Consumptive Water Use by Sub‐irrigated Turfgrasses under Desert Conditions1

Irrigation is essential for turfgrass growth in the arid southwest. Water conservation is equally essential. To irrigate properly, levels of consumptive water use and the factors which affect them must be known. This study evaluated effects of management, local climate, species, and cultivars upon water use. Three bermudagrasses (Cynodon dactylon L. Pers.), a zoysiagrass (Zoysia japonica Steud.), St. Augustinegrass [Stenotophrum secundatum (Walt.) Kuntze], and tall fescue (Festuca arundinacea Schreb.) were grown in a local washed mortar sand in percolation lysimeters with measured subirrigation at Tucson, Ariz. There were no significant differences in consumptive water use among the bermudagrasses and zoysiagrass at either of two managements. Raising the water table 10 cm and overseeding with annual ryegrass in winter significantly increased consumptive use. St. Augustinegrass and tall fescue used significantly more water than the bermudagrasses and zoysiagrass. Consumptive water use varied with evaporative demand as measured by Class A pan. Consumptive use values expressed as percentage of evaporative pan losses ranged from 42 to 80% depending upon management and grass. Mean annual percentages were 46 for bermudagrasses and zoysiagrass, 58 for St. Augustinegrass, and 64 for tall fescue grown with the same water table. The same percentage was 58 for bermudagrasses and zoysiagrass overseeded with ryegrass in winter and maintained with a 10 cm higher water table.