Which irrigation method uses subsoil watering below the surface?

• A. Subsurface irrigation
• B. Surface irrigation
• C. Drip irrigation
• D. Sprinkler irrigation

Answer: (A)

Subsurface irrigation delivers water below the soil surface directly into the root zone, usually through buried pipes or emitters. Keeping moisture underground minimizes evaporation and surface runoff, and it can reduce weed growth, making water use more efficient for crops with established root systems. This approach is distinct from surface irrigation, which wets the soil surface and relies on infiltration from above; sprinkler irrigation, which applies water with overhead sprays; and drip irrigation, which typically targets the root zone near or at the surface but not deeply buried. Since the question specifies watering below the surface, subsurface irrigation is the best fit.