Topdressing and Aeration Programs on Creeping Bentgrass Fairways.

Topdressing and aeration are routinely used on golf course greens to improve soil and turf quality.  Topdressing and aeration on fairway soils, however, has not been fully researched.  The objective of this study is to determine if different schedules of topdressing and aerification have an effect on soil water content before the winter freeze/thaw cycle, and how the volumetric water content affects soil compaction.   The study is being conducted in Ames, IA, and Fargo, ND. This experiment is being conducted as a split-plot design with topdressing at the main plots and aerification as the split-plot treatments.  Data were collected on bulk density, volumetric water content, organic matter, water infiltration, and overall turf quality. The soil evaluated at the Ames location is a 1:1:1 sand: peat: soil mixture. The soil at the Fargo site is a Fargo-Ryan silty clay [(fine, montmorillonitic, frigid Vertic Haplaquall)-(fine, montmorillonitic, Typic Natraquoll)]. Both areas were established to creeping bentgrass (Agrostis stolonifera L.), maintained at 1.27 cm. At both sites, there were no differences in the volumetric water content in the fall of 2006. In the spring of 2007, there were differences in the bulk densities within the different topdressing schedules at both sites. Bulk densities of the topdressed areas were reduced by 5.24% at the Iowa site. At the Fargo site, turf visual quality improvement was observed in the topdressing and aerification treatments, while there was no visual difference in Iowa. Soil penetration-resistance decreased from 1 to 7%, and water infiltration increased from 5 to 21% in aerated treatments at the Fargo site in the spring of 2007. Throughout the fall of 2007, fall aerification increased volumetric water content. The October ratings in Iowa, for the two-pass fall aerification, saw an increase of 5.9% volumetric water content in comparison to the untreated control.