- Match soil horizons with processes occurring within the zone
- Identify horizons given characteristics
- Predict potential management or use challenges based upon given horizon sequence
Sometimes a layer is not clearly one process or another, but rather where two are combining. These are called transitional horizons, and indicated by two capital letters like AB or BA. The first of the two is the more dominant of the two processes. A similar-looking notation but with an added /, like E/B or B/E mean that there are distinct areas of each in the layer rather than a smooth transition.
Additional lowercase letters are used to further differentiate horizons.
In order to distinguish one horizon from another, numbers at the end indicate multiple of the same zone, split by other differences like structure, redox features, or color.
Numbers at the beginning of the horizon indicate it is part of a different deposit or parent material. Because we might not know how many exist or be able to dig down far enough to find all parent materials, we start numbering from the surface even though the older deposit is on the bottom.
- Horizons are general concepts used to describe the major process(es) happening in the layer
- Not all horizons are found in every soil, sometimes multiple of the same horizon are found in one profile