EN
The aim of the study was to determine the ratios of N in relation to P, K, Ca, Mg, S, Cl in grain and straw of spring cereals under conditions of differentiated fertilization of very acid soil. The grain mass and straw mass of spring wheat, spring barley, oat was grow diminishing due to the lower fertilization levels used. The molar ratios in kernels of the tested plants were the highest on the I (first) level and lowest an the VI fertilization level, only the ratio of N/Cl was always the highest on VI fertilization level. In the straw, ratios of N/P, N/Mg, N/S were highest only on the first level and for other ratios no difference was observed on all fertilization levels. The ratio of N/Cl similar as in grain was higher on the VI fertilization level.