|Zondag, Randall - OSU EXTENSION|
Submitted to: Transactions of the ASAE
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: October 25, 2004
Publication Date: December 20, 2004
Citation: Zhu, H., Krause, C.R., Derksen, R.C., Brazee, R.D., Zondag, R., Fausey, N.R. 2004. Real-Time Measurement of Drainage From Pot-in-Pot Container Nurseries. Transactions of the ASAE. 47(6):1973-1979. Interpretive Summary: The Nursery and Floricultural industry is one of the fastest growing areas of the U.S Agriculture. Nursery growers are using a new method, the pot-in-pot system, to produce higher quality crops at reduced labor costs. However, frequent irrigation practices with this production method have raised concerns over water use efficiency because of drainage water loss through the containers. Also, irrigation management in pot-in-pot production is limited because drainage water loss through the in-ground containers cannot be directly observed during irrigation. To obtain high water use efficiency and to implement automatic irrigation control, it is important to know how much water can be applied to each container before drainage begins. An experimental system has been developed to provide real-time measurement of drainage due to irrigation and rainfall for pot-in-pot nursery production. With this system, now we can provide an experimental means to gain knowledge on irrigation management techniques to improve irrigation water use efficiency and reduce water and nutrition losses, plus provide a research tool to evaluate strategies for nurseries to better manage irrigation schedules.
Technical Abstract: In pot-in-pot nursery production, information on the amount of drainage water loss from the pots due to irrigation and rainfall is beneficial to improving irrigation water use efficiency and optimizing nutrition management. An experimental field site, consisting of 50 container-grown trees, 10 rain gage tipping bucket units and a portable weather station, was established to determine drainage water loss from pot-in-pot container nurseries with drip irrigation. The rain gage units were calibrated in four different ways to determine the repeatability and reliability for real-time measurement of the drainage water. The volume of water was calculated from the product of number of tips and volume per tip. The accuracy of the measurement was verified with the amount of drainage water collected weekly in collection buckets located under the rain gage units for various irrigation applications and rainfall events. The maximum difference in the weekly amount of drainage water collected with the collection buckets and measured with rain gage units was 1.215 L (or 5.3% error) when the daily irrigation application was 15.5 L. The system reported real-time measurement of drainage water due to irrigation and rainfall, and provided a research tool to evaluate strategies for nurseries to better manage irrigation schedules.