Influence of CULTAN method (Controlled Uptake Long Term Ammonium Nutrition) on the iron and zinc uptake by winter wheat (Triticum aestivum L.) and spring barley (Hordeum vulgare L.) was observed at four-year small-plot field experiments under conditions of the Czech Republic. No significant differences in iron and zinc concentration in grain of winter wheat as well as spring barley between conventional and CULTAN treatment were found. Neither increased supply of nitrogen fertilizer nor sulphur containing fertilizer resulted in significant differences in iron and zinc concentration in grain of winter wheat as well as spring barley at both nitrogen nutrition systems. No significant differences in sulphur concentration in aboveground biomass of winter wheat and spring barley between conventional and CULTAN treatment were recorded. Iron and zinc harvest index were not influenced by the CULTAN system. Because of no significant differences in iron and zinc concentration in grain of winter wheat as well as spring barley between conventional and CULTAN treatment, it can be assumed that nitrogen is taken up by CULTAN-treated plants in nitrate form.
