The aim of this study was to examine the possibilities of reducing the mineral nitrogen fertilizers by applying the free‐living (Azotobacter chroococcum) and associative (Azospirillum brasilense) nitrifying bacteria in the sugar beet production, without a reduction in the yield and quality of the sugar beet root. Along with the vegetables, most nitrates are collected by the species of the family Chenopodiaceae, to which the sugar beet belongs. Nitrogen is one of the most vital elements in the achievement of high yields, so it is used in large quantities in fertilization. However, it is the most unstable macroelement that flushes into the deeper soil layers, and a groundwater eutrophication is caused very often. Numerous diseases are associated with the high amounts of nitrates, nitrites, and nitroso compounds, i.e., the nitrite and nitroso compounds originating from the foodstuffs having a plant origin, water, and the cured meat products. The results of the study have demonstrated that it is possible to reduce a mineral nitrogen fertilizer quantity by using the nitrogen‐fixing bacteria while even obtaining a higher quality of the studied parameters. The nitrogen‐fixing bacteria predominate in the rhizosphere, so the plants could use the amounts of nitrogen necessary in a given vegetation period, which is not the case upon a nitrogen fertilization.
Suzana Kristen, Josip Juraj Strossmayer of Osijek, Faculty of Agrobiotechnical Sciences Osijek, Vladimira Preloga 1, 31000 Osijek, Croatia, firstname.lastname@example.org