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Steven C. Wiest

A system for the digital analysis of photographic prints of turfgrass plots is being developed. The 3-year-old turfgrass plots included Meyer zoysiagrass, Midlawn bermudagrass, Prairie buffalograss and Mustang tall fescue. The plots were photographed by a camera with a small dual bubble level on the camera back and a 28-mm-wide angle lens. Photographs were digitized with flatbed scanners. The images can then be analyzed in a variety of ways. For example, a series of photographs were taken from mid-Sept. through late Oct 1995 and spectral analysis of the resultant digital images were made. The initial RGB (red-greenblue) format of the images was converted to HSI (hue-saturation-intensity) for analysis. The results indicate, obviously, that hue changed from 104 (i.e., green) to 75.7 degrees (i.e., brownish) between the beginning and end of Oct. 1995. Similarly, intensity changed from ≈0.12 to ≈0.16 during the same time period, indicating that the images became darker over time. These phenomena were observed in all four species examined. However, the saturation value evoked a significant species * date interaction. The three warm-season species showed a decrease in saturation, while Mustang had no significant decrease during Oct. Spectral as well as textural analysis are likely the two most useful techniques in the digital analysis of turfgrass plots. Examples of both will be presented.

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Benjamin Wherley and Thomas R. Sinclair

Nitrogen (N) is the nutrient used in greatest quantity by plants and, consequently, is the element around which most turfgrass fertility programs are centered. Nitrogen is a component of many of the biochemical constituents of plants, including

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Donald M. Vietor, Ronnie W. Schnell, Tony L. Provin, Richard H. White, and Clyde L. Munster

Topdressing or incorporation of large, volume-based rates of composted biosolids (CB) can increase storage of soil organic carbon (SOC), supply essential mineral nutrients, and enhance turfgrass coverage during sod establishment and regrowth

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Tim R. Pannkuk

., 2009 ; Pannkuk et al., 2010 ; Parsons et al., 2010 ). Landscape irrigation based on mixed species crop coefficients is an emerging area of water conservation based on climatological conditions. Crop coefficients for irrigation exist for most turfgrass

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J. Norrie and A. Gosselin

The behavior of turfgrass grown on paper-sludge-amended soils was evaluated over 2 years. Two experiments were performed, one with deinked sludge and another with primary sludge. Four paper sludge, sand, and organic soil substrate mixtures with proportions ranging from 0% to 50% paper sludge were incorporated into existing soils. Two fertilization levels were applied in strip plots across sludge treatments and three turfgrasses of seeded Kentucky bluegrass (Poa pratensis L. `Georgetown'), Kentucky bluegrass sod, and an 80 Kentucky bluegrass: 20 perennial ryegrass (Lolium perenne L. `Prelude') seed mix were arranged within split plots. Effects of deinked and primary sludge experiments were similar. Supplemental N and, to a lesser degree, P and K fertilization with N at ≈4.5 to 5.5 t·ha–1, P at 1.18 to 1.26 t·ha–1, and K at 1.34 to 1.46 t·ha–1 improved ground cover, turf color, and stand quality. Despite differences in visual evaluations, leaf mineral nutrition was only slightly affected by fertilization treatments. Soil in nonfertilized plots was several times lower in N-NO3 when compared to fertilized plots, regardless of sludge rate. Soil in fertilized plots had higher concentrations of inorganic N regardless of sludge amendment. The soil C: N ratio was ≈13:1 in nonamended plots and more than 15:1 under the highest sludge rate. Deinked and primary paper sludges can be used effectively as soil amendments if turfgrass receives adequate supplemental N, P, and K.

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Reagan W. Hejl, Benjamin G. Wherley, and Charles H. Fontanier

Turfgrass landscapes provide numerous functional and aesthetic benefits in urban environments ( Beard and Green, 1994 ); however, supplemental water, via irrigation, is often required when rainfall is not sufficient to sustain plant health

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Chase M. Straw, Rebecca A. Grubbs, Kevin A. Tucker, and Gerald M. Henry

Performance testing of natural turfgrass sports fields requires sampling to obtain information on surface properties (e.g., soil moisture, soil compaction, surface hardness, and turfgrass vigor) ( Carrow et al., 2010 ; McAuliffe, 2008 ). Several

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Kari L. Hugie and Eric Watkins

Turfgrass species traditionally used in residential and commercial lawns in Minnesota, such as kentucky bluegrass ( P. pratensis ) and perennial ryegrass ( L. perenne ), can require significant management inputs to maintain acceptable cover and

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Eric Watkins, Andrew B. Hollman, and Brian P. Horgan

irrigation water use standards that limit the amount of irrigation water that can be applied to turfgrass ( USEPA, 2009 ). As restrictions continue to increase, golf course managers will need options for managing turf that are not viewed as risks to the

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George C.J. Fernandez and Belinda Love

Twenty-five commercially available turfgrass cultivars were evaluated for cumulative evapotranspiration (ETcum) attributes under progressive water stress for 0 to 21 and 0 to 24 days using the gravimetric mass balance method in two greenhouse studies. At the end of the water-stress treatment, the cultivars were scored visually for their green appearance on a 0 (no green) to 10 (100% green) scale. The Gompertz nonlinear model gave a best fit to ETcum vs. days adjusted for pan evaporation variation in the greenhouse compared with monomolecular and logistic nonlinear regression models. Two ETcum attributes—maximum evapotranspiration rates (ETmax) and inflection time (ti) (the time when the change in ET becomes zero)—were estimated for each cultivar using the Gompertz model. Based on final ETcum, ETmax, ti, and greenness score, `Bristol', `Challenger', and `Wabash' Kentucky bluegrass (Poa pratensis L.); `Shademaster' creeping fescue (Festuca rubra L.); `FRT-30149' fine fescue (F. rubra L.); and `Aurora' hard fescue (F. ovina var. duriuscula L. Koch.) were identified as low water-use cultivars.