Okay dear, so you know how there are different types of soils like the ones you see in the garden or at the park? Well, ustic is one of those types of soil.
Ustic soils are usually found in dry and arid areas where there isn't a lot of rain or water. These soils are kind of like a sponge, they absorb water quickly but also lose it just as fast.
Now, ustic soils are made up of different things like sand, silt, and clay. These materials are mixed together in the soil and give it certain properties like its ability to hold water or how hard or soft it is.
Sometimes, when there is a lot of wind in an area with ustic soils, they can become really dry and dusty, making it hard for plants to grow. But when it does rain, these soils can be really fertile and great for growing crops, which is why people who live in those areas may want to use them for farming.
So, in summary, ustic soils are soils that are found in dry areas, made up of materials like sand, silt, and clay, and have the ability to hold water but also lose it quickly.