What are the different classifications of Soil Water?
There are mainly four types of Soil water
Structural water or Molecular bounded water – It cannot be removed by oven drying.
Gravitational water – The water in the soil due to the movement of water under gravitational forces. It moves into. through and out of soil due to gravity.
Hygroscopic water – Water which is absorbed from the atmosphere and which is held tightly by the soil particles, and which is unavailable for plants to absorb is called hygroscopic water. It is the water lost from an air-dry soil when it is heated to 105ºC.
Capillary Water – Water that is retained in the soil along with hygroscopic moisture and water vapor, after the gravitational water has drained off. Capillary water is held by surface tension as a film of moisture on the surface of soil particles and peds. It is retained as minute bodies of water filling part of the pore space between particles.