Cool‐season golf course fairway species irrigation requirements under limited irrigation

Improving water conservation efforts for golf course turf is a constant industry goal. While creeping bentgrass (Agrostis stolonifera L.; CBG) is the preferred fairway species throughout most of the cool-humid regions, water requirements of alternative cool-season species with better acute drought tolerance at fairway mowing heights (e.g., <0.5 inch) are not well documented. A 2-yr field study compared two irrigation strategies (80% reference evapotranspiration, ETo, replacement or a green cover threshold, GCT, response-based approach) for a 60-d summer period for six cool-season species grown under a fixed roof rainout structure on a silt-loam soil. For the GCT approach, plots were imaged three times per week and if a plot fell below the GCT, 55 and 65% green cover in 2017 and 2018, respectively, a predetermined amount of water was added. The 80% ETo replacement plots received a total of 8.63 and 8.26 inches of irrigation in 2017 and 2018, respectively. By contrast, the GCT strategy required substantially less water which varied by species and year. Among species, turf-type tall fescue [Festuca arundinacea Schreb.; syn. Schedonorus arundinaceus (Schreb.) Dumort., nom. cons.] and a Mid-Atlantic type Kentucky bluegrass (Poa pratensis L.) required approximately 45 and 52% less irrigation compared to CBG in 2017 and 2018, respectively. Where water conservation is paramount, planting more drought tolerant species and cultivars and employing alternative irrigation strategies like a GCT can result in significant water savings.