EN
In pot experiments the effect of various Ca, Mg and K saturation of CEC and cation ratios in soil on magnesium concentration in plants was studied. Magnesium content in green mass ofitalian ryegrass and sunflower depended most on the Mg/K ratio in soil (100R2 =91 J***) and less on Mg saturation of CEC (100R2=49,4*). In seeds and straw of spring rape Mg saturation of CEC had the strongest influence on Mg content in plant and the effect of K saturation of CEC was insignificant.