TerrHum: An iOS application for classifying terrestrial humipedons and some considerations about soil classification

The name TerrHum is an abbreviation of the words “Terrestrial” (not hydro- morphic, not submerged) and “Humipedon” (organic and organic-mineral humus horizons). With this application, it is possible to describe and classi- fy terrestrial forest and grassland topsoils in a system published as a Special Issue entitled “Humusica 1– Terrestrial Natural Humipedons” in the jour- nal Applied Soil Ecology. The iOS application TerrHum allows the storage of the main content of Humusica 1 on a cellular phone. Images, diagrams and simplified tables of classification may be recalled with a few touches on the screen. Humus forms, representing five humus systems, are classified based on the vertical arrangement of diagnostic horizons and their attributes. TerrHum allows accessing specific figures that are stored in a virtual cloud and can be downloaded the first time the user recalls them. Once all figures have been opened in the device, the application is ready to use, without any further internet connection. The application is in continuous evolution.