11th Class Biology Mineral Nutrition In Plants Factors Affecting Mineral Absorption

The process of mineral absorption is influenced by the following factors :

Temperature : The rate of absorption of salts and minerals is directly proportional to temperature.

The absorption of mineral ions is inhibited when the temperature has reached its maximum limit, perhaps due to denaturation of enzymes.

Light : When there is sufficient light, more photosynthesis occurs. As a result more food energy becomes available and salt uptake increases.

Oxygen : A deficiency of \[{{O}_{2}}\] always causes a corresponding decrease in the rate of mineral absorption. It is probably due to unavailability of ATP. The increased oxygen tension helps in increased uptake of salts.

pH : It affects the rate of mineral absorption by regulating the availability of ions in the medium. At normal physiological pH monovalent ions are absorbed more rapidly whereas alkaline pH favours the absorption of bivalent and trivalent ions.

Interaction with other minerals : The absorption of one type of ions is affected by other type. The absorption of \[{{K}^{+}}\] is affected by \[C{{a}^{++}},M{{g}^{++}}\]and other polyvalent ions. It is probably due to competition for binding sites on the carrier. However, the uptake of \[{{K}^{+}}\] and \[B{{r}^{}}\] becomes possible in presence of \[C{{a}^{++}}\] ions. There is mutual competition in the absorption of K, Rb and Cs ions.

Growth : A proper growth causes increase in surface area, number of cells and in the number of binding sites for the mineral ion. As a result, mineral absorption is enhanced.