Ped

In soil science, peds are aggregates of soil particles formed naturally as a result of pedogenic processes; this natural organization of particles forms discrete units separated by pores or voids.

The term is generally used for macroscopic (visible; i.e. greater than 1 mm in size) structural units when observing soils in the field.

[1] An artificially formed aggregate of soil particles can be called a clod.

[2] There are five major classes of macrostructure seen in soils: platy, prismatic, columnar, granular, and blocky.

Others have compound structure, in which large units are composed of smaller units separated by persistent planes of weakness.