Soil survey and descriptions
Soil geography has mixed methods between Agronomy, Soil sciences, Ecology and all the geographical sciences. Therefore, sources and methods are common to these sciences. Among the methods we can establish an additional sequence, not always common to other disciplines, and which particularizes soil-geographic studies.
The first step in the sequence is, strictly speaking, geomorphological mapping, through which the location of the drillings and surveys of soil profiles is designated, after which comes the essential laboratory analysis.
After this step, it is necessary to proceed to the classification (Senciales, 2002). But, once again, once the soil has been classified, it is necessary to rethink the cartography, establishing groups of soils that allow working at very diverse scales, as well as abstracting the territorial systematics of the soils.
Once these steps have been completed, it is essential to be clear about the field of application of the studies to be carried out since, in principle, the type of classification will depend on it and, later, the fields of the analytical and cartographic database with which it should work. Thus, an important aspect of the application of Soil Geography coincides with Applied Soil Science, in the sense that the results are directly useful for Territorial Planning (Porta and López-Azevedo, 2005).
In fact, frequently, the agronomic analyzes of the territory tend to ignore the general characteristics of the environment, prioritizing its productive and economic values against the integral vision.
Soil survey or evaluation, therefore, must be followed by land evaluation if it is to be of any use; thus, although soil survey and mapping are not synonymous, nevertheless, soil survey should lead to the production of a map and, with it, the possibility of application for subsequent studies.
The fundamental objective when carrying out a taxonomy on soils is the establishment of territorial zoning of the types and subtypes with their subsequent cartographic representation, knowing the specific areas that each one occupies on the territory. Thus, we will be able to understand and relate pedogenetic processes with the previously explained factors, evolutionary or dynamic, and properties or intrinsic characteristics of the soil for its agricultural, scientific and territorial analysis application.
Soil types will be grouped into a series of classes and subclasses, whose meaning is totally abstract and not natural. There are many types of classifications and very valid depending on the area of study to which it is applied. In our case, to classify the soils , we use apply the IUSS-WRB 2015 Soil classification by FAO, although others such as Soil Taxonomy could also be used, both with a great impact on the disciplines that deal with soil science. On the other hand, and with less widespread use, we find those of a genetic type, where those of Kubiena or Duchaufour stand out.