Question

The useful soil moisture for plant growth is ______

(a) capillary water

(b) gravitational water

(c) hydroscopic water

(d) permanent wilting point

This question was posed to me in a dream while sleeping

This intriguing question originated from Water Requirements in division Water Requirements of Crops of Irrigation Engineering

Answer 1

The correct answer is (a) capillary water

The explanation is: Capillary water exists in the porous space of the soil by molecular attraction. This is the useful moisture for the growth of plants. Hydroscopic water and gravitational water cannot be absorbed by the root zone.