Physical_Classification_of_Soil_water 1. Hygroscopic water. 2. Capillary water. 3. Gravitational water. Hygroscopic_water It held mostly by soil colloids. Such water is held at hygroscopic coefficient. Tension varies from 31-10,000 Atm Mostly non liquid therefore biologically inactive. Moves mostly in vapour form. Capillary_water Such water is present in capillaries of soil. Mostly available form of water to crops. Capillary water functions as soil solution. Concept of capillary potential is given by Buckinghum (1907). Capillary water held between field capacity (1/3 Atm ) and wilting Coefficient is (15atm) is called available water I.e. capillary water. Gravitational_water It held by a negative tension of less than 0.3 ATM Free water which drains out also called drainage water. Usually present in macro pores. Undesirable and nutrient leaching takes place. Downward movement of water due to gravitational force. https://t.me/agricultureexams2020 2.7K views03:45
