Carlos Alberto Ortiz-Solorio and Ma del Carmen Gutiérrez-Castorena. Colegio de Postgraduados, km 35.5 carretera Mexico-Texcoco, Texcoco, Estado de México, 56230, Mexico
The Ethnopedology, understood as the study of indigenous, native, popular or farmer knowledge of soil (4), has been researched in Mexico for more than 25 years. However, this kind of research has not been easy, because traditional knowledge has been, historically and currently, in conflict with scientific knowledge at least for soil studies. The absence of communication between tradition and science was resolved understanding correctly the farmer's concepts. The procedure was through farmer's interviews on the field, which was free, spontaneous, and not paid. With this methodology, it was possible to get a direct contact with them (1). The farmers do not use the term soil as scientists do; they use the equivalent term of land class. The land class can be defined as terrestrial area that includes all attributes of biosphere observed them directly (on topsoil and in subsoil) or indirectly (on plants and animals behaviors), in time and space, affecting its use or management. Despite the land nomenclature is apparently with only one descriptive phrase, as black land or sandy land in reality, it is a multidimensional concept and not simplistic and superficial knowledge, as it has been interpreted by many researchers. Characterization of land classes by farmers is taking into account a group of attributes that in technical language would be equivalent to color, texture, consistence, moisture retention, workability, salinity among many others. This knowledge has been generated through direct contact with the soil, using observation and comparison between and within the different land classes for some years or even more for centuries. Land classification has been carried out since prehispanic times. Two codices: Vergara and Santa María Asunción, showed that Acolhua-Aztec group had information about land classes, its areas, dimensions and the owners and members of the families represented by glyphs. However, during the process of culturization, the majority of prehispanic evidence was eliminated. Now, it is practically impossible to know the principles on which the ethnic groups of the past based the classification of their lands. For this reason, it was necessary to accept evaluate the current native soil knowledge with the rules of other disciplines. Ortiz and Gutiérrez (2001) applied the principles for the biological phenomena to folk taxonomy in several ethnic communities. First, they concluded that local land classification could be considered as formal taxonomy, because it meet the requisites established as different hierarchic levels, its own nomenclature and that they are related. However, after 4 years of work, Ortiz et al. (2005) recognized that this procedure was an imposition or a grouping of classes according to adopted methodology. Generic level is considered the most detailed of local classification, because it is related to adaptable crops, management (methods and working tools), amount of fertilizers, weeds (food, forages, medicinal, and ornamental plants), reclaiming land methods (for saline–sodic and eroded soils) and non-agricultural uses. Local land classes can be related with scientific classification until soil series level with ST or to be more detailed than WRB to subunit level. Also, land classes have a geographical location whose cartographic representation meet the requirements of quality (precision, 76% and accuracy, 94%) established by Soil Survey Manual. For their attributes of simplicity, speed and low cost is a procedure recommended for the countries with an agricultural tradition and scarce resources.