Creeping Bentgrass Fairway Wear Resistance by Granular Topdressing of Ca/Mg-rich Liming Agents

Abstract

Depletion of extractable silicon (Si) from surface soil depths has been observed in managed production systems. While not characterized as a plant essential nutrient, Si accrues in epidermal and vascular tissue of monocotyledonous plants. A field evaluation of granular Ca/Mg-rich liming agents was initiated on a creeping bentgrass (Agrostis stolonifera L. cv. Declaration) fairway in 2010. Excluding the control, treatments comprised 2440 kg (ha year)−1 topdressing of calcitic/dolomitic blended limestone or Ca/Mg-SiO3 in semi-annual or more frequent “split” applications. Each week of the 2011 and 2012 growing seasons, a dedicated wear simulator trafficked the fairway plots. Measures of canopy quality, clipping yield, tissue composition, soil pH, and plant-available soil Si levels were collected frequently. The described Ca/Mg-SiO3 annual topdressing rates correlated with acetic acid extractable Si levels >30 mg kg−1 in the 0- to 5-cm soil depth. Neither creeping bentgrass vigor, nutrition, nor leaf water content was influenced by significantly elevated levels of soil and tissue Si. Relative to non-trafficked plots, all split plots within trafficked main plots showed similarly reduced canopy quality regardless of topdressing treatment. If a critical threshold leaf Si concentration for creeping bentgrass wear tolerance enhancement exists, it is unlikely <11 g Si kg−1.