Applied Turfgrass Science最新文献

A discussion of how using amendments to mimic a soil in sand based soil environments helped to build over 100 golf course and sports fields. A colloidal soil has a nutrient holding capacity, an organic matrix and a mineral matrix all of which are missing in sand based soil mixes.

The use of various soil amendments were tilled into the soil surface to the depth of 6-8 inches showing results such as quicker turf establishment and nutrient stabilization. Physical and nutrient based rock minerals were combined with carbon based amendments to help build up the soils cation exchange capacity and provide a stronger level of nutrient and biological support. Fertilization and water inputs were reduced and turf quality improved.

Recommendations for golf course green construction have been for rootzone mixes with at least 90% sand while the remainder is typically peat or other organic material. This type of construction mix initially facilitates water movement through the profile but provides an environment conducive to soil hydrophobicity. Several factors such as sand texture, frequent wet to dry cycles, and accumulation of organic matter and thatch contribute to the development of soil water repellency in golf course greens. In research studies conducted over the past fifteen years in several locations across the United States, water drop penetration tests (WDPT) on golf greens have shown slightly and strongly water repellent soil is prevalently found at 0 and 1 cm depths. In the majority of locations, as the depth of profile increased, soil hydrophobicity decreased and was mostly non-existent at the 6 cm depth. These results suggest that despite soil texture and management practices, soil hydrophobicity in a managed turfgrass area is most severe in the thatch and mat area of the profile. While the knowledge of what contributes to water repellency is critical for alleviating symptoms associated with hydrophobic coatings, management practices may be more successful if the focus was on the depth of the repellency.

Dollar spot (Sclerotinia homoeocarpa), Waitea patch (Waitea circinata var. circinata) and fairy ring (many basidiomycete sp.) are considered some of the most common, persistent and troublesome diseases of golf course turf. Golf course superintendents employ cultural practices (i.e., mowing, fertilization/plant nutrition, irrigation/soil moisture management, selection of improved turfgrass cultivars, topdressing practices, core cultivation practices, soil amendment practices, dew removal and other practices), fungicide products, soil surfactants and other strategies to manage turfgrass diseases on golf course greens. Recent attention to an overall plant and soil health approach has warranted research into improving turfgrass disease management programs for golf course greens. This presentation provides a contemporary review of these three complex diseases (i.e., dollar spot, Waitea patch and fairy ring) of golf course turf, and the various strategies and practices used to manage these diseases, with particular emphasis on greens with constructed rootzones.

A short game practice facility was constructed at North Shore Country Club, Glenview Illinois in the summer of 1997. In addition to it being a functional practice area, the design included various research objectives including field-testing several rootzone amendments in the 7,200 square feet putting green. All rootzones were constructed with the same sand, meeting USGA specifications in particle size and distribution and built to a USGA profile standard. 20 different rootzone mixes were used in cells measuring 14’ × 15’ and 12” deep. A permanent 80-mil high-density polyethylene barrier extending from the top of the pea gravel bed to the surface divided the cells. All plots were seeded with a 50/50 blend of L-93 and SR-1119 at 2 lbs/1,000 ft².

A seed blanket was used to assist grow-in and protect from any potential erosion until seedling establishment. All plots were managed equally and topdressed with straight sand as the turf matured. Rootzone cells consisted of: Straight Sand; 85/15 Sphagnum Peat; 90/10 Dakota Peat; 90/10 Dakota Peat plus Chip Humate (250#); 90/10 Dakota Peat plus 22.5% Profile (porous ceramic); 90/10 Dakota Peat plus 15% (v/v) Profile and 350 pounds ZeoPro (zeoponic zeolite); 90/10 Dakota Peat plus 10% (v/v) Zeopro; 90/10 Dakota Peat plus 10% Axis (calcined diatomaceous earth); 90/10 Dakota Peat plus 10% Axis and 350 pounds Zeopro; 90/10 Dakota Peat plus 100 pounds OptiMil (granular Sea Plant Meal and Milorganite with sunflower seed hull ash, total N-P-K of 3-1-4); 90/10 Dakota Peat plus 100 pounds OptiMil and Emerald Isle Microbial Trichoderma harzianum and endomycorrhizal fungi; 90/10 Dakota Peat plus 60 pounds SAND_AID (granular Sea Plant Meal, 1-0-1); 90/10 Dakota Peat plus 60 pounds SAND-AID and Emerald Isle Microbial Trichoderma harzianum and endomycorrhizal fungi; 90/10 Dakota Peat plus 300 pounds Paramagnetic basalt rock, 40 pounds Hard Rock Phosphate and 40 pounds Greensand; 90/10 Yardwaste Compost; 90/10 Biosolids; 90/5/5 yardwaste/biosolids; Sand mixed with 10 pounds Hydrozone (water absorbing polyacrylamide copolymer); Sand mixed with 5 pounds Hydrozone and earthworm castings; and 90/10 local peat. The results will be presented and discussed.