The Influence of Various Cultural Practices On Sand-Based Putting Green Firmness.

The surface hardness or firmness of putting greens is a key playability factor in the game of golf.  Soil compaction, thatch accumulation, and most importantly soil moisture content have been implicated as factors that affect surface hardness.  However, the interaction these individual components interaction and their influence on putting green firmness is not well understood.  The objectives of this research are to determine if these factors interact to influence surface hardness, if so, how they interact, their effect on turfgrass quality, and to develop management strategies for establishing and maintaining putting green firmness at suitable levels.  The experiment includes three levels of soil compaction, two levels of organic matter control, and three levels of irrigation on sand-based, Agrostis stolonifera/Poa annua mix greens.  Measurements include:  percent organic matter, bulk density, turfgrass quality, soil infiltration rate, soil moisture content, and surface hardness.  Treatments with lower levels of soil moisture and organic matter are expected to be more firm than those with greater levels.  Treatments with high levels of soil compaction are also expected to be firmer than those that are less dense.  High levels of soil compaction should reduce infiltration rates, thereby increasing soil moisture content, particularly at high levels of irrigation, causing the green to be less firm.