Soft ground is a type of terrain that is composed of soil, MUD, or sand. It is often found in areas with high levels of moisture and is characterized by its soft, spongy texture. The term 'MUD' is used to describe this type of ground, as it is often wet and muddy. Soft ground can be difficult to traverse, as it can be slippery and unstable. It is often used in sports such as horse racing, as it provides a softer surface for the horses to run on.