CONTENT OF MAGNESIUM AND CALCIUM IN CULTIVATED PLANTS DEPENDING ON VARIOUS SOIL SUPPLY WITH NITROGEN, POTASSIUM, MAGNESIUM AND SULFUR

In view of the important role of magnesium and calcium in yield formation, this study has been undertaken to analyze the Mg and Ca content in winter forms of oilseed rape and wheat as well as in spring barley in the context of a certain deficiency of some nutrients (N, K, Mg, S) in the plant growth environment. The present study also evaluated the effect of meteorological conditions on the magnesium and calcium content in the test plants. The research hypothesis is that mineral fertilization and meteorological conditions significantly affect the content of magnesium and calcium in the test plants. A four-year, two-factor experiment was established on soil with the particle-size distribution of silt loam. It was shown that the investigated experimental factors (mineral fertilization and years of experiment) resulted in distinctly seen differences in the magnesium and calcium content in the test plants. In winter oilseed rape, this study found a significant decrease in the content of magnesium in seeds when there was a deficity of this nutrient in fertilization, and a decrease in the calcium content in the generative organs if nitrogen, potassium and magnesium were excluded from a fertilizer dose. A significant reduction in the calcium content in winter wheat straw was associated with nitrogen deficiency in fertilization, whereas the lack of potassium in fertilization resulted in a significant increase in the calcium content in winter wheat straw. In the case of spring barley, nitrogen deficiency in the plant growth environment resulted in a significant decrease in the calcium content in the vegetative organs, deficiency of magnesium contributed to a significant decrease in its concentration in grain and straw, while the lack of sulfur caused a significant reduction in the Mg content and a significant increase in the Ca content in straw. The meteorological conditions during the experiment had a significant effect on the magnesium and calcium content in the test plants.