The name TerrHum comes from the abbreviation of the words Terrestrial (not hydromorphic, not submerged soils) and Humipedon (superficial part of a soil, richer in organic matter and composed of organic and organo-mineral soil horizons). This application allows classifying all forest topsoils except submerged ones. The app is built on the
indications about humus diagnostic horizons, humus Forms and humus Systems reported and illustrated in 8 articles
published in an Applied Soil Ecology Special Issue entitled Humusica .
(https://www.sciencedirect.com/journal/applied-soil-ecology/vol/122/part/P1).
During the field observation and description of the soil upper layers, the user is assisted with touches that may display many photographs corresponding to types of soil horizons (first line-touch in Fig. 1, left). A finger onto the line, and a new screen opens; if the operator wants to display examples of diagnostic horizons, he only has to touch the screen at the level of the name of them (Fig. 1, centre and right). A legend will appear while touching the figure. Enlarging the fingers on the screen allows to magnify the picture. With the same process, on the first screen (Fig. 1 left) there is a “O/A Transition” touch (second line-command) that allows to display examples of transitions between organic and organo-mineral horizons (Fig. 2).
