Artificial turf: Some artificial surfaces are made from synthetic nylon fibers that resemble very short blades of grass; other artificial surfaces have tightly woven fibers that give the feel of a cushioned carpet. Artificial surfaces are cheaper to maintain than natural grass. Plus, many football stadiums are multipurpose facilities that are used for outdoor concerts, political and religious rallies, and other sports, such as baseball and soccer. When such events are held, some areas of the grass can become trampled and destroyed by the thousands of fans sitting or walking on it, so having an artificial surface is advantageous.
Then again, in many stadiums, the artificial surface is also harder than natural grass because it’s often laid over cement, blacktop, or dirt. And on extremely hot days, artificial surfaces retain the heat, making a day that’s 95 degrees Fahrenheit feel like a 100-degree day.