The Effect of Core Recycling on Putting Green Performance.

Core cultivation and sand topdressing are standard cultural practices for most golf course putting greens. The problem for many superintendents, especially rural or low-budget courses, is acquiring topdressing sand that is economical and also compatible with the current rootzone properties. Previous research has demonstrated that consistent aeration and topdressing regimes improve both plant health and playing surface conditions. Core recycling using the Weidenmann Core Recycler may reduce the amount of topdressing sand required, thus also a reduction of incorporating sand with differing properties. Benefits of core cultivation paired with sand topdressing have been well documented; however little is known on if core recycling will negatively influence putting green properties such as rootzone organic matter levels, water infiltration rates, recovery timeframe, or ball roll. A trial was conducted at the Iowa State University Horticulture Research Station in Ames, IA, during 2016 and 2017 comparing traditional core cultivation, core collection, and topdressing to core cultivation, core recycling, and topdressing. Additionally, sand topdressing was applied before and after cultivation as strip-plot treatment to test improvements in sand incorporation. Percent organic matter, percent cover/recovery, ball roll, soil moisture, sand usage, and water infiltration rates were evaluated. The trial was conducted on a USGA sand-based rootzone creeping bentgrass (Agrostis stolonifera L.) green, maintained at 3.25mm. Preliminary data show no differences between treatments for water infiltration, recovery time, ball roll, and soil moisture. Core recycling increased percent organic matter (15.9% in the recycled treatments vs. 8.7% in the traditional treatments) and reduced amount of additional topdressing sand required by 91.8% compared to traditional cultivation. While this data suggests a cost savings with little impact on the putting green performance, further research is needed on long-term effects of core recycling.