Temperature Increase on Synthetic Turf Grass

Artificial turfgrass is a synthetic material made to resemble real grass. A new generation of synthetic turfgrass is made of plastics with different composite materials, and is supported by a sand and/or rubber infill material and subsurface base layer. Synthetic turfgrass is being increasingly used on many athletic fields, such as soccer, football and rugby, as well as in urban landscapes. It is superior to natural grass in aspects, such as lower maintenance, no irrigation required, and surface uniformity. However, high temperatures on synthetic turfgrass surface during hot weather may be dangerous and could result in heat related health problems, such as heat stroke. The objective of this study was to evaluate the temperature increase among different synthetic turfgrass types and to predict temperature increase on the synthetic turfgrass surfaces. In this study, four types of synthetic turf grasses (1 – 4) with four infill materials and base layers (A – D) were installed in central Florida, surrounded by large irrigated natural grass fields. Temperature measurements were taken at 23.5 cm above the ground and 5 cm below the ground. The results indicated that there were no differences in air temperatures above the ground between the synthetic turfgrass and the natural turfgrass, due to the small size of the plots and the high wind speed during the daytime. The temperature below the surface (base temperature) for the synthetic turfgrass was always higher than the natural surfaces at noon time. The base temperature differences between the two surfaces were higher in July and August and lower in November. Overall, the infill temperature difference increased with an increase of the depth of the base layer and the color of synthetic turfgrass. Base temperature increase on synthetic turfgrass (T_syn) was linearly related to the incoming solar radiation (R_s). Relationships based on solar radiation and temperature on natural surfaces (T_nat) (both natural grass and bare soil surface) were developed for all units (T_syn – T_nat = a R_s + b) so that the temperature increase on synthetic turfgrass could be predicted.