Discuss the factor affecting the water absorption.
The factor affecting the water absorption are : (1) Temperature : Optimum temperature for absorption is 20-30°C. Absorption decrease at low temperature by decreasing permeability, retarding in growth of root and availability of water and by increasing viscosity of water. (2) Concentration of soil solution: Absorption decreases with increase in concentration of soil solution, e.g. Halophytes (Rhizophora) are able to grow in swamps with high salt cont-entration because their cell sap concentration is also high. (3) Soil aeration : Flooding of fields reduces soil air (02). Hence metabolic processes and absorption are also reduced. (4) Increase in C02 : High C02 concentration lowers the rate of respiration and thus influence metabolic processes. These result low water absorption. (5) Available soil water : Maximum absorption occurs when the available soil water is in the range of field capacity and permanent wilting coefficient. (6) Root growth : Deep rooted plant absorb more water. Older roots are suberized and absorb slowly.
