Dirt and Grass
The soil of living worlds. A spade moves it quickly, and a hoe turns it into a field.
Grass is dirt with a living top. Both count as soil, which a Spade digs fastest. Grass and dirt are also where saplings can be planted, and a Hoe turns them into tilled soil for crops.
Grass blocks carry tall grass you brush through without stopping. Cutting it sometimes drops Seeds.