Since the IUSS Rome Congress in 1924, where the scientific community decided to use the expression Soil Science instead of Pedology or Edaphology, criteria for the formation of new words in Spanish concerning the study of the soil have not been established. New terms in English are formed by giving priority to the Greek root πἐδον in front of the root ἒδαψοξ. This criterion does not take into account the fact that in Greek the term πἐδον refers to the soil we walk on and not to the soil where plants grow, which is expressed by the term ἒδαψοξ. This paper proposes criteria based on etymological, semantic and pragmatic linguistics for the formation of new or the equivalent of English soil-related words in Spanish. The analysis is based on: authorities in this field; etymological elements; aspects of phonetic and orthographic ambiguity; the equivalences between similar terms in English, Spanish and French; the usage of the expression at university level, by soil societies, and by scientific journals; and on aspects of linguistic good taste in certain geographic areas of Spanish language. The scope of this paper is not to contest the use of terms already in existance, recognizing that there may be strongly entrenched terms in some countries having Spanish as their own language. These terms should be referred to as varieties for a particular geographical area according to the specific regional Spanish semantics in America.