Magnesium inhibits the harmful effects on plants of some toxic elements.

Cadmium and aluminium ions - especially in acid soils - are taken up by plants which then become poisoned by them. As a result the roots of the plants become deformed, and the green parts become chlorotic and underdeveloped. The yield will thus be sharply reduced. Culture fluid and culture pot experiments have shown that the toxic effects can be inhibited by magnesium. Investigations have proved that the inhibition is competitive and is based on the antagonism of cadmium and aluminium towards magnesium. Toxic cadmium and aluminium concentrations in the soil can be decreased by the use of non-acidifying fertilizers, and inhibited or prevented with fertilizers containing magnesium, eg Agronit (28% N and 2.5% Mg) or Kardonit (28% N and 5.5% Mg) (Borsod Chemical Works). Cadmium and aluminium taken up by plants are equally detrimental to animal and human organisms through the nutrition chain. For example cadmium may cause sterility, while aluminium may be implicated in Alzheimer's and Parkinson's disease. Magnesium moderates the effects of these two toxic elements in the human organism as well as in plants.