Which irrigation method typically loses about 5% of water?

• A. Flood irrigation
• B. Drip irrigation
• C. Furrow irrigation
• D. Spray irrigation

Answer: (B)

Efficiency in irrigation is about how much water actually reaches the crop versus being lost to evaporation, runoff, or deep percolation. Drip irrigation delivers water directly to the plant’s root zone through emitters at low pressure, so water is applied slowly where it’s needed and little is wasted. This targeted delivery minimizes evaporation and runoff, keeping losses very small—around 5%.

Flood irrigation, by contrast, wets the entire field. Water spreads across the surface and much is lost to evaporation, surface runoff, and deep percolation beyond the root zone, resulting in far larger losses. Furrow irrigation uses water in trenches between rows; some water goes where it’s needed, but a significant portion still leaks into the soil outside the root zone and evaporates, increasing losses. Spray irrigation squirts water into the air and onto the field, where wind drift and evaporation also waste a notable share of water.