Soil morphology deals with the form and arrangement of soil features. Micromorphology is using micromorphological techniques (e.g. thin sections) and measurements in the laboratory. Field morphology is the study of soil morphological features in the field by thorough observation, description and interpretation. Observations may be refined with the aid of a hand lens. Simple tests are also used in the field to record salient chemical properties (e.g., pH, presence of carbonates). In addition, field observations and measurements may be refined through a range of laboratory analytical procedures that include more sophisticated evaluation of chemical, biological and physical attributes. However, the quality of field description and sampling ultimately defines the utility of any subsequent laboratory analyses. A keen eye that can discern specific features and their relationship to adjoining features coupled with well-calibrated fingers that can distinguish among relative differences in physical properties of soil material are essential and can only be acquired and maintained through practice. In this course we will focus on field morphology.
Field morphology starts with an in situ examination of a soil profile. Field descriptions are organized by subdividing a vertical exposure of the soil (soil profile) into reasonably distinct layers or horizons that differ appreciably from the horizons immediately above and below in one or more of the soil features listed below. The delineation of horizons is necessarily a somewhat subjective processes because changes in soil attributes are often gradational rather than abrupt. Thus, obvious boundaries between horizons are not always apparent and their assignment may require integrated assessment of changes in several attributes before a sensible and defensible delineation can be made. Knowledge of similar soils and a well-defined rationale for the purpose of the description helps considerably in development of systematic criteria for defining and delineating horizons.
The following information is collected for assembling standard profile descriptions:
..Depth intervals of horizons or layers (measured from the top of the mineral horizon)
Differences between horizons generally reflect the type and intensity of processes that have caused changes in the soil. Ideally, we should always be striving in our descriptions to maintain a link between process and morphology. In many soils, these differences are expressed by horizonation that lies approximately parallel to the land surface, which in turn reflects vertical partitioning in the type and intensity of the various processes that influence soil development. However, there are many exceptions to this preferred horizontal organization.
Information provided by: http://www.soils.wisc.edu