A Rhizo L Mull develops at forest sites with very easily decomposable litter but low tree density or at permanent grassland sites under low-intensity management. In the A horizon, showing signs of high biological activity, the thick ground vegetation develops a dense system of living fine roots, a root feltwith a typical thickness of 3–5 cm. The distinct features of a Rhizo L Mull are:
- Ol horizon is present, which is mostly patchy or sparse and patchy.
- Olf horizon is temporarily present.
- Adx horizon, Adu horizon, or Adh horizon is observed with signs of high biological activity.