Problem set#7
Question 3, soil (e)
I am confused with this soil. I am trying to identify the order but cannot figure it out. The description of the vegetation matches with Chernozemic, however, the Ah thickness does not. I was going to say then Regosolic, but Regosolics do not have B horizons and this soil does.
I am not sure what should I consider to classify this soil.
Not sure what question you are referring to, but description of a soil in question #3d in the lab assignment #7 does not match Chernozem, which is a typical grassland soil and has a chernozemic Ah horizon as a diagnostic horizon. Soil in question #3d is located in a coniferous forest and it does not have any Ah horizon. It does, however, have 2 diagnostic horizons typical for one other soil order.
The original question posted here was about soil in question #3d, but since that has been changed to #3e, let me provide additional explanation about #3e:
Soil described in question #3e has distinct couple of soil formation processes present in both B and C horizons that are typical for one of 10 soil orders. Those 2 soil formation processes affect horizons starting at 9 cm depth all the way down to 120 cm, which is a clear sign that this soil belongs to that order (and no, I am not telling which one it is... ;-) ). This particular soil order occurs in various ecosystems, including grasslands, hence, type of ecosystem provided in the question #3e is not the main clue on which to decide the soil order.
In these types of questions (which you will also see on the final exam), the background information about a soil is to be used as a confirmation does the soil fit within the order you selected as your answer, but it is never the main source of information when deciding about the soil order. The type of horizons, their thickens, and additional info (if provided like in the case of one of the soils in question #5 of the last practice exam session) are the main guidance for deciding about soil orders.