Effects of Varying Spring Hollow Tine Aerification Size and Timing on Bentgrass Greens

The desire to maintain optimal turfgrass and surface properties often leads turfgrass managers to minimize impact from cultural practices like hollow tine aerification (HTA). Comprehensive research is essential to developing aerification programs which allow optimal use of turfgrass surfaces without sacrificing overall turf health. A two-year field experiment was conducted on a 14-year-old U.S. Golf Association (USGA)-specified Crenshaw creeping bentgrass [Agrostis stolonifera L. var palustris (Huds.)] research putting green in Clemson, SC, to evaluate the effects of varying spring HTA size and timing on turfgrass, surface, organic matter (OM), and soil properties. Spring HTA treatments included 1.2-cm i.d. tines spaced at 5.1 cm x 5.1 cm in March and May (standard); 1.2-cm i.d. tines spaced at 3.8 cm x 3.4 cm in March only (2x); 0.9-cm i.d. tines spaced at 3.8 cm x 3.4 cm in March and May; and 0.6-cm i.d. tines spaced at 3.8 cm x 3.4 cm in March, April, May and June. All aerification was to a depth of 7.6 cm, with cores removed. Varying spring HTA tine size and timing did not affect TQ within or across years. Reducing surface area impacted by a single HTA event contributed to increases in turfgrass quality (TQ), recovery (TREC), and regrowth (TREG) up to 4 wk and decreased the time required for turfgrass to recover to acceptable levels by 1 - 4 wk. Even though surface properties fluctuated significantly, treatment effects were not observed within or across study years and lasted ≤ 2 wk. Repetitive equal depth aerification did not create a layer of increased compaction. Plots aerified with 0.6-cm tines had the least 2-year reduction in dry root weight (DRW). Plots aerified with 1.2-cm tines in March only (2x) had the greatest reduction in DRW and had the deepest thatch mat depth (TMD) across both years. This “doubling up” treatment would not be advisable on greens where low root mass or thatch accumulation is a concern. Plots aerified with 1.2-cm tines had higher thatch OM content in Year 2. Plots aerified with 0.6-cm tines had higher soil OM content across both years. Turf managers can vary their spring HTA size and timing to increase TQ during periods where this is important (e.g. for a tournament) with manageable effects on surface, OM, and soil properties