Types of Soil Water | Botany | Plant Physiology | Bareilly Tuitions | By Sharma Sir | New Batches |

Types of Soil Water -

1. Run-away water-The soil water is the main source of water supply of plants. After heavy rain fall, some amount of water run-off along the slopes and reaches to deeper layers of soil. This type of water is not available to the plants and is known as run-away water. 

2. Gravitational water-Some amount of water percolates through the interspaces present in soil particles and reaches to such depth due to gravitational force where roots cannot utilize this water, this type of soil water is, known as Gravitational water. 

3. Capillary water-When the gravitational water descends it moistens the soil particles in the path and a large amount of water is retained between the soil particles due to the phenomenon of surface tension. This retained water is called "capillary water", and is the main source of water supply to the plants. 

4. Hygroscopic water- This type of water is the vapor form and occurring in the atmosphere and upper layer of soil. It remains attached to soil particles in thin film, therefore, not available to the plants. This type of water can be absorbed by epiphytes which develops special hygroscopic roots for absorbing this type of water. 5.Chemically combined water- If the soil is heated in a oven at Approximately 105°C hygroscopic water can be evaporated. After the Hygroscopic water is gone, only water that remains in the soil is in hydrates Of aluminum, iron and silicon etc. Such chemically combined water can be driven off only by heating the soil at much higher temperatures. 

6.Water vapor- That portion of the pore space in a soil which is not occupied by liquid water contains a soil atmosphere that always includes water vapor.