Soils are comprised generally of three horizons, the A, the B and the C. They are labeled as they are encountered when you dig a pit.The C Horizon is most like the parent material that the soil developed on. It is regolith. Eventually mosses, lichens, and other non-vascular plants colonize and prepare the substrate for the establishment of vascular plants by improving soil, organic matter and freeing up some nutrients somewhat. This creates the A horizon eventually, as vascular plants colonize, creating a thicker A Horizon. Over time, the B horizon forms from the bottom of the A, and though any leaching or deposition from the A.
While it is the second horizon encountered, it is the last formed!
Soils are comprised generally of three horizons, the A, the B and the C. They are labeled as they are encountered when you dig a pit.The C Horizon is most like the parent material that the soil developed on. It is regolith. Eventually mosses, lichens, and other non-vascular plants colonize and prepare the substrate for the establishment of vascular plants by improving soil, organic matter and freeing up some nutrients somewhat. This creates the A horizon eventually, as vascular plants colonize, creating a thicker A Horizon. Over time, the B horizon forms from the bottom of the A, and though any leaching or deposition from the A.
While it is the second horizon encountered, it is the last formed!