Question

The state of the soil when plants fail to extract sufficient water for their requirements is____.

• A. Maximum saturated point
• B. Permanent wilting point
• C. Ultimate utilization point
• D. None of these

Answer 1

The correct option is B Permanent wilting point

1. Maximum saturation point/saturation capacity: It is defined as the total water content of a soil when all the pores of the soil are filled with water. At saturation capacity, soil moisture tension is almost equal to zero.
2. Field capacity: Field capacity is defined as the maximum amount of moisture that can be held by a soil against gravity. Field capacity is the upper limit of the capillary water or the moisture content available to the plant roots.
3. Permanent wilting point (PWP): PWP is the moisture content at which the films of water around the soil particles are held so tightly that plant roots cannot extract enough moisture at a sufficiently rapid rate to satisfy transpiration requirements thus resulting in the wilting of the plants.
4. Ultimate wilting point: Point after which plant is not able to extract any water from the soil and gets wilted and dies.