Once we agree that we do not see rock structure we then continue to determine soil structure.

Soils may be structured or without structure (structureless). The term structureless is rather confusing. If there is no clear aggregate to recognize and the soil material is coherent we speak of massive, but if non-coherent we speak of single grained. These are considered soil structure, although we used the term "structureless" (USAD Soil Survey Manual, Page 157).

• If aggregates are formed, their forms may be plate-like, block-like, or prism-like. Beside the form, a full description of soil structure, including ‘size' and ‘degree of development' is required.
• In terms of size, you need to decide if the soil structure is fine, medium or course.
• In terms of  degree of development, you need to decide on whether the structure is weakly, moderately or strongly developed.

Below, you can find some examples of different soil structures.  

Figure7.1: Soil Structure Example 1

Figure7.2: Soil Structure Example 2

Figure 7.3: Soil Structure Example 3

As you notice (see Figure 7.2 and 7.3), structure is described according to its form, size and the degree of development. It is not  difficult to learn about the form and the size, but to determine the degree of development one needs some experience (for example by watching how a senior soil surveyor is doing).

Figure 7.4: Description of Soil Structure (size, form or shape, and degree of development)

Use the hand-grip of you knife to gently hit a clod of soil that you hold in the hand and watch how the clod breaks into smaller pieces (aggregates). The easier the clod breaks into smaller peds the better developed the structure is. The clod breaks along the developed planes of weakness (tiny openings between structural elements). A strongly developed structure won't leave behind (after having been gently hit by your knife)any wastes, that is, all broken pieces will be smaller structural elements. In massive soils, no planes of weakness are developed. Breaking of the clod, in this case, would only be possible by exerting force.