Which of the following is an advantage of a tile drain?

Option 3 : Removes the free gravity water that is not directly available to the plants

Explanation:

Tile drain:

Tile drainage is in the form of water management that removes water from the subsurface of the soil.

Advantages of tile drain:

• Improved root development and increased crop yield.
• Earlier and more timely planting.
• Better germination and crop stand.
• Less runoff.
• Removes the free gravity water that is not directly available to the plants.
• Less crop stress from waterlogged conditions.
• Higher spring soil temperature.
• More efficient use of nitrogen fertilizers.
• More days of machinery operation.
• Reduced soil compaction 
• Making a better environment for plant health and growth.
• Increased land value.