Turfgrass Evapotranspiration1

Abstract The evapotranspiration of turfgrasses grown on loam and sandy loam soils in lysimeter tanks was measured for three growing seasons. The irrigation schedules were set to approach drought conditions. Twice weekly irrigation was necessary to permit lawngrass grown on sandy loam soil to maintain good appearance during hot weather. Once a week irrigation was sufficient to maintain lawngrass in the same manner when grown on loam soil. Once a week irrigation sustained Tifway and Tifgreen bermudagrasses on both loam and sandy loam soils. The quantity of water applied in each case was 5.08 cm (two surface inches) per week, enough to bring the root zone to field capacity at each irrigation. Evapotranspiration was compared with pan evaporation, net radiation, and the Olivier and Penman methods. Monthly Blanev‐Criddle coefficients were also determined.