The type of soil around plant roots affects how dense it is. By using X-ray imaging, researchers studied how maize roots change soil density in different soil types. In uniform soil, roots make their own spaces by moving soil particles. In more varied soil, roots grow in existing spaces without compacting the soil. Root size matters more in sandy soil than loamy soil. Small roots make sand grains line up, while big roots break the grain arrangement. Factors like root hairs and plant growth stage don't have much impact. This information can help us understand how water and nutrients move around plant roots, which can affect how well plants grow.