How does the plant water requirement (PWR) compare to irrigation water requirement (IWR)?

• A. PWR is higher than IWR
• B. PWR is lower than IWR
• C. PWR and IWR are the same
• D. PWR is independent of IWR

Answer: (B)

The plant water requirement (PWR) is lower than the irrigation water requirement (IWR) because PWR refers specifically to the amount of water that a plant needs to maintain optimal health and growth, considering factors like transpiration and soil moisture needs. This requirement is determined by the specific needs of the plant species and the environmental conditions affecting it.

On the other hand, IWR typically includes additional factors such as inefficiencies in the irrigation system, loss of water due to evaporation, runoff, and other dynamics related to how water is delivered to plants. Thus, IWR is generally calculated to ensure that the PWR is met considering these additional requirements.

This distinction is crucial in water-efficient landscaping practices, as understanding the differences between these two concepts helps in designing efficient irrigation systems that minimize water waste while adequately meeting the needs of the plants.