Effect of traffic stress on cool-season turfgrass under a Mediterranean climate

Cool-season turfgrass for sporting use is an agronomic cultivation whose green surface is used for professional activities. On ecological grounds, turfgrass in towns is a system that can reduce atmospheric pollution, e.g. by CO$_{2}$ sequestration. Here, I studied the impact of traffic on turf quality traits of turfgrass. The experiment, established in Southern Italy in the years 1999 to 2004, evaluated the impact of 2 levels of traffic stress on 3 types of turfgrass binary blends made by cultivars of tall fescue, Kentucky bluegrass, perennial ryegrass and bermudagrass species. Grasses were grown on 4 different substrates established by a mix of soil sand at 2 fertilization levels of 100 and 200 N units kg h$^{-1}$ yr$^{-1}$. I evaluated the effect of the impact on three turfgrass qualitative traits, visually assessed using rating scores from 1 to 9. The lowest score values of turf quality, color and cover traits were, respectively, 5.6, 5.7 and 5.8 recorded for blend Kentucky bluegrass and perennial ryegrass under United States Golf Association sandy soil substrate, using 200 N fertilizer units and a high level of traffic stress. The highest score was 7.1 for turf quality and color and 8.0 for cover traits assessed for autochthonous soil substrate under 200 N fertilizer units and the second level of traffic stress. Furthermore, the 200 N units increased all the qualitative characteristics of turf lawn. The turfgrass growing on 65–70% sand substrate with 100 N units fertilizer and a high level of traffic stress was an ecological green structure able to sustain the physiological process for reducing pollution in the atmosphere