There is a high tension and low pressure created in the root hair epidermis. This is because of the transpiration pull exerted by loss of water by transpiration. This low pressure favors osmotic uptake of water and minerals from the soil into the root.
Cells of root are in close contact with soil and so actively take up ions. The ion-concentration, increases inside the root and hence osmotic pressure increases the movement of water from the soil into the root which occurs continuously.
