Humusica 2, Article 15: Agro humus systems and forms

Agro humus systems correspond to agricultural humipedons. Specific terms and diagnostic horizons are defined and topsoil profiles are described. With this new vocabulary, which focuses on the biological structure of the A horizon, we can compare these humipedons with their original natural expression. Under human pressure for agricultural purposes, natural humipedons evolve toward anthropic Mull (See Humusica 1, articles 5 and 6 for natural humus horizons) or Amphi (Mull with layers of still not incorporated OH organic horizons) humus systems. In each humus system, we define a few humus forms in order to estimate the biological health of the soil, with a rapid observation realisable in the field by the naked eye. Histic anthropic Anmoor is also possible, as well as Hydro or Epihistic intergrades to Terrestrial systems. WRB qualifiers and Soil Taxonomy subgroup adjectives are reported at the end of the article and can be used for a more detailed classification.