Comparison of Shockwave aerification and conventional aerification methods on athletic fields

Abstract

The Shockwave (Imants) offers the potential to minimally disrupt the playing surface, relieve soil compaction, and potentially lower surface hardness. However, data are lacking on how the Shockwave compares to traditional aerification. The effects of hollow-tine (HT), solid-tine (ST), and Shockwave with a single pass (SW1) and perpendicular passes (SW2) were investigated and compared to an untreated control (C) for surface hardness, surface stability, soil moisture, water infiltration, percent green cover, and bulk density on established cultivar Rush Kentucky bluegrass (Poa pratensis L.) turf growing on native soil. Treatments were applied June-August with SW1 and SW2 receiving an additional treatment in September of each year. A modified Baldree traffic simulator was used to simulate 28 traffic events in the fall of each year. Data were analyzed using an exponential decay model, and the slope indicating cover loss event-1 was used to compare treatments. In both years of the study, the HT (-0.031 in 2017 and-0.085 in 2018) treatment had the least green cover loss per event. The SW2 (-0.051) had the greatest cover loss event-1 in 2017, while the C (-0.102) treatments experienced the largest cover loss event-1 in 2018. In 2017 after 20 simulated traffic events, surface hardness on SW2 treatments were 30% lower than the highest surface hardness. After simulated traffic in 2018, SW1 treatments resulted in 10% lower surface hardness compared to the hardest surface, indicating the Shockwave can reduce surface hardness. This research indicates that the Shockwave could replace ST in maintaining athletic fields.

Evaluation of Humic Fertilizers on Kentucky Bluegrass Subjected to Simulated Traffic

“…The native soil was classified as a Clarion loam soil (Fine-loamy, mixed, superactive, mesic Typic Hapludolls) and contained 5.2% organic matter. The experiment was maintained at a 51 mm height of cut using a rotary mower three times week −1 [48]. The clippings were returned to the experimental site and irrigation was applied as needed to prevent drought stress [13,48].…”

“…The experiment was maintained at a 51 mm height of cut using a rotary mower three times week −1 [48]. The clippings were returned to the experimental site and irrigation was applied as needed to prevent drought stress [13,48]. The average high and low temperatures for 2019 and 2020 while simulated traffic was being applied were 27.…”

“…Simulated traffic events were applied using a modified Baldree traffic simulator following methods by Dalsgaard et al [48] and Dickson et al [50]. The Baldree traffic simulator has been used to simulate athletic field traffic in many previous studies [8,48,50]. Traffic was initiated on 29 July in 2019 and 2020 to coincide with the start of the Iowa High School Football Season [48].…”

“…The Baldree traffic simulator has been used to simulate athletic field traffic in many previous studies [8,48,50]. Traffic was initiated on 29 July in 2019 and 2020 to coincide with the start of the Iowa High School Football Season [48]. Three traffic events week −1 were applied to EU until 25 traffic events were completed.…”

“…Surface hardness was measured on three random locations EU −1 using a 2.25 kg Clegg impact tester (Turf-Tec International, Tallahassee, FL, USA). Shear strength was using a shear strength tester (shear vane; Turf-Tec International, Tallahassee, FL, USA) following techniques described by Dalsgaard et al [48]. Soil and surface parameters were measured before simulated traffic began and then after every three traffic events until traffic concluded.…”