Irrigation scheduling of cool and warm seasonturfgrass irrigated with sub-drip irrigation method

The aim of this study is to determine the irrigation scheduling of cool-season and warm turfgrass species under sub-drip irrigation method. Field experiments were conducted in the experimental fields of Silivri municipality in Gümüsyaka village located between boundaries of Tekirdag and İstanbul cities (41° 03ˈ North, 28° 00ˈ East, Turkey) during the summer of the 2017. In the research, three different irrigation strategies for two different turfgrass species were treated in split-plots in randomized blocks design with three replications. As irrigation treatments; for both turfgrass species different depletion levels of available soil moisture in effective root zone of 30 cm were monitored in each day and when approximately 30%, 50% and 70% of total available soil moisture were consumed irrigation water was applied up to field capacity. At the end of the study, it has been determined that significant differences between cool-season and warm-season turfgrass species in the aspect of actual evapotranspiration values, turfgrass quality etc. For cool-season turfgrass species; amount of irrigation water applied in different irrigation treatments are between 324,2 – 195,7 mm; total actual evapotranspiration are 382,7 – 260,2 mm; daily evapotranspiration values are 5,38– 3,69 mm/day; same values for warm-season turfgrass species are between 298,6 – 117,1 mm ; 357,9 – 180,4 mm; 5,03 - 2,53 mm/day, respectively. Finally, when all parameters such as the amount of irrigation water, irrigation and mowing frequency, grass quality parameters are together evaluated it is suggested that irrigation should be applied when 50% and %70 of available soil moisture is consumed for cool season turfgrass and warm season turfgrass species, respectively. The amount of irrigation water applied and actual evapotranspiration are 43% and 52% less in cool-season turfgrass species, respectively. Besides, the most suitable reference evapotranspiration estimation method under the experimental condition is Blaney-Criddle method for cool season turfgrass species and Blaney-Criddle method for warm season turfgrass, and crop coefficient (kc) curves are prepared for both turfgrass species.