Potassium Fertilization and Stress Tolerance of Intensely Managed Creeping Bentgrass Putting Greens
Open Access
- Author:
- Brace, Benjamin
- Graduate Program:
- Agronomy
- Degree:
- Master of Science
- Document Type:
- Master Thesis
- Date of Defense:
- February 27, 2019
- Committee Members:
- Maxim J Schlossberg, Thesis Advisor/Co-Advisor
Benjamin A Mcgraw, Committee Member
Charlie White, Committee Member
Michael Fidanza, Committee Member - Keywords:
- Potassium
Creeping Bentgrass
Putting Greens
Stress
Fertilization - Abstract:
- Potassium (K) requirement of creeping bentgrass putting greens is a highly-debated topic. Recent studies evaluating K fertilization requirements contend its importance, but golf course superintendents still apply it regularly, their justification being that golf course putting greens established on sand-based rootzones have limited K retention and that sufficiency is crucial during stress periods. A two-year study was conducted to quantify Penn A- and G-series creeping bentgrass (Agrostis stolonifera L.) putting green performance and stress-tolerance response to soluble K fertilizer rate and/or frequency, to develop K fertilization guidelines and identify a critical K deficiency thresholds. Foliar applications of KCl (0-0-60) were made on 7- or 14-day intervals to supply 0, 15, 30, or 45 kg K2O ha-1 per growing month. Three putting greens were maintained under an intense double-cutting, rolling, and limited soil moisture management regime and in the second season height-of-cut was lowered and management intensified to simulate tournament conditions for a three-week period. Monthly clipping yields and associated leaf nutrient status indicated optimal vigor and nutrient sufficiency for throughout most of the study. Mehlich-III soil analysis revealed concentrations below recommended levels, but deficiency symptoms were never seen. Canopy density and color, measured using multispectral radiometers, were not influenced by the K fertilizer treatments. Leaf water content was influenced more by environmental conditions than K fertilizer treatment. Under simulated duration of extreme drought and wear stress, K fertilizer treatments did not benefit turfgrass canopy density or survival.