Photo: Moyan Brenn (flickr)
You probably already know that trampling harms grass. However, you may not realize exactly how it damages your lawns. You see, the part of grass that’s responsible for new growth is at the base of the plant, so even if the blades are harmed, it isn’t a big deal. This allows us to mow grass without killing it.
Most of the long-term harm from trampling is due to compacted soil. For example, the compaction can reduce the amount of air and water available to a plant. When it rains on compacted soil, the water runs off instead of being absorbed. Even worse, water can sometimes puddle and drown the plant.
You may be wondering how grass on football and baseball fields stays so green, especially with all that heavy traffic. The answer is that grass on athletic fields is often planted over a layer of sand, which greatly reduces the problem of compaction.
- How Grass Works (HowStuffWorks)