MINERAL RATIOS IN BEETROOT UNDER DIFFERENT FERTILIZATION

Besides the absolute values of mineral content in plant tissue, particularly is important their relative relationship. Imbalance in nutrient uptake very often is result of extensive fertilization with one nutrient, which is then in excess, so can prevent uptake of other nutrients what may cause disturbances in metabolism. Therefore, the goal of present research was to determine the influence of fertilization on mineral ratios in beetroot. A field trial (2003-2005) was set up in a hilly part of Croatia according to the Latin square method with four types of fertilization (control, 50 t stable manure ha-1, 500 and 1000 kg NPK 5-20-30 ha-1). Some investigated ratios ranged as follows: N+P+K 4.08-8.17, K+Ca+Mg 2.83-5.14, K/Ca 6.8-18.1, K/Mg 4.3-19.3, K/(Ca+Mg) 2.6-9.3, (N+P)/K 0.70-1.26, Ca/P 0.7-2.0, Ca/Mg 0.65-1.07, K/Mn 297-789, N/Zn 501-786, P/Zn 41-92, Fe/Mn 1.6-2.8, Fe/Cu 1123, Fe/(Cu+Zn) 2.1-4.2, Zn/Cu 3.3-7.6, Mn/Zn 1.5-1.8, Mn/Fe 0.38-0.62. In order to achieve high mineral content and its favorable ratio is necessary to combine the organic and mineral fertilizers with foliar fertilization.