Magnésio, fósforo, enxofre, potássio, cálcio e ferro em Braun-Blanquet (1932)

The dissolved mineral matter is, in part, indispensable to the plant (as potassium, magnesium, sulphur, phosphorus, iron, and for higher plants calcium) and, in part, exerts a favorable influence upon the growth of the plant or, again, it may be of no effect at all or even be harmful. Highly concentrated solutions are injurious to most plants. The capacity to endure certain ions in large quantities is a specific property of the species or genus (cf. also Iljin, 1925). (Braun-Blanquet 1932:180)

BRAUN-BLANQUET, Josias. 1932. Plant sociology: the study of plant communities. (Trans.: George D. Fuller; Henry S. Conard) New York: McGraw-Hill Book Company.