Water-use rate is the total amount of water needed for turfgrass growth minus the quantity lost via evapotranspiration.

Water-use rate is the total amount of water needed for turfgrass growth minus the quantity lost via evapotranspiration.

• A. Yes
• B. No
• C. Not defined
• D. It equals precipitation

Answer: (B)

Water-use rate is about how much water the turf loses to the atmosphere through evapotranspiration in a given period, not a difference between growth needs and losses. In practice, irrigation planning aims to replace that ET loss (often called ETc, crop evapotranspiration), so the amount you must add each day matches ET. Subtracting evapotranspiration from the water needed for growth would misrepresent what’s being consumed and lost by the plant–the plant’s actual water loss is what irrigation must replace. Precipitation can offset that need, but it isn’t equal to the water-use rate itself. So the statement is not correct; the water-use rate corresponds to evapotranspiration.

Water-use rate is about how much water the turf loses to the atmosphere through evapotranspiration in a given period, not a difference between growth needs and losses. In practice, irrigation planning aims to replace that ET loss (often called ETc, crop evapotranspiration), so the amount you must add each day matches ET. Subtracting evapotranspiration from the water needed for growth would misrepresent what’s being consumed and lost by the plant–the plant’s actual water loss is what irrigation must replace. Precipitation can offset that need, but it isn’t equal to the water-use rate itself. So the statement is not correct; the water-use rate corresponds to evapotranspiration.