Absorption of Ions and Nutrients

Abstract

In the previous chapter it was emphasized that, after the utilization of the nutrient and ionic reserves of the seed, the autotrophic activities of land plants depend on the absorption of mineral ions from the soil just as they depend on the harvest of solar energy and atmospheric carbon. This dependence on ion absorption is expressed both in the requirement for nutrient ions, which are incorporated into or complexed with organic molecules in the cytoplasm and metabolic machinery of living cells, and in the requirement for nonnutrient ions which do not participate directly in metabolism, but which play a role in turgor regulation and ionic balance. Some nonnutrient ions may have distinctly unfavorable effects on plant growth due to their interference with metabolism or with the absorption of nutrient ions.

“The amount of salt contained by halophytes is not exclusively determined passively by that of their substratum, but depends chiefly on a craving for salt in the plant itself, since plants that naturally grow in such localities are in ordinary soil also in the habit of storing up larger quantities of sodium chloride than most nonhalophytes”. (Schimper, 1903)