Wetting Agent Influence on Putting Green Surface Firmness

Abstract

Soil wetting agents are commonly used in the golf course industry for managing soil moisture. Recently, there has been an interest in the influence wetting agents have on the firmness characteristics of putting surfaces. To date, there has been no established relationship between wetting agents and surface firmness of putting greens. Research was conducted in St. Paul, MN, to evaluate the surface firmness impacts from 13 commercially available wetting agents applied individually or in combination to a creeping bentgrass (Agrostis stolonifera L.) research green. Treatments were evaluated as season‐long wetting agent programs with applications every 4 wk. Data collection included surface firmness (Clegg Impact Soil Tester), turfgrass quality (TQ), chlorophyll index (CI), volumetric water content (VWC), and spring water drop penetration tests (WDPT) to assess residual of fall‐applied wetting agents. Firmness measurements were not affected by wetting agent applications in 2014. In 2015, Duplex (15% alcohol ethoxylates, 2% alkyl sulfonate, 7% ethylenediaminetetraacetic acid), Aquicare (100% blend of alkoxylated alcohols), and Primer Select (100% alkoxylated polyols) provided the firmest surfaces. Ratings for TQ and CI demonstrated only minor influence of wetting agent applications, as did VWC measurements. Spring WDPT tests indicated wetting agent residual from late‐fall applications, and persistence was most evident at shallow depths. Revolution (100% modified alkylated polyol) demonstrated the greatest residual, whereas Duplex and Aquiflo (45% poloxanlene, 2‐butoxyethanol, siloxane surfactants) had the least residual. These results indicate that firmness can be influenced by wetting agent applications, and that persistence in the soil through the winter months is possible.