Irrigation scheduling based on Crop Water Stress Index (CWSI) for cool and warm-season turf grass under subsurface-drip irrigation method

Authors : Çayan ÖNCEL, Mladen TODOROVIC, Halim ORTA

Pages : 24-40

View : 22 | Download : 14

Publication Date : 2019-12-27

Article Type : Research Paper

Abstract :This study was conducted to determine irrigation scheduling based on the Crop Water Stress Index insert ignore into journalissuearticles values(CWSI); of cool insert ignore into journalissuearticles values(CS); and warm-season insert ignore into journalissuearticles values(WS); turf grass species under subsurface-drip irrigation method. The field experiment was carried out during the summer period of 2018 in the Agricultural Production and Research Centre insert ignore into journalissuearticles values(TURAM); of Silivri municipality, Istanbul,-Turkey insert ignore into journalissuearticles values(41°03ʹN; 28°00ʹE; 46 m a.s.l.);. Specific objectives were to measure actual evapotranspiration insert ignore into journalissuearticles values(ETc); values for both turf grass species, to compare cool and warm season turf grass in the concept of ETc and their responses to different water levels, to determine CWSI values for both turf grass species under different irrigation scheduling and opportunity of using CWSI in irrigation timing, to compare ETc with reference to evapotranspiration insert ignore into journalissuearticles values(ETo); calculated with five different methods and to determine crop coefficient curve insert ignore into journalissuearticles values(kc); for experimental conditions, and to focus on the crop growing and irrigation management parameters under subsurface-drip irrigation method. Three irrigation strategies [I1:30%, I2:50%, and I3:70%); were tested in a split-plot randomized complete block design with three replications. These strategies corresponded, respectively, to 30%, 50% and 70% of total available soil moisture depletion at 0-30 cm of the effective root zone and returning soil moisture back to field capacity. The results indicated that colour, quality, fresh yield, dry matter yield, irrigation water use efficiency, water use efficiency, vegetation height and mowing were significantly different in terms of irrigation strategies for both species. The most appropriate irrigation strategies were I2:50% for CS and I3:70% for WS turf grass which corresponded to a CWSI of 0.47 and 0.45, respectively. The amount of applied irrigation water in WS turf grass was 53% less than in CS turf grass. Actual evapotranspiration was 26% lower for WS than for CS turf grass. The most suitable reference evapotranspiration insert ignore into journalissuearticles values(ETo); methods were Jensen-Haise insert ignore into journalissuearticles values(JH); and Penman-FAO modification insert ignore into journalissuearticles values(P-FAO); for both species, a crop coefficient insert ignore into journalissuearticles values(kc); curve was prepared based on those methodologies.
Keywords : Landscape irrigation, irrigation scheduling, evapotranspiration, canopy temperature, water use efficiency, , crop coefficient