Evapotranspiration and irrigation scheduling for three landscape ornamentals in Beijing, China

To achieve possible water savings in irrigation, the maximum crop evapotranspiration (ETc) of three perennial flower plants (Sedum spectabile, Iris tectorum, and Dianthus chinensis) commonly used for landscaping in Beijing, China was studied in 2006 and 2007 using mini‐lysimeters. The plants were provided sufficient water based on the ETc measurements. Although meteorological conditions differed significantly between 2006 and 2007, each species had similar evapotranspiration curves in both years. The reference evapotranspiration ET0 during the growth stage (May‐October) in the 2 years was similar, being 524.93 mm in 2006 and 572.15 mm in 2007. However, marked monthly variations were noted in ET0 as well as in crop coefficients Kc. Based on the precipitation, the plants required supplemental irrigation during September and October of 2006, and May, June, August, and September of 2007. Using 20 years’ average precipitation for further analysis, we estimated that the plants would require supplementa...