Many organic products have been used effectively in turfgrass management progranns, but their exclusive use in athletic field maintenance and effect on playing surface quality has not been extensively researched. The objectives were to determine the effects of management regimes and overseeding during simulated traffic on (i) turfgrass color and quality, (ii) percent cover, and (iii) weed populations. The experimental design was a 2 X 6 factorial, with two overseeding levels (overseeded and not overseeded) of a perennial ryegrass (Lolium perenne L.) blend during traffic and six management regimes: (i) conventional, (ii) organic manure (OMan), (¡ii) organic protein (OPro), (iv) organic manure plus compost tea (OMan+GT), (v) organic protein plus compost tea (OPro+GT), and (vi) none or the control. This research was conducted over 2 yr on a mature stand of 'Lángara' Kentucky bluegrass {Poa pratensis L.) on a Paxton sandy loam soil. Fall traffic was simulated with a Gady Traffic Simulator. The conventional treatment consistently produced higher quality turfgrass, lower weed counts, and better mid-to late-fall color. Weed populations were significantly less with the conventional regime. Overseeding increased cover at the end of the traffic periods by 32% in the first year and by 103% in the second year. Overseeding was also beneficial to turfgrass color and quality and in reducing weeds. The conventional treatment also retained significantly higher turfgrass cover than the organic regimes under trafficked conditions late into the fall in 2008. However, no difference in late fall cover between the conventional and organic management regimes was observed in late fall 2009. Gompost tea applications showed no enhancement of turfgrass color, quality, or cover over the entire duration of the study.

Sands used to construct athletic fields and golf course putting greens are characterized in laboratory tests to evaluate their suitability before construction. Many of these tests provide quantitative measurements of soil physical properties; however current evaluation procedures for particle shape rely on subjective visual assessments. The objective was to quantify differences in the particle shape complexity of sands using a dynamic, digital image analyzer, the Camsizer, and correlate those values to current quantitative and qualitative methods of particle shape analysis. The Camsizer uses two cameras to capture images of randomly falling particles at a rate of 60 frames s−1 These images are analyzed and shape parameters such as sphericity and aspect ratio are calculated. Five monosize sands of varying shape were evaluated, as well as a rounded and angular control. The dynamic method showed significant differences between sphericity and aspect ratio values of all sands, indicating these parameters can be used to quantitatively assess particle shape complexity. The values obtained with the Camsizer and with a well accepted static, quantitative technique that uses light microscopy were correlated for both aspect ratio (r = 0.935) and sphericity (r = 0.982). The Camsizer values also exhibited a positive relationship with the qualitative shape parameters, sphericity, and angularity. The coefficient of variation values for the aspect ratio and sphericity data, as determined by the dynamic method, were significantly lower than the static method or the qualitative analysis. These results indicate that this digital imaging analysis tool provides an accurate, objective means of quantifying particle shape complexity.

Securing adequate time for proper turfgrass establishment following athletic field construction or renovation is a significant challenge. Spring construction and renovation projects often get delayed thereby diminishing the necessary time for sufficient root development before anticipated athletic field use. An alternative sod installation timing following fall sports may provide adequate root development during a typical period of minimal to no field usage. Five sod installation treatments (December covered, December uncovered, May, June, and July) were evaluated for rooting strength monthly and spring color. The May sod installation timing was used as the control, representing the typical sod installation time with anticipated intense field use in the fall. The objective of this field study was to quantify the effect of sod installation timing on the rooting strength and spring color of Kentucky bluegrass. December covered treatments consistently increased rooting strength over all other treatments in 2006. December covered and uncovered treatments consistently increased rooting strength over all other installation dates in 2007, indicating a considerable advantage to late fall sod installation for more extensive root development throughout the subsequent growing season.

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Particle shape of prospective root-zone sands is evaluated qualitatively, but a quantitative shape determination may be more useful for sand selection. The objectives of this research were to: determine how particle shape complexity relates to bulk density, total porosity, and mechanical behavior (resistance to displacement given a vertical load); correlate quantitative shape parameters to these properties; determine how water content influences these relationships; and establish if quantitative shape parameters can be used to predict mechanical behavior in the absence of turfgrass roots. Seven materials of various shapes were separated into the medium size class (0.25 to 0.50 mm) to limit variability introduced by particle size distribution. A dynamic, digital imaging machine was used to quantify particle sphericity, symmetry, and aspect ratio. Bulk density, total porosity, and stress at multiple displacements were determined for the materials at two water contents, oven-dry and 5% gravimetric water content. As sphericity, symmetry and aspect ratio increased, bulk density increased and total porosity decreased. Sphericity, symmetry, and aspect ratio were negatively correlated with stress under a vertical load. The addition of water at compaction did not affect the correlations of the shape parameters with either bulk density or porosity; correlations of symmetry and sphericity with these were stronger at 5% water content for some displacements. Multiple regression analysis indicated that sphericity can be used to predict stress characteristics of sands compacted at 5% water content for specific testing conditions. These data indicate that particle shape complexity is related to bulk properties and has potential for predicting the stress characteristics of prospective root zone materials prior to construction.