CONSUMPTIVE WATER-USE OF 3 INTENSIVELY MANAGED BERMUDAGRASSES GROWING UNDER ARID CONDITIONS

In order for turfgrass managers to meet government mandated irrigation water requirements, conserve limited water resources, and still provide aesthetically appealing and functional turf, field measured consumptive water use requirements of intensively managed bermudagrass (Cynodon sp.) turfs growing in arid regions must be determined. Because bermudagrasses produce deep and extensive root systems, the incorporation of a more infrequent irrigation regimen might result in an acceptable turf while significantly reducing water use. To field test this hypothesis, we measured the consumptive water use, water use by soil depth, and the turf quality of C. dactylon (L.) Pers. x C. transvaalensis Davy cv. 'Tifgreen' and 'Midiron' and C. dactylon cv. 'TexTurf-10' bermudagrasses growing on a Gila loam (coarse-loamy, mixed (calcareous), thermic Typic Torrifluvent) maintained with a deep and infrequent irrigation regime under fairway conditions. Irrigations were applied only when turf showed symptoms of wilt. Total annual consumptive water use values were approximate to 60% of reference crop evapotranspiration (ET(o)), but daily values typically ranged from 70 to 90% of ET(o) following irrigation or rain to <10% when turf began to wilt. Wetter soil conditions promoted water use from the shallower depths. Turf extracted water from the soil to pressures equivalent to < -1.5 MPa. Overall turf quality, stand density, color, and percent groundcover were considered better than acceptable. Our data shows that bermudagrass growing in an arid environment can be maintained under fairway conditions without a loss in overall turfgrass quality, stand density, color, and groundcover with 834 to 930 mm H2O annually, depending upon variety and ET(o).