Question

Which of the following statements regarding the drainage system are correct ?
A. It maintains favourable salt and air environments in the crop root zone
B. It does not promote beneficial soil bacteria activity
C. It allows for timelier field operations
D. Crop yields are increased because of improved water management and uptake of plant nutrients
E. There is more surface runoff and soil erosion on drained land
Choose the correct answer from the options given below:

• A. A, B and D only
• B. A, C and D only
• C. A, B, C and D only
• D. A and E only

Hint:

A simple way to analyze drainage benefits:
Drainage replaces excess water with air.
More air in the soil promotes beneficial aerobic bacteria and healthy root growth, which directly increases crop yields.

Answer 1

The Correct Option is B

Step 1: Understanding the Concept:
Agricultural drainage is the artificial removal of excess surface or subsurface water from land.
It is designed to prevent waterlogging and maintain an optimal environment for root growth.
Detailed Explanation:
Let us evaluate each statement:
- Statement A:
Drainage lowers the water table, which prevents waterlogging.
This allows oxygen to reach the root zone and helps wash away harmful soluble salts.
Thus, Statement A is correct.
- Statement B:
Removing excess water improves soil aeration.
This oxygen-rich environment actually promotes the activity of beneficial aerobic soil bacteria, which are crucial for nutrient cycling.
Thus, Statement B is incorrect.
- Statement C:
Well-drained soils dry out faster in the spring and after heavy rains.
This prevents machinery from getting bogged down, allowing farmers to plant, cultivate, and harvest on time.
Thus, Statement C is correct.
- Statement D:
Proper drainage prevents root rot and encourages deep root growth.
This healthier root system improves the plant's ability to absorb water and nutrients, resulting in higher crop yields.
Thus, Statement D is correct.
- Statement E:
Subsurface drainage allows water to filter down through the soil rather than flowing over the surface.
This increased infiltration actually reduces surface runoff and soil erosion.
Thus, Statement E is incorrect.

Step 2: Final Answer:
The correct statements are A, C, and D only.