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Issue link: http://gcmdigital.gcsaa.org/i/632307
02.16 GOLF COURSE MANAGEMENT 107 CUTTING EDGE Teresa Carson Soil properties determine site selection for application of compost to fairways Soil properties can vary widely across land- scapes and infuence the effect of soil man- agement practices, such as compost applica- tion. Joint Base Lewis-McChord (JBLM), a military base near Tacoma, Wash., produces compost (Earthworks) for waste diversion and cost savings. JBLM's Eagles Pride Golf Course has implemented an Integrated Pest and En - vironmental Management Plan that includes the application of Earthworks compost to fair - ways. A two-year experiment assessing com- post application on soil and turfgrass quality parameters is underway. To account for dif - fering soil properties, 17 transects were estab- lished including 152 geo-referenced points. Soils were analyzed for chemical and physical parameters at each geo-referenced site. The percent sand ranged from 74 to 98, organic matter depth from ~0.4 to 3 inches (~1 to 7.7 cm), and percent clay from 0.3 to 8.2. Sites for the study were selected by grouping fve of the geo-referenced points into a soil "window." Using percent sand, percent clay, organic mat - ter depth and pH as factors, soil windows were compared with one another, with the specifc goal of fnding similar underlying properties. Two windows (a pair) matching across the four factors were considered a viable location for plot placement. The window pairs were then used as a guide for selecting three differ - ent sites across the property. The experiment is split-split-plot design with fertilizer as the main plot, sand as the subplot, and compost as the sub-subplot replicated three times on each of the three sites. — Nathan E. Stacey (na- email@example.com); Douglas P. Collins, Ph.D.; and Andy I. Bary, Washington State University, Puyallup, Wash.; Joan Davenport, Ph.D., Wash - ington State University, Prosser, Wash.; and Gwen Stahnke, Ph.D., Walla Walla Community College, Walla Walla, Wash. Zinc for Poa annua control in hybrid bermudagrass Preliminary greenhouse research revealed that application of zinc had some effcacy as a pre-emergent herbicide for control of annual bluegrass (Poa annua L.). The objective of this research was to further evaluate the suit - ability of zinc to control annual bluegrass in a hybrid bermudagrass (Tifway) fairway. In two years (2012 and 2013), zinc was applied (as zinc sulfate) every other week at rates of 40, 80, 160 or 320 pounds zinc/acre (4.5, 9, 18 or 36 grams/square meter) via a soluble spray application. Zinc was applied as a one-time application to different plots every other week from August to December. Thus, every other week, four replicate plot areas received zinc (a total of 16 application dates). A zero-zinc con - trol was also included, as was a standard her- bicide treatment. Collected data included per- cent Poa annua control, bermudagrass shoot density, relative color and quality of bermuda - grass, and soil zinc (EDTA extractable). As the rate of zinc increased, control of Poa annua increased, but never to the levels measured in plots to which standard herbicide treatments had been applied. Bermudagrass shoot den - sity and color were unaffected by application of zinc over the two-year period. Subsequent studies will evaluate whether continued Poa annua control is realized via the accumulated, residual soil zinc. We must also determine whether such accumulation could pose future environmental issues. — Elizabeth A. Guertal, Ph.D. (firstname.lastname@example.org), and J. Scott McElroy, Ph.D., Auburn University, Auburn, Ala. Teresa Carson (email@example.com) is GCM's science editor. Photo by Nathan Stacey Photo by Caleb Bristow