If the cell sap of root hair cells contains a high concentration of ions, then more water will enter the root cells by osmosis. This is because the high concentration of ions in the cell sap creates an osmotic gradient between the soil and the root hair cells, resulting in endosmosis and the conduction of water into the root cells. The root hair cells will have a higher concentration of ions compared to the soil water. Overall, the high concentration of ions in the cell sap of root hair cells will result in an increase in water absorption by the roots.