Aminopyralid (2-pyridine carboxylic acid, 4-amino-3, 6-dichloro-2-pyridine carboxylic acid) is an auxin herbicide that has been used widely to control broadleaf weeds in pasture and hay fields. With no post-application withdrawal time, aminopyralid absorbed into forage material can contaminate compost feed stocks such as hay, grass bedding material, and manure. Composts derived from such feed stocks raises concerns about after-effect injuries to sensitive crops by residual aminopyralids. Biochar (BC) additive may affect the composting process and immobilizes organic pollutants. This study examined the effect of composting dairy manure/sawdust 1:1 mixture containing 10 ppb (wet) of aminopyralid with 0%, 2%, 4%, and 10% (w/w) BC levels on chemical and biological characteristics of compost, residual aminopyralid concentration, and intensity of plant injury to tomato (Lycopersicon esculentum L.) plants after composting in 140 L plastic rotary drum reactors for two 6-month cycles. Biochar addition decreased organic matter degradation and intensified reduction in residual aminopyralid levels in a dose-dependent manner. Composting with BC concentrated more N, P, and K, caused mild plant injuries, and increased the above ground biomass compared to the no BC incorporation. Addition of BC for composting aminopyralid-contaminated dairy manure can increase the phyto safety level of compost while enhancing the key fertilizer values.

Horses can become obese and develop related health issues such as laminitis from excessive grazing on high-quality pasture grass; limiting pasture intake can allow weight loss to occur. The objective of this study was to determine the effect of space-restricted rotational grazing on body weight (BW) and time budgets in horses. Eight mature geldings and mares with maintenance-only requirements were randomly assigned to either a space-restricted rotational grazing group (SRG; BW 512 ± 6 kg; n = 4) or a continuous grazing group (CG; BW 517 ± 49 kg; n = 4) for 42 d SRG horses grazed an area with dimensions to provide 80–90 % of mean digestible energy requirement for the 4 horses over a 7-d grazing period; whereas, the CG horses continuously grazed similar non-toxic endophyte-infected tall fescue pasture providing greater than maintenance requirements for the 42 d Horses in the SRG group were moved to a new area every 7 d for 6 weeks. On d 7 at 1600 h of each week, horses were brought inside, and feed was withheld overnight. At 0700 h the next day, BWs were recorded prior to turnout. Observers recorded behaviors simultaneously on SRG and CG horses every six minutes throughout the day three days per week according to an ethogram. This included 30 s scans of all horses. Proportion of grazing and standing had an inverse relationship. Proportion of grazing was affected by the treatment by time interaction, which grazing was displayed more in SRG than CG during weeks 2 and 3, and then reversed weeks 4, 5 and 6.

Athletic field managers often adjust agronomic practices according to the desires of coaches and athletes. One such agronomic practice often adjusted is mowing height. In an attempt to have athletes run faster, field managers are persuaded to reduce mowing height, thereby reducing potential friction from the surface on an athlete. With newer bermudagrass [ Cynodon datylon (L.) Pers.] and hybrid bermudagrass [ Cynodon dactylon (L.) Pers. × C. transvaalensis Burtt Davy] cultivars, maintaining a field at reduced mowing heights is much easier to achieve without apparent negative effects on surface performance. However, these expected effects have not been verified through rigorous research and are solely dependent on anecdotal data. The objectives of this study were to compare traffic tolerance of four hybrid bermudagrass cultivars - ‘Latitude 36 Turf Bermudagrass’ (Latitude 36) and ‘Northbridge Turf Bermudagrass’ (Northbridge), ‘Tifway’, and ‘Patriot’ - and two bermudagrass cultivars - ‘Riviera’, and ‘Hollywood’ - and determine the effect of mowing height on traffic tolerance. Treatments were arranged in a randomized complete block design with eight replications. Measurements of percent green cover, surface hardness, and peak rotational traction were collected before, during, and after simulated traffic. Latitude 36 and Northbridge were more traffic tolerant than any of the other cultivars tested. While there was not an interaction between cultivars and mowing height, the higher mowing height had greater traffic tolerance.

The objective of this study was to investigate the impact of brushing and infill maintenance of third generation (3G) synthetic turf on field safety. A split-plot randomized complete block design was used with six different fiber pile heights, infill depths, and shock pad combinations subjected to 120 games in the summer of 2017 at the Center for Athletic Field Safety (CAFS) in Knoxville, TN, USA. Traffic was applied with a CAFS traffic simulator. Half of the plots received maintenance every 20 games with a rotating power broom and infill applied to those below manufacturer’s recommendations. All 3G synthetic turf systems required maintenance to the same degree, and maintenance was necessary to keep surface hardness of 3G synthetic turf systems consistent and acceptable. Overall, field safety and consistency increased in this study due to maintenance, thus suggesting brushing and infill maintenance plays a vital role in maintaining high performance on 3G synthetic fields.

The objective of this study is to determine the impact of three alternative infills of various particle size on athlete performance and safety in a third generation (3G) synthetic fields. A complete randomized design composed of three different infill materials (thermoplastic elastomer, coconut and cork mixture, and recycled Nike shoes (Nano)) with all infills having the same infill depth, fiber length, fiber density, and shock pad. The study took place at the Center for Athletic Field Safety (CAFS) during the summer of 2017 in Knoxville, TN. Each plot received 120 traffic events with the CAFS traffic simulator. This study found that alternative infills do impact the safety and performance of the field, while showing a variation of performance properties among the alternative infills. The results of this study indicate that particle size and distribution of the infill plays a key role in the superior field performance in 3G turf.

Core Ideas Limited impact of lower clip of the reel is noticed in bentgrass green quality and color. Double cutting and lower clip of the reel does not always lower green speeds. Lower clip of the reel picks up more sands than higher clip of the reel.

Studies are warranted to evaluate head injury criterion (HIC) on athletic fields to determine baseline numbers and compare those findings to current critical thresholds for impact attenuation. A two year (2016 and 2017) study was conducted on University of Tennessee athletic fields (Knoxville, TN, USA) to determine the effect of soil type (cohesive soil, United States Golf Association sand specifications) and grass species (Poa pratensis and Cynodon dactylon × C. transvaalensis) on HIC. Additionally soil moisture conditions monitored were: dry (0.06–0.16 m3/m3), acceptable (0.17–0.29 m3/m3), and wet (0.30–0.40 m3/m3). A linear relationship (r = 0.91) was identified between drop height (0.5–2.9 M) and HIC value (35-1423 HIC) on granular root zones of both grass types. However, HIC on cohesive soil is a function of soil water content in addition to drop height. These results demonstrate to aid in head injury prevention on cohesive soil athletic fields the HIC can be lowered by managing soil water content.

Core Ideas Backtrack mowing produced the fastest green speeds compared with all other treatments. Shortening the clip of the reel or mowing in multiple directions removes more sand topdressing than standard mowing practices. Mowing patterns or clip of the reel had no visual effect on plant health.

Soil water content (SWC) influences the consistency and performance of athletic field surfaces. Two studies were conducted at the University of Tennessee Center for Athletic Field Safety, Knoxville, TN, to determine how SWC affects wear tolerance of hybrid bermudagrass [Cynodon dactylon (L.) Pers. × C. transvaalensis Burtt‐Davy, ‘Tifway’] on root zones composed of either silt loam (cohesive) or sand meeting US Golf Association specifications (noncohesive). Soil water content treatments for cohesive root zones averaged low (0.06–0.13 m3 m−3), medium (0.14–0.21 m3 m−3), medium‐high (0.22–0.29 m3 m−3), and high (0.30–0.37 m3 m−3); comparatively, SWC on noncohesive averaged low (0.05–0.11 m3 m−3), medium (0.12–0.19 m3 m−3), and high (0.20–0.27 m3 m−3). Differences in the amount of ranges between root zones were due to plant available water of the soil texture. Plots were subjected to 50 traffic events for 5 wk each fall over a 2‐yr period. Green turfgrass cover was reduced four times faster at high SWC than the low and medium SWC treatments on cohesive soil. All SWC treatments on noncohesive soil lost green turfgrass cover at a predictable rate. Surface hardness increased as SWC decreased for both root zones. Turfgrass shear strength decreased with traffic for all treatments on cohesive soils. Soil water content of noncohesive soils did not compound the effect of traffic on turfgrass shear strength. The optimal mean SWC ranges to maximize hybrid bermudagrass wear tolerance on cohesive soils were low to medium, and low to medium on noncohesive soils.

Research has evaluated golf ball lie as means to compare various management techniques, determine the influence of nitrogen fertility, and separate turfgrass species and cultivars. However, little work has been performed to determine the impact of golf ball lie on playability, and therefore, the objective of this study was to evaluate the effects of golf ball lie on golf shot characteristics such as carry distance, backspin, ball speed, smash factor, club speed, and accuracy. Two golfers differing in handicaps struck balls using a seven‐iron from various ball lies created by ranging mowing heights from 0.5 to 4.0 inches in Agrostis stolonifera L., Poa pratensis L., and Festuca arundinacea Schreb. Ball lie was measured as the percentage of golf ball exposed within and above a turf canopy using digital image analysis, and golf shot characteristics were measured using a launch monitor. Mowing heights of the turf and ball lies were significantly correlated (P < 0.001, r2 = 0.863). Ball lie significantly affected carry distance (P < 0.001, r2 = 0.357) and ball speed (P < 0.001, r2 = 0.517), both exhibiting logarithmic relationships. Smash factor was linearly related to ball lie (P < 0.001, r2 = 0.518). Comparison of the regression coefficients for models specific to each golfer indicated that carry distance, backspin, ball speed, and smash factor were affected equally for both golfers. However, accuracy of golf shots was only significantly related to ball lie for the better golfer (P = 0.004, r2 = 0.158). Results from this study confirm conventional wisdom concerning the effects of golf ball lie on golf shot characteristics.