Solution:
The water which cannot be easily drained under the action of gravity and has its presence in the root zone is called field capacity.
The permanent Wilting point is the water content in the root zone below which the roots can no longer extract water for their growth and dies up.
Hence, therefore it can be concluded, that the water which is available to the plant is the difference between field capacity water and permanent wilting water. This available water is also known as available moisture.
