Here's why:
* Grazing Mechanism: Horses have a unique grazing mechanism. They use their strong, flat teeth to tear off grass blades close to the ground. They don't pull or dig into the soil.
* Root Structure: Grass roots are often deep and strong. Even if a horse tried to pull them up, they wouldn't be able to easily do so.
* Pasture Health: Ripping up grass roots would damage the pasture and prevent the grass from growing back.
However, horses can sometimes disturb the soil:
* Hooves: Their hooves can compact the soil, especially in wet conditions.
* Heavy Grazing: If a pasture is overgrazed, horses might eat the grass down to the ground, potentially damaging the roots over time.
Overall: Horses are designed to graze on grass without damaging the root systems.