|Author: Bob Graham Created on: 8/31/2012 MessageID: 1562|
|Thank you for your input. I respect your experience and you bring up some interesting observations. I will comment relative to them.|
Yes, platy structure is often, but not always, a part of vesicular horizons. This is noted in the V horizon proposal. In general platy structure is restrictive to infiltration, but reduced infiltration due to lack of pore continuity can occur as well in vesicular horizons that do not have platy structure.
The role of crusting is described in the V proposal and in studies referenced in the proposal.
The fact that V horizons might form easily or even be lost is not unique to master horizons. Most notably, O horizons can be completely destroyed by fire, and they can reform quickly from litter accumulation. A horizons can be eroded away.
Not having seen the soils you describe, I can’t directly address those cases. I will note that the V horizon requires a “predominance of vesicular pores”. If vesicular pores are present but are not predominant, that horizon does not qualify as a V horizon. If vesicular pores predominate in localized compacted soils down to 2 feet then I don’t see the problem with designating them V horizons. They probably have reduced infiltration, a common characteristic of V horizons, so it might be advantageous to designate them this way. But I suspect that these conditions are not extensive, not to say that they aren’t locally important, so they cannot be the basis for judging validity of the proposed horizon.
Vesicular horizon thicknesses are discussed in the V horizon proposal.
Misuse of horizon designations for series differentiation: This sounds like a management issue within the NRCS. Perhaps it would happen even if a suffix (Avv) was used. This consideration should not stand in the way of change that is so widely acknowledged as needed.
We used the NRCS database in our proposal to obtain an objective view of vesicular horizons. We can all relate examples of the ends of the spectrum that are odd. We can do this for any horizon (A, B, etc.).
|Total messages in this thread... 2|
Support for J.Chiaretti's vesicular crust proposal