Certified Landscape Irrigation Auditor

What is the definition of application efficiency in irrigation?

1. The ratio of surface water to ground water

2. The ratio of infiltrated water to water applied

3. The amount of water sprayed

4. The total area covered by irrigation

The correct answer is: The ratio of infiltrated water to water applied

Application efficiency in irrigation refers to the effectiveness with which the applied water is utilized by the plants or infiltrates into the soil. Specifically, it is defined as the ratio of the volume of water that actually enters the root zone of the plants (infiltrated water) to the total volume of water that has been applied through the irrigation system. This definition emphasizes the importance of ensuring that most of the water applied is beneficially used rather than wasted through runoff, evaporation, or deep percolation beyond the root zone. High application efficiency indicates that a system is effectively delivering water where it is needed, while low efficiency suggests that significant amounts of water are not being utilized effectively. In contrast, the other options do not accurately describe application efficiency in the context of irrigation systems. The ratio of surface water to groundwater, the amount of water sprayed, and the total area covered by irrigation do not provide insights into how efficiently the water applied is being used by the plants.