini istraživanja. Utjecaj gnojidbe ureom u osnovnoj gnojidbi na prinos korijena i šećera zavisio je o godini, tlu i ukupno dodanome dušiku. U vlažnoj 2010. godini, na siromašnome tlu T-1, te u sušnoj 2009., na plodnome tlu T-2, na varijanti N-0 (bez prihrane), dodavanje dušika u jesen (G-46) uvjetovalo je značajno povećanje prinosa korijena i šećera. Na tlu T-1, najveći prinos korijena i šećera (9,54 tha-1) dobiven je na varijanti G-46 i bez dodavanja dušika u vegetaciji, a na T-2 tlu na varijanti bez gnojidbe dušikom u jesen (G-0) i uz prihranu 13,5 kgha-1N, dobiven je najveći prinos šećera (11,48 tha-1).In 2009 and 2010 we studied effect of nitrogen fertilization on the yield values on two soil types of different physical and chemical properties. Nitrogen was applied in autumn as a pre-sowing treatment on the basis of Nmin supplies in the soil, and as a top dressing. The obtained results showed significantly higher root and sugar yield values on the T-2 soil of better quality in the second year of the study. Effects of urea treatment in basic fertilization on the root and sugar yield values depended on the season, soil quality and total amount of the nitrogen added. In wet 2010 on barren T-1 soil and in dry 2009 on fertile T-2 soil with the variant N-0 (no top dressing application), nitrogen treatment in autumn (G-46) induced significant increase in the root and sugar yield values. On T-1 soil the highest root yield and sugar yield (9.54 tha-1) values were obtained with the variant G-46 even with no nitrogen application in the growing season (N-0), whilst on T-2 soil with no nitrogen application in autumn (G-0) and with top dressing up to 13.5 kgha-1N that significantly increased results in production, i.e. obtained sugar yield was 11.48 tha-1