scholarly journals Matching Subjective Assessments of Sod Strength to Quantitative Measurements of Peak Shear Force with Predominately Kentucky Bluegrass Sod

HortScience ◽  
2015 ◽  
Vol 50 (8) ◽  
pp. 1248-1251
Author(s):  
Karl Guillard ◽  
Richard J.M. Fitzpatrick ◽  
Holly Burdett
Keyword(s):  
Shear Strength ◽  
Rhode Island ◽  
Shear Force ◽  
Quantitative Methods ◽  
Poa Pratensis ◽  
Kentucky Bluegrass ◽  
Peak Force ◽  
Growing Seasons ◽  
Quantitative Measurements ◽  
Subjective Assessments

Adequate turfgrass sod strength for harvesting and handling is typically determined by the producer’s past experience and subjective appraisal. This study was conducted to determine the relationship between producer subjective sod-strength assessments and quantitative shear-strength measurements with predominantly kentucky bluegrass (Poa pratensis L.) turf. Across three consecutive growing seasons, 93 samples were collected from sod fields in Rhode Island and assessed for sod strength by subjective and quantitative methods. Producer subjective ratings of sod strength were significantly (P < 0.0001) associated with quantitative measurements of peak force required to shear a sod strip. Minimally acceptable strength occurred most frequently when peak shear force was between 55 and 85 kg·m−1 width of sod; whereas preferred sod strength occurred most frequently when peak shear force was between 70 and 140 kg·m−1 width of sod. Once peak force exceeded 58 and 86 kg·m−1, there was a > 50% probability that sod strength would be judged at least adequate and at preferred strength, respectively, up to a peak force of 140 kg·m−1. The results suggest that quantitative measurements of shear strength can be related to producer subjective assessments, and provide unbiased benchmark values to guide management decisions for kentucky bluegrass sod production.

scholarly journals The Use of Soil Amendments to Improve Survival of Roadside Grasses

HortScience ◽  
2011 ◽  
Vol 46 (10) ◽  
pp. 1404-1410 ◽  
Author(s):  
Rebecca Nelson Brown ◽  
Josef H. Gorres
Keyword(s):  
Organic Matter ◽  
Salt Tolerance ◽  
Rhode Island ◽  
Tall Fescue ◽  
Festuca Arundinacea ◽  
Poa Pratensis ◽  
Perennial Grass ◽  
Kentucky Bluegrass ◽  
Perennial Grasses ◽  
Red Fescue

Highway rights-of-way are routinely planted with turfgrasses to prevent erosion, filter runoff, and improve aesthetics. However, the roadside is a harsh environment, and perennial grasses often die within the first year, leading to bare ground and annual weeds, which do not prevent erosion during the winter. To improve the survival of perennial vegetation on the roadside, it is necessary to identify the factors limiting vegetation growth and then to either identify plants that can tolerate those factors or identify ways to ameliorate the stresses while still maintaining safety. This study was designed to evaluate the effects of improved cultivars, salt tolerance, and organic matter amendments on perennial grass survival along two highways in Rhode Island. The amendments tested were processed biosolids and composted yard waste, each applied in a 50:50 mixture by volume with existing roadside soil; plain soil was included as a control. We tested 20 improved turfgrass cultivars and one seed mixture with common creeping red fescue (Festuca rubra L.) as the standard. Turfgrass species tested were perennial ryegrass (Lolium perenne L.), tall fescue (Festuca arundinacea Schreb.), red fescue, alkali grass [Puccinellia distans (Jacq.) Parl.], idaho bentgrass (Agrostis idahoensis Nash), tufted hairgrass [Deschampsia cespitosa (L.) P. Beauv.], and kentucky bluegrass (Poa pratensis L.). We found that soil amendment was more effective than either improved genetics or salt tolerance. Establishment, vertical growth, and persistence of vegetation cover were significantly improved by amendment with organic matter, particularly biosolids. In Summer 2009 (the second growing season), turf cover exceeded 50% in the biosolids plots but was below 20% in the plain soil plots with complete loss of cover in the plain soil plots at one location. Kentucky bluegrass, tall fescue, red fescue, and idaho bentgrass showed the best persistence at the species level, and there were no consistent differences among cultivars.

Grazing exclosures reveal divergent patterns of change in bunchgrass grasslands of Western Canada

Botany ◽  
2021 ◽  
Vol 99 (1) ◽  
pp. 9-22
Author(s):  
Gary E. Bradfield ◽  
W.F. Preston Cumming ◽  
Reg F. Newman ◽  
Maja Krzic
Keyword(s):  
Vegetation Change ◽  
Structural Changes ◽  
Poa Pratensis ◽  
Kentucky Bluegrass ◽  
Growing Seasons ◽  
South Central ◽  
Species Cover ◽  
Rough Fescue ◽  
Dominant Grasses

Thirty-six long-term (14–83 years) cattle grazing exclosures and adjacent grazed pastures spanning a climatic gradient from cooler–wetter to warmer–drier growing seasons in south-central British Columbia were compared for temporal vegetation change. Trajectories of temporal vegetation change from non-metric multidimensional scaling were mostly scattered for the grazed areas, but more directed toward the dominant grasses, primarily rough fescue (Festuca campestris) or Kentucky bluegrass (Poa pratensis), for the exclosures. Plant community differences, detected only after 10 years of grazing exclusion, were primarily due to structural shifts in overall species cover related to growth increases of the dominant grasses inside exclosures. Species richness remained unchanged between the first and last sampling dates in both grazed areas and exclosures, with both treatments showing moderate degrees (15%–30%) of turnover in species composition. Shannon diversity declined in both treatments as a result of the structural changes in species cover. The results highlight the value of repeated monitoring of long-term exclosures for assessment of grassland resiliency to grazing. Further studies of the interaction of grazing and climate are needed for a more complete understanding of the ongoing vegetation change.

STUDIES ON THE DURATION OF Poa pratensis CULTIVAR TESTING

1985 ◽  
Vol 65 (2) ◽  
pp. 351-356 ◽  
Author(s):  
S. H. NELSON
Keyword(s):  
Relative Stability ◽  
Poa Pratensis ◽  
Kentucky Bluegrass ◽  
Considerable Change ◽  
Early Years ◽  
Growing Seasons ◽  
Changing Trends ◽  
Color Density ◽  
Statistical Separation

Color (C), density (D), and weediness (W) score data of Kentucky bluegrass cultivars were evaluated individually, as well as indices (C + D)/2, (C + D)/2-W, (C + D–W)/2, for Kentucky bluegrass cultivars in their second to seventh growing seasons. Considerable change in ranking occurred in the early years and relative stability was not achieved until the fifth year. Thus, the averaging of changing trends in the early years could be misleading. The use of indices added a degree of uniformity which identified poor and good cultivars, but the statistical separation was not enhanced among the cultivars. The (C + D)/2 index is recommended since weediness seemed to be a function of density and weediness can be controlled. The study identified the need for at least 5 years of testing, particularly on the Canadian prairies.Key words: Kentucky bluegrass, color, density, weediness, indices

Herbicide and Fire Effects on Smooth Brome (Bromus inermis) and Kentucky Bluegrass (Poa pratensis) in Invaded Prairie Remnants

2011 ◽  
Vol 4 (2) ◽  
pp. 189-197 ◽  
Author(s):  
Matt A. Bahm ◽  
Thomas G. Barnes ◽  
Kent C. Jensen
Keyword(s):  
Untreated Control ◽  
Poa Pratensis ◽  
Plant Cover ◽  
Growing Season ◽  
Kentucky Bluegrass ◽  
Perennial Grasses ◽  
Native Plant ◽  
Smooth Brome ◽  
The Third ◽  
Growing Seasons

AbstractSmooth brome and Kentucky bluegrass are introduced cool-season perennial grasses known to invade grasslands throughout North America. During the fall of 2005 and spring of 2006, we implemented a restoration study at six native prairie sites in eastern South Dakota that have been invaded by smooth brome and Kentucky bluegrass. Treatments included five herbicide combinations, a fall prescribed burn, and an untreated control to determine the potential of each for renovation of invaded native grasslands. Herbicide treatments tested were sulfosulfuron, imazapyr, imazapic + sulfosulfuron, and imazapyr + imazapic, and were applied in late September 2005 and mid-May 2006. Untreated control plots averaged 64% (± 3.1) smooth brome cover and 38% (± 5.5) Kentucky bluegrass cover after the third growing season. Smooth brome cover in herbicide treated plots ranged from 6 to 23% and Kentucky bluegrass cover ranged from 15 to 35% after the third growing season. Smooth brome cover was 20% (± 2.9) and Kentucky bluegrass cover was 19% (± 4.0) in burned plots after the third growing season. Spring and fall treatments had similar native plant cover after three growing seasons. Spring and fall application of 0.33 kg ai ha−1 imazapyr and 0.10 kg ai ha−1 imazapic + 0.16 kg ai ha−1 imazapyr had ≤ 10% smooth brome cover and increased native species cover after three growing seasons. Herbicides were effective at reducing cover of smooth brome and Kentucky bluegrass, and can be incorporated with other management strategies to restore prairie remnants.

scholarly journals Effect of the root system of Kentucky bluegrass (Poa pratensis L.) on shear strength of finegrained soil.

2018 ◽  
Vol 44 (1) ◽  
pp. 15-20
Author(s):  
SONG Baiyang ◽  
NAKAMURA Dai ◽  
KAWAGUCHI Takayuki ◽  
KAWAJIRI Shunzo ◽  
YAMAGUCHI Kohei ◽  
...  
Keyword(s):  
Shear Strength ◽  
Root System ◽  
Poa Pratensis ◽  
Kentucky Bluegrass

scholarly journals Sand Topdressing Applications Improve Shear Strength and Turfgrass Density on Trafficked Athletic Fields

2010 ◽  
Vol 20 (5) ◽  
pp. 867-872 ◽  
Author(s):  
Alexander R. Kowalewski ◽  
John N. Rogers ◽  
James R. Crum ◽  
Jeffrey C. Dunne
Keyword(s):  
Shear Strength ◽  
Root Zone ◽  
Sandy Loam ◽  
System Development ◽  
Poa Pratensis ◽  
Dry Weight ◽  
Kentucky Bluegrass ◽  
Shoot Density ◽  
Surface Shear ◽  
Surface Stability

Drain tile installation into a native-soil athletic field and subsequent sand topdressing applications are cost-effective alternatives to complete field renovation. However, if cumulative topdressing rates exceed root system development, surface stability may be compromised. The objective of this research was to evaluate the effects of cumulative topdressing, over a compacted sandy loam soil, on the fall wear tolerance and surface shear strength of a kentucky bluegrass (Poa pratensis)–perennial ryegrass (Lolium perenne) stand. Research was initiated in East Lansing, MI, on 10 Apr. 2007. A well-graded, high-sand-content root zone (90.0% sand, 7.0% silt, and 3.0% clay) was topdressed at a 0.25-inch depth [2.0 lb/ft2 (dry weight)] per application, providing cumulative topdressing depths of 0.0, 0.5, 1.0, 1.5, or 2.0 inches applied from 11 July to 15 Aug. 2007. Fall traffic was applied twice weekly to all treatments from 10 Oct. to 3 Nov. 2007. In 2008, topdressing applications and traffic, as described earlier, were repeated on the same experimental plots. Results obtained from this research suggest that the 0.5-inch topdressing depth applied over a 5-week period in the summer will provide improved shoot density and surface shear strength in the subsequent fall. Results also suggest that topdressing rates as thick as 4.0 inches accumulated over a 2-year period will provide increased shoot density, but diminished surface shear strength.

scholarly journals Relative Rooting Depths of Native Grasses and Amenity Grasses with Potential for Use on Roadsides in New England

HortScience ◽  
2010 ◽  
Vol 45 (3) ◽  
pp. 393-400 ◽  
Author(s):  
Rebecca Nelson Brown ◽  
Cynthia Percivalle ◽  
Sophia Narkiewicz ◽  
Samantha DeCuollo
Keyword(s):  
Rhode Island ◽  
Perennial Ryegrass ◽  
Tall Fescue ◽  
Poa Pratensis ◽  
Kentucky Bluegrass ◽  
Bromus Inermis ◽  
Rooting Depth ◽  
Native Grasses ◽  
Red Fescue ◽  
Little Bluestem

Erosion is a significant problem on highway embankments in Rhode Island. At present, a mixture of red fescue (Festuca rubra L.), perennial ryegrass (Lolium perenne L.), and kentucky bluegrass (Poa pratensis L.) is planted to stabilize the soil. However, only the red fescue survives long term on slopes. Red fescue is shallow-rooted, leading to sod sloughing after heavy rains. The objective of this study was to compare the rooting depth, plant height, and adaptation to roadside conditions of 16 native grasses and five amenity grasses with red fescue to identify species that could be used to reduce sod sloughing. Research was conducted from May 2006 through Aug. 2009 in the greenhouse at the University of Rhode Island in Kingston and on the shoulder of state Route 4 in North Kingstown, RI. The cool-season grasses smooth brome (Bromus inermis Leyss. ssp. inermis), Pumpelly's brome [Bromus inermis Leyss. ssp. pumpellianus (Scribn.) Wagnon], Canadian wildrye (Elymus canadensis L.), Virginia wildrye (Elymus virginicus L.), silky wildrye (Elymus villosus Muhl. ex Wild.), eastern bottlebrush (Elymus hystrix L.), perennial ryegrass, and tall fescue (Festuca arundinacea L.) and the warm-season grasses little bluestem [Schizachyrium scoparium (Michx.) Nash] and purple lovegrass [Eragrostis spectabilis (Pursh.) Steud.] were similar in height to red fescue while rooting significantly more deeply. Of these 10 species, little bluestem, purple lovegrass, and tall fescue showed the best survival on the roadside.

Liquid-Phase Peak Force Infrared Microscopy

2020 ◽  
Author(s):  
Haomin Wang ◽  
Joseph M. González-Fialkowski ◽  
Wenqian Li ◽  
Yan Yu ◽  
Xiaoji Xu
Keyword(s):  
Liquid Phase ◽  
Spatial Resolution ◽  
Shear Force ◽  
Polymer Surface ◽  
Surface Damage ◽  
Peak Force ◽  
Infrared Microscopy ◽  
Contact Mode ◽  
Force Microscopy ◽  
Hydrogen Deuterium

Atomic force microscopy-infrared microscopy (AFM-IR) provides a route to bypass Abbe’s diffraction limit through photothermal detections of infrared absorption. With the combination of total internal reflection, AFM-IR can operate in the aqueous phase. However, AFM-IR in contact mode suffers from surface damage from the lateral shear force between the tip and sample, and can only achieve 20~25-nm spatial resolution. Here, we develop the liquid-phase peak force infrared (LiPFIR) microscopy that avoids the detrimental shear force and delivers an 8-nm spatial resolution. The non-destructiveness of the LiPFIR microscopy enables <i>in situ</i> chemical measurement of heterogeneous materials and investigations on a range of chemical and physical transformations, including polymer surface reorganization, hydrogen-deuterium isotope exchange, and ethanol-induced denaturation of proteins. We also perform LiPFIR imaging of the budding site of yeast cell wall in the fluid as a demonstration of biological applications. LiPFIR unleashes the potential of in liquid AFM-IR for chemical nanoscopy.

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