Question

If the infiltration rate is higher than 30 mm/hour, which irrigation method is suitable?

• A. Furrow irrigation
• B. Basin irrigation
• C. Sprinkler irrigation
• D. Flood irrigation

Hint:

Surface irrigation (flood, basin, furrow) requires heavy, low-infiltration soils (like clay) to allow water to spread across the surface.
Light, sandy soils with high infiltration rates require pressurized irrigation systems (sprinkler or drip).

Answer 1

The Correct Option is C

Step 1: Understanding the Concept:
Soil infiltration rate is the speed at which water enters the soil surface, typically measured in millimeters per hour.
The choice of irrigation method depends on soil texture and its infiltration rate to ensure uniform water application and prevent water losses.

Step 2: Detailed Explanation:
An infiltration rate higher than 30 mm/hour is considered very high, typical of coarse-textured, sandy, or gravelly soils.
When water is applied to these soils using surface irrigation methods (such as furrow, basin, or flood irrigation), it infiltrates rapidly near the inlet.
This leads to excessive water loss through deep percolation below the root zone, leaving distant parts of the field dry and resulting in poor water application uniformity.
To irrigate high-infiltration soils efficiently, water must be applied uniformly at a controlled rate that does not exceed the soil's capacity.
Sprinkler irrigation is highly suitable for these conditions.
It sprays water into the air to mimic natural rainfall, allowing the application rate to be adjusted to match the soil's properties, which prevents runoff and deep percolation.

Step 3: Final Answer:
For soils with a high infiltration rate ($>30\text{ mm/hour}$), sprinkler irrigation is the most suitable and efficient application method.