What does application rate refer to in irrigation?

Application rate in irrigation is specifically concerned with the rate at which a head applies water to a certain area, typically measured in inches per hour or gallons per minute over a given area. This concept is crucial for ensuring that an irrigation system delivers water effectively and efficiently, meeting the needs of the plants without causing runoff or deep percolation losses. Understanding application rate helps in designing systems that can provide uniform water distribution across various landscapes, which is essential for optimal plant growth and health.

In contrast, the efficiency of water use by plants, the volume of water in the system, and the duration of watering activities are related but distinct concepts that do not specifically define application rate. The former addresses how well plants utilize the water applied, while the latter two involve the total water quantity used and the timing of water delivery, neither of which directly describes how fast water is being applied to the area by the irrigation head.