1. Ion concentration: If the concentration of ions in the soil solution is high, the rate of absorption of mineral salts increases. Increasing the ion concentration up to a certain limit increases the rate of mineral salt absorption.
2. Temperature: Increase in temperature up to a narrow range increases the rate of absorption of mineral salts. Absorption rate decreases when the temperature is below or above a certain limit.
3. Light: Light indirectly increases the rate of absorption of mineral salts. Light regulates stomatal opening and closing and the rate of respiration. Therefore, light regulates the absorption of mineral salts.
4. Perfusion: If the perfusion rate increases, the absorption rate also increases. Increased transpiration rate increases water transport to plant roots, stems and leaves. As a result, the absorption rate of mineral salts also increases.
5. Oxygen: When oxygen is low, respiration is low and absorption rate is also low.
6. Respiratory matter: If respiratory matter is low, respiration rate decreases and mineral absorption also decreases.
7. Ion interactions: The presence of Ca+ + and Mg+ + ions inhibits the absorption of K+ ions.
8. Plant Growth: Physical growth of plants increases mineral salt absorption rate. Therefore, large plants absorb mineral salts to a greater extent and smaller plants to a lesser extent.
9. pH: A change in pH beyond a certain range causes cell damage. Hence mineral salt absorption is disturbed.
10. Growth Zone: Absorption of mineral salts occurs mostly in the growth zone and cell division zone of the plant.