Build the canonical Vertisol fixture — make_vertisol

Synthetic Vertisol from a smectite-rich plain: deep clay (50-55%) with strong slickensides in the Bss horizon. Surface chroma 4 (above the mollic cap) so that vertic_properties is the only v0.2 diagnostic that passes. By construction:

vertic_properties: PASSES on Bss and BC.
argic, ferralic, mollic, cambic, plinthic, spodic, calcic, gypsic, salic: FAIL.

Usage

make_vertisol_canonical()

Value

A PedonRecord.