Question

Amount of water in a soil available to plants is determined by:

• A. Saturation capacity - field capacity
• B. Field capacity - wilting point
• C. Wilting point - oven dry soil
• D. Porosity of soil - drainable porosity

Hint:

Available water = Field capacity - Wilting point.
This is the water that plants can use.
Hygroscopic water is not available.

Answer 1

The Correct Option is B

Step 1: Understanding the Concept:
Available water is the water that plants can extract from the soil.
It is the difference between field capacity and permanent wilting point.

Step 2: Key Formula or Approach:
Available water = Field capacity - Wilting point.

Step 3: Detailed Explanation:
Field capacity is the water held after gravitational water drains.
Wilting point is the water content at which plants wilt permanently.
The water between these two points is available to plants.
Saturation capacity is the total water content.
Thus, the available water is field capacity minus wilting point.

Step 4: Final Answer:
Amount of water available to plants is determined by field capacity - wilting point.
Hence, the correct option is (B).