Let us make an in-depth study of the theories of selective absorption, ion exchange and active absorption, antagonism of salts or ions and synergism. Theories of Selective Absorption: We know that a perfectly true semipermeable membrane allows diffusion of only the solvent molecules and not the solutes. It is clear then that if the plasma membrane of the root cells [...]
Root Pressure in Plants (With Experiment)! If a well-aerated plant growing vigorously in spring is cut off slightly above the ground, water is seen to exude from the cut end of the stump through the xylem. This positive pressure occurs in the xylem either in deciduous trees when the leaves are shed in early winter or when the plant is [...]
The following points highlight the four soil factors influencing the water absorption rate by roots. Factor # 1. Concentration of the External Soil Solution: Absorption of water, in general, depend upon the difference between the osmotic concentration in the cell sap and the external soil solution. Thus an increase in the concentration of the external water medium, must reduce the [...]