Foliar absorption and transport of inorganic nutrients

All plant cells — those of roots, leaves, or other parts — are capable of absorbing water and solutes as well as gaseous substances. This trait, derived by terrestrial plants during evolution from their ancestral aquatic habitat, is exploited in many agronomic practices. The pathway of entry of nutrients supplied to the leaf involves penetration of cuticular membranes enveloping it, absorption by the cells within, and transport away from the leaf. These processes are affected by humidity, temperature, and physiology of the leaf and influenced by surfactants and growth substances. Foliar injury due to sprays is associated with concentration and nature of the solutes. Considerable knowledge has been acquired in the last few years on the mechanisms of foliar absorption and mobility of several elements. Greater importance is now attached to foliar feeding, when soil‐ground water pollution is attendant with soil fertilization.