ODM2 Variable Name Controlled Vocabulary ODM2 Working Group A vocabulary for describing the name of Variables. Humification index Humification index. Hummification is the processes by which organic matter decomposes to form humus. In humus the initial structures or shapes can no longer be recognized. See also humus. http://sis.agr.gc.ca/cansis/glossary/h/index.html Added to support Critical Zone Observatory (CZO) data use cases.