Agronomy Degree Practice Exam

Which irrigation system loses the least amount of water to evaporation?

1. Center pivot

2. Flood

3. Drip irrigation

4. Furrow irrigation

The correct answer is: Drip irrigation

Drip irrigation is recognized for its efficiency in minimizing water loss due to evaporation. This system delivers water directly to the plant roots through a network of valves, pipes, tubing, and emitters. Because the water is applied in small quantities and localized to the root zone, it reduces the exposure of the water to the air, significantly limiting evaporation losses. In contrast, other systems such as flood irrigation distribute water broadly across the field, making it more susceptible to evaporation before it reaches the roots. Center pivot and furrow irrigation methods also result in some degree of water loss through evaporation, as water is applied to the soil surface, leaving it exposed and vulnerable to evaporative losses. Thus, the precise targeting of water application in drip irrigation not only conserves water but also ensures that plants receive the moisture they need effectively, making it the irrigation method that loses the least amount of water to evaporation.