Turfgrass Soil Management and Stress Tolerance

Dr. Douglas E. Karcher

turfgrass plotsThe central focus of my research program has been to improve the functional and aesthetic quality and stress tolerance of turfgrass through the refinement of cultural practices, especially those pertaining to soil management. Several research projects have focused on using improved irrigation technology, surfactant application, alternative mowing and rolling, and cultivation practices to improve the summer stress quality of creeping bentgrass putting green turf. This is important because the management of creeping bentgrass putting greens is the most difficult aspect of golf course management in northern and central Arkansas, and throughout much of the United States. Other projects have focused on improving the stress tolerance (drought, traffic, etc.) of golf, sports, and lawn turf through cultivar selection and various management practices. Specific research projects are described in the following paragraph.

A current research project has demonstrated that establishing sports turf with alternative methods (aerified sod and washed sod) on sand-capped root zones will improve soil physical properties and enhance overall establishment. These findings will provide golf and sports turf managers with methods to rapidly establish turfgrass areas with sand-based root zones, where sand-based sod is not available. A current research project is investigating the soil phosphorous requirements of several turfgrass species during establishment. Preliminary results have indicated that P application to turfgrasses may only be necessary on soils with extremely low soil-test P values. These findings may ultimately result in reduced P fertilizer use in turf, resulting in;obvious economic and environmental benefits.

Recently completed projects have determined that putting green summer stress tolerance may be improved through reduced irrigation (with surfactant application) and reduced mowing (with rolling) without a;negative effect on playability of the putting green. Incorporation of these management practices by golf course superintendents will;result in putting greens with better turf health and putting quality during the summer, and likely concurrently reduced irrigation and pesticide inputs. A recently initiated project is investigating the use of ethylene inhibition to improve the stress tolerance of creeping bentgrass putting green turf. Results from this study will potentially benefit golf course superintendents who manage creeping bentgrass putting greens during stressful conditions by minimizing leaf senescence and improving turf quality and shortened recovery times following intense management and traffic.

The University of Arkansas turf research program (in collaboration with Dr. Michael Richardson) continues to be a leader in developing innovative methods to objectively evaluate turfgrass quality using digital image analysis. Following the success of techniques developed to evaluate turf cover and color, the National Turfgrass Evaluation Program has funded research to incorporate these techniques into their variety trials. More recently methods have been developed to evaluate ball lie, ball mark injury, and ball mark recovery. Several leading turfgrass research universities have incorporated this technology into their study evaluations. This research continues to benefit all end-users of data generated from turfgrass research institutions using digital image analysis.