The correct option is C. Surface irrigation. Explanation of the Correct Answer Surface irrigation is a method where water is applied directly to the soil surface and allowed to flow over the land by gravity. This technique typically involves the use of furrows, basins, or channels that guide the water to the plant roots. Here’s a step-by-step breakdown of how surface irrigation works:

1. Water Application: Water is introduced to the field through channels or furrows. The water then spreads across the surface of the soil.
2. Gravity Movement: The force of gravity pulls the water down the slope of the land, allowing it to infiltrate the soil and reach the root zone of the plants.
3. Soil Infiltration: As the water moves, it infiltrates the soil, which is crucial for plant growth. The rate of infiltration depends on soil type, moisture content, and other factors.
4. Root Access: The water eventually reaches the root zone of the plants, providing them with the necessary moisture for growth and development.

Why Other Options Are Incorrect A. Drip irrigation: This method involves delivering water directly to the base of each plant through a network of tubing and emitters. It is highly efficient and minimizes water loss due to evaporation and runoff. However, it does not involve the direct application of water to the soil surface in the way that surface irrigation does. B. Sprinkler irrigation: In this technique, water is sprayed over the crops in the form of droplets, simulating rainfall. While it is effective for many crops, it does not utilize gravity to move water across the soil surface, which is a key characteristic of surface irrigation. D. Subsurface irrigation: This method involves placing water delivery systems below the soil surface, allowing water to be applied directly to the root zone without wetting the soil surface. Like drip irrigation, it does not involve the direct application of water to the soil surface. Summary of Key Points

• Surface irrigation uses gravity to move water across the soil surface, allowing it to infiltrate and reach plant roots.
• Other methods like drip, sprinkler, and subsurface irrigation do not apply water directly to the soil surface in the same manner.
• Understanding the differences between these irrigation techniques is crucial for effective water management in agriculture.

Revision Summary

• Surface irrigation involves direct water application to the soil surface using gravity.
• Drip irrigation delivers water directly to plants, minimizing evaporation.
• Sprinkler irrigation sprays water over crops, simulating rainfall.
• Subsurface irrigation applies water below the soil surface, avoiding surface wetting.